FASTENER RETENTION AID APPLICATION APPARATUS AND RELATED METHOD
20170122362 ยท 2017-05-04
Inventors
Cpc classification
F16B11/006
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
C09J177/00
CHEMISTRY; METALLURGY
F16B2200/83
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F16B43/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
C09J177/00
CHEMISTRY; METALLURGY
B29C65/48
PERFORMING OPERATIONS; TRANSPORTING
C09J5/04
CHEMISTRY; METALLURGY
Abstract
An apparatus and method that apply retention aid material to an inner diameter of an apertured part, such as a washer, a collar or the like. The method can include: moving a apertured parts linearly, optionally horizontally, along a conveyor, each apertured part defining an aperture and including upper surface and opposing lower surfaces with an inner diameter surface therebetween; dispensing a liquid retention aid material from a dispenser so that the material engages and/or spatters against the inner diameter surface as the apertured parts move linearly, optionally horizontally, along the conveyor; and curing the material to join it with the inner diameter surface, thereby forming a resilient retention aid projection extending inward from the inner diameter surface. The apparatus can perform the method, which can include seeping the material under the lower surface to form a seepage portion. An apertured part with a retention aid is also provided.
Claims
1. A method of applying a retention aid to an apertured part comprising: feeding an apertured part onto a conveyor, the apertured part including an upper surface and a lower surface with an aperture extending between the upper surface and the lower surface, the apertured part including an inner diameter surface that faces generally toward an axis of the apertured part within the aperture; moving with the conveyor the apertured part along a substantially horizontal pathway, the upper surface of the apertured part being parallel to a substantially horizontal plane that is parallel to the substantially horizontal pathway, the conveyor including an upper surface having an associated release agent; dispensing a liquid retention aid material so that the liquid retention aid material enters the aperture as the apertured part moves along the substantially horizontal pathway; colliding the liquid retention aid material against the upper surface of the conveyor and at least a portion of the inner diameter surface as the apertured part moves along a substantially horizontal pathway; curing the liquid retention aid material so that it joins with the at least a portion of the inner diameter surface, thereby forming a retention aid projection that extends from the inner diameter surface toward the axis of the apertured part.
2. The method of claim 1, wherein the aperture part is at least one of a washer and a collar, wherein the lower surface is horizontal and in a horizontal plane when the apertured part is moved along the substantially horizontal pathway with the conveyor.
3. The method of claim 2, wherein the liquid retention aid material is dispensed from a dispenser disposed above the conveyor, wherein a trailing edge of the inner diameter surface collides with the liquid aid retention material in such a manner that the liquid aid retention material engages against and moves upwardly along the inner diameter surface, along the trailing edge.
4. The method of claim 1, wherein the inner diameter surface includes a trailing edge, and wherein the trailing edge operates as a backstop to engage the liquid aid retention material when the liquid aid retention material, in liquid form, enters the aperture during the colliding step.
5. The method of claim 1 comprising: seeping the liquid aid retention material under the apertured part so that the liquid aid retention material engages the lower surface of the apertured part.
6. The method of claim 5 comprising: engaging the liquid aid retention material with the inner diameter surface and the lower surface of the apertured part before the curing step.
7. The method of claim 1 comprising: disposing a first plurality of N-S pole magnets on a first side of a centerline of the conveyor; disposing a second plurality of N-S pole magnets on a second side of a centerline of the conveyor, opposite the first plurality of N-S pole magnets; wherein each of the first plurality of magnets and the second plurality of magnets are oriented so that either a North pole or a South pole of each of the first plurality of magnets and the second plurality of magnets face toward the centerline and one another, wherein the first plurality of magnets and the second plurality of magnets cooperatively generate a magnetic field to urge the apertured part toward the centerline of the conveyor due to the magnetic field.
8. The method of claim 1 comprising: moving the apertured part linearly at least one of adjacent and on a centerline of the conveyor; and pressing an outer diameter leading edge, and an inner diameter trailing edge past a dispenser, before the colliding step.
9. The method of claim 1, wherein the liquid retention aid material is an ultraviolet light curable material, wherein during said curing, light having a wavelength of 200 nm to 600 nm is projected on the liquid retention aid material.
10. The method of claim 1 comprising: moving the apertured part with an adjustment guide extending adjacent the conveyor so as to move the apertured part relative to a centerline of the conveyor.
11. The method of claim 1 comprising: engaging the apertured part with a metering wheel to space the apertured part at a preselected distance relative to another apertured part as the apertured part and the other apertured part are moved with the conveyor, wherein the preselected distance enables the liquid retention aid material to be dispensed toward the apertured part and the other apertured part in a sequential manner.
12. The method of claim 1, wherein the apertured part is a metal washer having a thickness between the upper surface and lower surface of less than inch, wherein the conveyor includes a width spanning between first and second edges of the conveyor, and comprising: orienting the metal washer at a preselected location between the first and second edges using a plurality of magnets disposed adjacent the conveyor as the metal washer moves linearly along the substantially horizontal pathway.
13. A method of applying a retention aid to an apertured part comprising: moving a plurality of apertured parts linearly along a conveyor past a dispenser, each apertured part including an upper surface and a lower surface with an aperture extending between the upper surface and the lower surface, the apertured part including an inner diameter surface that faces generally toward an axis of the apertured part within the aperture; dispensing a liquid retention aid material from the dispenser so that the liquid retention aid material engages the inner diameter surface as the plurality of apertured parts move linearly along the conveyor; and curing the liquid retention aid material so that the material joins with the at least a portion of the inner diameter surface, thereby forming a retention aid projection that extends away from the inner diameter surface.
14. The method of claim 13 comprising: seeping the liquid retention aid material under at least a portion of an apertured part from the plurality of apertured parts so that the liquid aid retention material engages the lower surface of the apertured part; and forming a layer of the liquid retention aid.
15. The method of claim 13 wherein each of the plurality of aperture parts is a washer, comprising: orienting the plurality of apertured parts vertically as they move linearly along the conveyor past the dispenser.
16. The method of claim 14 comprising: dropping an amount of the liquid retention aid material in liquid form while the washer is vertically oriented, so that the liquid aid retention material engages a lower inner diameter surface, located under an outer diameter of the washer.
