Clip Tool And Method Of Clinching

Abstract

A magazine fed clip tool of the stationary anvil type, and which utilizes closely nested clips or seal blanks for clinching ligatures or wires in the anvil. A clip is automatically fed to the clip tool and the clip tool preforms the clip into a non-nestable condition, after which the preformed clip is driven into the anvil jaw to be clinched about ligatures or wires. The method provides for stripping a clip from a closely nested stack, preforming the clip to a non-nestable condition and then clinching it about at least a pair of wires to form a clinched assembly.

Description

This invention relates to a clinching method and to an improved clip tool, and particularly to an improved pneumatically operable clip tool in which at least a pair of wires are clinched with a clip in a stationary anvil.

One such tool generally related to the clip tool of this invention is illustrated by Blumensaadt U.S. Pat. No. 2,574,811. A principal disadvantage of known tools such as that is that they can use only preformed, non-nestable clips. Non-nestable clips occupy a great deal of space and severely limit the load which a given length of magazine may carry.

Other clipping tools exist which are adapted to utilize nested stacks of clips. However, those are of the movable crimping jaw type, are not adapted to withstand the crimping load that a stationary anvil type of tool can withstand, and are otherwise less desirable in some uses and operations than tools of the general character illustrated in the Blumensaadt patent. Such other tools are illustrated, for example, in Lingle et al. U.S. Pat. No. 3,068,485 and Ohgren U.S. Pat. No. 3,133,288.

In accordance with this invention an improved tool of the stationary anvil type is provided which can efficiently and effectively utilize nestable clips for clinching two or more wires of a spring assembly such as one used in an automobile seat. The improved tool of this invention is relatively lighter in weight than presently available tools adapted to utilize nested clips. By virtue of the use of a lever mechanism for driving and clinching clips rather than a direct impact mechanism, the shock load in the tool of this invention is minimized. Also the tool is more universally adapted to clinch different sizes and numbers of wire combinations, while providing the very substantial and hitherto unavailable advantage of being operable with closely nested clips that increase the capacity of a given tool magazine by a factor of about three.

The tool of this invention is preferably pneumatically operable upon nested clips each having a pair of diverging leg sections. It includes a clip magazine and means for stripping a clip from the magazine and for injecting the clip into the main body of the clip tool. A driver assembly is provided to drive the clip into a stationary clinching jaw to clinch the clip about two or more wires.

After the clip is injected into the tool body it is acted upon by a preformer which reduces the divergence of the leg sections. The driver assembly drives the clip past the preformer and cooperates with the preformer to bias it against the clip. Desirably a ball transfer system is used which includes a ball, a cam slot in the driver assembly and a ball notch in the preformer, the ball being transferred between the cam slot and ball notch.

The driver assembly may be a one-stage or two-stage assembly. In the one-stage assembly the clip is preformed and is then moved directly into the clinching jaw. In the two-stage assembly the preformed clip is retained at a position remote from the clinching jaw and on the next actuation of the tool is driven into the clinching jaw. In that case the driver assembly includes a pair of driving blades and operates on two clips on each stroke of the tool.

The method of this invention for clinching at least a pair of wires preferably includes the steps of stripping a clip having a pair of diverging leg sections from a closely nested stack of clips, decreasing the divergence of said leg sections and then clinching the clip about the wires to form a clinched assembly.

Further objects and advantages of this invention will become apparent from the following description and drawings of which:

FIG. 1 is a vertical view, partially in cross section, of a clip tool of this invention taken substantially along the line 1--1 of FIG. 5;

FIG. 2 is a fragmentary view taken substantially along the line 2--2 of FIG. 1 of a portion of FIG. 1;

FIG. 3 is a fragmentary view taken substantially along the line 3--3 of FIG. 2;

FIG. 4 is a perspective view of a closely nestable clip adapted for use with the clip tool of FIG. 1;

FIG. 5 is a fragmentary view taken substantially along the line 5--5 of FIG. 1;

FIG. 6 is a fragmentary view of FIG. 1 in a second position;

FIG. 7 is a general organizational view of FIG. 1;

FIG. 8 is an enlarged view of the clinching operational aspect of the tool of FIG. 1;

FIG. 9 is an enlarged view like FIG. 8 at a later clinching stage;

FIG. 10 is an enlarged view like claim 9 showing a clinched assembly;

FIG. 11 is a view similar to FIG. 1 of a further embodiment of this invention; and

FIG. 12 is a view of the tool of FIG. 11 similar to the view of FIG. 6.

