US3199335A

US3199335A - Crimping tool

Info

Publication number: US3199335A
Application number: US172354A
Authority: US
Inventors: Marion B Holmes; Bossert Margaret Anna
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-02-09
Filing date: 1962-02-09
Publication date: 1965-08-10
Anticipated expiration: 1982-08-10

Description

Aug. 10, 1965 M. HOLMES ETAL CRIMPING TOOL 2 Sheets-Sheet 1 Filed Feb. 9, 1962 1965 M. a. HOLMES ETAL 3,199,335

CRIMPING TOOL 2 Sheets-Sheet 2 Filed Feb. 9, 1962 United States Patent Office 3,199,335 Patented Aug. 10, 1965 3,199,335 (IRHMPENG TDUL Marion B. Holmes, 3785 Lakewood Drive, Drayton Plains, Mich, and Arthur G. Bossert, In, deceased, late of Clarlrston, Mich, by Margaret Anna Bossert, administratrix, 6150 Clintonville Road, Clarisston, Mich. Filed Feb. 9, 1962, Ser. No. 172,354 11 Claims. (Cl. 72410) The present invention relates generally to crimping tools and, more particularly, to a crimping tool which locates a connector in the optimum crimping position with respect to the crimping punches, and which automatically applies the required amount of pressure upon the punches to effect an optimum crimp for a particular connector-conductor combination.

In crimping a connector to the end of an electrical conductor there are two basic criteria by which the quality of the connection is determined. First, there must be no appreciable voltage drop across the connection; and secondly, since the connector may be frequently engaged with, and disengaged from, a matching socket, the connection must exhibit a certain predetermined minimal tensile strength. It has been found that these requirements are best fulfilled by forming the indentations of the crimp at positions symmetrically spaced about the circumference of the connector and at the axial center of the conductor-receiving, or barrel, portion of the connector. The depth of the indentations so formed should be uniform and great enough to provide the required electrical and tensile properties at the connection without unduly distorting, or rupturing, the barrel wall section. It is also desirable that a crimping tool be adapted to accommodate a relatively wide range of connector and conductor sizes.

The crimping tool comprising the present invention incorporates a connector locating device for positioning a relatively wide range of connector sizes in such relation to the crimping punches that the indentations of the crimp are symmetrically spaced on the connector barrel, of uniform depth, and formed at the axial center thereof. There is also provided an overload release mechanism which serves to assure that the punch pressure applied to a particular connector-conductor combination is large enough to form indentations whose depth is suflicient to yield the required tensile strength, yet not great enough to cause rupturing of the connector barrel. In addition a ratchet mechanism is employed in the tool to insure that the required punch pressure is applied before the punches are disengaged from the connector. These characteristics of the tool provide for crimped connections which are of consistently high quality irrespective of variations in the size and hardness of the connectors and conductors being crimped.

It is, therefore, the primary object of the invention to provide a crimping tool which will consistently form crimped connections of high quality.

Another object is to provide a crimping tool incorporating a connector locating device which will position a rela tively wide size range of connectors in such a relation to the crimping punches that the crimp indentations will be symmetrically spaced on the connector barrel, of uniform depth, and formed at the axial center thereof.

Another object resides in the provision of a crimping tool incorporating an overload release mechanism which will prevent undue distortion and rupturing of the connector being crimped, while assuring a depth of crimp indentation which will yield the required electrical and tensile characteristics of the connection.

Another object is to provide a crimping tool wherein a predetermined pressure must be applied to the connector before the punches may be disengaged from the connector.

These and other objects and features of the invention will be more apparent to those skilled in the art upon consideration of the following description of the appended drawings wherein:

FIGURE 1 is an exploded isometric view of the subject crimping tool showing the various components thereof, certain of such components being shown in section to better illustrate their construction;

FIGURE 2 is a side elevation of the tool, with portions removed for clarity, showing the handles thereof in the fully open position;

FlGURE 3 is also a side elevation of the tool showing the handles in the fully closed position;

FIGURE 4 is a view looking into the outer end of the connector locating device, portions of which are shown removed to better illustrate its construction; and

FIGURE 5 is a sectional View taken along line VV in FIGURE 4 showing the connector locating device in assembled form.

Referring now to FIGURES 1 and 2 of the drawings, the present crimping tool, generally indicated by the numeral 10, includes a pair of

handle members

11, 12 adapted for pivotal interconnection at one of their ends. Handle 11 consists of a body portion 13 and a pair of

side plates

14, 15 af'nxed to the body portion by means of a plurality of fasteners 17. Aligned apertures 18 extend through the

side plates

14, 15 for receiving the connector to be crimped. Also extending through such side plates are a plurality of slotted apertures 20 which lie on a circle concentric about the openings 18. Handle 12 consists of an enlarged end portion 21 integrally connected with an elongated portion 22. On the elongated portion 22, adjacent the end portion 21, is an integral, medial, raised portion 23, the purpose of which will be explained below, whose width is somewhat less than that of the former. An enlarged opening 24 extends through the enlarged end portion 21 of the handle 12 and is provided with a plurality of equally spaced cam surfaces 25, preferably four in number. A cylindrical punch holder 27, having a central aperture 28 aligned with, and of a slightly smaller diameter than, openings 18 in

