WO1999045293A1

WO1999045293A1 - Universal clamp

Info

Publication number: WO1999045293A1
Application number: PCT/US1999/004618
Authority: WO
Inventors: Bradley W. Boesel
Original assignee: Boesel Bradley W
Priority date: 1998-03-03
Filing date: 1999-03-02
Publication date: 1999-09-10
Also published as: WO1999045293A8; WO1999045293A9

Abstract

A universal clamp has a slide (30) an anchor (50) and a toggle assembly (90). The toggle assembly has a toggle handle (92) and a link (94). The toggle handle is pivotally joined to the slide. The link connects the toggle handle to the anchor. The anchor contains a gripper assembly (60) that will grip a track assembly (80) when actuated. A cam bushing (33) in the slide operates the gripper assembly. The combination of the cam bushing and the gripper assembly form a slidable connection between the slide and the anchor. Both the slide and the anchor ride on a track assembly. The universal clamp may be converted to a universal belt tensioner (10d) by the addition of an idler bushing (20, Fig 50) to the slide. The drive belt runs over and is tensioned by the idler bushing.

Description

UNIVERSAL CLAMP

This application claims the benefit of U.S. Provisional Application No. 60/076,654, filed March 3, 1998, titled "UNIVERSAL BELT TENSIONER".

BACKGROUND OF THE INVENTION

1. Field of the Invention. This invention relates generally to devices used to clamp or hold articles in place, and more particularly to devices used to clamp or hold articles in place where the size of the clamp opening is adjustable, where the amount of clamping pressure may be user selectable, and where the clamp pressure is maintained by a mechanical linkage.

2. Description of the Related Art.

Adjustable clamps have long been used in the construction, manufacturing, and repair industries. The classic clamps used to hold articles are "C" clamps or bar clamps. These clamps often require turning a threaded shaft to set the clamping pressure. This method often results in the clamp applying too little or too much pressure. Additionally using this method it is difficult to apply a consistent clamping pressure each time the clamp is used. An improperly tightened clamp will often result in damaged, lower quality, out of manufacturing tolerance, or weak products.

Clamps or grips enable robots to grip, hold, and move articles. Typically the clamps or grips use a linear actuator to effect this gripping. However, in the event the robot loses power, the grip will tend to loosen or release and the gripped article slides, falls, or flies out of the grip, depending on the direction of travel of the grip when the robot loses power. Therefore, a clamp is needed that will enable an operator to quickly and consistently set the proper clamp pressure without having to manually adjust the clamp and a clamp that is not dependent on a power source to maintain the clamping pressure.

Additionally, adjustable belt tensioning devices have long been used to tension drive belts. The classic belt tensioner comprises an idler pulley or bushing mounted to a bracket. This bracket is usually mounted to a rigid support or foundation with at least two fasteners. One of these fasteners typically serves as a pivot point. The second fastener slides in a curved slot. To tension the drive belt both fasteners are loosened slightly and the belt is manually tensioned, usually with a pry bar or lever forcing the idler pulley or bushing against the drive belt. With the proper tension applied the fasteners are tightened and the pry bar removed. This method often results in the drive belt having too little or too much tension. An improperly tensioned drive belt typically results in increased drive belt wear, reduced drive belt life, and damage to the other components in the drive system, particularly drive shafts and bearings.

In an effort to improve repeatability of the belt tensioning process and as an aid in setting the proper drive belt tension, two different approaches have been taken. The first, shown in U.S. Patent 4,969,859 (Holbrook), uses a built in tension meter. Holbrook uses an idler bushing mounted to a slide member. This member slides within a housing that is slidably mounted to a support. A tab on the end of the slide member indicates the correct tension. A spring provides a biasing force between the member and the housing. To use this device the fastener is loosened and the belt tension adjusted by sliding the housing until the tab on the slide member indicates the proper tension has been applied. After setting the tension, the fastener is tightened to hold the tensioner in place and maintain the belt tension. This device, while providing an indication of the belt tension, still relies on the operator to properly set the tension. Additionally, the operator must still tighten the fastener while holding the belt tensioner in place. The second approach is shown in U.S. Patent 4,993,993 (Gill). Gill discloses the use of a spring to urge the idler bushing against the drive belt. These devices still require the operator to tighten the fastener while holding the tensioner in place. The use of a spring with the characteristics described by Gill should reduce the likelihood of the operator setting the incorrect drive belt tension. The spring, however, will be subject to fatigue and so may have a limited life.

Therefore, a drive belt tensioner is needed that will enable an operator to set the proper drive belt tension quickly and easily without having to loosen and tighten fasteners or to check an indicator for proper belt tension.

SUMMARY OF THE INVENTION

The present invention has solved the clamping problems cited above and generally comprises a universal clamp. There is a slide, an anchor and a toggle assembly. The toggle assembly has a toggle handle and a link. The toggle handle is pivotally joined to the slide. The link connects the toggle handle to the anchor. The anchor contains a gripper assembly that will grip a track assembly when actuated. A cam bushing in the slide operates the gripper assembly. The combination of the cam bushing and the gripper assembly form a slidable connection between the slide and the anchor. Both the slide and the anchor ride on a track assembly. The addition of a bushing to the present invention has solved the belt tensioning problems cited above and generally comprises a universal belt tensioner. There is an idler bushing, over which a drive belt runs, mounted to the slide. As discussed above, the toggle handle is pivotally joined to the slide. The link connects the toggle handle to the anchor. The anchor contains the gripper assembly that will grip the track assembly when actuated. The cam assembly in the slide operates the gripper assembly. The combination of the cam assembly and the gripper assembly form a slidable connection between the slide and the anchor. Both the slide and the anchor slide or ride on the track assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:

Figure la is a side view of a universal clamp, in accordance with a first embodiment of the present invention.

Figure lb is a section taken through the cam slot of the universal clamp, in accordance with a second embodiment at the present invention. Figure lc is a center cross section of the universal clamp in accordance with a third embodiment at the present invention.

Figure 2 is a top view of the universal clamp shown in Figure 1.

Figure 3 is a center cross section taken at 3-3 of Figure 2.

Figure 4a is a front-end view of the slide shown in Figure 1. Figure 4b is a top view of the slide shown in Figure 4a.

