US2941432A - Clamp - Google Patents

Description

June 21, 1960 R. w. WILLIAMSON 2,941,432

CLAMP Filed May 7, 1958 3 Sheets-Sheet 1 14 a;

IN VEN TOR.

June 21, 1960 i R, w, WILLIAMSQN 2,941,432

CLAMP Filed May 7, 1958 3 sheets-sheet 2 IN V EN TOR. F6287; 'MZ' dZYiS'O 7K June 21, 1960 Filed May '7, 1958 R. W. WILLIAMSON CLAMP 3 Sheets-Sheet 3 IN V EN TOR. a E Fa s); 144722 477750 7 d ZZ;? BY fi fiw w pw L arn/Ere.

United States Patent CLAMP Robert W. Williamson, New Baltimore, Mich., assignor of one-fourth to 0. D. Herr-on, Grosse Pointe, Micln, one-fourth to J. H. Zimmers, Frankfort, Ky., and onefourth to Dudley A. Hunter, Utica, Mich.

Filed May 7, 1958, Ser. No..733,751 9 Claims. (Cl. 81-17.2)

The present invention relates to clamps and more particularly, to power operated clamps adapted for gripping metal moulding strips to securely hold the strip during the performance of various operations on the strip.

It is an object of the present invention to provide an improved clamp of the above mentioned type which is adapted to securely hold the metal moulding strip without deforming or otherwise damaging the portion of the strip engaged by the clamp.

It is a further object of the present invention to pro vide an improved clamp of the above mentioned type which opens widely to facilitate movement of the strip into position to be clamped.

It is also an object of the present invention to provide an improved clamp of the above mentioned type which is quickly operable from its fully open position to its fully clamped position and in which a movable jaw is rapidly moved in the opening direction and from the open position substantially to the fully closed position and in which a very high mechanical advantage is provided in the final movement to the clamped position.

It is a further object of the present invention to generally improve the design of clamps of the above mentioned type and to provide clamps which are simple in design, economical of manufacture, durable in construction and reliable and efiicient in operation.

Other and more detailed objects of the present invention will be apparent to those skilled in the art from a consideration of the following specification, the appended claims and the accompanying drawings wherein:

Figure 1 is an elevational view of a two-way horizontal clamp constructed according to the present invention and showing the clamp in the closed position;

Figure 2 is an elevational view of the clamp illustrated in Figure 1, showing the clamp in the open position;

Figure '3 is a rear view of the clamp showing the clamp in the open po'sition;

Figure 4 is a side elevational view of a two-way vertical clamp constructed according to the present invention showing the clamp in the closed position;

Figure 5 is a broken elevational view of the clamp shown in Figure 4 showing the clamp in the open position;

Figure 6 is a sectional view of the structure illustrated in Figure 5, taken along the line 6-6 thereof;

Figure 7 is an end elevational view of the clamp illustrated in Figure 5;

Figure 8 is a side elevational view of a three-way clamp constructed according to the present invention and showing the clamp in the closed position;

Figure 9 is a side elevational view of the clamp illustrated in Figure 8, showing the clamp in the open position; and,

Figure 10 is a rear elevational view of the clamp in the open positio'n illustrated in Figure 9.

Referring to the drawings, and more particularly to Figures 1, 2 and 3 thereof, the clamp 20 there illustrated is herein referred to as a two-way horizontal clamp for suitably secured in a desired position as, for example, on

a machine for stretch bending metal moulding strips 22.

A pair of spaced upwardly extending stationary supporting arms 26 and 28 are welded to and extend upwardly from the fo'rward or left-hand portion of the base plate 24, as viewed in Figures 1 and 2. At the rear or right-hand portion of the base plate 24, as viewed in Figures 1 and 2, a third stationary arm '30 is welded to the base plate 24 and aligned with the space between the arms 26 and 28. A stationary jaw plate 32 extends transversely of the forward portion of the base plate 24 and is welded to the base plate 24 and to the stationary arms 26 and 28. This stationary jaw plate 32 carries a stationary pad 34 having a surface 36 which is shaped to engage the one side of the moulding 22 to be engaged by the clamp 20'.

