Securement Clip for Pipe and Scaffold Engaged Fabric

Abstract

A clip configured for compressive engagement of fabric to pipe or similar elongated members such as those of a scaffold. The clip has a body with opposing sidewalls separated by a gap. The sidewalls are formed of elastic or flexible material which will temporarily deflect to temporally increase the diameter of the gap, to allow passage of the pipe through the gap. The sidewalls thereafter return to the original position wherein interior surfaces of the sidewalls and an axial cavity of the body compressively engage with the pipe and any fabric adjacent thereto to hold the fabric in a compressive sandwiched engagement between the clip and the pipe.

Claims

1. A clip, comprising: a body of said clip extending between a first side edge and a second side edge, said body having a central portion; two sidewalls extending from said central portion in-between said first side edge and said second side edge to respective distal edges of each of said two sidewalls; said body having an interior surface extending in a curve within said central portion to said distal edges of said two sidewalls; said interior surface defining a curved axial passage communicating through said body along an axis; said axial passage having a first diameter; a projecting portion formed on at least one of said two sidewalls at a central area thereof located in-between said first side edge and said second side edge of said body; each said projecting portion defining a respective curved distal edge section, located along a respective said distal edge of said sidewalls; a first gap running between said distal edges of said sidewalls, said first gap being smaller than said first diameter; each said projecting portion having an outwardly curved portion of said interior surface of a respective said sidewall which extends to a respective said curved distal edge section; each said curved distal edge section defining a ledge; said two sidewalls being flexible and adapted for a temporary deflection in opposing directions expanding said first gap during forced contact of said distal edges against a pipe; said temporary deflection forming a temporary increase of said first gap to a size substantially equal to or larger than said first diameter; said clip being removably engageable to a compressed engagement with said pipe communicated through said gap during said temporary deflection, to form a contact of said interior surface against said pipe upon a cessation of said temporary deflection; and each said ledge adapted for contact against one or both of said curved portion of said interior surface of said sidewall and said curved distal edge section, to pull said clip from said compressed engagement with said pipe.

2. The clip of claim 1 additionally comprising: a said projecting portion formed on both of said two sidewalls at a central area thereof located in-between said first side edge and said second side edge of said body; each said projecting portion having an outwardly curved portion of said interior surface of a respective said sidewall which extends to a respective said curved distal edge section; said curved distal edge sections on said sidewalls defining a pair of said ledges; said pair of ledges adapted for concurrent contact with both of said pair of ledges against one or both of said curved portion of said interior surface of said sidewall and said curved distal edge section, to pull said clip from said compressed engagement with said pipe at two points of contact.

3. The clip as in claim 2 additionally comprising: said curved distal edge sections of said distal edge at each said projecting portion in each respective said sidewall, extending at opposing angles to each other and thereby defining respective opposing ramps positioned in respective central portions of each of said sidewalls; and said opposing ramps spaced a separation distance from each other exceeding said first gap and thereby generating a mechanical advantage during said forced contact of said curved distal edge sections with said pipe to thereby move said sidewalls toward said temporary deflection.

4. The clip of claim 1, additionally comprising: a projecting area of said body positioned at one of said first edge or said second edge of said body; and said projecting area forming a secondary ledge adapted for imparting force thereon to pull said clip from said compressed engagement with said pipe.

5. The clip of claim 2, additionally comprising: a projecting area of said body positioned at one of said first edge or said second edge of said body; and said projecting area forming a secondary ledge adapted for imparting force thereon to pull said clip from said compressed engagement with said pipe.

6. The clip of claim 3, additionally comprising: a projecting area of said body positioned at one of said first edge or said second edge of said body; and said projecting area forming a secondary ledge adapted for imparting force thereon to pull said clip from said compressed engagement with said pipe.

7. The clip of claim 1, additionally comprising: a first projecting area of said body positioned at said first edge of said body; a second projecting area of said body positioned adjacent said second edge of said body; each of said first projecting area and said second projecting area forming a pair of secondary ledges in opposing position on said body; and said pair of secondary ledge in said opposing positions on said body being adapted for concurrent imparting of force thereon to pull said clip from said compressed engagement with said pipe from both said first edge and said second edge concurrently.