17. An apparatus adapted to apply a retention aid to an aperture part, the apparatus comprising: a horizontal conveyor including a conveyor upper surface having a release agent; a feed station located adjacent the horizontal conveyor and adapted to feed a plurality of apertured parts, each defining an aperture, onto the horizontal conveyor so that the apertured parts are conveyed with an upper surface of each apertured part being parallel to a substantially horizontal plane and facing upward, and a lower surface of each apertured part being parallel to the substantially horizontal plane and facing downward and engaging the conveyor upper surface; a liquid retention aid material dispensing station located adjacent the horizontal conveyor, the liquid retention aid material dispensing station adapted to dispense liquid retention aid material in liquid form in a sequential manner so that an amount of retention aid material moves through air toward the conveyor and into the aperture of one of a plurality of apertured parts so as to engage an inner diameter surface of the aperture while the upper surface is parallel to the substantially parallel plane; and a curing station located adjacent the horizontal conveyor, the curing station emitting at least one wavelength of light toward the apertured parts as the apertured parts are conveyed along the conveyor so as to solidify the amount of liquid retention aid material engaged with the inner diameter surface of the aperture and form a semi rigid retention tab that projects inwardly from the inner diameter surface of the aperture.
18. The apparatus of claim 17, wherein the dispensing station includes a dispenser that dispenses the amount of liquid retention aid material in a timed manner so that the amount of liquid retention aid material is passed by an outer diameter leading edge and an inner diameter leading edge before the liquid retention aid material engages a trailing edge of the inner diameter surface as the respective apertured part moves under the dispenser.
19. The apparatus of claim 17 comprising: an adjustment guide projecting over the conveyor, the adjustment guide adapted to bump each apertured part of the plurality of apertured parts when passing the adjustment guide so as to move the respective apertured parts toward or away from a centerline of the conveyor.
20. An apertured part including a retention aid comprising: a part body comprising: an upper surface; a lower surface disposed opposite the upper surface; an outer circumferential edge forming an outer boundary of at least one of the upper surface and the lower surface; an inner circumferential edge forming an inner boundary of at least one of the upper surface and the lower surface, the inner circumferential edge bounding an aperture defined by and extending between the upper surface and the lower surface, the aperture including an aperture axis corresponding to a center of the aperture; and a retention aid body constructed from a polymeric material, the retention aid body joined with the inner circumferential edge, the retention aid body extending inward toward the aperture axis a preselected distance, the resilient retention aid body including a free end that is adapted to flex and engage a complimentary part inserted through the aperture, wherein the resilient retention aid body at least one of: curved along a length of the free end when viewed from a top view of the washer, and includes a seepage portion that extends outwardly, beyond the inner circumferential edge toward the outer circumferential edge, the seepage portion being joined with the lower surface of the apertured part.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF THE CURRENT EMBODIMENTS
[0048] A method and related apparatus for performing the method will now be described in connection with
[0049] For purposes of simplicity, the embodiments herein will be described in connection with washers, however, it will be appreciated that any other apertured part, such as collars, short tubes or other similar parts, can likewise be processed via the apparatus and method. The washers 80 herein can have particular features. For example, with reference to
[0050] Each washer 80, when conveyed on a conveyor, can include respective leading and trailing edges of the respective inner diameter surface and outer diameter surface. For example as shown in
[0051] With a description of one kind of apertured part suitable for use with the apparatus 10 described, explanation of the illustrated apparatus will resume. The feed station 20 can be any vibratory and/or rotary feeder bowl or other feeder device that is adapted to feed apertured parts onto the conveyor 70. The feed station 20 feeds and orients the washers so that they lay flat against the conveyor 70, and so that the conveyor can convey those washers along a horizontal pathway, with the washers each laying generally horizontally throughout their entire conveyance along the conveyor. In this configuration, the washer axis WA is generally perpendicular to an upper surface of the conveyor along the entire pathway through the apparatus 10 on the conveyor 70.
[0052] The conveyor 70 can be in the form of a linear belt conveyor, with an upper surface 70U that is oriented in and travels within a substantially horizontal plane, and therefore along a substantially horizontal pathway. Of course in some cases the upper surface can be slightly offset from a true horizontal plane, for example, optionally about 0 to about 5, and further optionally about 1 to about 5, even further optionally about 1 to about 3, with the washers moving along a similar path, and with the washers still travelling in what is considered herein a substantially horizontal plane. If there is no offset, the washers can travel in the true horizontal plane. When traveling along the substantially horizontal pathway, the upper and/or lower surfaces of the washer can be parallel to the substantially horizontal plane as well.
[0053] The conveyor can be constructed so that the upper surface 70U of its belt or support surface includes a release agent and/or release layer that facilitates the release of a variety of polymeric and other materials from the conveyor with minimal to zero force. As an example, the release agent or layer can be or can include polytetrafluoroethylene (PTFE), commercially available under the trade name, Teflon, perfluoroalkoxy polymer resin (PFA), fluorinated ethylene propylene (FEP) or similar materials that have a low propensity to chemically and/or mechanically bond with liquid and/or solid materials placed thereon. The conveyor belt and/or its components can be constructed from the release agent. Alternatively, a coating, layer or parts of the release agent can be applied to the structure of the conveyor and/or its components.
[0054] The conveyor 70 can be constructed to include a magnetic bed 70M that exerts one or more magnetic fields MF (
[0055] As shown in
[0056] Generally, when the washers 80 are fed onto the conveyor 70, their upper surfaces 80U face upward and their lower surfaces 80L face downward and contact the upper surface 70U of the conveyor, which again can include a release agent. Sometimes, the lower surface 80L of the washers can include imperfections and/or can be un-smooth or porous. In this case, the lower surfaces 80L of the washers do not fully contact the release agent and/or the upper surface 70U of the conveyor. In such a case, there can be a small cavity or space formed under the washer 80, generally between the upper surface 70U of the conveyor and the lower surface 80L of the washer. This space can be largest in the region near the inner diameter surface 80I. Generally, this space can be optimally 0.001 inches to 0.2 inches, and further optimally 0.01 inches to 0.1 inches. As explained below, this space can facilitate the seeping of liquid retention aid material under the washer, adjacent the lower surface and/or between the lower washer surface 80L and the upper surface 70U of the conveyor and/or release agent.
