Abstract
A vacuum diverter defined by a housing or hollow body having a first end, a second end, a plurality of sides, and an opening formed in one of the plurality of sides. A valve flap is disposed within the hollow body and moveable between a first position and a second position. The valve flap is supported by a shaft that extends across a cavity defined by the housing and which is rotationally supported by the housing such that the shaft and valve flap can be removed from the housing in a crossing direction relative to an axis of rotation of the shaft. Rotation of the shaft effectuates rotation of the valve flap relative to the cavity to selectively fluidly connect the discrete vacuum flow passages defined by the housing.
Claims
1. A vacuum diverter assembly comprising: a hollow body having a first end, a second end, a plurality of sides, and a window formed in one of the plurality of sides; a valve flap disposed within the hollow body and moveable between a first position and a second position relative to the hollow body; a bearing associated with each of two opposite sides of the hollow body; a shaft that extends between the bearings and is rotatable relative to the hollow body; and wherein the valve flap is coupled to the shaft, wherein the second end and the window are fluidly connected to each other via the hollow body, wherein the first end and second end are fluidly connected to one another, and wherein the window is oriented to allow visual inspection of the position of the valve flap relative to the hollow body, wherein the window is further defined by a window frame that is removably coupled to one of the plurality of sides of the hollow body, wherein a gasket is disposed between the hollow body and the window frame.
2. The vacuum diverter assembly of claim 1 wherein the valve flap extends from a location adjacent the first end of the hollow body to a location spaced apart from the second end of the hollow body.
3. The vacuum diverter assembly of claim 1 further comprising a linear actuator that is coupled to the shaft and is operable between an extended position and a retracted position to transition the valve flap from the first position to the second position.
4. The vacuum diverter assembly of claim 1 further comprising a mesh grill disposed within an opening of the window.
5. The vacuum diverter assembly of claim 1 further comprising a service plate that removably cooperates with a sidewall of the hollow body along a portion of the sidewall associated with the shaft and a gasket that is disposed between the hollow body and the service plate.
6. The vacuum diverter assembly of claim 5 wherein a top end of the valve flap engages the gasket underneath the service plate when the valve flap is in the first position.
7. The vacuum diverter of claim 6 wherein the valve flap includes a gasket that sealingly cooperates with an inner surface of the hollow body.
8. A water jet system comprising: a frame; a buck plate disposed atop the frame; a tub disposed underneath the buck plate; and a vacuum diverter disposed adjacent the tub, the vacuum diverter comprising: a housing having a first end, a second end, a plurality of sides, and an opening formed in one of the plurality of sides; a first bearing and a second bearing associated with opposite lateral sides of the housing; a shaft supported by the first bearing and the second bearing and extending across a cavity defined by the housing and supported by the housing such that the shaft can be removed from the housing in a direction transverse to an axis of rotation of the shaft; and a valve flap disposed within the housing and coupled to the shaft, the valve flap being moveable relative to the housing between a first position and a second position, wherein the opening and the second end defined by the housing are fluidly connected to one another and to the second position via the cavity, and wherein the first end and the second end of the housing are fluidly connected to one another via the cavity, and a linear actuator coupled to a first end of the shaft and operable between a retracted position and an extended position; and wherein operation of the linear actuator between the extended position and the retracted position causes the shaft to rotate and the valve flap to transition between the first position to the second position.
9. The water jet system of claim 8 further comprising a window frame removably coupled to one of the plurality of sidewalls of the housing and extending about the opening and a gasket disposed between the housing and the window frame.
10. The water jet system of claim 9 further comprising an expanded metal grill supported by the window frame and traversing the opening.
11. The water jet system of claim 8 further comprising a service plate removeably coupled to a sidewall of the housing along a portion of the sidewall associated with the shaft and a gasket disposed between the housing and the service plate.
12. The water jet system of claim 11 wherein a free end of the valve flap engages the gasket disposed between the housing and the service plate when the valve flap is oriented in the first position.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout.
