US3074458A - Compound linkage hydraulic tool - Google Patents

Description

Jan. 22, 1963 w. R. EVANS I COMPOUND LINKAGE HYDRAULIC TOOL 3 Sheets-Sheet 1 Filed April 22, 1960 INVENTOR. Rober' va ns William Jan. 22, 1963 w. R. EVANS 3,074,458

COMPOUND LINKAGE HYDRAULIC TOOL Filed April 22, 1960 5 Sheets-Sheet 2 laco W Total Die Travel l Travel o Die Hcfldev 6 'E INV EN TOR.

2'// m obcr Evan Rom Travel [a R 5 Jan. 22, 1963 w. R. EVANS 3,074,458

COMPOUND LINKAGE HYDRAULIC TOOL Filed April 22, 1960 3 Sheets-Sheet 3 INVENTOR. WNam fioberf vdn BY ww -'W United States Patet 3,074,458 COMPOUND LINKAGE HYDRAULIC TOOL William R. Evans, Hersley, Pa., assignor to AMP Incorporated, Harrisburg, Pa. Filed Apr. 22, 1960, Ser. No. 23,985 6 Claims. (Cl. 153-1) This invention relates to compressing tools of the type particularly, but not necessarily exclusively, intended for nsage in the crimping of electrical terminals and connectors onto wire ends.

One widely used type of electrical connector is provided with a ferrule-forming portion of generally U- shaped cross-section which is adapted to be crimped onto a wire by bending the sidewalls of this ferrule-formng portion over the wire or inwardly and against each other and into crimped relationship with the wire. Terminals and connectors of this general type are usually manufactured in the form of substantially endless strips with the successive terminals of the strips oriented in either sideby-side or end-to-end relationship to each other. The conventional crimping tools for crimping such connectors provide in addition to the crimping dies a shearing means 'for shearing the leading connector of the strip from the next adjacent Connector, and/or from the strip itself, and a feeding means for feeding the strip of connectors at the end of each cycle of the tool. With tools of this type then, the operator need only position the end of the wire in the U-shaped ferrule-forming portion of the leading Connector which is disposed between the crimping dies and actuate the tool to send it through its crimping cycle. Thereafter, the dies move relatively towards each other, the leading terminal is sheared from the strip of terminals, and the next adjacent terminal is fed to a position between the dies in preparation for the next crimping operation.

'ihere are several obvious requirements which must be met by tools for crimping terminals of the abovedescribed type. It will be apparent that the crimping dies must be capable of movin-g apart a distance which is sufiiciently great to permit unimpeded feeding of the terminal strip to position the leading terminal thereof between the dies. A further important requirement which must be met is that this leading terminal must be precisely positioned with respect to the crimping dies for the reason that the crimping of terminals is a precise and exacting operation and if the terminal is not properly positoned, the finished crimped connection will be inferior in its physical or electrical properties. In conventional crimping tools adapted to crimp strip type terminals, the terminal is held in position between the dies by the strip itself which in turn is held in the strip feedng means. has been initiated, the terminal will be moved relatively into a female die and held between the sides of this die and a male die during the actual crimping operation. After the terminal has been thus gripped between the dies and is firmly held by the dies, the severing operation can be carried out since the strip is no longer required to hold the leading terminal With respect to the crimping dies.

In the prio' art type of crimping tools in which one die is fixed and the other die is movable towards and After the crimping cycle of the tool 4 ice away from the fixed die, the above requirements have necessitated the use of crimping tools which are larger and more bulky than would be required to merely perform the crimping operation itself. For example, open U-type electrical connectors intended for crimping onto wires in the size range of AWG-14-22 can be crimped with a total die movement of only about 0.2"; in other words, the actual compressng force, by virtue of which the terminal is crimped, is developed during a period during which the dies move relatively towards each other a total distance of 0.2". The actual tools, however, provide i`or a die movement of about 0.5" in order to separate the dies a distance sufiicent to permit feeding of the terminal strip at the end of the crimping cycle. It can easily be seen that it would be desirable to provide a tool having a much shorter ram travel than 0.5" and still accomplish complete crimping of the terminals. Such a tool would be easier to use since it would be smaller and lighter and would be more efiicient since the total travel of the ram would be utilized for the actual crimping operation and would not be wasted.