Figure 4c is a rear end view of the slide shown in Figure 4a.

Figure 4d is a side view of the slide shown in Figure 4a.

Figure 5a is a front-end view of the slide shown in Figure lb.

Figure 5b is a top view of the slide shown in Figure 5a. Figure 6 is a rear end view of the slide shown in Figure 5a.

Figure 7 is a side view of the slide shown in Figure 5a.

Figure 8 is an end view of a cam bushing adjustment plate shown in Figure lb.

Figure 9 is a top view of the cam bushing adjustment plate shown in Figure 8.

Figure 10 is a side view of the cam bushing adjustment plate shown in Figure 8. Figure 1 1 is a top view of a cam bushing adjustment pivot shown in Figure lb.

Figure 12 is an end view of a cam bushing adjustment pivot shown in Figure 1 1.

Figure 13 is a side view of the cam bushing adjustment pivot shown in Figure 1 1.

Figure 14 is a top view of a cam bushing adjustment lever shown in Figure lb. Figure 15 is a side view of the cam bushing adjustment lever shown in Figure 14.

Figure 16 is a front-end view of the anchor shown in Figure lb.

Figure 17 is a top view of the anchor shown in Figure 16.

Figure 18 is a back end view of the anchor shown in Figure 16.

Figure 19 is a cross-section taken at 19-19 of Figure 17. Figure 20 is a top view of the anchor front plate shown in Figures la and lb.

Figure 21 is an end view of the anchor front plate shown in Figure 20.

Figure 22 is a top view of the anchor back plate shown in Figures la and lb.

Figure 23 is an end view of the anchor back plate shown in Figure 22.

Figure 24 is a top view of the gripper assembly shown in Figure lb. Figure 25 is a side view of the gripper assembly shown in Figure 24.

Figure 26 is a front view of the anchor front plate shown in Figures 21 and 24 with mostly hidden grippers.

Figure 27 is a top view of the grippers shown in Figure 24.

Figure 28 is a side view of the grippers shown in Figure 27. Figure 29 is an end view of the grippers shown in Figure 27.

Figure 30 is a top view of one of the cam arms shown in Figure 24.

Figure 31 is a side view of the cam arm shown in Figure 30.

Figure 32 is a top view of a slide shown in Figure lc.

Figure 33 is an end view of the slide shown in Figure 32. Figure 34 is a side view of the slide shown in Figure 32.

Figure 35 is a side view of the anchor shown in Figure lc.

Figure 36 is a cross-section taken at 36-36 in Figure 35 of the anchor.

Figure 37 is a side view of the anchor shown in Figure 35. Figure 38 is an end view of a cam arm shown in Figure lc.

Figure 39 is a side view of the cam arm shown in Figure 38 where the slot in the cam arm is designed to cause the gripper to secure the anchor to the track assembly as the slide is separated from the anchor.

Figure 40 is an end view of a second embodiment of the cam arm in accordance with the third embodiment of the present invention.

Figure 41 is a side view of the cam arm shown in Figure 40 where the slot in the cam arm is designed to cause the gripper to secure the anchor to the track assembly as the slide is pulled closer to the anchor.

Figure 42 is a top view of a gripper shown in Figure lc. Figure 43 is an end view of the gripper shown in Figure 42.

Figure 44 is a side view of the gripper shown in Figure 42.

Figure 45 is a top view of a second embodiment of a cam bushing adjustment pivot in accordance with the second or third embodiment of the present invention;

Figure 46 is an side view of the cam bushing adjustment pivot shown in Figure 45. Figure 47 is a top view of a cam bushing adjustment plate shown in Figure lc.

Figure 48 is a side view of a cam bushing adjustment plate shown in Figure 47.

Figure 49a is a top view showing the interconnection of the pivot shown in Figures 45 and 46; the plate shown in Figures 47 and 48; and the arm shown in Figures 38 - 44. Figure 49b is a side view of the universal clamp together with a linear actuator in accordance with a fourth embodiment of the present invention.

Figure 49c is a side view of the clamp shown in Figure 49b in the engaged position.

Figure 50 is a side view of a universal belt tensioner, in accordance with a fifth embodiment of the present invention;

Figure 51 is a top view of the universal belt tensioner shown in Figure 50;

Figure 52 is a center cross section of the tensioner taken at 52-52 of Figure 51;

Figure 53 is a top view of the gripper assembly shown in accordance with the fifth embodiment of the present invention. Fig 54 is a side view of the gripper assembly shown in Figure 53.

Figure 55 is a front view of the anchor front plate shown in Figures 50, and 52 - 54

Figure 56 is a is a top view of the of a sixth embodiment of the universal belt tensioner in accordance with the present invention.

Figure 57 is a side view of the tensioner shown in Figure 56. Figure 58 is top view of a seventh embodiment of a universal belt tensioner in accordance with the present invention.

Figure 59 is a side view of the tensioner shown in Figure 58.

Figure 60 is top view of a eighth embodiment of a universal belt tensioner in accordance with the present invention. Figure 61 is a side view of the tensioner shown in Figure 60.

Reference will now be made in detail to the present preferred embodiment of the invention, an examples of which are illustrated in the accompanying drawings. DETAILED DESCRIPTION

The purpose of the universal clamp is to provide a device that will permit an operator to consistently apply the correct clamping pressure to an article or the correct tension to a drive belt. A mechanical linkage maintains the clamping pressure or belt tension. Thus, a consistent pressure or tension can be applied. Additionally, the mechanical linkage permits the clamp or tensioner to be used in conjunction with a linear actuator in an automated or robotic assembly line. Consequently, even in the event of a loss of power to the linear actuator, the article held in the clamp would not be released. This is particularly important in manufacturing plants using robots or automated clamping on an assembly line.