[0057] As mentioned above and shown in
[0058] The apparatus 10 and related method can implement certain adjustment guides 75, also referred to as bumpers, belt guides and/or part guides. These bumpers 75 can include an end 75E that engages washers being conveyed along the conveyor 70. The adjustment guides can project outwardly and over the upper surface 70U of the conveyor. The adjustment guides also can include an adjustment mechanism 75A that allows the guide 75 to be disposed at any angle AN relative to the centerline CL of the conveyor.
[0059] Generally the adjustment guide can be oriented to precisely position each washer on the conveyor for subsequent application of the retention aid material at the dispensing station. As one example, upon exit of the feed wheel 73, sometimes washers can be aligned horizontally to the left or right of the centerline CL of the conveyor 70. The adjustment guide 75 can engage each individual washer with its end 75E, which optionally can be rounded and/or angled, to alter the direction of the washer into direction A. This, in turn, bumps the washers toward the centerline CL of the conveyor. Alternatively, of course, the adjustment guide can be fitted on the opposite side of the conveyor to reposition certain washers horizontally toward the centerline of the conveyor in a different direction. Each guide 75 can be mechanically adjustable within a horizontal plane, as well as vertically, to accommodate varying dimensioned and thickness washers. Optionally, the adjustment guide 75 can be used in case the magnetic bed 70M fails, or in some constructions, the magnetic bed 70M can be completely absent, with the adjustment guides performing the lateral movement of the washers relative to the centerline CL of the conveyor 70 so that they are properly aligned with dispensers in the dispensing station.
[0060] After the washers 80 are precisely positioned and/or spaced along the linear conveyor 70, optionally utilizing the feed wheel 73, magnetic bed 70M and/or adjustment guide 75, the conveyor 70 moves the washers 80 toward the dispensing station 30. Optionally, the washers can pass by series of sensors, such as fiber-optic sensors that time the precise application of retention aid material from the dispensers. Each sensor optionally can be used to signal, through a relay, a solenoid valve disposed in individual dispensers, 30A, 30B, 30C and 30D that are disposed adjacent and over the respective portions of the conveyor, generally along a centerline CL of the conveyor. The dispensers optionally can be in the form of a zero cavity gun module and/or diaphragm style dispensing valve. Of course, other types of dispensers, such as eccentric screw applicators for dispensing viscous and/or liquid materials, can be used in the apparatus and method herein.
[0061] The respective individual dispensers, 30A 30B, as shown in
[0062] In some cases, there can be four separate sensors, each associated with the four respective dispensers 30A, 30B, 30C and 30D. The sensors can trigger dispensing of the retention aid material from the respective dispensers. Optionally, the dispensers and sensors can have a staggered position, with two sensors and two dispensers mounted to the right hand side of the centerline CL of the conveyor, and two other sensors and associated dispensers mounted to the left hand side of the centerline CL of the conveyor. Each respective sensor can have fine and/or rough horizontal and vertical adjustment mechanisms that enable proper positioning along the conveyor. The respective dispensers 30A, 30B, 30C and 30D also can have fine and/or rough horizontal and vertical adjustment mechanisms that precisely position the dispensing ends 30E of each dispenser in proper alignment with the respective washers.
[0063] Optionally, the sensors and dispensers can be configured to actuate or not actuate as each washer passes by the sensor. If desired, the precise timing of dispensation of the material from a dispenser can be adjusted relative to the sensing event through a control 40 of the apparatus. This control can be a touchscreen and/or human machine interface that enables the operator to adjust certain parameters of the apparatus, for example conveyor speed, sensor sensitivity, feed wheel rotation rate, material dispensing timing, adjustment guide orientation, curing irradiation intensity and/or wavelength at the curing station 50, and/or other parameters depending on the application.
[0064] In some applications, the different dispensers can be utilized in different combinations. For example in some cases, only the first dispenser 30A and its associated sensor can be configured to dispense material onto washers. The remaining dispensers 30B, 30C and 30D and their associated sensors can be idle, and not dispense any material. As another example, every dispenser 30A-30D can be activated so that each associated dispenser dispenses material to respective washers along the conveyor under the respective dispensers. In yet other examples, one sensor and a first dispenser can be utilized for the application of liquid retention aid material on a first portion of the washer, while a second dispenser and sensor can be utilized for the application of liquid retention aid material on a second portion of the same washer, distal from the first portion, for a two shot application.
[0065] As shown in
[0066] As shown in
[0067] As shown in
[0068] Optionally, as mentioned above, the washers 80 can have a small space 80S defined between the lower surface 80L and the upper surface 70U of the conveyor. Due to the liquid and/or flowable nature of the material M, certain amounts of the material can seep or otherwise enter into this space 80S. When the material M seeps between the lower surface 80L and the upper surface 70U of the washer, a seepage portion SP is formed, as described further below.
[0069] After the material M is applied to the moving washers, it is further conveyed along the conveyor 70 to the curing station 50, where the material can be cured optionally with irradiation. As mentioned above, the material optionally can be curable with UV/EB wavelength light. The material can be optionally acrylate, methacrylate, vinyl functional monomers and/or oligomers, optionally convertible from a liquid to solid and/or gel or semisolid state via application of certain wavelengths of light. As illustrated in
[0070] The irradiators can optionally project UV light from a 12 inch bulb onto an area of approximately 24 in.sup.2 on the conveyor. The irradiator can project the light optionally for 1 second to about 10 seconds, further optionally about 5 seconds. Generally, the irradiators output light at greater than 300 W/inch.sup.2, and further optionally greater than 400 W/inch.sup.2 onto the washer and material. Utilizing a UV curable acrylic-based material can provide enhanced process speeds. The optional wavelength of light projected by the irradiators onto the washers can be optionally 200 nm to 600 nm, further optionally 150 nm to 450 nm, even further optionally 300 nm to 350 nm, and yet further optionally about 320 nm.
[0071] Optionally, the irradiators can be able to toggle between mercury, iron and/or gallium lamps to increase the spectrum range of the wavelengths exerted by the same. It is also to be noted that the irradiators can be positioned so that, relative to the washer, the irradiators are vertical and above the washer, generally projecting downward. This can provide full vertical adjustment of the irradiators, and also can enhance the full depth of cure of the liquid material when initially applied to the washers. The respective lamps also can be positioned inline along the linear conveyor as desired.
[0072] As noted above, the curing station 50 can include a second irradiator 52. While the first irradiator 51 fully cures most material, this second irradiator 52 can be included to ensure this is always the case, and to act as a backup in case the first irradiator fails.