It is accordingly an object of the present invention to provide an improved crimping tool for open U-type connectors. A further object is to provide a tool which is more compact than previously known crimping tools for open U-type connectors. A still further object is to provide a tool having a reciprocable ram with a relatively short stroke, the length of the stroke being only slightly greater than the distance the crimping dies must move during an actual crimping operation and particularly during the compressing portion of the crimping operation, but which at the same time permits substantial die movement which is in excess of the ram stroke to permit feeding of a terminal strip.

These and other objects of the invention are achieved in a preferred embodment comprising a ram having a first set of crimping dies on its end 'for cooperation with a second set of crimping dies. The second set of crimping dies are mounted on end of the pivotally mounted :lever which can be swung from a first position in which the second set of dies are in alignment With the first set of dies to a second position in which the second set of dies are in alignment with the first set of dies. A cam means on the ram and a linkage between this cam means and the lever is provided to swng the lever and the second set of dies from the first position to the second position during the nitial portion of the stroke of the ram. The arrangement is such that the swinging of the lever takes place during only the first half of the movement or stroke of the ram so that the dies which are mounted on the lever reach their second (crimping) position and come to rest in this position during the very first portion of the crimping cycle. In a preferred embodiment of the invention, the dies are permitted to be moved apart a distance which is over twice as great as the actual stroke of the ram.

In the drawing:

FIGURE 1 is a perspective view of a preferred embodiment of the invention.

FIGURE 2 is a graphical representation of the movement of the two dies during a crimping stroke of the preferred embodiment.

FIGURE 3 is a side view of the preferred embodiment 3 showing the position of the parts at the beginning of a crimping stroke.

FIGURE 4 is a View similar to FIGURE 3 but showing the positions of the parts -at the end of the crim-ping stroke.

FIGURE 5 is a frontal View with parts broken away showing particularly the strip feeding mechanism.

FIGURE 6 is a -fragmentary view illustrating the operation of the strip feeding mechanism.

FIGURE 7 is a fragmentary View showing the shearing blocks for shearing the terminal from the strip.

FIGURE 8'is a sectional View taken along the lnes 8--8 of FIGURE 5; and

FIGURE 9 is a fragmentary perspective view showing the shearing blocks.

Referring first to FIGURES l-4, the disclosed embodiment comprises a tool body 2 having a reciprocable ram 4 therein and a head 6 mounted on itsend. Tool body 2 may comprise the cylinder of a hydraulic piston and cylinder adapted to be manually held or may comprise the body of a suitable mechancal tool. It is sufiicient to say that the tool body will contain means to reciprocate-the ram 4 and that the stroke of the ram can be relatively short for purposes of the instant invention.

Head 6 has extendng therefrom -a pair of parallel plates 8 which are connected by a web 10 and which have ends 12 extending nwardly over the axis of the ram 4. A die holder 14 is mounted on the end of ram 4 and has lower crimping die means generally indicated at 16 Secured thereto by a threaded fastener as shown. Ears 18 extend from each side of the die holder towards the plates 8 and bear against the outside surfaces of these plates. The ends of these ears are connected by a pin 20 which-extends through aligned slots 22 in the plates to permit reciprocation of the head and die holder. Between plates 8 there is provided a block 24 having a notch through which pin 20 extends and which is adjustably clamped by means of a fastener 26 to a second block 28. This block bears against the surface of web 10` and has on its upper end as viewedin FIGURES 3 and' 4, an inclined cam surface 30 and an adjoining surface 32 which extends parallel to the axis of the ram. These surfaces engage a cam follower 34 which is ro'- tatably mounted between the sides of a generally channel-shaped member 36 between the sidewalls of which there is disposed ,a lever 38. A pin 40 extends through this lever at its lower end and through the sidewalls of chan'nel-s'haped member 36 'and is mounted in plates S to permit' oscillation of the lever and channel-shaped member about the axis of the pin '40. At its upper end lever 38 provides a recess within which there is disposted the enlarged 'head 42 of a fastener which is threaded through the lever. The end' 46 of the fastener bears against a spring seat on the end of a coil spring' 48'in -a r'eces's 50 in' the web 10 of the tool head. Norrnally this spring biases the parts to the position shown in' FIGURE 3 but pe'rmits' movement of the lever in a clockwise direction with concomitant compression of the spring as shown in FIGURE 4. i

The channel-shaped member 36 and the lever 38 are not Secured together, however, they' act as a single lever since the spring 48 normally urges lever 38 in a counterclockwise direction, as viewed in FIGURES 3 and 4, so' that' the head of the fastener 42 always bears against the web of 'the channel. Since counterclockwise movement of this channel-shap'ed member is limited by cam s'urfaces 30, 32, the lever and channel must act as a single lever. An opening 44 in the channel permits adjustment of fastener 42 for the purpose of adjusting in tum the movement of lever 38.