Referring now to the drawings in detail, wherein like numerals indicate the same elements throughout the views, Figure la shows a side view of universal clamp 10. Universal clamp 10 has the following components: slide 30, anchor 50, gripper assembly 60, and toggle arm assembly 90. In some applications, it may be desirable to use the universal clamp 10 as a belt tensioner. Clamp 10 can be converted to a belt tensioner by the addition of a bushing 20 (Figure 50). The belt tensioner also rides or slides on a track assembly 80. 1. Basic Clamp

The clamp 10 has a slide 30 slideably connected to anchor 50 with gripper assembly 60. Slide 30 is also connected to anchor 50 with toggle assembly 90. The toggle assembly 90 has a toggle handle 92 and a link 94. The toggle handle 92 is pivotally joined to the slide 30. The link 94 connects the toggle handle 92 to the anchor 50. The anchor 50 contains the gripper assembly 60 (Figure 24) that will grip track assembly 80 when actuated. Cam bushings 33 (Figure 3) in slide 30 operate the gripper assembly 60. The combination of cam bushings 33 and the gripper assembly 60 form a slideable connection between the slide 30 and the anchor 50. Both the slide 30 and the anchor 50 slide or ride on track assembly 80.

Figures 4a-d show slide 30 in greater detail. Slide 30 rides or slides on track assembly 80 (Figure la) and comprises a slide block 31 and cam bushings 33. Slide block 31 can be manufactured from a single piece of metal, plastic, ceramic, or other engineering material by machining, molding, casting, or other suitable forming method. Additionally, slide block 31 may be assembled from two or more pieces provided that block 31, as assembled, has the required strength and toughness for the particular application. Additionally, there may be a clamp pad 35 and a cover plate 36 (Figure 2). Clamp pad 35 is a generally resilient layer of material fastened or bonded to the front face of block 31. Preferably, pad 35 will be made from polyurethane, however, any other resilient material could be used. The use of a resilient pad 35 will help prevent damage to the surface of the object held in the clamp. Additionally, the pad 35 will permit the distance that the slide 30 will move after the gripper 60 grabs track 80 to be longer. Cover plate 36, if used, is typically, fastened to slide block 31 with fasteners 42. Alternatively, cover plate 36 could be glued or bonded to block 31. The cover plate 36 is typically used in the non-adjustable configuration to indicate nameplate data.

Slide block 31 has a generally "C" shaped section as shown in Figures 4a and 4c. Each leg of slide block 31 has a respective groove 62a in each inside face. These grooves are sized and shaped to permit slide 30 to slide or ride on the track assembly 80 selected for a particular application. Fixed to a roof 37 of slide block 31 are cam bushings 33 that form part of the slidable connection between slide 30 and anchor 50. Typically, cam bushings 33 are dowels of sufficient diameter to provide the strength required for a specific application selected from a material that is compatible with slide block 31. In the non-adjustable configuration the cam bushings 33 project from roof 37. The placement or location of the cam bushings 33 is discussed below. A second embodiment of slide 30 is shown in Figures 5a, 5b, 6 and 7 (adjustable horizontal slide 30a) and a third embodiment of slide 30 is shown in Figures 32-34 (adjustable vertical slide 30b).

Anchor 50, shown in greater detail in Figures 16 - 23, comprises anchor front plate 52 (Figures 20-21), anchor midsection 54 (Figures 16-19), and anchor back plate 56 (Figures 22- 23). Anchor front plate 52 and anchor back plate 56 are joined to anchor midsection 54 with fasteners (not shown). Front plate 52, anchor midsection 54, and back plate 56 have respective grooves 62b, 62c, and 62d configured and sized to fit the shape of track assembly 80 selected for a particular application. Anchor front plate 52, anchor midsection 54 and back plate 56 can be manufactured form similar materials and using similar methods as discussed above for the slide 30. The anchor front plate 52 and anchor back plate 56 limit the movement of the gripper assembly 60 in the manner described below. An alternative embodiment of anchor 50 is shown in Figures 35 - 44. The alternate embodiment of anchor 50 uses a gripper assembly 60 that grips the track assembly 80 in the vertical plane. The gripper assembly 60 that grips track 80 in the horizontal plane is horizontal gripper assembly 60a. The horizontal gripper assembly 60a, shown in Figures 24 - 31 grips the track assembly 80 generally in the horizontal plane and typically comprises cam arm(s) 68a and grippers 70a. Each cam arm 68a has cam end 72a and gripper end 74a. The gripper end 74a of cam arm 68a has a slot 76a. Each cam arm 68a is slidably and pivotally connected to one gripper 70a with roll pin 78a. Each roll pin 78a fits through a respective opening in each gripper 70a and can slide along slot 76a in cam arm 68a. Additionally, in the horizontal gripper embodiment, the cam arms 68a are pivotally connected to anchor front plate 52a with dowels 64a. Dowels 64a fit into openings 66a in front anchor plate 52 (Figures 20 and 21) and pivotally connect cam arms 68a to anchor plate 52. Cam arms 68a rotate freely around respective dowels 64a and roll pins 78a.

Typically, each gripper 70a will have a respective gripping surface 71a (Figures 26 and 29) configured to grip the track assembly 80. In the embodiment shown, the gripping surface 71a is a semi-circle in cross-section and is threaded with the threads matching the threads on threaded rod 84 of track assembly 80. The embodiment described herein shows track assembly 80 having both a track 82 and a rod 84. However, track assembly 80 can be any single object or group of objects that will provide a surface that can be reliably gripped and provide for the approximately continuous adjustment of the position of the clamp 10a. The horizontal gripper assembly 60a also has a cam cutout 100a in the cam end 72a of cam arm 68a. Cam bushing(s) 33 (Figs 4a and 4c) of slide 30 ride in the respective cam cutout(s) 100a and slidably connect slide 30 to anchor 50. Relative motion between slide 30 and anchor 50 will cause cam bushing 33 to slide in cam cutout 100a. In the typical clamp 10, slide 30 is proximate anchor 50 when the cam bushing 33 is proximate the released end 102a and when slide 30 is spaced apart from anchor 50 and the toggle arm 92 is proximate anchor 50, the cam bushing 33 will be proximate engaged end 104a.