A movable jaw member 38 is pivotally supported on the stationary arms 26 and 28 by a pivot pin '40 and has a transversely extending movable jaw portion 42 which carries a movable jaw pad 44 which may be welded or otherwise suitably secured thereto and which has a surface portion 46 of a contour adapted to engage the opposite side of the strip 22. The movable jaw member 38 has a cam arm 48 and the stationary arm 30 carries a cam follower carrier generally indicated at 50 which carries a pair of cam follower rollers 52 and 54 adapted to co-operate with the cam arm 48 to effect the desired movement of the movable jaw member 38. The cam follower carrier 50 comprises a pair of spaced plates 56 and 58 which are interconnected and held in spaced parallel relation by an angle member 60, one leg of which is secured to the plate 58 by suitable means such as the weld 61, and the other leg of which overlies the outer face of the plate 56 to which it is secured by a plurality of screws 62. The spaced plates are generally triangular in shape and receive a portion of the stationary arm 30 therebetween at one apex. A pin 64 extends through the plates 56 and 58 and the arm 30 to pivotally mount the cam follower carrier 50 on the arm 30. The cam followers 52 and 54 are in the form of cylindrical rollers and the roller 52 is supported on a pin 66 located at another apex of the triangular plates 56 and 58. As best illustrated in Figure 1, the plate 58 is larger than the plate 56 and at its third apex supports the roller 54 on a pin .68 fixed in the plate 58. During operation of the clamp 20, the cam followers 52 and 54 co-operate with the cam arm 48 which is provided with a rapid travel cam portion '70 which co-operates with the cam follower 52 for effecting rapid movement of the movable jaw member 38 from the open position toward, and substantially to, the closed position. The cam arm 48 also has a clamping cam portion 72 which co-operates with the cam follower 52 during the final movement of the movable jaw member 38 to the fully clamped position to provide a relatively slow movement of the jaw member 38, but a correspondingly high mechanical advantage between the movement of the cam follower carrier 50 and the movable jaw member It will be appreciated that these cam portions 70 and 72 may be so related to the other dimensions of the clamp as to provide any desired rate of initial closing-and any desired mechanical advantage during the final clamping movement. The cam arm 48 also has a clamp opening cam po'rtion 74 adapted to co-operate with the cam follower 54 to effect a rapid movement of the movable jaw member '38 from its closed position to its open position.

It will be appreciated that at all times the force exerted on the cam arm will be at'righ't angles to the surface of the cam follower roller at the point of the engagement thereof with the cam arm. As a limiting condition, the shape of the rapid travel cam portion 70 must be such that the line of action of the force .between the cam follower 52 and the cam portion 70 always passes between the axes of the pivot pins 48 and 64. The closer it is to the axis of the pin 40, and the further it is from the axis of the pin 64, the more rapid will be the movement of the jaw 42, for a given movement of the cam follower carrier 50. Also, as a limiting condition, the line of action between the follower 52 and the clamping cam surface 72 must also at all times pass between the axes of the pivot pins 49 and 64. The closerthis latter line of action passes to the axis of the pin 64 and the farther from the axis of the pin 40; the greater the force which will be exerted upon the jaw 42 for a given force applied to the follower carrier 50. The controlling considerations in the shape of the clamp opening cam surface 74 are that it must cooperate with the cam follower 54 during movement of the follower carrier 50 from its closed position illustrated in Figure l, to its open position illustrated in Figure 2 to move the jaw 42 from its closed to its open position, without any interference between the follower 52 and the cam surfaces 72 and 70.

It will be noted that the cam arm 48 is offset relative to the main portion of the movable jaw member 38, along the line 75 to prevent interference between the cam arm 48 and the stationary arm 31) when the clamp is in the open position illustrated in Figure 2.