[0073] As shown in
[0074] As illustrated in
[0075] An attribute of the completed washers, particularly where acrylic based UV curable materials are used to form these retention aid bodies with the washer aperture, is the good to excellent adhesive properties of the retention aid bodies. This allows numerous reuses of the washer on complementary threaded fasteners inserted into the washer aperture, as well as other fasteners such as shoulder bolts, sheet metal screws, unthreaded pins and the like.
[0076] A first experiment was conducted on washers constructed according to the current embodiments having three retention aid bodies B1, B2 and B3 placed approximately 120 degrees from one another about a central axis WA of the washer 80, as shown in
TABLE-US-00001 TABLE 1 Three Tab Retention Element Performance 1.sup.st Push 1.sup.st Push 5.sup.th Push In lbf Out lbf Out lbf 1 5.2 13.6 9.4 2 5.0 12.7 7.1 3 7.7 19.1 7.4 4 4.5 12.3 6.8 5 5.2 14.5 5.3 6 4.8 12.4 5.6 7 8.1 18.7 9.3 Average 5.8 14.8 7.3
[0077] A second experiment was conducted on washers constructed according to the current embodiments having one retention aid body B about a central axis WA of the washer 80, as shown in
[0078] As seen in Table 2 below, bidirectional use was tested on multiple washers, also referred to as Part X in Table 2, six times for each of the six Parts, listed in the leftmost column of that table. In particular, each washer was assembled and pushed on the bolt FT. The maximum installation force in lbf to seat the washer in place against a head of the bolt was recorded as In in Table 2. After installation, each washer was pulled completely off the bolt FT. The maximum removal force in lbf to remove the washer from the bolt was recorded as Out in Table 2.
[0079] This experiment illustrated that the current embodiments of the washer, even after six applications to and five previous removals from threaded fastener FT, still required at least about 5 lbf to about 12 lbf to remove the washer from the fastener. Optionally, even after six applications and five removals from the threaded fasteners, the current embodiments of washers can utilize optionally at least 4.9 lbf, further optionally at least 6.5 lbf, even further optionally at least 11.5 lbf, and yet further optionally at least 11.7 lbf to remove the washers. In addition, the ratio of average values (the two leftmost columns) of installation (In) to removal (Out) forces was optionally less than 1:13 and further optionally less than about 2:8.
TABLE-US-00002 TABLE 2 One Tab, Tab Down, Retention Element Performance Size: M10 Configuration: 1 Tab Orientation: Tab Down Shot Time: 0.17 s Tab Weight: ~0.036 g 1 2 3 4 5 6 Ave Ave Part In Out In Out In Out In Out In Out In Out In Out 1 2.3 13.4 0.8 6.6 1.8 6.9 2.4 7.7 1.9 16.0 0.8 11.5 1.7 10.4 2 4.7 4.7 1.4 5.9 1.7 5.1 2.3 10.4 2.4 12.6 1.5 6.5 2.3 7.5 3 1.7 5.7 0.9 28.4 1.7 11.3 2.0 13.0 1.7 11.4 0.9 4.9 1.5 12.5 4 2.5 9.6 2.6 3.3 6.3 5.2 4.2 6.6 2.3 25.8 1.9 5.0 3.3 9.3 5 1.9 8.3 1.4 6.6 2.0 4.7 4.6 9.9 2.6 17.3 1.7 11.7 2.4 9.8
[0080] A third experiment was conducted on washers constructed according to the current embodiments having two retention aid bodies B about a central axis WA of the washer 80, as shown in
[0081] As seen in Table 3 below, bidirectional use was tested on multiple washers or Parts as described in connection with the experiment represented in Table 2 above. The same measurements and indications, e.g., In, Out, Tab Down, etc. in the experiment above apply to this experiment as well.
[0082] This experiment illustrated that the current embodiments of the washer, even after six applications to and five previous removals from threaded fastener FT, still required at least about 20 lbf to about 30 lbf to remove the washer from the fastener. Optionally, even after six applications and five removals from the threaded fasteners, the current embodiments of washers can utilize optionally at least 21.1 lbf, further optionally at least 23.2 lbf, even further optionally at least 25.1 lbf, and yet further optionally at least 27.2 lbf to remove the washers. In addition, the ratio of average values (the two leftmost columns) of installation (In) to removal (Out) forces was in some cases optionally less than 6:26 and further optionally less than about 8:19.
TABLE-US-00003 TABLE 3 Two Tabs, Tab Down, Retention Element Performance Size: M10 Configuration: 2 Tab Orientation: Tab Down Shot Time: 0.10 s Tab Weight: ~0.021 g 1 2 3 4 5 6 Ave Ave Part In Out In Out In Out In Out In Out In Out In Out 1 6.4 42.2 7.4 35.7 4.2 16.4 4.5 15.2 5.7 23.4 6.6 27.2 5.8 26.7 2 9.4 26.1 8.4 28.5 2.5 15.5 4.4 18.1 6.1 15.9 5.5 25.1 6.1 21.5 3 16.3 17.9 6.7 26.3 2.5 13.5 3.9 15.4 6.2 28.5 7.6 23.2 7.2 20.8 4 17.9 21.5 6.5 27.1 4.8 13.8 4.6 17.3 5.9 14.9 6.0 21.1 7.6 19.3 5 10.6 20.0 5.5 17.9 3.4 11.7 3.2 12.6 2.6 13.7 5.5 23.3 5.1 16.5
[0083] A fourth experiment was conducted on washers constructed according to the current embodiments having three retention aid bodies B1, B2, B3 about a central axis WA of the washer 80, as shown in
[0084] As seen in Table 4 below, bidirectional use was tested on multiple washers or Parts as described in connection with the experiment represented in Table 2 above. The same measurements and indications, e.g., In, Out, Tab Down, etc. in the experiment above apply to this experiment as well.
[0085] This experiment illustrated that the current embodiments of the washer, even after six applications to and removals from threaded fastener FT, still required at least about 20 lbf to about 30 lbf to remove the washer from the fastener. Optionally, even after six applications and five removals from the threaded fasteners, the current embodiments of washers can utilize optionally at least 21.5 lbf, further optionally at least 23.3 lbf, even further optionally at least 26.8 lbf, and yet further optionally at least 27.3 lbf to remove the washers. In addition, the ratio of average values (the two leftmost columns) of installation (In) to removal (Out) forces was in some cases optionally less than 7:28 and further optionally less than about 9:20.