This shape of the cam cutouts 100a in the horizontal gripper 60a cause gripper(s) 70a to be spaced apart from threaded rod 84 while the cam bushing 33 is located in the area of cutout 100a from the released end 102a to the jog 106a. When cam bushings 33 enter the jog 106a the respective cam ends 72a of cam arm(s) 68a move outward forcing the gripper ends 74a and attached gripper(s) 70a to move inward. When the cam bushings 33 have completed the jog 106a in cam cutout 100a the gripper(s) 70 will be engaging the threaded rod 84. The gripper(s) 70a will continue to engage threaded rod 84 while the cam bushings 33 slide in cam cutout 100a from jog 106a to engaged end 104a of cam cutout 100a. In addition to the sliding connection between slide 30 and anchor 50 provided by the respective cam bushing 33 sliding in its respective cam cutout 100a there may be a biasing spring 110a (Figure 57) that will pull the slide 30 and anchor 50 together when toggle assembly 90 is released.

Returning to Figure la, toggle assembly 90 typically comprises a toggle arm 92, link 94, and latch assembly 98. Toggle arm 92 has a support end 93 and a handle end 95. The support end 93 of toggle arm 92 is pivotally fastened to slide 30 with fasteners 96. A first end of link 94 is fastened to toggle arm 92 intermediate the support end 93 and handle end 95 with fasteners 96. A second end of link 94 is fastened to gripper block 50 with fasteners 96. Typically, toggle arm 92 and link 94 are fastened to slide 30 and anchor 50 such that toggle assembly 90 forms an over-center toggle. Latch assembly 98 (Figures 2 and 3) can be any mechanism that will releaseably secure toggle assembly 90 to anchor 50.

The installation and operation of the universal clamp 10 is very simple. The clamp 10 is installed by attaching track assembly 80 to a solid support or foundation. The user must determine the distance that the slide 30 will need to travel to impart the proper compression force to hold the object in place between slide block 31 or clamp pad 35, if used, and stop 86. Each cam bushing 33 is positioned in slide 30 such that the cam bushing 33 will complete its travel of the jog 106a in cam cutout 100a and the gripper(s) 70a engage rod 84 when the length between the fastener 96 on slide 30 and fastener 96 on anchor 50 added to the proper compression distance will equal the distance between the two fasteners 96 on the toggle arm 92 combined with the distance between the two fasteners 96 on link 94. Some embodiments of the universal clamp 10 (Figures 7 - 11) will provide for changing the relative position of cam bushings 33 (horizontal gripper) or roll pin 78 (vertical gripper) with respect to jog 106 without having to disassemble the clamp 10 as discussed in detail below. Operation

In the typical clamp 10 using a horizontal gripper, with the cam bushing(s) 33 properly positioned and the toggle arm 92 in an open position (spaced apart from anchor 50); the clamp 10 is slid along track assembly 80 until the slide 30 makes contact with the object to be held in place The handle end 95 of toggle arm 92 is pushed toward anchor 50. Initially, the combined movement of toggle arm 92 and link 94 will cause anchor 50 to separate from slide 30. The anchor 50 will move with respect to both the track assembly 80 and slide 30 until the cam bushing(s) 33 travel to the end of the jog 106a in cam cutout 100a in cam arm 68a and the gripper(s) 70a engage rod 84. When the gripper(s) 70a engage threaded rod 84 the anchor 50 will stop moving with respect to the track assembly 80 and will be secured to track assembly 80. The continued motion of the toggle assembly 90 toward anchor 50 will now result in slide 30 moving away from anchor 50 and compressing the object being held by clamp 10. The object between stop 86 and slide 30 should be under the appropriate compressive force when the toggle arm 92 is past center and proximate the anchor 50 and latch assembly 98, if used, latches the toggle assembly 90 to anchor 50.

2. Clamping Pressure Adjustment

Second and third embodiments of the universal clamp 10 provide the user the ability to select and adjust the pressure to be applied by universal clamp 10a. The pressure applied is adjusted by changing the throw or the distance that the slide 30 will move relative to anchor 50 after the gripper assembly 60 secures the anchor 50 to the track assembly 80. The throw is adjusted by moving the position of the cam bushing 33 (horizontal gripper) or roll pin 78 (vertical gripper) relative to jog 106. This relative position change can be accomplished by either moving the position of the cam bushings 33 as shown for the horizontal gripper assembly 60a in Figure lb (second embodiment), or by moving the cam arm 68b as shown for the vertical gripper assembly 60b in Figure lc (third embodiment). The moving of the cam arm 68b will be discussed below, together with the vertical adjustable clamp 10c.

The second embodiment of the present invention is shown in Figure lb and adds the ability for the user to adjust the clamping pressure applied by clamp 10a. Typically, the clamping pressure adjustment requires modifications to slide 30 (Figures 5a, 5b, 6 and 7), together with an adjustment assembly (Figures 8-15).

The basic slide 30 is modified to an adjustable slide 30a by modifying slide block 31, and adding a cam bushing adjustment plate 43a, a pivot 44 and a lever 46. Slide block 31 is modified to slide block 31 a by making an indentation 48a and cam opening 49a in the top of slide 31. The indentation 48a is sufficiently deep to accommodate the height of cam bushing adjustment plate 43a. The combined length of cam opening 49a and indentation 48a permit the cam bushing adjustment plate 43a to travel the distance required to provide the amount of adjustment desired in the force applied by clamp 10a. The cam bushings 33 project through opening 49a and below roof 37 whereby each cam bushing 33 can each engage its respective cam cutout 100a in the respective cam arm 68a. Moving the cam bushings 33 is accomplished by using cam bushing adjustment plate 43a that can move in indentation 48 with respect to slide 30. Typically, this movement will be along the longitudinal axis of clamp 10a. Cam bushing adjustment plate 43a has cam bushings 33 fixed at one end and a pivot dowel slot 45b located in the body of the cam bushing adjustment plate 43a. Typically, this dowel slot 45b is located at the end of cam bushing adjustment plate 43a opposite the cam bushings 33. One location for cam bushing adjustment plate 43a is shown in Figure 5b.