The upper end of lever 38 is slotted and is pivotally connected at 52 with a link 54 which, at its other end has a pivotal connection on' a common pivot pin 56 with a pair of upper links 58 and a pair of lower links 60',"th 58' and `60 constituting"a*toggle; Upper links 58 are pivoted at their ends 62 to a pin in the plates 8 and the lower links 60 are pivotally con'nectedt an ear 64 which extends upwardly from an upper die holder 66. Upper crimping die means complementary to the die means 16 are Secured to this upper die holder by means of a threaded fastener and suitable spacers as shown, and ears 70 similar to the ears 18 extend from this die holder over the external surfaces of the plates 8. These ears are rotatably mourted on a common pin 72 in the plates 8.

It will be apparent from FIGURES 3 and 4 that as the ram moves upwardly, the cam and linkage 30, 38, 56, 58, 60 cause clockwise movement of the upper die holder from' the position of FIGURE 3 to theposition of FIG- URE 4.' As shown in FIGURE 4, the toggle 58, 60 is slightly over center when the lever 38 has been swung by the cam surfaces 30, 32. It is advantageous to have this toggle over center in order to preclude the possibility of its being opened orbroken by the compressive forces developed during crimping. In the preferred em- `bodiment, a set screw 73 is provided to act as a stop for the toggle and to define its final position.

The amount by which the die holder 66 is swung can' be varied by adjustment of the block 28. Thus, if the block 28 is lowered in FIGURE 3, the length of the arc over which the die' holder 66 is swung will be in' creased. An added advantage in making the block 28 adjustable s that the precise point in the ram stroke at which the swinging of the'die holder 66 is completed can be varied. The adjustng screw 42 onlyrfor the purpose of compensating for manufacturing tolerances since,

as mentioned above, channel 36 and lever 38 act as 'ai single unit. The adjusting screw 42 is adjusted to position roller 34 against cam surface 30 when the parts are in the position of FIGURE 3 and may be adjusted to compensate for wear after the tool has been subjected to usage.

A preferred form of feeding' means in accordance with the invention is mounted on a sector 74 which in turn is Secured to the head 6 by means of fasteners as shown in FIGURE 1. This sector provides an arcu'ate track over which the terminals T, in side-by-side strip form, are fed from a suitable source. A pair of parallel plates' 76 are' secured to the sector adjacent the upper die holder and a slide 80 is recprocably mounted between 'suitable' guides on these plates. A feed finger for feeding the strip of terminals is pivotally mounted on ears' which extend from the slide and is normally biased upwardly as' viewed in FIGURE 5 by -means of a spring 82. The arrangement is such that the slide can be moved rightwardly from the position shown in FIGURE 5 by the depression of the feed pawl against the force of the spring while'leftward movement of the slide will result in the strip being fed a distance equal to the pitch of the strip.