TABLE-US-00004 TABLE 4 Three Tabs, Tab Down, Retention Element Performance Size: M10 Configuration: 3 Tab Orientation: Tab Down Shot Time: 0.10 s Tab Weight: ~0.021 g 1 2 3 4 5 6 Ave Ave Part In Out In Out In Out In Out In Out In Out In Out 1 4.8 25.0 10.0 37.3 8.0 27.3 2.1 21.9 8.1 31.3 5.8 26.9 6.5 28.3 2 5.0 28.3 10.0 43.3 10.4 27.1 4.8 15.2 15.4 31.9 5.5 27.3 8.5 28.9 3 4.0 20.1 11.7 33.9 6.6 28.1 3.7 12.5 7.8 29.8 6.1 21.5 6.7 24.3 4 13.2 17.3 8.4 31.6 10.7 18.5 2.2 13.1 6.8 24.8 11.9 26.8 8.9 22.0 5 8.6 10.5 21.7 21.7 10.0 24.7 2.8 14.1 6.3 21.9 7.8 23.3 9.5 19.4
[0086] A fifth experiment was conducted on washers constructed according to the current embodiments having one retention aid body B about a central axis WA of the washer 80, as shown in
[0087] As seen in Table 5 below, bidirectional use was tested on multiple washers, also referred to as Part X in Table 5, six times for each of the six Parts, listed in the leftmost column of that table. In particular, each washer was assembled and pushed on the bolt FT. The maximum installation force in lbf to seat the washer in place against a head of the bolt was recorded as In in Table 5. After installation, each washer was pulled completely off the bolt FT. The maximum removal force in lbf to remove the washer from the bolt was recorded as Out in Table 5.
[0088] This experiment illustrated that the current embodiments of the washer, even after six applications to and removals from threaded fastener FT, still required at least about 1 lbf to about 3 lbf to remove the washer from the fastener. Optionally, even after six applications and five removals from the threaded fasteners, the current embodiments of washers can utilize optionally at least 1.1 lbf, further optionally at least 1.7 lbf, even further optionally at least 2.1 lbf, and yet further optionally at least 2.6 lbf to remove the washers.
TABLE-US-00005 TABLE 5 One Tab, Tab Up, Retention Element Performance Size: M10 Configuration: 1 Tab Orientation: Tab Up Shot Time: 0.17 s Tab Weight: ~0.036 g 1 2 3 4 5 Ave Ave Part In Out In Out In Out In Out In Out In Out 1 5.2 8.1 4.7 6.4 9.9 6.3 6.0 6.3 0.9 1.5 5.3 5.7 2 4.6 2.7 8.9 5.0 5.8 6.2 3.1 7.7 0.6 2.1 4.6 4.7 3 3.0 3.8 9.9 3.9 6.5 7.5 6.2 9.5 0.9 1.7 5.3 5.3 4 2.7 6.6 3.9 4.2 4.5 7.0 6.4 3.4 0.8 2.6 3.7 4.8 5 6.0 6.6 4.4 3.1 4.7 10.4 7.8 4.9 1.5 1.1 4.9 5.2
[0089] A sixth experiment was conducted on washers constructed according to the current embodiments having two retention aid bodies B about a central axis WA of the washer 80, as shown in
[0090] As seen in Table 6 below, bidirectional use was tested on multiple washers or Parts as described in connection with the experiment represented in Table 5 above. The same measurements and indications, e.g., In, Out, Tab Up etc. in the experiment above apply to this experiment as well.
[0091] This experiment illustrated that the current embodiments of the washer, even after six applications to and five previous removals from threaded fastener FT, still required at least about 6 lbf to about 12 lbf to remove the washer from the fastener. Optionally, even after six applications and five removals from the threaded fasteners, the current embodiments of washers can utilize optionally at least 7.4 lbf, further optionally at least 10.9 lbf, and even further optionally at least 15.1 lbf, to remove the washers.
TABLE-US-00006 TABLE 6 Two Tabs, Tab Up, Retention Element Performance Size: M10 Configuration: 2 Tab* Orientation: Tab Up Shot Time: 0.10 s Tab Weight: ~0.021 g 1 2 3 4 5 Ave Ave Part In Out In Out In Out In Out In Out In Out 1 14.9 10.3 16.7 16.9 16.4 14.5 14.0 15.2 13.7 12.2 15.1 13.8 2 10.0 8.6 14.9 15.9 9.0 14.8 12.6 14.3 8.0 8.9 10.9 12.5 3 9.6 10.7 8.1 14.7 6.6 10.4 7.3 11.2 5.5 6.6 7.4 10.7 4 1.9 9.4 9.6 12.9 10.3 10.5 5.4 12.0 4.8 8.2 6.4 10.6 5 7.2 10.1 8.9 13.8 4.9 7.9 4.6 11.9 11.0 6.7 7.3 10.1 *Note: Some parts had partial delamination of 1 tab after 3-5 uses.
[0092] A seventh experiment was conducted on washers constructed according to the current embodiments having three retention aid bodies B1, B2, B3 about a central axis WA of the washer 80, as shown in
[0093] As seen in Table 7 below, bidirectional use was tested on multiple washers or Parts as described in connection with the experiment represented in Table 5 above. The same measurements and indications, e.g., In, Out, Tab Up etc. in the experiment above apply to this experiment as well.
[0094] This experiment illustrated that the current embodiments of the washer, even after six applications to and five previous removals from threaded fastener FT, still required at least about 10 lbf to about 17 lbf to remove the washer from the fastener. Optionally, even after six applications and five removals from the threaded fasteners, the current embodiments of washers can utilize optionally at least 14.6 lbf, further optionally at least 18.5 lbf, and even further optionally at least 22.8 lbf, to remove the washers.