With reference now to Figures 11-13 the cam bushing adjustment plate 43a is moved by pivot dowel 45a that projects from the underside of pivot 44. Pivot dowel 45a is radially spaced from the center of pivot 44. The radial distance is determined by the desired amount of movement of cam bushing adjustment plate 43 for a given angular rotation of pivot 44. Lever 46 (Figures 14 and 15) is set into pivot slot 44b and fastened to pivot 44. Typically, lever 46 has a detent mechanism 47 that helps to hold lever 46 at a specific location. Preferably, cover plate 36 will have indents located at predetermined force settings if a detent mechanism 47 is used. Cover plate 36 will have an opening sized to permit pivot 44 with the exception of lip 44a to project therethrough. Alternatively, cover plate 36 may have an opening sized to permit a portion of lever 46 to project therethrough and engage pivot 44. Thus, cover plate 36 will maintain pivot 44 positioned over/in cam bushing adjustment plate 43 with the pivot dowel 45a engaging pivot slot 45b.

In operation, the rotation of lever 46 will rotate pivot 44, together with pivot dowel 45a. The rotary movement of pivot dowel 45a, which rides in pivot slot 44b, will cause adjustment plate 43a to move in indentation 48a along the longitudinal axis of slide block 31a.

Thus, cam bushing(s) 33 fixed to adjustment plate 43a will also move along the longitudinal axis of slide block 31a. This movement of the cam bushings 33 will change the distance anchor 50 will move before gripper assembly 60a engages track 80. Consequently, this movement of cam bushings 33 will also change the clamping pressure exerted by clamp 10a.

3. Vertical Gripper Adjustable Clamp

A center cross section of a third embodiment of the universal clamp 10 is shown in Figure lc. This adjustable vertical grip universal clamp 10b grips the track assembly 80 in a generally vertical plane using a gripper assembly 60b. To accommodate the vertical gripper assembly 60b, both slide 30 and anchor 50 are modified.

The slide block 31b used with the vertical gripper assembly 60b is shown in Figures 32-

34. The principle difference between horizontal slide block 31a and vertical slide block 31b is in the size and location of indentation 48 and cam opening 49. The cam opening 49b now extends almost the full length of indentation 48b. The cam opening 49b is now centered such that indentation 48b is in essence just a lip on either side of opening 49b.

The primary modification to the adjustment assembly is to the cam adjustment plate 43 (Figures 47 and 48). This plate 43b is typically a flat plate with a dowel slot 45b located in a similar fashion to the dowel slot 45a discussed above. Instead of cam bushings 33 there is a cam opening 140 that is sized to slip over the cam end 72b of cam arm 68b. Additionally, anchor 50 is also modified as shown by Figures 35-37. These modifications entail making provision for gripper 70b to be restrained within a cavity in anchor 50b and making provision for cam 68b to be able to slide between anchor 50b and gripper 70b. This cavity is closed by track assembly 80.

The vertical gripper assembly 60b, shown in Figures 38 - 44 grips the track assembly 80 in the generally vertical plane, typically employs cam arm(s) 68b and gripper(s) 70b. Each cam arm 68b has cam end 72b and gripper end 74b. The gripper end 74b of cam arm 68b has a slot 76b. Each cam arm 68b is slidably and pivotally connected to one gripper 70b with roll pin 78b. Each roll pin 78b fits through a respective opening in each gripper 70b and can slide along slot 76b in cam arm 68b. Cam arms 68b rotate freely around respective roll pins 78b. Typically, each gripper 70b will have a respective gripping surface 71b (Figure 43) configured to grip the track assembly 80. In the embodiment shown, the gripping surface 71b is a semi-circle in cross-section and is threaded with the threads matching the threads on threaded rod 84 of track assembly 80. The embodiment described herein shows track assembly 80 having both a track 82 and a rod 84. However, track assembly 80 can be any single object or group of objects that will provide a surface that can be reliably gripped and provide for the approximately continuous adjustment of the position of the clamp 10b.

The gripper end 74b of cam arm 68b has a cutout 76b. Roll pin 78b, in gripper 70b rides in the cutout 76b and slidably connects slide 30 to anchor 50. Relative motion between slide 30 and anchor 50 will cause roll pin 78b to slide in cutout 76b. When slide 30 is proximate anchor 50 the roll pin 78b will be proximate the released end 102b and when slide 30 is spaced apart from anchor 50 and the toggle arm 92 is proximate anchor 50 the roll pin 78b will be proximate engaged end 104b. The operation of the clamp 10b is discussed in greater detail below.

The shape of the cutouts 76b in the vertical gripper cause gripper(s) 70b to be spaced apart from threaded rod 84 while the roll pin 78b is located in the area of cutout 76b from the released end 102b to the jog 106b. When roll pin 78 enters the jog 106b the gripper(s) 70b move downward. When the roll pin 78b has completed the jog 106b in cutout 76b the gripper(s) 70b will be engaging the threaded rod 84. The gripper(s) 70b will continue to engage threaded rod 84 while the roll pin 78 slides in cutout 76b from jog 106b to engaged end 104b of cutout 76b. In addition to the sliding connection between slide 30 and anchor 50 provided by the roll pin 78b sliding in cutout 76b, there may be a biasing spring 110 (Figure 57) that will pull the slide 30 and anchor 50 together when toggle assembly 90 is released.

In the typical clamp 10b using a vertical gripper, with cam arm 68b properly positioned and the toggle arm 92 in an open position (spaced apart from anchor 50); the clamp 10b is slid along track assembly 80 until the slide 30 makes contact with the object to be held in place The handle end 95 of toggle arm 92 is pushed toward anchor 50. Initially, the combined movement of toggle arm 92 and link 94 will cause anchor 50 to separate from slide 30. The anchor 50 will move with respect to both the track assembly 80 and slide 30 until the roll pin 78b travels to the end of the jog 106b in cutout 76b in cam arm 68b and the gripper 70b engages rod 84. When the gripper 70b engages threaded rod 84 the anchor 50 will stop moving with respect to the track assembly 80 and will be secured to track assembly 80. The continued motion of the toggle assembly 90 toward anchor 50 will now result in slide 30 moving away from anchor 50 and compressing the object being held by clamp 10b. The object between stop 86 and slide 30 should be under the appropriate compressive force when the toggle arm 92 is past center and proximate the anchor 50 and latch assembly 98, if used, latches the toggle assembly 90 to anchor 50.