(2) FIG. 1 is a perspective view of a water jet cutting device having a vacuum diverter assembly according to an embodiment of the invention;
(3) FIG. 2 is an enlarged perspective view of a portion of the water jet device of FIG. 1 associated with a vacuum diverter;
(4) FIG. 3 is a first perspective view of the vacuum diverter shown in FIG. 2;
(5) FIG. 4 is a second perspective view of the vacuum diverter shown in FIG. 2;
(6) FIG. 5 is a graphical side elevation view of a simplified vacuum diverter constructed in accordance with the vacuum diverter illustrated in FIGS. 3 & 4;
(7) FIG. 6 is an enlarged side elevation detail view of a diverter valve flap or valve plate drive arm arrangement of the vacuum diverter shown in FIG. 5 and that preferably is driven by a prime mover, such as a fluid powered prime mover, e.g., a pneumatic or hydraulic cylinder (not shown in FIG. 6) to displace the valve flap or valve plate between at least a plurality of, preferably at least a plurality of pairs, i.e., at least three, vacuum diverter operating positions;
(8) FIG. 7 is a graphical end elevation view of the simplified vacuum diverter shown in FIG. 5; and
(9) FIG. 8 is a graphical top plan view of the simplified vacuum diverter shown in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(10) Referring now to the drawings and specifically to FIGS. 1 and 2, a perspective view of a water jet cutting system, assembly, or device 10 is shown. The water jet device 10 includes a frame 12, a vacuum table, plate, or buck plate 14, a tub 16, a vacuum diverter 18 (FIG. 2), and preferably a moveable or removeable shroud, guard, cover, or guard cover 20 (FIG. 2) associated therewith. The water jet frame 12 includes a front wall 22 and a rear wall 24 that are preferably spaced apart from each other by an opening 26. The buck plate 14 and the guard cover 20 are preferably placed on an upper surface 28 of the water jet frame 12, which supports the weight of the water jet components.
(11) As shown in FIG. 1, the buck plate 14 and guard cover 20 are disposed adjacent each other on the upper surface 28 of the frame 12 and extend from the front wall 22 of the frame 12 to the rear wall 24 of the frame 12. The buck plate 14 is a rectangular section of material that acts as the cutting surface of the water jet device 10. The buck plate 14 may also include a plurality of orifices 30 formed therein. During operation of the water jet device 10, a nozzle (not shown) ejects a fluid, such as water, to effectuate cutting operations associated with an object or material placed on an upper surface 34 of the buck plate 14. Depending upon the material being worked, the working fluid flow may or may not include a suspended aggregate or abrasive material intended to manipulate the cutting performance associated with the flow discharged from the cutting nozzle. Regardless of the nature of composition of the cutting flow, orifices 30 formed through the buck plate 14 allow the cutting fluid associated with the cutting operation to drain through the buck plate 14 and to the tub 16 disposed underneath the buck plate 14 and within the opening 26 of the frame 12. It should be appreciated that debris associated with the cutting operation, particularly particulate cutting debris can be carried with the cutting fluid through orifices 30 during draining operations. During operation of the water jet device 10, a vacuum system (not shown) is commonly activated to retain parts relative to the cutting table or buck plate 14 and operate to draw the cutting fluid, air, and particulate debris through the orifices 30 of the buck plate 14 and into the tub 16.
(12) Referring to FIGS. 1-3, vacuum diverter 18 is preferably disposed adjacent tub 16 within the opening 26 of the frame 12. Vacuum diverter 18 is disposed between and fluidically coupled to the tub 16 and the vacuum source. Vacuum diverter 18 is operative to selectively secure parts or materials being processed relative to the cutting or buck table 14 and allow removal of processed parts therefrom. Said in another way, vacuum diverter 18 selectively introduces the vacuum flow pressure signal or vacuum flow to the cutting table—and any parts associated therewith, and allows bypass of the vacuum flow from the cutting table thereby allowing processed parts to be removed from the vacuum cutting table and subsequent placement of yet to be processed materials relative to the cutting table.
(13) In the representative embodiment of the invention, a first end 36 of the vacuum diverter 18 (FIGS. 2 and 3) is directly coupled to the tub 16. However, in other embodiments of the invention, the first end 36 of the vacuum diverter 18 and the tub 16 may be indirectly fluidly connected to one another. A second end 38 (FIGS. 2 and 3) of the vacuum diverter 18 may be either directly or indirectly coupled to the vacuum source. Regardless of its position relative to the vacuum source and the tub or other structure associated with the vacuum cutting table, vacuum diverter 18 is constructed to selectively fluidly couple the vacuum source and the tub 16 associated with the cutting buck. Preferably, vacuum diverter 18 is disposed proximate tub 16 and the vacuum source to effectuate the selectively communication of the vacuum flow pressure signal therebetween and such that vacuum diverter 18 is conveniently accessible relative to the other structures of the waterjet vacuum table cutting system.