8. The clip of claim 2, additionally comprising: a first projecting area of said body positioned at said first edge of said body; a second projecting area of said body positioned adjacent said second edge of said body; each of said first projecting area and said second projecting area forming a pair of secondary ledges in opposing position on said body; and said pair of secondary ledge in said opposing positions on said body being adapted for concurrent imparting of force thereon to pull said clip from said compressed engagement with said pipe from both said first edge and said second edge concurrently.

9. The clip of claim 3, additionally comprising: a first projecting area of said body positioned at said first edge of said body; a second projecting area of said body positioned adjacent said second edge of said body; each of said first projecting area and said second projecting area forming a pair of secondary ledges in opposing position on said body; and said pair of secondary ledge in said opposing positions on said body being adapted for concurrent imparting of force thereon to pull said clip from said compressed engagement with said pipe from both said first edge and said second edge concurrently.

10. The clip of claim 1, additionally comprising: said body formed of polymeric material having reinforcing fibers therein at a ratio by weight of 12 to 40 percent of a total weight of said body.

11. The clip of claim 7, additionally comprising: said body formed of polymeric material having reinforcing fibers therein at a ratio by weight of 12 to 40 percent of a total weight of said body.

12. The clip of claim 8, additionally comprising: said body formed of polymeric material having reinforcing fibers therein at a ratio by weight of 12 to 40 percent of a total weight of said body.

13. The clip of claim 9, additionally comprising: said body formed of polymeric material having reinforcing fibers therein at a ratio by weight of 12 to 40 percent of a total weight of said body.

14. The clip of claim 1, additionally comprising: a tether extending from a first end to a distal end; said first end engaged to said body; a removably engageable connector attached to said distal end of said tether; and said connector adapted for engagement to a user of said clip prior to positioning to said compressed engagement with said pipe, whereby said clip is prevented from dropping.

15. The clip of claim 2, additionally comprising: a tether extending from a first end to a distal end; said first end engaged to said body; a removably engageable connector attached to said distal end of said tether; and said connector adapted for engagement to a user of said clip prior to positioning to said compressed engagement with said pipe, whereby said clip is prevented from dropping.

16. The clip of claim 5, additionally comprising: a tether extending from a first end to a distal end; said first end engaged to said body; a removably engageable connector attached to said distal end of said tether; and said connector adapted for engagement to a user of said clip prior to positioning to said compressed engagement with said pipe, whereby said clip is prevented from dropping.

17. The clip of claim 6, additionally comprising: a tether extending from a first end to a distal end; said first end engaged to said body; a removably engageable connector attached to said distal end of said tether; and said connector adapted for engagement to a user of said clip prior to positioning to said compressed engagement with said pipe, whereby said clip is prevented from dropping.

18. The clip of claim 8, additionally comprising: a tether extending from a first end to a distal end; said first end engaged to said body; a removably engageable connector attached to said distal end of said tether; and said connector adapted for engagement to a user of said clip prior to positioning to said compressed engagement with said pipe, whereby said clip is prevented from dropping.

19. The clip of claim 9, additionally comprising: a tether extending from a first end to a distal end; said first end engaged to said body; a removably engageable connector attached to said distal end of said tether; and said connector adapted for engagement to a user of said clip prior to positioning to said compressed engagement with said pipe, whereby said clip is prevented from dropping.

20. The clip of claim 9, additionally comprising: a tether extending from a first end to a distal end; said first end engaged to said body; a removably engageable connector attached to said distal end of said tether; and said connector adapted for engagement to a user of said clip prior to positioning to said compressed engagement with said pipe, whereby said clip is prevented from dropping.

Description

BRIEF DESCRIPTION OF DRAWING FIGURES

[0019] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate some, but not the only or exclusive, examples of embodiments and/or features of the invention. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting. In the drawings:

[0020] FIG. 1 shows a view of a perspective view of the clip herein showing the U-shaped body having an open side defined by a gap running opposite to a central portion of the body, and an axial passage running there through.

[0021] FIG. 2 shows a side view of FIG. 1.

[0022] FIG. 3 shows an end view of the U-shaped body and shows the axial passage running through the clip which has an interior diameter D1 equal to or smaller than an exterior diameter of a pipe to which the body engages, and showing a gap on the open side which is smaller than the diameter.