side plates

14, 15, is disposed within enlarged opening 24 in handle 12. A plurality of equally'spaced, transverse grooves 30 are formed in the punch holder. Radial passageways 31 connect the inner surfaces of the grooves 30 with the center aperture 28. Within each of the grooves 39 is positioned a punch member 32 comprising an enlarged head portion 33, having an arcuate outer surface adapted for slidable engagement of the adjacent cam surface 25, and an integral cylindrical body portion 34 which extends into the passageway 31. The

inner ends of the body portions 34 of the punches 32 are ground into a substantially pointed shape whereby the crimp indentations are more readily formable. About each of the body portions 34 of the punches is disposed a spring 35 which continually urges the punch head 33 into contact with the corresponding cam surface 25. The punch holder 27 is connected to the

side plates

14, 15 of handle 11 by means of bolts 37 which extend through slotted apertures 20 in the latter and through the apertures 38 in such punch holder. It may be readily seen that closure of the

handles

11, 12 will cause the punch heads 33 to slide along the cam surfaces 25, thereby forcing the punches 32 to move inwardly against the action of springs 35.

In FIGURES l, 4 and 5 there is shown the preferred configuration of the device employed in the subject crimping tool for locating the connector to be crimped in the proper position with respect to the punches 32. The connector locating device includes a cylindrical guide plate dill rigidly connected to the handle 11, by bolts 37 which engage threaded apertures 41 in such a manner that the axis of the guide plate at corresponds to the centerline of apertures in handle 11. Extending through the guide plate 4t} is an eccentrically located, cylindrical opening 42 having a rearwardly directed flange 44 thereabout. Such flange 44 has a plurality of equally spaced longitudinal slots 45 formed therein, the outer ends of which are open. Attached to the guide plate so, by means of a bolt 46, is a housing member 47. Such bolt extends through an aperture 4*) in the housing 47 and engages threaded aperture 5% in guide plate td. Housing 37 is formed with a first cylindrical cavity 51 therein, for accommodating the guide as, and a second, eccentrically located, cylindrical cavity 52 within which is disposed a turret 54. An inwardly directed flange 55 at the outer end of the second cavity 52 serves to retain the turret 54 therein. When the components of the connector locating device are assembled, the cavity 52 in housing 47 and opening 4-2 in guide plate 44) are axially aligned. The turret 54 consists of a forward portion 56 and a rear portion 57, the latter having a collar 59 formed thereabout. The diameters of the forward portion 56 and collar 5'? are slightly smaller than, respectively, the diameters of opening 42 in guide plate at) and cylindrical cavity 52. in housing d7, such that the plunger 54 is freely rotatable about its axis and movable in an axial direction. Extending through the turret 54 are a plurality of apertures 66, the centerlines of which lie on a common radius about the axis of the turret. Such radius is equal to the distance separating the centerline of aperture 13 in handle 11 and the axis of the turret $4, so that by rotating the turret any one of the apertures 6t may be aligned with the apertures 1%. Within each of the apertures tl are disposed a connector locator 61, a spring 62 and a retainer button 63, the latter preferably being force fitted into the aft end of the aperture until its rear surface is flush with that of the turret 54. At the forward end of each of the locators 61 is a reduced portion es, the diameter of which is slightly less than the diameter of central aperture 28 in punch holder 27. A shoulder 66 interconnects the reduced portion with the remainder of the locator er, the diameter of the latter being slightly less than that of apertures 18 in side plate 14. The springs 62 act against the rear surfaces of locators 61 to urge same in a forward direction so that they normally protrude from the front face of the turret 54-. The forward movement thereof is limited by an outstanding flange 67 about the rear edge of each locator 61 which abuts a shoulder 69 in each of the apertures 66?. Extending through each of the locators is a central, longitudinal aperture 769, the respective diameters of such apertures 70 being different so that a dilferent size connector is accommodated by each locator. Disposed about the turret 54- is a compression type spring '71, the forward end of which abuts the back side of guide plate tit, and the aft end of which abuts the forward side of collar 59, thereby urging the turret 54 in a rearward direction. The turret is held in a forward or in position, against the action of spring 71 by means of a trigger 72 which engages the rear side of collar 59. Such trigger 72 is pivotally positioned on a pin 74 within a slot 75 in the side of housing 47, such slot '75 communicating with the cavity 52 wherein turret is disposed. The trigger is urged in a counterclockwise direction (as viewed in FIGURE 4) by means of a spring-loaded plunger 76 disposed within a cavity 77 formed in the housing 47. One end '79 of trigger 72 is formed with a curved outer surface approximating that of the housing 47, while the opposite end 80 extends therebeyond so as to be easily accessible to the tool operator. The trigger 72 is so located that the distance separating its forward face and the outer surface of handle face plate 14 is equal to the distance between the front surface of turret 54 and the rear edge of collar 59. This arrangement is illusr connections of consistently high quality.

trated in FIGURE 5, wherein the plane of the forward face of the trigger '72 is indicated by the broken line at 81.