Movement of the cam follower carrier 50 is efiected by a power cylinder 76 which is mounted on an extension 78 of the arm 28 which extends upwardly and forwardly, or to the left, as illustrated in Figures 1 and 2 and has a laterally turned end portion 80 which carries a connecting boss 82 received between spaced projections 84 on one end of the cylinder 76 and pivotally connected thereto by -a pin 86 extending through the projections 84- and the boss 82. A piston (not shown) disposed within the cylinder 76 is provided with a piston rod 88 extending outwardly of the opposite or right-hand end of the cylinder 76, as viewed in Figures 1 and 2, and carrying an end fitting 90 which is pivotally connected to the cam follower carrier 50 by a pin 92 which extends through the fitting 90 and through the plate 56 at one apex thereof. The just mentioned apex of the plate 56 is received in a slot 94 formed in the piston rod end fitting 96. It will be noted that in the preferred embodiment illustrated, the end fitting98 has its under side relieved as indicated at 96 m prevent interference with the plate 56 and particula'rl'y, the apex portion thereof in which the pin 66 is mounted. Also, it will be noted that the plate 56 is relieved between the pins 66 and 32 as indicated at 98 to prevent interference with the end fitting 90. Lines 99 and 108 are connected to 'the opposite ends of the cylinder 76 for providing fluid under pressure from a suitable source, to the opposite ends of the cylinder 76 for moving the piston and its associated piston rod 88 in opposite directions.

Figures 4 through 7, inclusive, illustrate a clamp 20 similar to the clamp 20 illustrated in Figures 1 to 3, inelusive, but differing therefrom in that, whereas the clamp 20 is generally known as a two-way horizontal clamp, the clamp 20 is generally known as a two-way'vertical clamp. In the clamp 20' the stationary jaw plate 32' which is carried by the supporting arms 26' [and 28' extending upwardly from the base plate 24, supports the stat' ionary jaw pad 34' with its surface 36 generally upwardly presenting for engaging one side of the moulding strip 22. The movable jaw member 38' carries the movable jaw pad 44' secui'ed to the movable portion 42' at the 'lower side thereof, when the clamp 20 is closed. In this position the surface 46' presents generally downwardly and engages the upper or opposite side of the moulding strip 22'. The "cam arm 48 "of the movable 4 jam member 38' differs from the cam arm 48 of the clamp 20, illustrated in Figures 1 to 3, inclusive, only in that it is not offset relative to the movable jaw member 38, since the stationary arm 30" is integral with and in-the plane of the supporting arm 28'. The cooperation of the cam arm 48' with the cam followers 52' and 54, carried by the cam follower carrier 50' and the movement of the cam follower carrier 50 by the cylinder 76' and the associated piston rod 88 is the same in the case of the clamp 28 as in the case of the clamp 20.

Figures 8, 9 and 10 illustrate a clamp of the three-way type embodying the present invention. The clamp 120 is adapted for securely holding moulding strips of a generally T- shaped cross section, such as the moulding strip 122. This strip includes a flange 124 which in use constitutm an attaching tongue by which the moulding strip 122 is held in place and a head portion 126. The clamp includes a base plate 128 which supports three similar spaced upwardly extending supporting arms 130, 131 and 132. These arms carry a transversely extending stationary jaw pad 134 having a surface 136 shaped to engage one side of the tongue 124 of the moulding strip 122 and an adjacent surface 138 adapted to engage the inner surface of the head 126 of the moulding strip '122, at one side of the flange 124. The arms 13!), 131 and 132 also support a lower movable jaw member 140 having a pair of spaced arms 142 and 144 disposed, respectively, between the supporting arms and 131 and 131 and 132. A pivot pin 146 extends transversely of and is supported in the lower portions of the arms 130, 131 and 132, and also extends through the arms 142 and 144 to pivotally support the lbw'er movable jaw member 140. This jaw member carries a lower movable jaw pad 141 which is adapted to engage "the under side of the tongue 124 and the inner surface of the head portion 1% below the tongue 124.