[0023] FIG. 4 shows a bottom side view of the clip, showing the gap upon the open side of the body, and showing opposing projections formed in the perimeter edge of the clip on at least one an preferably opposite edges of the open side.

[0024] FIG. 4A depicts the installation of the clip upon a member such as a pipe or tube, showing that a downward force on the body of the clip will cause contact of opposing ramps formed by projecting portions on both sides of the body, which provide mechanical advantage to flex the sidewalls temporarily outward as the clip body slides to an engagement on the pipe.

[0025] FIG. 5 shows the clip herein in an as-used or engaged position, wherein the body is positioned in a compressive sandwiched engagement of a portion of fabric between the interior surface of body of the clip and the exterior surface of the pipe or tubing.

[0026] FIG. 6 depicts a mode of the clip device herein having fibers extending within the material forming the body of the clip and also depicting at least one opening formed through one of the secondary projecting areas.

[0027] FIG. 7 shows the clip device having a tether engaged with the opening with a removable attachment connected to a distal end of the tether and also depicting an aperture communicating through at least one of the side-positioned projecting portions of the device.

[0028] Other aspects of the present invention will be more readily understood when considered in conjunction with the accompanying drawings, and the following detailed description, neither of which should be considered limiting.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0029] In this description, the directional prepositions of up, upwardly, down, downwardly, front, back, top, upper, bottom, lower, left, right and other such terms refer to the nose engagement device as it is oriented and appears in the drawings and are used for convenience only; they are not intended to be limiting or to imply that the device has to be used or positioned in any particular orientation.

[0030] Now referring to drawings in FIGS. 1-7 wherein similar components are identified by like reference numerals, there can be seen in FIG. 1 a perspective view of the clip 10 which has a body 12 which is substantially U-shaped. By substantially U-shaped is meant that the body 12 is formed of any exterior shape but has a curved interior surface 31 running across a center portion 15 of the body 12 and both sidewalls 18 extending therefrom, and has a gap 14 in-between the distal ends 23 of the two sidewalls 18. This gap 14 defines an opening or open side of the clip 10 opposite the central portion 15 of the body 12 and at the distal ends 23 of both of the sidewalls 18. An axial passage 16 communicates through the body 12 of the clip from a first edge 17 to a second edge 19 of the body 12.

[0031] Shown in FIG. 2 is a side view of the body 12 of the clip 10, showing one curved sidewall 18 having a curved interior surface 31 wherein the sidewall 18 extends from the central portion 15, to a distal edge 23 at a lower end 20 of the sidewall 18. At this lower end 20 in a central position in-between the first edge 17 and second edge 19 of the body on one sidewall 18, but preferably both sidewalls 18, is formed at least one projecting portion 22, which has a cavity forming a ledge 21 on an underside. This projecting portion 22 is formed by an outward curve or projection of the distal edge 23 of the sidewall 18 and a portion of the sidewall 18 adjacent thereto.

[0032] Each formed ledge 21 on the lower ends 20 of one or both sidewalls 18, provides a gripping location for the fingers of a user. As noted the clip can have only one such projection portion 22 which will define one ledge 21 or gripping location for removal of the body 12 of the clip from engagement over a tube or pipe 30 as in FIG. 5. However, preferred is two opposing such projection portions 22 which form opposing ledges 21 or gripping locations for the thumb and fingers of the user during such removal.

[0033] During experimentation it was found also, that two such projection portions 22 formed by curved areas on opposing positions on the sidewalls 18 are preferred because such a configuration provided a significant mechanical advantage during clip installation to the installed position one a member such as a pipe 30 shown in FIG. 5. This is because as can be seen in FIG. 3 and FIG. 4, the projecting portion 22 formed by the curve of the distal end 23 and adjacent portions of the sidewalls 18, positions a central portion of the distal edge 23 at the projecting portion 22 on the sidewalls 18, further from the center axis 27 (FIG. 4) of the body 12, than the distal edges 23 of the sidewall 18 which are located adjacent the first edge 17 and second edge 19. This positioning as such, provides contact points at the central portions of the distal edge 23 defined by the projecting portions 22, which are further from the axis 27. This extra distance provides mechanical advantage in flexing and spreading the sidewalls 18 to enlarge the gap 14 when the body 12 of the clip is pushed onto a member or pipe 30 form the sandwiched engagement of the fabric 32 therebetween as in FIG. 5.