Referring first to FIGS. 1 to 7, a clip tool 10 of this invention comprises a housing 12 defining a cylinder bore 14 and an integral handle 15. Handle 15 is connected to a source of high pressure air by a fitting 16 and a hose 18. Handle 15 defines an air conduit 20 which communicates with a suitable valve assembly 22 which is operated by a trigger 24 which acts against a valve actuating pin 26. Suitable valve assemblies adapted to supply and port high pressure air to the cylinder bore 14 are well known in the art.

Valve assembly 22 is adapted alternately to supply air to and to vent air from opposite sides of a piston 28. When the piston is to be driven downwardly air is admitted by valve assembly 22 to passage 30 which communicates with the upper side of the piston. When the piston 28 is to be raised for its next stroke, air is admitted by valve assembly 22 to passage 32 which communicates with the lower side of the piston 28. Valve assembly 22 also acts to vent high pressure air from the opposite side of the piston to which high pressure air is supplied during the driving and return strokes of the piston in a known manner.

Piston 28 centrally mounts a piston rod 34 which extends downwardly through the base of housing 12. Cylinder bore 14 is closed at its base by a cylinder head 36. Cylinder head 36 defines a section 38 which nests within bore 14 and which sealingly engages the wall of the cylinder bore by a sealing ring 40 and which sealingly engages the piston rod 34 by a sealing ring 42. Cylinder head 36 also provides a pair of spaced mounting ears 44 which supportingly mount a frame assembly including a pair of spaced side plates 46 via bolts 45. Side plates 46 in turn mount and guide operating members of clip tool 10.

Each of the side plates 46 defines a vertical guide slot 50 which slidably receives a slide pin 52. Slide pin 52 extends between plates 46 and is fixedly mounted to the forked end 54 of piston rod 34. Between the fork arms of forked end 54 a crank 56 is disposed. Crank 56 defines a cam slot 58 which receives slide pin 52 for articulation with respect thereto.

Crank 56 is pivotally mounted on side plates 46 on a pivot pin 60 which may comprise a bolt secured by a nut to the side plates 46. Pivot pin 60 is remote from cam slot 58. An elongate driver link 62 is pivotally connected by an axle 64 to crank 56 at a point remote from both pivot pin 60 and cam slot 58. The other end of driver link 62 is pivotally connected to a driver assembly 66 by a further pivot pin 68.

Driver assembly 66 in the embodiment of FIGS. 1 to 7 includes a driver blade 70 and a clincher blade 72. The driver blade cooperates to preform a clip C to the condition of preformed clip C' and to drive it into a position from which the clinching blade drives it into the jaw of a stationary clinching anvil 74 in the manner to be described.

Blades 70 and 72 are reciprocable between the positions illustrated in FIGS. 1 and 6. FIG. 1 illustrates the uppermost position of the blades and FIG. 6 illustrates the lowermost position of the blades. The movement between these positions is effected by alternately supplying air to and venting air from opposite sides of piston 28 through passages 30 and 32 in response to the actuation of valve assembly 22. When in the position of FIG. 1 driver blade 70 is slidably positioned against a guide surface 76 provided by a frame assembly member 78 which is secured to plates 46 by bolts 80. Clincher blade 72 is slidably disposed against an upper integral extension of clinching anvil 74. Anvil 74 is secured to side plates 46 by a pair of bolts 82. As crank 56 moves from the position of FIG. 1 to the position of FIG. 6, link 62 pivots, and pivot pin 68 moves downwardly a distance substantially equal to the distance between the axes of pivot pins 60 and 64 less the vertical distance between those pivot pins in the position of rest (FIG. 1). This movement of the link 62 causes the blades 70, 72 to slidably move downwardly against the opposed guide surfaces to perform their respective functions.