TABLE-US-00007 TABLE 7 Three Tabs, Tab Up, Retention Element Performance Size: M10 Configuration: 3 Tab* Orientation: Tab Up Shot Time: 0.10 s Tab Weight: ~0.021 g 1 2 3 4 5 Ave Ave Part In Out In Out In Out In Out In Out In Out 1 22.4 21.6 25.2 31.1 25.0 34.0 20.1 24.9 21.5 17.3 22.8 25.8 2 15.2 17.5 22.6 23.8 21.6 27.7 16.3 19.4 17.0 15.9 18.5 20.9 3 11.7 14.5 19.9 25.5 19.5 25.2 11.4 17.1 10.5 14.9 14.6 19.4 4 9.9 11.7 13.5 23.1 13.3 22.1 9.9 14.1 14.0 13.3 12.1 16.9 5 4.5 21.1 10.9 24.1 13.1 21.0 13.3 15.0 7.2 10.3 9.8 18.3 *Note: Some parts had delamination of 1 tab after 3-5 uses.
[0095] Eight through thirteenth experiments were conducted on washers constructed according to the current embodiments having one, two or three retention bodies or tabs, with tabs up or down, similar to those experiments above, and as indicated in Tables 8-13 below. The tab weight in grams for each Part or washer tested, and shot time for depositing the liquid material that forms the bodies was also recorded in the respective tables. The fasteners FT used in this experiment were fully threaded bolts, size inch, and the washers were constructed primarily from zinc.
TABLE-US-00008 TABLE 8 One Tab, Tab Down, Retention Element Performance Size: ths Configuration: 1 Tab Orientation: Tab Down Shot Time: 0.17 s Tab Weight: ~0.036 g 1 2 3 4 5 Ave Ave Part In Out In Out In Out In Out In Out In Out 1 1.2 11.1 5.2 4.6 2.7 3.7 3.3 6.8 5.2 4.6 3.5 6.2 2 1.1 7.3 4.6 3.7 2.9 6.9 1.0 7.6 3.1 5.5 2.5 6.2 3 2.7 7.2 2.4 3.9 2.5 6.7 2.0 6.3 2.7 6.2 2.5 6.1 4 2.0 5.3 2.6 3.3 2.0 12.7 0.8 4.3 2.9 4.8 2.1 6.1 5 1.8 7.9 1.8 6.8 0.8 12.9 1.6 3.3 2.5 7.5 1.7 7.7
TABLE-US-00009 TABLE 9 Two Tabs, Tab Down, Retention Element Performance Size: ths Configuration: 2 Tab* Orientation: Tab Down Shot Time: 0.17 s Tab Weight: ~0.036 g 1 2 3 4 5 Ave Ave Part In Out In Out In Out In Out In Out In Out 1 5.5 13.7 4.2 12.3 3.8 12.2 4.2 12.8 3.1 12.0 4.2 12.6 2 4.0 12.1 4.8 9.9 3.7 9.9 4.0 12.8 2.7 10.9 3.8 11.1 3 3.9 12.7 4.1 10.6 5.3 11.8 3.4 12.5 3.1 8.1 4.0 11.1 4 4.0 8.9 3.9 11.4 4.1 10.1 3.9 12.1 2.5 5.9 3.7 9.7 5 3.3 9.7 4.0 9.0 4.6 9.5 2.4 7.5 3.2 8.1 3.5 8.8 *Note Partial delamination of 1 tab after 3-4 uses.
TABLE-US-00010 TABLE 10 Three Tabs, Tab Down, Retention Element Performance Size: .sup.ths Configuration: 3 Tab Orientation: Tab Down Shot Time: 0.08 s Tab Weight: ~0.025 g 1 2 3 4 5 Ave Ave Part In Out In Out In Out In Out In Out In Out 1 4.2 13.6 3.9 14.5 3.0 8.9 4.7 14.7 3.3 10.0 3.8 12.3 2 4.5 13.1 4.4 10.8 2.9 8.2 4.9 15.2 2.5 8.0 3.8 11.1 3 5.9 10.9 5.5 11.0 3.2 7.9 4.2 12.8 2.3 9.7 4.2 10.5 4 4.1 11.4 4.3 13.4 4.9 6.8 5.1 16.0 6.0 10.1 4.9 11.5 5 5.8 12.9 6.3 13.6 2.7 7.4 5.1 13.2 4.0 10.6 4.8 11.5
TABLE-US-00011 TABLE 11 One Tab, Tab Up, Retention Element Performance Size: ths Configuration: 1 Tab Orientation: Tab Up Shot Time: 0.17 s Tab Weight: ~0.036 g 1 2 3 4 5 Ave Ave Part In Out In Out In Out In Out In Out In Out 1 4.4 6.0 3.4 6.9 11.4 5.7 6.1 6.7 6.4 6.6 6.3 6.4 2 4.8 10.5 3.7 3.8 4.0 8.4 6.8 7.7 2.7 3.3 4.4 6.7 3 4.1 8.3 4.6 6.5 9.3 6.4 3.5 7.1 4.9 4.1 5.3 6.5 4 5.3 4.7 5.7 6.5 9.5 9.9 5.0 5.4 2.2 6.8 5.5 6.7 5 4.7 6.2 6.0 6.5 8.9 6.8 9.7 4.9 2.7 3.8 6.4 5.6
TABLE-US-00012 TABLE 12 Two Tabs, Tab Up, Retention Element Performance Size: ths Configuration: 2 Tab* Orientation: Tab Up Shot Time: 0.17 s Orientation: Tab Up 1 2 3 4 5 Ave Ave Part In Out In Out In Out In Out In Out In Out 1 7.6 13.7 11.0 15.8 9.0 14.4 9.3 13.2 14.5 17.1 10.3 14.8 2 9.0 10.9 8.5 9.0 11.1 15.8 9.7 9.6 5.4 10.1 8.7 11.1 3 7.4 11.8 9.1 9.9 8.3 10.7 7.2 11.9 9.9 6.5 8.4 10.2 4 5.7 7.4 6.5 6.8 5.4 10.7 6.2 11.1 6.1 7.8 6.0 8.8 5 3.1 6.9 5.0 5.4 6.0 2.5 6.9 14.1 3.2 6.0 4.8 7.0 *Note: Partial delamination of 1 tab after 3-4 uses.