(14) While FIG. 2 illustrates a connection tube 32 disposed between the second end 38 of the vacuum diverter 18 and the vacuum source, it is contemplated that the second end 38 (FIGS. 2 and 3) of the vacuum diverter 18 may be directly coupled to the vacuum generation source in other embodiments of the invention. Additional elements of vacuum diverter 18 and the configuration thereof are described in further detail below with respect to FIGS. 2-4.
(15) Still referring to FIG. 1, guard cover 20 is disposed adjacent buck plate 14 and extends from the front wall 22 to the rear wall 24. It is further contemplated that the guard cover 20 is disposed generally above and in spaced relation to vacuum diverter 18 and mitigates the collection of cutting material debris proximate vacuum diverter 18. In the illustrated embodiment of the invention, guard cover 20 is a transparent material, such as, but not limited to, a LEXAN™ polycarbonate or glass sheet. In alternative embodiments of the invention, the guard cover 20 may be transparent, opaque, or any variant thereof. The guard cover 20 may also be transitionable or moveable between an open position 40 (FIG. 2) wherein diverter 18 is accessible or serviceable and a closed position 42 (FIG. 1) associated with preventing access by personnel and/or debris to areas proximate diverter 18. In the embodiments of the invention using a transparent or semi-transparent guard cover 20, the components under the guard cover 20, such as the vacuum diverter 18, can be visually inspected when the guard cover 20 is in the closed orientation or position 42.
(16) In the closed position 42, the guard cover 20 is preferably oriented horizontally, or substantially horizontally and positioned such that a lower surface 44 of the guard cover 20 is supported by the upper surface 28 of the frame 12. In the open position 40, the guard cover 20 is oriented at an angle such that service personnel or the like can access those components, such as the vacuum diverter 18, disposed generally underneath the guard cover 20 when guard cover 20 is oriented in the closed position 42. It is contemplated that the guard cover 20 may be rotated or raised from the closed position 42 to the open position 40 and rotated or lowered from the open position 40 to the closed position 42.
(17) FIG. 2 is a partial detail perspective view of a portion of frame 12 and vacuum diverter 18 of the water jet device 10 and shows guard cover 20 oriented in an open position 40 relative to frame 12 thereby exposing vacuum diverter 18. The vacuum diverter 18 includes a housing or hollow body 46 that is defined by a first end 36 that is adjacent tub 16 and buck plate 14, a second end 38 that is opposite the first end 36 and directed toward a vacuum source, and a plurality of sidewalls 48 that extend between respective ends 36, 38.
(18) Referring to FIGS. 2, 3, and 8, at least one side wall 48 of the hollow body 46 preferably includes a window or opening 50 that is formed therethrough. Opening 50 provides an inspection/safety window 52 through which a user may visually inspect a portion of the interior passage defined by vacuum diverter 18 and which is described further below with respect to FIGS. 3-4 and 7. In order to mitigate the passage of debris or other unintended materials into the interior spaces defined by vacuum diverter 18, an expanded metal panel or mesh grill is preferably disposed across opening 50 associated with inspection window 52. Inspection window 52 allows users or service personnel to remotely visually inspect the status and condition associated with the internal portions associated with operation of vacuum diverter 18. As disclosed further below, such a consideration allows ready and remote visual inspection as to the operating condition of internal workings of vacuum diverter 18 so as to maintain the desired condition thereof and/or provide access upon the need to service the same.
(19) FIGS. 3 and 4 depict an end perspective view and a lateral side perspective view of vacuum diverter 18, respectively. While the representative embodiment of the housing or hollow body 46 of vacuum diverter 18 is shown as having a generally rectangular shape and cross-section, it is appreciated that hollow body 46 could be provided in any number of cross-sectional shapes which are considered within the scope of the present application.