It will be seen that driver blade 70 defines a cam slot 84 in which a cam ball 86 is disposed. Cam ball 86 is captured between blade 70 and a confronting preformer member 90. Preformer member 90 is oscillatably mounted on a pin 92 on frame assembly member 78 to oscillate between the positions of FIGS. 1 and 6, and defines a ball notch 94 confronting the driver blade 70. The upper end of the ball notch 94 is sufficiently close to a keeping surface 95 of a member 78 to keep the ball 86 as the driver blade 70 moves between the positions of FIGS. 1 and 6.

As cam slot 84 is carried from the position of FIG. 1 by blade 70, the ball 86 is cammed outwardly against preformer member 90 and is transferred into notch 94 causing the preformer member to oscillate in a counterclockwise direction (FIG. 1) about pin 92. Preformer member spring 96 resiliently opposes that motion to retain a tight fit between the ball and the surfaces acting against it. As the upper end of the preformer member rotates so does the lower preforming end 100. As that occurs the ends of the leg sections of a clip C are gradually pushed or squeezed together to the preformed condition of clip C' as it is being driven downwardly by the lower end of driver blade 70 to the position of clip C' (see FIG. 6). It is held in that lower position against the reactive surface of clinching blade 72 by an extension of spring 96. When the driver assembly is moved from the position of FIG. 6 to that of FIG. 1, spring 96 biases clip C' into the position of FIG. 1 directly underlying the clinching blade 72. On the next stroke clip C' is driven by clinching blade 72 into the jaw of anvil 74 to form the crimped assembly A.

Thus, it is seen that an open nestable clip is preformed on a first downward stroke of piston 28 to preform clip C to the form of clip C' and preformed clip C' is clinched on a second stroke of piston 28 to form clinched assembly A. During each stroke of piston 28 one clip C is preformed and a second clip C' is clinched.

Simultaneously with each return stroke of piston 28 a clip C is fed into the position occupied by clip C in FIG. 1. The feeding of such clips is from a clip magazine 120 (FIG. 5) which is suitably secured to side plates 46 and in association with an air-operated clip ejecting and feeding mechanism 121. Ejecting and feeding mechanism 121 includes a pneumatic double acting cylinder assembly which is supplied by air through a pair of air tubes 122, 124. Air tube 124 is in flow communication with passage 32 below piston 28 via an air passage 126, whereas air tube 122 is in flow communication with passage 30 via an air passage 128. The lower ends of tubes 122 and 124 feed into a manifold 129 secured by screws 131 to a cylinder block 130 defining an ejector cylinder 132. Cylinder block 130 defines a pair of air ports 134 and 136 which are in flow communication with tubes 122 and 124, respectively. Cylinder block 130 is mounted to one of the side plates 46 by a pair of screws 133. Port 136 (FIG. 2) is positioned substantially at the end of block 130 opposite port 134. An extension passage 138 provides communication between tube 124 and port 136.

A double acting piston 140 is disposed within ejector cylinder 132 (FIG. 2). It is exposed at opposite faces to ports 134 and 136. Its movement outwardly (FIG. 2) is limited by a stop surface 142 integral with a threaded cylinder closing nut 144. At its outer end, piston 140 mounts an elongate link 146 held thereagainst by a nut 148 threadedly secured to a threaded reduced diameter section 150 of piston 140. The other end of link 146 (FIG. 5), is secured to an ejector rod 152 which is slidably mounted in slide section 156 of clip guide 154. Clip guide 154 is open-topped adjacent slide section and beneath the magazine to receive clips C (FIG. 5). Clips C are biased by a spring-loaded follower 158 against ejector rod 152 and towards the surfaces 153 of clip guide 154 in the open-topped slide section. When the ejector rod is in the position of FIG. 5, the central web 160 of clip C lies against the rod and the outwardly diverging leg sections 162 straddle rod 152 and straddle surfaces 153. When the ejector rod is retracted (moved to the left in FIG. 5) by supplying high pressure air to port 134 to drive it outwardly, the pusher end 159 of ejector rod 152 is moved out of the path of the clips C and the clips are then biased downwardly into engagement with the surfaces 153. When the ejector rod is then moved to the right the pusher end 159 contacts a side surface of the lowermost clip C and ejects it from the magazine and thrusts it to the right along slide surfaces 153 and into the position of the clip C shown in dotted line in FIG. 5, again positioning the rod under the next clip C for the next feeding operation. The ejector rod moves the clip C in a direction normal to the direction of movement of the driver assembly 66.