[0034] While not required, it is preferred that at one or both the first side edge 17 and second side edge 19 of the body 12 at the central portion 15 thereof positioned across from the gap 14 on the open end, are formed at least one and preferably a second pair of projecting areas 26 each of which has form a secondary ledge 28 underneath the curved second projecting areas 26. As noted, one such second projecting areas 26 will provide the user a secondary ledge 28 for one finger or a thumb to pull upward during removal of the clip. However, two opposing secondary ledges 28 for the opposing fingers and the thumb of the user, doubling the force employable during removal by pulling the body of the clip from the pipe 30 engagement shown in FIG. 5. FIG. 3 shows an end view of the U-shaped body 12 and shows the axial passage 16 running through the clip 10. The diameter of the axial passage D1 between the interior surface 31 area on both sidewalls 18, is larger than a diameter of the gap 14 between the distal ends 23 at the sidewalls 18, shown as D2. Currently, for example, the diameter of the axial passage D1 to engage upon a pipe 30 with an exterior diameter of 2 inches, would be 1.8 to 2 inches whereby the clip 10 formed of flexible elastic material will impart a compressive sandwiched engagement upon the pipe 30 and fabric 32 when engaged thereupon as shown in FIG. 5. In experimentation to achieve a solid grip of the body 12 on a member such as a pipe 30 (FIG. 5) it has been found that forming the diameter D2 of the static or initial gap 14 between the distal edge 23 of the un-flexed sidewalls 18, in a range between 30-60 percent smaller than the diameter D1 of the axial passage 16, works well to form and maintain this compressive engagement. The diameter D1 of this gap 14 can be adjusted by lengthening the sidewalls 18 to curve for a longer distance and place the distal ends 23 closer to each other thereby decreasing the diameter D2, or, shortening the sidewalls 18 to place the distal ends 23 thereof further apart thereby increasing the diameter D2. As depicted in FIG. 3, the diameter D2 is a first diameter between the distal ends 23 of both sidewalls 18 prior to the sidewalls 18 being temporarily flexed or bent in a direction away from the gap 14 during installation as shown in FIG. 4A.

[0035] During that installation shown in FIG. 4A, the gap 14 reaches a temporary second diameter, which as noted will be substantially equal to or slightly larger than the depicted diameter D1 (FIG. 3) of the axial passage 16, since the pipe 30 to be engaged preferably is slightly larger in diameter than D1 of the axial passage 16. By substantially is meant plus or minus 1-20 percent.

[0036] During installation to the engaged position of FIG. 5, a user pressing on the top portion of the body 12, such as the central portion 15 between the two secondary projecting areas 26, will cause a temporary deflection of the flexible sidewalls 18 and flexing movement of both sidewalls 18 in a direction away from the gap 14. This action causes a temporary increase in the diameter D2 of the gap 14. This temporary deflection is caused by force imparted against the distal edge 23 at the lower end 20 of both sidewalls 18 of the body 12 when in contact the pipe 30 and/or fabric 32 thereon as shown in FIG. 5. During this temporary deflection of both sidewalls 18, the gap 14 increases to a size equal to or slightly larger than the diameter D1 of the axial passage.

[0037] In this fashion, the clip body 12 is engageable around a pipe 30 having a diameter equal to or larger than that the diameter D1 of the axial cavity, when the pipe 30 is communicated through said gap 14 during the temporary deflection. Thereafter, the sidewalls 18 return to their original position and having the original gap 14 therebetween having a diameter D2. Upon a cessation of the deflection, the sidewalls 18 return to their original or first position. This causes a biased contact of the interior surface 31 with the pipe 30 and with any fabric 32 placed adjacent the pipe 30 and thereby holds the clip body 12 on the pipe 30 along with maintaining the fabric 32 in contact with the pipe 30.

[0038] As noted, the distal edge 23 of the sidewalls 18 curving around along the projecting portions 22 on the sidewalls 18, forms a wider spaced pair of angled planar surfaces depicted in FIG. 3 which run in opposing angles R1 and R2. This provides angled contact and mechanical advantage for the temporary deflection of the sidewalls 18 from their first or static position, in a direction away from the gap 14, to form the temporary increase of the diameter D2 of the gap 14, to a second diameter which is of a size equal to or larger than the diameter D1 of the axial passage. As noted, during this temporary increase of the diameter D2, a pipe 30 can slip through the gap 14 and be compressibly engaged when the sidewalls 18 un-flex and return to their original position which forms the diameter D2 of the gap 14 smaller than the diameter D1 of the axial passage.