Reciprocation of this slide' 'is achieved by means of a lever 88 pivoted to the sector plate 74 at 90 and connected by a link 92 to the feed slide 80. Normally this lever is biased to the position shown in FIGURE 5 by means of a spring 94 having one end secured to the plate 78 and its opposite end Secured to the lever. A plate 98 is clamped to lever 88 near the lower end thereof by means of an adjustable clamping means 96. This plate has a notch 108 on its left hand side and a surface 102 adjacent to the notch against which the end 104 of a locking pawl normally bears. This locking pawl is pivoted to the sector plate at 106 has an adjustable stop 108 in its opposite end which stop is adapted to be engag'ed by an extension 112 of a plate 110 mounted on the tool head andreciprocable therewith. A spring 107 acting between the lefthand arm of the pawl and the tab 112 of plate 110 normally biases this pawl in a clockwise direction. The lower end of plate 112 has a similar lateral extension-114 which is adapted to engage a finger 116 on plate '98 s'o-that upon upward movement of the rain and the tool head, the lever 88 is swung in a clockwise direction against the force of spring 94 until the end 104 of the pawl is seated in the notch 100. This Upward movement of the ram then cocks the feed mechanism so that upon return movement of the ram, the extension or arm 112 will rotate the looking pawl in a counterclockwise direction and release the lever 88. The spring 94 then causes leftward movement of the lever and the feed slide to feed the terminal strip. Advantageonsly, a stop 118 is provided on the tool head to prevent over-feeding of the strip. As shown in FIGURE 5, the end of the strip comes to rest against this stop to define the limit of the feeding stroke and to position the leading terminal between the crimping dies. In order to prevent retractile movement of the strip it is desirable to provide a locking finger 120 on a pivotal mounting on a plate 122 which extends laterally from the mounting plate 118. This locking finger permits leftward movement of the strip as viewed in the drawing while preventing n'ghtward movement thereof.

During the crimping cycle, it is necessary to sever the terminal from the carrier strip C, to which it is attached and, advantageously, to sever the carrier strip at some point adjacent the crimping zone in order to simplify its disposal. The severance of the terminal is accomplished by means of an L-shaped member 122 Secured to the inside surface of the righthand one of the plates 8 and having its foot portion 124 extending substantially parallel to the fed carrier strip. As the ram moves upwardly, the lower crimping die displaces the terminal upwardly but the carrier strip is restrained from upward movement by this foot portion 124 so that the terminal is severed from the carrier strip along the edge of the die. It will be noted that the central portion of foot 124 is relatively thin so that the wire can be positioned over the foot and over, and in alignment with, the terminal. in the disclosed embodiment the carrier strip is sheared into short lengths by a fixed shear block 126 over which the carrier strip is fed and which cooperates with the edge of the L-shaped shear block 122 during upward movement of the ram to perform the shearing operation.

In operation the parts will normally be in the position shown in FIGURES l and 3. The operator first positions the stripped end of a wire over the uncrimped terminal which is positioned between the crimping dies and thereafter actuates the tool, for example, by supplying compressed air or fluid in the case of a hydraulic tool. During initial upward movement of the ram as shown in FIGURE 2, the linkage between the lower die holder and the upper die holder is effective to cause swinging of this upper die holder from the position of FIGURE 3 to the position of FIGURE 4. The amount of move ment of this upper die holder Will of course vary and may be made to vary as desired. However, where substantial movement is desired as in the instant case, it is entirely practical to achieve an amplitude of movement of the upper die which is three times the movement of the lower die during the interval when both dies are moving. As shown in FIGURE 2, during the first half of the upward stroke of the ram, this ram may move 0.1" and during the same interval, the upper die may move along an arcnate path having a vertical Component (i.e. its Component as measured along the ram axis) of 0.3". When the parts have achieved this position, 0.1" of movement rcmains for the lower ram and it is during this period that the crimping of the terminal takes place. Also during upward movement of the ram the feeding mechanism is cocked as described above and during downward movement is released to feed the next adjacent terminal of the strip.

Changes in Construction will occur to those skilled in the art and various apparently dierent modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is of- 6 fered by way of illustraton only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

I claim:

l. A crimping tool comprising, a reciprocable ram ha ing a first crimping die thereon, a pivotally mounted die holder, a second crimping die on said pivotally mounted die holder, said die holder being movable along an arcuate path from a first position, in which said second die is disposed laterally of the axis of said ram and laterally of said first crimping die, to a second position in which said second die is diametrically opposed to said first die and in algnment therewith, said arcuate path being substantially tangent to the aXs of said ram when said die holder is at said second position, resilient means normally biasing said die holder to said first position, and means acting between said ram and said die holder for swinging said die holder from said first position to said second position during the initial portion of the crimping stroke of said ram.

2. crimping apparatus as set forth in claim l wherein said means acting between said ram and said die holder comprises a toggle linkage on said die holder which swings said die holder upon being straightened, a cam on said ram, and a linkage between said cam and said toggle linkage for straightcning said toggle linkage during initial movement of said ram.