The clip tool 10 of FIGS. 1 to 7 operates as follows. A closely nested stack of clips C (FIG. 4) or clips such as those illustrated and described in Kuster U.S. Pat. No. 3,032,184 or Childress U.S. Pat. No. 2,871,536, is loaded into magazine 120 and is biased downwardly by follower 158. When clips C are so closely nested, the leg sections 162 diverge so far that they cannot readily be clinched in a clinching anvil 74 without first preforming the legs to a lesser divergence.

The lowermost clip C of the stack rests against ejector rod 152. Trigger 24 is squeezed admitting air to the top of piston 28 and to port 134 causing the piston 28 to move down and causing the ejector rod 152 to be retracted to allow a clip C to be biased into engagement with guide surfaces 153. The trigger is released and high pressure air is vented from above the piston 28 and from port 134 while high pressure air is admitted below the piston and to port 136 to retract the driver assembly and to thrust ejector rod inwardly to strip a clip from the nested stack and to thrust it into the position in the tool illustrated in FIG. 5.

Upon the next actuation of the trigger, rod 152 moves outwardly, the leg sections of clip C (FIG. 1) are gradually decreased in divergence (preformed) by preformer member 90 and as the clip is moved vertically from that first position by driver blade 70 to the vertical elevation of clip C' (FIG. 6), remote from the jaw of clinching anvil 74. When the trigger is next released, spring 96 biases clip C' horizontally into the position of FIG. 1 directly beneath the clinching blade. At the same time the ejector rod 152 moves inwardly again to position a new clip C.

Upon the next operation of the trigger the two foregoing steps are repeated in sequence but clip C' is now moved down from the position of clip C' in FIG. 1 by clinching blade 72 along and into the jaw of anvil 74. Immediately prior to this operation two or more wires have been positioned generally in the space between the legs of the jaw of the clinching anvil 74 (FIG. 8). As the clip C' descends it reaches under and around the wires (FIG. 9) and is finally formed and wrapped about wires to crimpingly hold them together to form a clinched assembly A (FIGS. 6 and 10). Thereafter, the piston 28 returns to the position of FIG. 1 (the trigger having been released) and a new clip C is injected by ejector rod 152.

Further operation and release of the trigger repeats these steps until the clips in the magazine are exhausted and a new supply needs to be added. It is to be noted that each stroke (after the initial two actuations) both preforms one clip C and clinches one clip C' simultaneously.

The embodiment of FIGS. 11 and 12 is quire similar to that of FIGS. 1 to 7, both in mode of operation and in terms of the structural organization, with but two principal exceptions. Those are that there is no driver blade, but only a clinching blade, and that the preforming and clinching steps take place sequentially on one stroke of the piston 28, rather than on succeeding strokes of the piston.

Accordingly the same part numbers will be used for common components and only those components which are different will be described.

In the embodiment of FIGS. 11 and 12, a driver link 62 of clip tool 10' is pivotally secured to a driver assembly 66' by a pivot pin 68. Driver assembly 66' includes a clincher blade 72' defining a cam slot 84' in which a ball 86' is disposed. Clincher blade 72' is slidably positioned between surface 76' of frame assembly member 78' and an upper integral extension of anvil 74'. Anvil 74' is secured to side plates 46' by bolts 82'. Preferably anvil 74' is magnetic or provides a magnetic insert 75 for a purpose to be described.

When the piston 28 is moved to the upper position (FIG. 11) ejector rod 152 thrusts a clip C into position against the anvil 74' where it is held below the end of clinching blade 72' by a magnetic insert 75. When the trigger 24 is moved to actuate valve assembly 22 the ejector rod 152 is retracted and the clinching blade 72' moves downwardly. The clinching blade 72' contacts clip C and moves it downwardly while preformer member 90 is oscillated (biased oppositely by spring 96') about pin 92 from the position of FIG. 11 to that of FIG. 12. Preformer member 90 and clincher blade 72' cooperate via notch 94, ball 86', cam slot 84' and the side of clinching blade 72' to preform a clip C intermediate the length of the stroke to the configuration of clip C' (shown in dotted line in FIG. 11). Following preforming, continued downward driving moves the clip C' through the stages of FIGS. 7, 8 and 9 until a clinched assembly A (FIG. 12) is formed.