(20) Referring to FIGS. 3, 4, and 8, inspection window 52 may be provided with a frame or window frame 56 configured to removably cooperate with a respective sidewall 48 of the hollow body 46 between ends 36, 38. When provided in such a methodology, the mesh grill 54 is preferably disposed within an opening 58 defined by window frame 56. In addition, a gasket 60 may be disposed between the frame 56 and an outer surface 62 of the sidewall 48 to establish a seal and maintain a vacuum pressure condition within the hollow body 46. As previously stated, the frame 56 may be removably coupled to the sidewall 48 to allow a user to remove the frame 56 to easily access the interior of the hollow body 46 for maintenance and/or service associated with maintaining the desired operability of vacuum diverter 18 as disclosed further below.
(21) FIG. 3 is a perspective view and FIG. 7 is a graphical elevation cross-section view of vacuum diverter 18 from a direction associated with second end 38 of the vacuum diverter 18 and provides a view of an interior or interior passage of hollow body 46. A valve, valve plate, or valve flap 64 is disposed within the hollow body 46 and moveable relative thereto. The valve flap 64 extends from a first end 66 that is located nearer the first end 36 of vacuum diverter 18 to a second end 68 that is spaced apart from the second end 38 of the vacuum diverter 18. As disclosed further below, first end 66 of valve flap 64 is secured to a shaft that extends through hollow body 46 such that second end 68 of valve flap 64 is oriented in a cantilevered fashion relative to the association of first end 66 of valve flap 64 with the shaft. Valve flap 64 is configured to extend laterally between opposing sidewalls 48 of the hollow body 46 and such that second end 68 of valve flap 64 can be selectively associated with the opposing laterally extending sidewalls to determine a discrete desired flow path associated with the vacuum pressure fluid flow during operation of diverter 18.
(22) First and second bearing mounts 70, 72 (FIGS. 5, 6, 8) are removably coupled to an outer surface 62 of opposing sidewalls 48 of the hollow body 46. Each bearing mount 70, 72 defines a respective orifice 74, 76 that is shaped and constructed to receive a respective bearing 78, 80. A shaft 82 extends across the cavity defined by hollow body 46 such that opposing end portions of shaft 82 are rotationally supported by cooperation with a respective bearing 78, 80. Shaft 82 is received in a respective orifice 84, 86 of each respective bearing 78, 80.
(23) As mentioned above, the first end 66 of valve flap 64 is coupled, attached, permanently affixed, welded, or otherwise secured to shaft 82 such that rotation of shaft 82 causes the valve flap 64 to pivot or rotate between a first position 88 (FIGS. 3, 7) and a second position (not shown) wherein valve flap 64 generally overlies or otherwise obstructs the fluid flow passage associated with window 52 as disclosed further below. As should be appreciated from FIG. 1, when valve flap 64 is oriented in first position 88 shown in FIG. 3, vacuum flow originating from the direction associated with second end 38 of vacuum diverter 18 is accommodated by a suitable flow through window 52 such that parts may be removed and/or otherwise freely associated with the cutting or buck table 14. Rotation of valve flap 64 relative to housing or hollow body 46 from the first position 88 toward the second position allows the vacuum flow associated with source and second end 38 to be directed toward first end 36 and diverter 18 and therefrom to the cutting table and tub environment. As disclosed further below, motion of the valve flap 64 between the first and second respective positions relative to the vacuum flow paths defined by hollow body 46 allow the selective vacuum securing and releasing of parts relative to the vacuum cutting support assembly.
(24) Referring to FIGS. 3, 4, 7, and 8, a service plate 90 preferably extends along a sidewall 48 of the hollow body 46 proximate the first bearing mount 70 to the second bearing mount 72. Service plate 90 is removably coupled to the sidewall 48 of hollow body 46 and, when removed therefrom, allows access to the shaft 82, and valve flap or valve plate 64 associated therewith. Alternatively, it is further appreciated that service plate 90 can be constructed to support bearing mounts 70, 72 and removeably cooperate with hollow body 46 such that removal of service plate 90 facilitates removal of shaft 82 and valve plate 64 from housing or hollow body 46 when service is required. It should be appreciated that each connection methodology allows both shaft 82 and the valve plate 64 associated therewith, to be removed from hollow body 46 via translation of the shaft and plate assembly in a crossing direction relative to the axis of rotation associated with shaft 82. Such considerations substantially improve the ability to expeditiously and efficiently service diverter 18 due to degradation of the components thereof.