[0039] This mechanical advantage provided by the configuration noted, and the flexing of the body 12 and sidewalls 18 under force, allows the user to place the gap 14 in the body 12 of the clip 10 on the fabric 32 and/or pipe 30 and simply press on the central portion 15 of the body 12. Thereafter they may use the mechanical advantage achieved to slide the body 12 into a compressive engagement around the exterior of the pipe 30 and concurrently form a compressive sandwiched engagement of any fabric 32 positioned between the interior surface 31 of the body 12 and the exterior of the pipe 30 as shown in FIG. 5. Forming the diameter D1 of the axial passage smaller than the diameter of the intended pipe 30 causes this compression which can be increased by decreasing D1.

[0040] Currently with the clip body 12 formed of a polymeric material such as nylon, or polypropylene, or polyethylene, or a similar elastic polymeric material, the body 12 has substantially 35 pounds of resistive force to the flexing of the sidewalls 18 from their static or first position where D2 is the gap 14 diameter, to form a temporary enlargement of the gap 14 to a second diameter which is equal to or exceeding the diameter D2 of the axial passage 16, where the clip body 12 will slip on, or off, to or from the engaged position with a pipe 30 and fabric 32, as shown in FIG. 5.

[0041] This resistive force, and thus the biased compressive engagement, can also be adjusted by changing the thickness of the sidewalls 18 and central portion 15 and/or changing the material forming the body 12 of the clip 10. Currently forming the body 12 of a flexible material and of a thickness where this resistive force to bending the sidewalls 18 is between 20 to 50 pounds, to form a clip body 12 configured to hold fabric 32 to a member such as a pipe 30 in varying wind and other conditions is preferred.

[0042] FIG. 4 shows a bottom side view of the clip 10, showing the open side of the body 12 formed by the gap 14. Also shown are the two projecting portions 22 which may be formed by curved sections of the sidewall 18 adjacent the distal ends 23 of the body 12 at a central areas of the sidewall 18. Each such projecting portion 22 defines a ledge 21 formed by an outward curve of the interior surface 31. As noted, while one such projecting portion 22 on one sidewall 18 forming one ledge 21 will aid in removal and engagement of the clip body 12 on a pipe 30, two such projecting portions 22 are preferred. It was found two projecting portions in opposing positions gives the user more leverage to remove the clip by providing two ledges 21. Further, two such projecting portions 22 will provide more leverage during engagement on the pipe 30.

[0043] Additionally, as shown in FIG. 4A, this leverage is enhanced by opposing angled ramps R1 and R2 formed on the distal end 23 of each of the two sidewalls 18. As can be seen, the projecting portions 22 form an outward deflection such as a curve in the sidewalls 18 and a downward lengthened positioning of the distal ends 23 in the area where the distal ends 23 intersect the projecting portions 22. This forms slanted portions and pair of opposing angled ramps R1 and R2 or opposing angled contact surfaces of said distal edge 23 of each of the first and of the second of the two sidewalls 18.

[0044] As the user imparts force F, to the exterior surface of the body 12, forcing it toward a pipe 30, the opposing angled contact surfaces defined by the formed ramps R1 and R2, are adapted to slide on the pipe 30 exterior and any fabric 32 placed thereon, and allow forced communication against the pipe 30 or fabric 32 thereon to act as a wedge.

[0045] Thus, the opposing angled contact surfaces provided by the ramps R1 and R2 allow the pipe 30 to be engaged to wedge into the gap 14 and act with mechanical advantage to temporarily deflect the sidewalls and enlarge the gap 14 to a second diameter noted herein. Further, the opposing angled contact surface afforded by the ramps R1 and R2, in combination with the extra distance the distal edge 23 is separated from the axis 27 through the body 12, can both act in combination, to gain additional mechanical advantage for the user. This mechanical advantage, as noted, helps the user during installation such as in FIG. 4A, to more easily temporarily deflect or bend the sidewalls 18 in a direction away from their first or static position on both sides of the gap 14, and thereby temporarily increase the size of the gap 14 to a second larger diameter.