Additionally, moving the cam arm 68 may be accomplished by using cam bushing adjustment plate 43b that can move with respect to slide 30 as shown for the vertical gripper in Figures 32, 34, and 45 - 49. Typically, this movement will be along the longitudinal axis of clamp 10b. Cam bushing adjustment plate 43b, show in Figures 47 - 49 is configured to retain the cam end 72b of cam arm 68b. The pivot dowel slot 45b is located in the body of the cam bushing adjustment plate 43b. Typically, this dowel slot 45b is located at the end of cam bushing adjustment plate 43b opposite the end that retains the cam end of cam arm 68b. A typical location in slide block 31 for cam bushing adjustment plate 43b is shown in Figures 32 and 49. The indentation 48b is sufficiently deep to accommodate cam bushing adjustment plate 43b and pivot 44b. The cam end 72b will project through opening 49b and engage adjustment plate 43b. The cam bushing adjustment plate 43 is moved by pivot dowel 45a that projects from the underside of pivot 44. Pivot dowel 45a is radially spaced from the center of pivot 44. The radial distance is determined by the desired amount of movement of cam bushing adjustment plate 43 for a given angular rotation of pivot 44. Lever 46 is set into pivot slot 44b and fastened to pivot 44. Typically, lever 46 has a detent mechanism 47 that helps to hold lever 46 at a specific location. Preferably, cover plate 36 will have indents located at predetermined force settings if a detent mechanism 47 is used. Cover plate 36 will have an opening sized to permit pivot 44 with the exception of lip 44a to project therethrough. Alternatively, cover plate 36 may have an opening sized to permit a portion of lever 46 to project therethrough and engage pivot 44. Thus, cover plate 36 will maintain pivot 44 positioned over cam bushing adjustment plate 43 with the pivot dowel 45a engaging pivot slot 45b.

4. Clamp Used With a Linear Actuator

The universal clamp 10 can be easily modified for use with a linear actuator 130. The use of the universal clamp 10 combined with a linear actuator 130 would enable a robotic grip to be constructed that would not relax its gripping or holding force in the event that the robot loses power to the linear actuator 130. Typically, the toggle assembly 90 is modified to attach the linear actuator to the clamp 10. Either or both the toggle handle 92 or the link 94 is modified. Toggle handle 92 would be modified to so that the toggle handle (not shown) would have a generally "L" shape with link 94 joined to toggle handle at the corner of the "L" with fasteners 96. One end of the "L" would be pivotally joined to slide 30 at a first end and the linear actuator would be attached to the toggle handle at a second end. Alternatively, link 94 could be modified to an "L" shape link 94c (Figures 49b and 49c) and the toggle handle 92 shortened to handle 92c. (Figures 49b and 49c). The toggle handle 92c in this embodiment would only have to extend past link 94c a sufficient distance to prevent a failure at the joint between link 94c and toggle handle 92c.

5. Clamp Used as a Belt Tensioner Figures 50-61 show the universal clamp converted to a belt tensioner lOd by adding bushing assembly 20 and modified slide 30d. Bushing assembly 20 is typically a standard industrial bushing assembly having a pulley, bushing or sprocket that makes contact and applies tension to a drive belt (shown in Figures 58 and 61) or gear chain. Herein the term bushing or bushing assembly means any device that can be used to tension a drive belt, chain or other device intended to transmit power between fixed center rotating members, such members rotating about centerlines which are not coincident. Additionally, the term drive belt means a drive belt, chain or other device intended to transmit power between fixed center rotating members, where such members rotate about centerlines which are not coincident

The bushing assembly 20 is connected to slide 30d by shaft 24. Typically, shaft 24 will be fixed to slide 30d using a threaded shaft, an interference fit or a fastener. Shaft 24 rotateably supports bushing 22 through bearings 26. Bearings 26 permit bushing 22 to rotate around shaft 24. Alternatively shaft 24 could be fixed to bushing 22 with shaft 24 being rotateably carried by slide 30d by bearings. Bearings means any device that can be used to reduce the friction between two materials moving relative to one another, including but not limited to roller bearings, ball bearings, needle bearings, bushings, journals, etc.

Slide 30 rides or slides on track assembly 80 and holds shaft 24 of bushing assembly 20. Referring to Figures 50-52, slide 30d may have a shaft support block 32, support sides 34, and cover plate 36d. Alternatively, slide 30d may be manufactured as described for the clamp above. Shaft support block 32 has a cylindrical threaded hole 38 that receives shaft 24 of bushing 20. Shaft support block 32 is mounted to support sides 34 with fasteners 40. Cover plate 36d is also fastened to support sides 34 with fasteners 42. Shaft support block 32, support sides 34, and cover plate 36d form a hollow box that has an open bottom, open front, and open back. Support sides 34 each have a groove in each inside face, this groove is similar to groove 62 shown in Figure 6. This groove has a size and shape configured to permit slide 30d to slide or ride on a track 82 of track assembly 80 selected for a particular application. Typically, track 82 has a "T" cross- section. Fixed to each side 34 is a cam bushing 33 (Figure lb or 4) that forms part of the slidable connection between slide 30d and anchor 50d.

Anchor 50d comprises anchor front plate 52d, anchor sides 54d, anchor back plate 56d, anchor cover plate 58d, and gripper assembly 60d. Alternatively, anchor 50d may be constructed as described above for the clamp. Anchor front plate 52d and anchor back plate 56d are joined to anchor side 54d with fasteners (not shown). Front plate 52d, sides 54d and 54d, and back plate 56d have grooves 62d (only shown for front plate 52 in Figure 55) configured and sized to fit the shape of track 82 selected for a particular application. The gripper assembly 60d, shown in Figures 53 and 54, typically comprises cam arms

68d and gripper 70d. Cam arms 68d have cam ends 72d and gripper ends 74d. Each respective gripper end 74d of cam arm 68d has a slot 76d. Each cam arm 68d is slidably and pivotally connected to one gripper half 70d with roll pin 78d. Roll pin 78d fits through an opening in the gripper 70d and slides through slot 76d in cam arm 68d. Additionally, cam arms 68d are pivotally connected to anchor front plate 52d with dowels 64d. Dowels 64d fit into openings 66d in front anchor plate 52d and slide through openings in cam arms 68d. Cam arms 68d rotate freely around both dowels 64d and roll pins 78d.