(25) It is also appreciated that the functionality associated with service plate 90 may be formed as a separate structure as described above, or, as shown in FIG. 8, be provided as a portion of frame 56 associated with inspection window 50. That is, it is envisioned that service plate 90 may be separate from or integrated with the window frame 56 as described above. Similar to the window frame 56, a gasket 92 is disposed between the service plate 90 and the outer surface 62 of the sidewall 48 to establish a seal and maintain passage of a desired vacuum flow signal through hollow body 46. In the representative embodiments of the invention, gaskets 60, 92 are urethane gaskets, but may individually comprise other materials in varying embodiments of the invention.
(26) FIGS. 3-7 further illustrate a crank or pivot arm 94 that is disposed along a sidewall 48 of the hollow body 46 and oriented perpendicular to the shaft 82. Said in another way, pivot arm 94 is secured to shaft 82 and extends in an outward radial direction relative thereto. Preferably, pivot arm 94 is secured to a distal end of shaft 82 with a secure and robust mechanical interaction therebetween. As shown in FIGS. 4-6, a square shaped interface is provided between pivot arm 94 and shaft 82 although other geometric lobed or keyed interactions could be provided between pivot arm 94 and shaft 82 to achieve the desired robust engagement therebetween such that rotation of pivot arm 94 is translated to shaft 82 to effectuate rotation of valve plate 64 relative to the passage defined by hollow body 46 so as to effectuate the desired passage of the vacuum pressure flow to either of buck plate 14 or to atmosphere to achieve the desired material securing or releasing operation. It is further appreciated that pivot arm 94 can be constructed to cooperate in a slideable manner generally aligned with the axis of rotation of shaft 82, or as shown in FIGS. 6 and 7, be constructed to include a split joint connection methodology wherein a portion of shaft 82 is selectively captured between respective separable portions of arm 94. As should be appreciated from FIGS. 6 and 7, a plurality of fastener passages 95, 97 effectuate securing of the respective portions of arm 94 to each other with the lobed driving arrangement defined by shaft 82 captured therebetween.
(27) Regardless of the specific construction, pivot arm 94 is coupled to a first end 96 of the shaft 82 that extends beyond the first bearing mount 70. In the representative embodiment of the invention, the shaft 82 is coupled to the pivot arm 94 adjacent a first end 98 of the pivot arm 94. However, in other embodiments of the invention, the shaft 82 may be coupled to the pivot arm 94 at any location along a length of the pivot arm 94. It should be further appreciated that the respective bearing mounts 70, 72 are not shown in the graphic representation of diverter assembly 18 shown in FIG. 7.
(28) As shown in FIG. 4, a second end 100 of the pivot arm 94 is coupled to a linear actuator such as a pneumatic cylinder 102. It is appreciated that the functionality of the linear actuator could be provided in various methodologies such as hydraulic, electric, or electromechanical actuators or other actuator methodologies such as rotational actuators such as electric, hydraulic, or pneumatic motors, worm, cam or linear drives, transmissions, or the like. When provided as a linear actuator, such as pneumatic cylinder 102 as shown in FIG. 4, operation of the actuator transitions between an extended position 104 (FIG. 4) and a retracted position (not shown) to manipulate a radial orientation of valve flap 64 relative to the interior passage of hollow body 46 as disclosed further below.
(29) As the pneumatic cylinder 102 transitions between the extended and retracted positions, pivot arm 94 rotates about the location or axis 106 associated with the coupling of pivot arm to shaft 82. Actuation of cylinder 102 effectuates rotation of shaft 82 relative to hollow body 46 and thereby translation of valve flap 64 relative to the fluid flow passage internal to hollow body 46. When pneumatic cylinder 102 is in the extended position 104, valve flap 64 is oriented in the first position 88 (FIGS. 3, 7) such that the vacuum flow communicated to hollow body 46 from the vacuum source is satisfied from a flow of ambient environment air communicated into hollow body 46 via opening 50. Alternatively, when pneumatic cylinder 102 is in the retracted position, valve flap 64 achieves a second position relative to the cavity defined by hollow body 46 such that the flow associated with the vacuum source is communicated through the respective first and second ends 36, 38 of hollow body 46 and thereby to the cutting table or buck plate 14. Actuation of the linear actuator or pneumatic cylinder 102 between the extended and retracted positions transitions valve flap 64 between the first and second positions relative to hollow body 46 so as to selectively effectuate a vacuum hold pressure associated with cutting operations relative to materials associated with buck plate 14.