TABLE-US-00013 TABLE 13 Three Tabs, Tab Up, Retention Element Performance Size: .sup.ths Configuration: 3 Tab Orientation: Tab Up Shot Time: 0.08 s Tab Weight: ~0.025 g 1 2 3 4 5 Ave Ave Part In Out In Out In Out In Out In Out In Out 1 10.3 11.2 13.0 18.7 12.3 14.7 15.0 18.4 17.1 21.3 13.5 16.9 2 8.7 9.6 11.1 10.9 11.4 13.8 15.0 15.7 14.8 20.9 12.2 14.2 3 10.2 7.8 10.5 9.8 10.0 10.1 9.5 18.6 13.4 13.4 10.7 11.9 4 8.6 8.8 8.8 6.4 9.0 10.2 7.3 11.9 10.2 13.9 8.8 10.2 5 7.5 9.2 8.9 10.9 14.6 10.1 8.8 5.7 11.4 12.0 10.2 9.6
[0096] A first alternative embodiment of the apparatus and related method is illustrated in
[0097] After the material M1 on the inner edge portion 180IA is cured, a magnetic wheel 123 or other flipping mechanism can be utilized to pick up and flip the washer 180 end over end in a direction N so that the cured retention tab body M1B is flipped 180 and basically upside down. With the flipped positioning of tab body M1B, that body, as flipped, is referred to as M1B. The washer 180 then passes the second dispenser 130Y, which dispenses a second amount of liquid retention aid material M2, which is forcefully projected along and/or falls downward and engages an opposing or second portion 80IB of the inner diameter surface, which can be diametrically opposed to the first surface 180IA where the body M1B is joined. This second amount of material M2 joins with and is bonded to the inner diameter surface to form a second retention aid projection M2B. Subsequently, the washer 180 moves in the direction of flow F, and is cured at a second curing station 152. The resulting cured washer can include a first retention aid projection M1B and a second opposing retention aid projection M2B, generally facing first toward or projecting toward one another. Additional retention aid projections can be added by duplicating the elements illustrated in
[0098]
[0099] As shown in
[0100] A second alternative embodiment of the apparatus and method is illustrated in
[0101] Due to the vertical orientation of the washers, as the amount of material M3 drops, the droplet passes through or by an outer diameter reference axis ODRA and passes through or by an inner diameter reference axis IDRA as the material M3 is forcefully projected and/or falls along the drop axis DA. Thus, the material M3 perfectly moves into an area of the aperture 280A of the washer 280 as the washer moves along the movement axis. This enables the liquid retention aid material M3 to continue to move and/or fall and to be deposited on the inner diameter surface 280I, generally between the upper and lower surfaces 280U and 280L of the washer 280. This is better illustrated in
[0102] A variation of the second alternative embodiment of the apparatus and method is illustrated in
[0103] As illustrated in
[0104] The apparatus 210 also can include a dispenser gun 230. The dispenser gun 230 can be offset laterally from the movement axis MA. The gun 230 can be aligned so that it projects material for deposition as a material body M3B on the inner diameter of the washer 280. The material can be shot into the aperture 280A laterally from the gun 230 toward the movement axis MA. The conveyor system can include a recess or window 277 adjacent the slot 274 so that the gun can have open access to the aperture of the washer for deposition of the material on the inner diameter of the washer.
[0105] Optionally, the slot 274 can be configured to include a portion having secondary guides 275 downstream of the gun 230. These guides can be constructed from transparent and/or translucent material, such as polycarbonate, borosilicate glass and other similar materials. The construction of the guides 275 can enable a light source, such as a UV curing light source 290, to project UV light CL, or light of some other wavelength, onto the material body MB3 to cure it as the washers travel along the conveyor system in the slot.
[0106] A third alternative embodiment of the apparatus and related method is illustrated in
[0107] As an example, the apparatus 310 can construct washers similar to those shown in
[0108] Optionally, the first conveyor 370 can include a belt 371 that is routed around a first roller or drum 372 and a second roller 372. The roller 372 can be a drive roller or it can be a free rolling roller. The roller 372 can rotate in direction A1 so that the belt 371 can convey product in the direction of product flow PF1. The first conveyor 370 can be similar to the conveyors noted above in other embodiments with several exceptions. For example, the first conveyor 370 can be placed adjacent a feeding station 320, which can be a vibratory bowl feeder or other feeder as described herein. The feeder 320 can feed apertured parts 380, such as washers, onto the conveyor belt 371. The conveyor belt 371 can include a magnetic bed and a release agent incorporated into an upper surface of the belt, similar to that described in the embodiments above. This conveyor also can include a feed wheel 373, similar to the feed wheel noted in the embodiments above, that meters and/or spaces washers at a consistent and/or preselected distance from one another as they travel on or are conveyed along the conveyor belt 371.
[0109] The apparatus 310 can include a preheat station 375, on the first conveyor 370. The preheat station 375 can include a heat source. The heat source can be an induction type heat source, an irradiation-based heat source, or any other type of heating element. The preheat station 375 can exert heat H on the washers 380 disposed on the conveyor after the feeding station 320, but before the dispensing station 330. The heating station 375 can exert enough heat so that the washers are brought to a temperature of optionally about 100 F. to about 500 F., further optionally 150 F. to about 400 F. before they reach the dispensing station 330. With this preheating of the washers, the hot melt materials can bond more easily and quickly to the surfaces of the washers 380. Of course, with certain hot melt materials, the heating station 375 can be eliminated or substituted with a simpler device that does not heat the washers conveyed thereon too significantly.
[0110] After the washers 380 are preheated at the heating station 375, they are conveyed along the conveyor 371 toward the dispensing station 330. The dispensing station 330 can include a tank or other source of hot melt material, and one or more dispensing gun modules that are configured to dispense the hot melt material, optionally in a heated liquid form therefrom. As with the embodiments above, shown in
[0111] The dispensing station 330 can be set up so that the dispensing gun modules dispense the hot melt material at particular viscosities. For example, the viscosity of the hot melt material when ejected from the dispensing gun module can be a viscosity of optionally 5000 cps to 40,000 cps, further optionally 7000 cps to 20,000 cps, and further optionally 10,000 cps to 15,000 cps. Where the hot melt material is a polyamide, the viscosity thereof as it exits the dispensing gun module can be about 25,000 cps. Where the hot melt material is a polyolefin, the viscosity, thereof, as it exits the dispensing gun module can be about 18,000 cps to 25,000 cps. Of course, other viscosities can be selected depending on the particular application, the hot melt material, the rate of dispensing, the speed of the conveyor, the size of the washers and other physical or operating parameters.