Typically, each gripper 70d will have a gripping surface 71 d (Figure 55) configured to grip the track assembly 80. In the embodiment shown, the gripping surface 71d is a semi-circle in cross-section and is threaded with the threads matching the threads on threaded rod 84 of track assembly 80. This embodiment shows track assembly 80 having both a track 82 and a rod 84. However, track assembly 80 can be any single object or group of objects that will provide a surface that can be reliably gripped and provide for the approximately continuous adjustment of the position of the tensioner lOd.

Each cam end 72d of the respective cam arm 68d has a cam cutout lOOd. Cam bushing(s) 33d, in slide 30d ride in the cam cutouts lOOd and slidably connect slide 30d to anchor 50d. Relative motion between slide 30d and anchor 50d will cause cam bushing(s) 33d to slide in cam cutout(s) lOOd. When slide 30d is proximate anchor 50d the cam bushing(s) 33d will be proximate the release end 102d and when slide 30d is spaced apart from anchor 50d and the toggle arm 92d is proximate anchor 50d the cam bushing(s) 33d will be proximate engaged end 104d. The operation of the tensioner lOd is discussed in greater detail below.

When the belt tensioner 10d' pulls on the belt, the shape of the cam cutouts lOOd' cause gripper(s) 70d to be spaced apart from threaded rod 84c while the cam bushing is located in the area of cutout lOOd from the released end 102d to the jog 106d. When cam bushings 33d enter the jog 106d the cam end 72d of each cam arm 68d moves outward forcing the respective gripper ends 74d and attached gripper(s) 70d to move inward. When the cam bushings 33d have completed the jog 106d in cam cutout lOOd the gripper(s) 70d will be engaging the threaded rod 84. The gripper(s) 70d will continue to engage threaded rod 84 while the cam bushings 33d slide in cam cutout lOOd from jog 106d to engaged end 104d of cam cutout lOOd.

When the belt tensioner lOd" pushes on the belt, the shape of the cam cutout lOOd" causes gripper 70d to be spaced apart from threaded rod 84 while the cam bushing is located in the area of cutout lOOd from the released end 102d to the jog 106d. When cam bushing(s) 33d enter the jog 106d the cam end(s) 72d of cam arm(s) 68d move outward forcing the gripper end(s) 74d and attached gripper(s) 70d to move inward. When the cam bushing(s) 33d have completed the jog 106d in cam cutout lOOd the gripper(s) 70d will be engaging the threaded rod 84. The gripper(s) 70d will engage threaded rod 84 while the cam bushing(s) 33d slide in cam cutout(s) lOOd from jog 106d to engaged end 104d of cam cutout lOOd. In addition to the sliding connection between slide 30d and anchor 50d provided by the cam bushing 33d sliding in cam cutout lOOd, there may be a biasing spring 110 (Figure 57) that will pull the slide 30d and anchor 50d together when toggle assembly 90d is released.

Toggle assembly 90d typically comprises a toggle arm 92d, link 94d, and latch assembly 98d. Toggle arm 92d has a support end 93d and a handle end 95d. The support end 93d of toggle arm 92d is pivotally fastened to slide 30d with fasteners 96. In the embodiment of the belt tensioner lOd that pushes on the belt to tension the belt, a first end of link 94d is fastened to toggle arm 92d intermediate the support end 93d and handle end 95d with fasteners 96. In the embodiment of the belt tensioner 1 Od that pulls on the belt to tension the belt, a first end of link 94d is fastened to toggle arm 92d proximate the handle end 95d with fasteners 96 as shown in Figure 60. A second end of link 94d is fastened to anchor 50d with fasteners 96. Latch assembly 98 can be any mechanism that will releaseably secure toggle assembly 90 to anchor 50d.

The installation and operation of the universal tensioner lOd is very simple. The tensioner lOd is installed by attaching track assembly 80 to a solid support or foundation. Preferably, the track assembly 80 will be approximately perpendicular to the drive belt to be tensioned. This orientation of the track assembly 80 will permit using the shortest length of track assembly 80. The user must determine the distance that the bushing 20 will need to travel to impart the proper tension in the drive belt after the slack has been removed from the drive belt. The cam bushing 33d is positioned in slide 30d such that the cam bushing will complete its travel of the jog 106d in cam cutout lOOd and the gripper(s) 70d engage rod 84 when the length between the fastener 96 on slide 30d and fastener 96 on anchor 50d added to the proper tension distance will equal the distance between the two fasteners 96 on the toggle arm 92d combined with the distance between the two fasteners 96 on link 94d. Some embodiments of the universal belt tensioner lOd will provide for the cam bushings 33d to be adjustable without having to disassemble the tensioner lOd. This embodiment would add the adjustment element(s) described above for the universal clamp.

The embodiment of belt tensioner lOd" that applies tension to the belt by pushing on the belt operates in the following manner. With the cam bushings 33d properly positioned in slide 30d and the toggle arm in an open position (spaced apart from anchor 50d); the tensioner lOd is slid along track assembly 80 until the slack has been removed from the drive belt. The handle end 95d of toggle arm 92d is pushed toward anchor 50d. Initially, the combined movement of toggle arm 92d and link 94d will cause anchor 50d to separate from slide 30d. The anchor 50d will move with respect to both the track assembly 80 and slide 30d until the cam bushings 33d travel to the end of the jog 106d in cam cutout lOOd in cam arm 68d and the gripper(s) 70d engage rod 84. When the gripper(s) 70d engage threaded rod 84 the anchor 50d will stop moving with respect to the track assembly 80 and will be secured to track assembly 80. The continued motion of the toggle assembly 90 toward anchor 50d will now result in slide 30d moving away from anchor 50d and tensioning the drive belt. The drive belt should be at the proper tension when the toggle arm 92 is proximate the anchor 50d and latch assembly 98d latches the toggle assembly 90d to the anchor 50d.