(30) In the first position 88, the valve flap 64 is oriented at an angle relative to the passage defined by hollow body 46 such that the valve flap 64 engages an interior surface 108 of each sidewall 48 of the hollow body 46 to form a vacuum seal within the hollow body 46 as a function of the desired vacuum pressure flow path. In a preferred embodiment, the first end 66 of the valve flap 64 engages gasket 92 below the service plate 90 thereby forming a seal therewith. When the valve flap 64 is in the first position 88, the valve flap 64 fluidically connects the second end 38 of the vacuum diverter 18 to the opening 50 in the sidewall 48. That is, the vacuum associated with the second end 38 of the vacuum diverter 18 pulls air from the opening 50 through sidewall 48. As such, the pull of air or vacuum flow pressure is disassociated with the buck plate 14 such that working materials can be translated relative thereto.
(31) When oriented in the second position relative to the cavity defined by hollow body 46, the valve flap 64 is oriented horizontally or substantially horizontally against the opening 50 in the sidewall 48 in order to form a vacuum seal against the sidewall 48 and insulate the interior of the hollow body 46 from the opening 50. When the valve flap 64 is in the second position, the valve flap 64 fluidically connects the second end 38 of the vacuum diverter 18 to the first end 36 of the vacuum diverter 18. In turn, the vacuum associated with the second end 38 of the vacuum diverter 18 pulls air from the tub 16 and buck plate 14 associate with the first end 36 of the vacuum diverter 18. As such, when valve flap 64 is oriented in the second position, working materials are secured to the upper surface 34 of the buck plate 14 by the vacuum flow. The vacuum flow also drawings a portion of the cutting fluid flow and particulate debris associated with the cutting operation toward the vacuum flow source.
(32) As shown in FIG. 3, the valve flap 64 may include a gasket 110 along its perimeter 112 to assist with sealing the valve flap 64 against the interior walls of hollow body 46. FIGS. 3 and 4 also illustrate that the first and second ends 36, 38 of the vacuum diverter 18 may include flange elements 114, 116, respectively, to assist with securing the vacuum diverter 18 between the vacuum source and tub 16 and providing a fluidly sealed connection therebetween.
(33) Referring briefly back to FIG. 1, water jet device 10 is shown as preferably including one or more light curtains 118. The light curtains 118 are preferably located adjacent the frame 12. As shown in FIG. 1, the light curtains 118 may be oriented both horizontally and vertically. In other embodiments of the invention, the light curtains 118 may be oriented at any angle. The light curtains 118 create a perimeter around the frame 12 of the water jet device 10 and are constructed to prevent operation of cutting devices and/or translation of automated systems, such as robots or the like, if any of the respective light curtains indicate the presence of obstructions, operators, or service personnel within the perimeter bounded by the light curtains.
(34) Preferably, the rigid structures of each of the hollow body 46, valve flap 64, and shaft 82 are constructed of stainless steel metal materials. Since valve flap 64 and shaft 82 can be removed from hollow body 46 in a crossing direction relative to the axis of rotation of shaft 82, valve flap 64 can be permanently affixed to shaft 82 with or without the use of extraneous fasteners. In a preferred embodiment, valve flap 64 is welded to shaft 82 such that shaft and valve flap can be replaced as a unit or serviced by suitable metal working methodologies. Constructing hollow body 46, valve flap 64, and shaft 82 from stainless steel materials allows vacuum diverter 18 to better withstand the harsh environment associated with the fluid and particulate debris flow through the diverter and the surrounding atmosphere associated with the water table cutting environment. Additionally, the ability to remove the shaft and valve flap in a lateral direction relative to the axis of rotation of the shaft allows expedient removal and replacement of the shaft and valve flap during servicing to mitigate downtime events associated with degradation of the ability of the diverter assembly to provide the desired vacuum pressure flow directions.
(35) Although the best mode contemplated by the inventor for carrying out the present invention is disclosed above, practice of the above invention is not limited thereto. It will be evident that various additions, modifications and rearrangements of the features of the present invention may be made without deviating from the spirit and the scope of the underlying inventive concept as defined by the appending claims.