[0112] Optionally, to keep the dispensing good modules operating properly, multiple components of the dispensing station 330 can be heated with a suitable heating element 331. This can ensure that the hot melt material flows through the components of the dispensing station without solidifying, coagulating, or otherwise plugging different components of the station, thereby inhibiting acceptable flow of the hot melt material through the system and ultimately out the dispensing gun modules toward the conveyor and apertures of the washers.
[0113] As shown in
[0114] After the washers 380 pass the curing station 350, they continue along the first conveyor 370, toward the transfer station 375 as illustrated in
[0115] When the individual washers 380 are constructed from ferromagnetic metals (in other cases they can be constructed from non-ferromagnetic materials, such as polymers, aluminum, brass and/or other non-ferromagnetic metals), those ferromagnetic washers are magnetically attracted via a magnetic force exerted by the roller 374 thereon. In particular, the magnetic elements 374M disposed on or within the roller 374 exert a magnetic field to attract the washers away from the belt 371 and into contact and direct engagement with the outer surface 376 of the roller 374, and/or the belt 371. In so doing, the magnetic elements 374M effectively hold the washers against the belt 391 of the second conveyor 390. While the washers are attracted to the magnetic elements 374M on the roller, they are effectively lifted off the belt 371 and transition in the direction A2 so that they come to rest on the second belt 391.
[0116] As the washers 380 transition around an axis 374A of the roller 374, they are held close to the conveyor belt 391 and prevented from dropping vertically off of the apparatus. When the washers transition to the upper portion of the belt 391, they are effectively pried away from the magnetic force of the magnetic elements 374M of the roller 374. For example, washer 380 moves along the upper portion of the belt 391 far enough so it is no longer magnetically attracted to the roller magnetic elements 374M. Thereafter, the washer continues in the direction of the product flow PF2 along the second conveyor 390.
[0117] As shown in
[0118] After the washers 380 become disposed in the upper portion of the belt 391, the continue to travel in direction of product flow PF2. As they travel in that direction, they pass by a second dispensing station 330, which is similar to the dispensing station 330 on the first conveyor 370. Optionally, they pass through a mild preheat station 375 to slightly warm the washers before application of the hot melt material HM via the dispensing gun module 335 at the second dispensing station 330. Of course, the preheat station 375 can be set up so that it does not substantially deform and/or melt the existing retention aid body MB10. In some cases, the curing station 350 on the first conveyor 370 can be eliminated so that the washers retain the heat applied in the first preheat station 375, in which case the second preheat station 375 can be eliminated.
[0119] The hot melt material HM can be applied slightly differently to washers on the second conveyor 390 than the hot melt material applied on the first conveyor 370. For example, as shown in
[0120] After the second amount of hot melt material HM is applied, the washer continues in the direction of product flow PF2 along the second conveyor belt 391. It then optionally passes second curing stations 350. These curing stations can be cooling and/or chilling stations similar to the first stations 350 on the first conveyor 370. At the second curing station, chilled air and/or water can be projected over the washers and the recently applied hot melt material to cure it and fully bond it to the respective washers.
[0121] With the hot melt material cured and the two opposing retention aid material bodies MB10 and MB20 formed, the conveyor 390 continues to convey the washers toward an ejection shoot 396 at which the washers travel along yet another product flow path PF3. This product flow path PS3 can be generally perpendicular to the paths PF2 and PF1. Optionally, the finished washers can be dumped into bins and/or packages along this product flow path PF3.
[0122] A fourth alternative embodiment of the apparatus and related method is illustrated in
[0123] Further, like the embodiment immediately above, the apparatus 410 can be set up to apply a type of retention aid material, for example, a hot melt adhesive, a polyamide, a polyolefin and/or PUR hot melt (all generally referred to herein as hot melt material), in liquid form, or some other liquid retention aid material to the non-ferromagnetic washers 480, at more than one location around an inner diameter of the washers 480. As an example, the apparatus 410 can construct washers similar to those shown in
[0124] The apparatus 410 can be further constructed similar to the embodiment described immediately above and shown in
[0125] The first/upper conveyor 470 can include components and stations similar to the first conveyor 370 in the embodiment above, such as feed wheel, a preheat station, a material dispensing station 430, a curing station (not shown) and the like. As above, the dispensing station 430 can dispense a first amount of hot melt material in the aperture of the washer, generally along the inner diameter. After the hot melt material on this conveyor is dispensed, it can be cooled a curing station (not shown) and proceed to the end of the conveyor.
[0126] Because of the non-ferromagnetic material of the washers, the transfer station 475 of the apparatus 410 however, can be slightly different in the embodiment above. For example, in this embodiment, neither of the rollers 474 or 472 are constructed with magnetic elements to hold the washers 480 thereon as the washers are flipped over and redirected on the second conveyor 490. More particularly, the transfer station 475 can include a redirector plate 476 which can generally be in the form of a rounded plate about the width of the conveyor. This redirector plate 476 can be configured so that when the washers 480 fall off the end of the conveyor 470, they are directed toward a slot or channel 477 that is formed between the redirector plate 476 and the roller 474. The washers 480 slide through this channel which includes an exit end 478 that is disposed adjacent the belt 491 of the second conveyor 490. Accordingly, the washers 480 can be ejected toward and/or drop onto the belt 491.
[0127] After being deposited on the belt 491, the second conveyor conveys the washers 480 in the direction of product flow PF5. On the second conveyor 490, with the washers 480 effectively flipped upside down relative to the washers 480 on the upper conveyor 470, another amount of hot melt material HM2 is dispensed via the dispensing gun 430 on an opposing portion of the inner diameter of the washers 480 Like the embodiment described immediately above, the washers 480 can be conveyed through a curing station to cure and/or cool the hot melt material, thereby further bonding it to the respective washers. Further, the resulting washers with retention aid bodies produced by the apparatus 410 can be similar to the washers shown in
[0128] Directional terms, such as vertical, horizontal, top, bottom, upper, lower, inner, inwardly, outer and outwardly, are used to assist in describing the invention based on the orientation of the embodiments shown in the illustrations. The use of directional terms should not be interpreted to limit the invention to any specific orientation(s).
[0129] The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles a, an, the or said, is not to be construed as limiting the element to the singular. Any reference to claim elements as at least one of X, Y and Z is meant to include any one of X, Y or Z individually, and any combination of X, Y and Z, for example, X, Y, Z; X, Y; X, Z; and Y, Z.