An upper movable jaw member 148 also has a pair'of spaced arms 150 and 152 which extend, respectively, between the upper end portions of the arms 130 and 131 and 131 and 132. A pivot pin 154 extends through the arms 130, 131 and 132 and portions of the arms 150 and 152 received therebetween, to pivotally support the upper movable jaw member 148. This jaw member 148 carries an upper movable jaw pad 149 which is adapted to engage the outer surface of the head portion 126 of the moulding strip 122. The spaced arms 150 and 152 each carry a cam plate 155 welded to the outer surface thereof along the line 157 so that the cam plates 155 are offset outwardly from the arms 150 and 152 and are disposed in the planes of the supporting members 130 and 132. These cam plates 155 co-operate :with cam follower rollers 162 and 164 supported on a cam follower carrier generally indicated at 166 and consisting of a pair of spaced generally triangularly shaped plates 168 and 170 which are interconnected along a part of one edge thereof by a transversely extending plate 172 which may be secured, as by welding, to the plates 168 and 170.

Because of the above described offset relation of the cam plates 155 at the outer sides of the movable jaw arms 150 and 152, these cam plates 155, when the clamp 120 is moved from the closed position illustrated in Figure 8 to the open position illustrated in Figure 9, overlie the outer surfaces of the spaced arms 142 and 144 of the lower movable jaw 140. The cam follower carrier 166 is pivotally mounted on the upper ends of the lower movable jaw arms 142 and 144 by a pin 174'extending transversely through the carrier plates 168 and 170 and the lower jaw arm's 142 and 144. The plates 168 and 170 of the carrier 165, in addition to being interconnected by the transverse plate 172, as above mentioned, are held in proper spaced relation with respect to the arms 142 and 144 by spacers 176 and 178. Also, suitablespacers (not shown) are preferably provided between the plates 168 and 170 on the pins '180 and 182 which carry the cam followers 162 and 164. It will be appreciated that the pin 180 carries a pair of cam follower rollers 182 individual to the spaced cam' 'plates 155. During movement ofthe clamp 12 0,fromthe openposition illustratedtin Figure 9, to: the closed position illustrated in :Figure 8,'the rollers 182 co=operate withithe:curved cam surfaces 156, of the cam plates 155.: for rapidly :;1 noving the movable jaw arms 14 0 and 448 from-ithezgpen position toward and substantially to the closed position. Just prior to reaching the closed position, the cam followers 162 move from the cam surfaces 156 onto the connecting cam surfaces 158 which provide a relatively slower final movement of the movable jaw arms to the fully closed position, but which co-operate with the cam followers 162 during this movement to provide a desired high mechanical advantage between the movement of the cam follower carrier 166 and the movement of the movable jaws 140 and 148.

The cam surfaces 160 are shaped to co-operate with the cam follower rollers 164 to efiect a rapid movement of the movable jaw arms 140 and 148 from the closed position to the open position. Movement of the cam follower carrier 166 during operation of the clamp is efiected by any suitable means and in the preferred embodiment illustrated in Figures 8 to 10, inclusive, a power operated cylinder 184 is mounted on upwardly and forwardly extending arms 186 which may be welded to the arms 130 and 132. The upper ends of the arms 186 are interconnected by a transverse plate 188 which carries an arm 190, the upper end of which is pivotally connected to the cylinder 184 by a pivot pin 192- extending through bosses 194 formed on the cylinder. The piston rod 196 of the cylinder 184 carries a fitting 198 which is pivotally connected by pin 200 to an arm 202 welded to the plate 172.

While only certain specific embodiments of the invention have been illustrated and described herein, it will be readily appreciated by those skilled in the art that numerous modifications may be made without departing from the spirit of the appended claims.

What is claimed is:

1. A clamp for gripping and securely holding a strip of metal moulding comprising a support having a stationary jaw thereon, a member pivotally mounted on said support and having a movable jaw adapted to cooperate with said stationary jaw in one position of said member for gripping a said strip of moulding, a cam arm on said member, a cam follower carrier movably mounted on said support, cam follower means on said carrier, said cam arm having a rapid travel cam portion co-operable with said cam follower means for effecting rapid closing of said movable jaw, a clamping cam portion co-operable with said cam follower means for providing a large mechanical advantage between said carrier and said movable jaw during the final closing movement of said movable jaw and a clamp opening cam portion co-operable with said cam follower means for positively effecting rapid opening of said movable jaw, and power means mounted on said support and connected to said carrier for moving said cam follower means along said cam portions.