When the operator desires to confirm or restore the tension in the drive belt, the latch assembly 98d is operated to release the toggle assembly 90d from the anchor 50d. A combination of the force from the biasing spring, if installed, and the belt tension will pull/push the slide 30d toward the anchor 50d. When the slide 30d and anchor 50d move toward each other the cam bushing will slide in the cam cutout lOOd and cause the gripper(s) 70d to disengage from rod 84 after the cam bushings 33d pass the jog 106d in cam cutout lOOd. With the universal tensioner lOd released from the track assembly 80 the tensioner lOd is slid along the track assembly 80 to remove the slack from the drive belt and then the tensioner lOd is operated to tension the drive belt as described above.

The embodiment of belt tensioner 1 Od' that applies tension to the belt by pulling on the belt, operates in the following manner. With the cam bushings 33 properly positioned in slide 30d and the toggle arm in an open position (spaced apart from anchor 50d); the tensioner lOd is slid along track assembly 80 until the slack has been removed from the drive belt. The handle end 95d of toggle arm 92d is pushed toward anchor 50d. Initially, the combined movement of toggle arm 92d and link 94d will cause anchor 50d to move toward slide 30d. The anchor 50d will move with respect to both the track assembly 80 and slide 30d until the cam bushings 33d travel to the end of the jog 106d in cam cutout lOOd in cam arm 68d and the gripper(s) 70d engage rod 84. When the gripper(s) 70d engage threaded rod 84 the anchor 50d will stop moving with respect to the track assembly 80 and will be secured to track assembly 80. The continued motion of the toggle assembly 90 toward anchor 50d will now result in slide 30d moving toward anchor 50d and tensioning the drive belt. The drive belt should be at the proper tension when the toggle arm 92d is proximate the anchor 50d and latch assembly 98d latches the toggle assembly 90d to the anchor 50d.

When the operator desires to confirm or restore the tension in the drive belt, the latch assembly 98d is operated to release the toggle assembly 90d from the anchor 50d. A combination of the force from the biasing spring, if installed, and the belt tension will pull/push the slide 30d away from the anchor 50d. When the slide 30d and anchor 50d move away from each other the cam bushing will slide in the cam cutout lOOd and cause the gripper(s) 70d to disengage from rod 84 after the cam bushings 33d pass the jog 106d in cam cutout lOOd. With the universal tensioner lOd released from the track assembly 80 the tensioner lOd is slid along the track assembly 80 to remove the slack from the drive belt and then the tensioner lOd is operated to tension the drive belt as described above.

In summary, numerous benefits have been described which result from employing the concepts of the invention. The foregoing description of the preferred embodiments of the invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. These embodiments were chosen and described in order to best illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.

Claims

What is claimed is:

1) A universal clamp comprising: a slide, said slide capable of sliding engagement with a track assembly; a gripping assembly, said gripping assembly in sliding engagement with said slide, said gripping assembly capable of gripping said track assembly when actuated by said slide; an anchor, said anchor capable of sliding engagement with said track assembly, said anchor containing said gripping assembly; and a toggle assembly, said toggle assembly connecting said slide to said anchor, whereby moving said toggle assembly from an open position where said toggle arm is spaced apart from said anchor to an engaged position where said toggle arm is proximate said anchor will cause said anchor and said slide to move from a first position where said slide is proximate said anchor to a second position where said slide and said anchor are spaced apart, and where said gripper assembly will engage said track assembly when said slide and said anchor are in a position intermediate said first and second positions.

2) A universal clamp comprising: a slide, said slide capable of sliding engagement with a track assembly; a gripping assembly, said gripping assembly in sliding engagement with said slide, said gripping assembly capable of gripping said track assembly when actuated by said slide; an anchor, said anchor capable of sliding engagement with said track assembly, said anchor containing said gripping assembly; and a toggle assembly, said toggle assembly comprising a toggle arm and a link, said toggle arm pivotally fastened to said slide at a support end of said toggle arm, a first end of said link pivotally fastened to said toggle arm intermediate said support end and a handle end of said toggle arm, a second end of said link pivotally fastened to said anchor, whereby moving said toggle assembly from an open position where said toggle arm is spaced apart from said anchor to an engaged position where said toggle arm is proximate said anchor will cause said anchor and said slide to move from a first position where said slide is proximate said anchor to a second position where said slide and said anchor are spaced apart, and where said gripper assembly will engage said track assembly when said slide and said anchor are in a position intermediate said first and second positions. 3) A universal clamp comprising: a slide, said slide capable of sliding engagement with a track assembly; an anchor, said anchor capable of sliding engagement with said track assembly, said anchor having a gripping assembly in sliding engagement with said slide, said gripping assembly capable of gripping said track assembly when acuated by said slide; and a toggle assembly, said toggle assembly comprising a toggle arm and a link, said toggle arm pivotally fastened to said slide at a support end of said toggle arm, a first end of said link pivotally fastened to said toggle arm proximate a handle end of said toggle arm, a second end of said link pivotally fastened to said anchor, whereby moving said toggle assembly from an open position where said toggle arm is spaced apart from said anchor to an engaged position where said toggle arm is proximate said anchor will cause said anchor and said slide to move from a first position where said slide and said anchor are spaced apart to a second position where said slide is proximate said anchor, and where said gripper assembly will engage said track assembly when said slide and said anchor are in a position intermediate said first and second positions. 4) A universal belt tensioner comprising: a bushing assembly, said bushing assembly configured to engage a drive belt; a bushing support, said bushing assembly fixed to said bushing support, said bushing support capable of sliding engagement with a track assembly; a gripper block, said gripper block capable of sliding engagement with said track assembly, said gripper block having a gripping assembly in sliding engagement with said bushing support, said gripping assembly capable of gripping said track assembly when acuated by said bushing support; and a toggle assembly, said toggle assembly comprising a toggle arm and a link, said toggle arm pivotally fastened to said bushing support at a support end of said toggle arm, a first end of said link pivotally fastened to said toggle arm intermediate said support end and a handle end of said toggle arm, a second end of said link pivotally fastened to said gripper block, whereby moving said toggle assembly from an open position where said toggle arm is spaced apart from said gripper block to an engaged position where said toggle arm is proximate said gripper block will cause said gripper block and said bushing support to move from a first position where said bushing support is proximate said gripper block to a second position where said bushing support and said gripper block are spaced apart, and where said gripper assembly will engage said track assembly when said bushing support and said gripper block are in a position intermediate said first and second positions.