To operate the clip tool 10' of FIGS. 11 and 12, the same series of operations indicated with respect to FIGS. 1 to 7 are practiced. However, only two actuations of the trigger are necessary to transfer a clip C from the magazine and to clinch it, rather than three.

In each embodiment, however, a nestable clip C requiring preforming is ejected from a magazine to a first position in the tool, is preformed to the shape of a clip C', and is thereafter driven into a stationary clinching anvil to clinch it about two or more wires.

In the embodiment of FIG. 1, the preforming and clinching is a two-step operation. This permits the use of a longer anvil extension below the cylinder block than in the embodiment of FIG. 11. That feature permits use of a clip tool of this character in more difficult to reach locations within an assembly to be clinched, for example in remote interior locations in a spring assembly such as for an automobile seat, than with the embodiment of FIG. 11.

Claims

What is claimed is:

1. A method of forming a clinched assembly of a clip and at least a pair of wires, the steps comprising providing a stack of closely nested clips having a central web and a pair of leg sections divergingly projecting from said central web, stripping a clip from said nested stack and moving it to a first position, moving it from said first position to a second adjacent position while decreasing the divergence of said leg sections, then moving it from said second position to a third closely adjacent position while wrapping said leg sections about said wires to form a clinched assembly.

2. In the method of claim 1 in which the steps of moving from said first to said third positions are continuous.

3. In the method of claim 1 in which said movement to said first position is in a direction normal to the direction of movement from said first and second positions.

4. In the method of claim 1 in which one clip is moved from said first to said second position and another clip is moved from said second to said third positions simultaneously.

5. In a power-operated clip tool for preforming closely nested clips each having a pair of diverging leg sections prior to clinching the clips about at least a pair of wires, means for stripping and feeding a nested clip into said clip tool, preforming means for reducing the divergence of said pair of leg sections by pushing the ends of said leg sections towards each other, a clinching anvil having a stationary jaw, driving means for driving a clip past said preformer toward and into said jaw, and means for moving said driving means between a first position remote from, and a second position in said jaw.

6. In the clip tool of claim 5 in which said preformer is oscillatably mounted to gradually push said leg section ends towards each other.

7. In the clip tool of claim 6 in which said driving means comprises a driver assembly defining a cam slot in which a cam ball is positioned, said driver assembly being movable between said first and second positions.

8. In the clip tool of claim 7 in which said preforming means confronts said cam ball and said cam ball oscillates said preforming means.

9. In the clip tool of claim 8 in which said preforming means defines a ball notch to which said cam ball is transferred by said driver assembly when said driver assembly is moved from said first position toward said second position and from which said cam ball is transferred as driver assembly returns to said first position.

10. In the clip tool of claim 5 in which said driving means comprises a driver assembly having a clinching blade for clinching a clip in said anvil.

11. In the clip tool of claim 10 in which said driver assembly further comprises a driver blade for moving a clip from said first position past said preforming means to an intermediate position remote from said second position, said clinching blade being adapted to move a preformed clip from said intermediate position to said second position.

12. In the clip tool of claim 10 in which said preforming means is oscillatably mounted and said driver assembly defines a cam slot seating a cam ball, and said preforming means defines a ball transfer notch, whereby said cam ball is transferred from cam slot to said transfer notch as said driver assembly is moved from first position to said second position.

13. A clip tool comprising in combination a housing and frame assembly, a stationary clinching anvil having a jaw secured to said housing, a clip magazine, a power-actuated clinching blade for driving a clip into said anvil to clinch said clip around a pair of members to be clinched, means for ejecting clips from a nested stack of clips from said magazine into said housing and frame assembly, and means in said housing and frame assembly for preforming a clip into a substantially non-nestable condition at a position remote from the jaw of said clinching anvil.