2. A clamp as defined in claim 1 including means mounting said cam follower carrier on said support for pivotal movement relative thereto.

3. A clamp as defined in claim 1 wherein said cam follower means includes a first cam follower movable along said rapid travel cam portion and said clamping cam portion and a second cam follower movable along said clamp opening cam portion.

4. A clamp as defined in claim 1 wherein said power means is fluid operated and includes a cylinder element and a piston element movable therein and having a piston rod extending outwardly from one end of said cylinder element, and including a supporting arm on said support jaw 15. 15. g'zlarnp' for gnipping and securely holding a 'strip o metal mo l n said .g am om i a vs ppo ngajstationaryjjaw atone side thereof, a movable member pivotally mounted on said support adjacent said stationary jaw for movement between 'an open position and a closed position, a cam arm on said movable jaw member, said cam arm being curved and extending toward the opposite side of said support and including an inner cam surface, an outer cam surface, and an end cam surface connecting with said inner cam surface and extending transversely of said arm toward said outer cam surface, a carrier mounted on said support at said opposite side thereof for pivotal movement relative thereto, first and second cam followers on said carrier, said first cam follower being adapted to co-operate with said inner cam surface during pivotal movement of said carrier in one direction to rapidly move said movable jaw member from said open position toward and substantially to said closed position and co-operating with said end cam surface upon continued movement of said carrier in said one direction to complete the movement of said movable jaw member to said closed position, said second cam follower co-operating with said outer cam surface during movement of said carrier in the opposite direction to return said movable jaw member from said closed position to said open position, and means for effecting said movements of said carrier.

6. A clamp as defined in claim 5 wherein the curvature of said inner cam surface decreases toward said end cam surface.

7. A clamp as defined in claim 5 wherein the curvature of said end cam surface is such that the line of action of the force exerted on said end cam surface by said first cam follower always passes between the axis of pivotal movement of the carrier and the axis of pivotal movement of the movable jaw member.

8. A clamp as defined in claim 1 including another movable jaw member movably mounted on said support and including a second movable jaw adapted to co-operate with said stationary jaw and said first named movable jaw to grip said strip of moulding, and wherein said carrier is pivotally mounted on said another movable jaw member.

9. A three-way clamp for gripping a T-shaped strip of metal moulding having a head section and a tongue section, said clamp comprising a support having a stationary aw adapted to engage one side of said tongue section and the adjacent surface of said head section, a first movable jaw member pivotally mounted on said support for movement between an open position and a closed position and having a first movable jaw adapted to engage the opposite side of said tongue section and the adjacent surface of said head section, a second movable jaw member pivotally mounted on said support for movement between an open position and a closed position and having a second movable jaw adapted to engage said head section at the side opposite said tongue section, a curved cam arm on said second member having an inner cam surface, an outer cam surface and an end cam surface, said first member having an arm movable in one direction for moving said first movable jaw against said strip, a carrier pivotally mounted on said last named arm and carrying first and second cam followers, means for moving said carrier between a first position and a second position, said first cam follower co-operating with said inner cam surface during movement of said carrier from said first position to move said jaws toward and substantially into engagement with said strip and co-operating with said end cam surface during the continued movement of said carrier to said second position to move said movable jaw members to said closed positions to clamp said movable jaws against said strip, said second cam follower co-operating with said outer cam surface during movement'of said carrier from said second position to said first position to. move said second movable jaw member to its open position and said means acting through said carrier References Cited in the file of this patent 9 H VUNYITEDVSTATES PATENTS Adamson -Jan.-14, 1919 Peterson et al. Apr. 23, 1935 Van Sittert Dec 20, 1938 Cross 'et al Apr.10, 1945 Hecker '-}n Aug. 19, 1947

Images