3. Apparatus as set forth in claim l wherein said means for swinging said die holder comprises a toggle linkage on said die holder which swings said die holder upon being straightened, a cam on said ram, a lever pivotally mounted intermediate its ends, said cam being engaged with one end of said lever to Swing said lever in a first direction during initial movement of said ram, a link connectng the other end of said lever with the common pivotal axis of said toggle linkage, and resilient means normally basing said lever in the direction op posite to said first direction.

4. Apparatus as set forth in claim 1 including means for feeding terminals in strip form to position the lead ing terminal of said strip between said dies, and means on said ram for actuating said feeding means at the end of the retractile stroke of said ram.

5. A crimping tool comprsing, a tool head, a ram reciprocable in said tool head, a first crimping die on said ram, a die holder having an arm which is pivotally mounted on said tool head, a second crimping die on said die holder, said die holder being movable along an arcuate path from a first position in which said second die is disposed laterally of the axis of said first crimping die, to a second position in which said second die is diametrically opposed to said first die and is in alignment therewith, said arcuate path being substantially tangent to the axis of said ram when said second die is at said second position, a toggle linkage between said tool head and said die holder, a lever pivotally mounted intermediate its ends on said tool head, a cam on said ram for swinging said lever in a first direction during initial movement of said ram towards said die holder, and a link connecting the other end of said lever with the common pivotal axis of said toggle linkage, said other end of said lever being movable relatively towards said common pivotal axs during swinging of said lever in said first direction wh reby, said toggle linkage is straightened out and said second die is aligned with said first die during initial movement of said ram towards said other die.

6. A crimping tool for crimping open U-type electrical terminals in strip form onto the ends of wires comprising, a reciprocable ram having a first crimping die thereon, a pivotally mounted die holder, a second crimping die on said pivotally mounted die holder, said second crimping die having convergent die surfaces to grip and inwardly bend the sidewalls of a terminal, said pivotally mounted die holder being movable along an arcuate path &074 458 I fron a first position in which said second die is dispoed laterallyof .the axis of said ram and laterally of said first crnpng die, to a second position in which said second die i's diametrically opposed to said first die and is in alignment therewith, said arcuate path being substantially tangent to the exist of said :am when said die. is at said second position, terminal strip feedng means on said tool forfeedng said strip e: terminals towards said, dies and to position the leading terminal of said strip between sad dies, and means acting between said ram and said die holder for swing ing said die holder and said second die along said arcuat e path to said second position during 'the intal portion of the crmping sti-oke of said ram 8 whereby, said dies are normally separated by a distance sufficient to permit feedng of said strip between said dies, and said dies move into gripping relation ship with the leading terminal of said strip during, said intial portion of the st'qke of said ram.

References Cited in the file of this petent UNITED STATES PATENTS 2,065',488 Carlson Dec. 22, 1936 2,208,819 Smith Iu1y'23, 1940 2,766,631 Van Sittert Oct. 16, 1956 2,887,916 Freedom May 26, 1959

Claims (1)

1. A CRIMPING TOOL COMPRISING, A RECIPROCABLE RAM HAVING A FIRST CRIMPING DIE THEREON, A PIVOTALLY MOUNTED DIE HOLDER, A SECOND CRIMPING DIE ON SAID PIVOTALLY MOUNTED DIE HOLDER, SAID DIE HOLDER BEING MOVABLE ALONG AN ARCUATE PATH FROM A FIRST POSITION, IN WHICH SAID SECOND DIE IS DISPOSED LATERALLY OF THE AXIS OF SAID RAM AND LATERALLY OF SAID FIRST CRIMPING DIE, TO A SECOND POSITION IN WHICH SAID SECOND DIE IS DIAMETRICALLY OPPOSED TO SAID FIRST DIE AND IN ALIGNMENT THEREWITH, SAID ARCUATE PATH BEING SUBSTANTIALLY TANGENT TO THE AXIS OF SAID RAM WHEN SAID DIE HOLDER IS AT SAID SECOND POSITION, RESILIENT MEANS NORMALLY BIASING SAID DIE HOLDER TO SAID FIRST POSITION, AND MEANS ACTING BETWEEN SAID RAM AND SAID DIE HOLDER FOR SWINGING SAID DIE HOLDER FROM SAID FIRST POSITION TO SAID SECOND POSITION DURING THE INITIAL PORTION OF THE CRIMPING STROKE OF SAID RAM.

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