[0046] During this process, as noted, the gap 14 increases in size from a static or first size diameter D2, where the sidewalls 18 are not bent or flexed, to the temporary and second diameter of the gap 14, will position the outwardly bent sidewalls 18 to form the gap 14 of a second diameter which is equal to or just slightly more than the diameter D1 (FIG. 3) of the axial passage 16. This diameter D1 of the axial passage 16 as noted, is adapted in size to be equal to or slightly smaller than the diameter of the intended pipe 30 for engagement. This causes the interior surface 31 of the body 12, once the sidewalls 18 return to the static or first diameter D1 of the gap 14, to grip the exterior surface of the pipe 30 and any fabric 32 thereon. This results in the body 12 of the clip holding the fabric 32 in a compressive sandwiched engagement between the interior surface 31 of the body 12 of the clip, and the exterior surface of the pipe 30.

[0047] Shown in FIG. 5, is a depiction of the clip 10 herein operatively engaged in a compressive engagement around a pipe 30, and forming a sandwiched biased compressive engagement of the fabric 32, in-between the interior 31 surface of the body 12 and sidewalls 18 thereof, and an exterior surface of the pipe 30.

[0048] Depicted in FIG. 6 is a preferred a mode of the clip 10 herein, wherein the body 12 is formed of polymeric material noted above, which includes reinforcing fibers 41 such as glass fibers within the polymeric material forming the body 12 of the clip 10. In colder weather it has been found that including reinforcing fibers 41 such as glass fibers which are of a material which melts at a higher temperature than the polymeric material forming the body 12, provides reinforcement against cracking during flexing of the body 12. Currently the inclusion of such reinforcing fibers 41 at a ratio by weight of 12 to 40 percent of the total weight of the material forming the body 12 of the clip, is preferred.

[0049] Also depicted in FIG. 6 and in FIG. 7 are at least one opening 42 formed into at least one of the projecting areas 26 of the body 12 or into one projecting portion 22. While the opening 42 might be formed elsewhere through the body 12 it was found that an opening communicating through a projecting area 26 or projecting portion 22 allowed for the engagement of a tether 44 there through, in a fashion which does not position the tether 44 compressed in-between the pipe 30 or fabric 32. This is preferred as it maintains maximum contact of the interior surface 31 with the pipe 30 or fabric 32 by preventing a deflection in the area of the tether 44 since it occupies the open area under the projecting portion 22 or projecting area 26.

[0050] In FIG. 7 is shown this engagement of a tether 44 with the body 12 of the clip 10 in a preferred embodiment. The tether 44 is connected at a first end thereof with the body 12 of the clip 10 either though an opening 42 or aperture 47 or by otherwise affixing the first end of the tether 44 in an engagement with the body 12.

[0051] A distal end of the tether 44 is engaged to a removable connector 46 such as the depicted spring loaded clip, or a magnet 48 or both, or another removably engageable connector 46. During use, the removable connector 48 is engaged to the user, such as by connection to their tool belt, or clothing, or a ring engaged therewith. As the user engages the clip 10 on a pipe 30 the removable connector 46 may be disengaged from their person thereby alleviating or significantly reducing the chance that the clip 10 can be dropped. When working at heights above a street or other support surface for the pipes 30 of a scaffold, this tethering means helps insure that clips 10 are not dropped where they might impact persons or property on the support surface causing damage or injury.

[0052] Also shown in FIG. 7 is an aperture 47 communicating through the body 12 at one or both of the projecting portions 22 which may be included along with the opening 42. This aperture 47 is adapted for communication of a support line 49 there through which may be engaged with a sign or tool or other item which needs positioning on the pipe 30 structure.

[0053] While all of the fundamental characteristics and features of the clip securement system for fabric invention have been shown and described herein, with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosure and it will be apparent that in some instances, some features of the invention may be employed without a corresponding use of other features without departing from the scope of the invention as set forth. It should also be understood that various substitutions, modifications, and variations may be made by those skilled in the art without departing from the spirit or scope of the invention. Consequently, all such modifications and variations and substitutions are included within the scope of the invention as defined by the following claims.