The trigger 72 also serves as a means of aligning the locators all with

apertures

18 and 28 in side plate 14 and punch holder 27, respectively. On the inner face of the trigger '72 there is formed a generally V-shaped, transverse protrusion 82 adapted to engage notches formed in collar 59 which are so located that the protrusion will engage one of the notches 84 only when one of the locators 61 is aligned as described above. Additional locator alignment means may be provided by affixing a small pin $5 in the forward portion as of the turret 5 at such a position that it will enter one of the slots 4-5 in flange 44 about opening 42 in guide plate l-ll only when one of the locators er is properly aligned. In order to indicate visually the proper alignment of the locators, a reference line 235 is scribed on the rear surface of the housing and index marks 87 are scribed radially outward from the locator centers on the rear surface of turret 54.

It is also necessary to indicate to the tool operator which of the locators s1 is aligned in crimping position. This is preferably done by coloring each of the rear surfaces of the spring retainer buttons differently. At some convenient position on the tool, a plate or decal (not shown) is applied thereto upon which the color code is explained.

From the foregoing description of the connector device, it may be seen that in order to crimp a connector of known size, the operator first consults the color code legend to obtain the appropriate setting for turret 5d. The operator next depresses the exposed end 3 of trigger 72, which moves the curved end 7% outwardly, thereby disengaging the forward face of the trigger from the rear face of collar 59 and allowing the turret 54 to move rearwardly, under the action of spring 71, to the out position as indicated by the broken line at 89 in FIGURE 5. The operator then grasps the protruding rear portion of the turret 54-, which is preferably knurled, and rotates same until the index mark 37 adjacent the appropriate locator 61 is aligned with the reference line 86. The turret 54 is then pressed inwardly until the curved end 7? of the trigger 72 engages the collar 59 Bit-ring such inward motion of the turret 5d, the selected locator all is maintained in alignment by the protrusion 82 on trigger 72 which is seated in one of the notches 84 in collar 59. The unaligned locators er, as the turret moves toward the in position, abut the outer surface of side plate 14 and are forced back into their respective apertures as against the action of springs ca. The aligned locatordl, however moves inwardly until the shoulder as contacts the punch holder 27, the reduced forward portion 65 of the locator extending into the latters central aperture 28. The connector is then inserted into the tool, the probe portion hi3 thereof extending into the aperture 79 through the aligned locator 61, until the collar 91 about the connector abuts tle forward end of the reduced portion 65 of the locator er. It may be readily observed that by making the diameter of the aperture 7d only slightly larger than the probe of the connector it is intended to accommodate, the barrel 92 of such connector will be radially centered between the punches 32:, and consequently that the crimp indentations will be symmetrically spaced about the connector barrel and of uniform depth. By properly adjusting the longitudinal dimension of the forward reduced portion 65 of the locator of, the connector may be axially positioned such that the crimp indentations are formed at the center of the barrel 92.

As a result of variations in the materials, or more specifically the hardness of the materials, from which connectors and conductors are made, it is necessary to provide the crimping tool with a mechanism which will compensate for such variations in order to obtain crimped In the subject crimping tool there is provided an overload release mechanism which includes a plate assembly compris ng a pair of spaced

face plates

95, 97 disposed, respectively, between side plate 14 and punch holder 27, and between side plate 15 and punch holder 27 (FIGURE 5). As shown in FIGURES l and 2 the face plates are provided with central apertures 99, the diameters of which are substantially the same as apertures 18 through

side plates

14, 15, to permit a connector to be inserted therethrough, and spaced apertures 100, which are aligned with apertures 38 in punch holder 27, through which pass bolts 37. As may be readily seen, the

face plates

96, 97 and punch holder are aflixed together by such bolts 37 and may be considered to be integrally connected. The

face plates

96, 97 extend rearwardly and are interconnected at their terminal ends by a transverse plate 101. Riding upon such transverse plate 101 are a pair of rollers 102 which are free to rotate about a pin 104 extending through the lower end of a linkage bar 105. The upper end of such linkage bar 105 is pivotally interconnected to handle 11, within a clevis 106 formed in body member 13, by means of a pin 107, which is located forward (to the left as shown in FIGURE 2) of pin 104. The lower end of linkage bar 105 is prevented from moving forward from the position shown in FIGURE 2 by a shoulder 108 on the forward face of the linkage bar which abuts the lower surface of body member 13 and thus serves as a position stop. Extending rearwardly from the lower end of linkage bar 105, and pivotally connected thereto by pin 104, is a clevis 109 to which is integrally connected a first rod 110 which is telescopically engageable with a second rod 111, the latter being provided with an end portion 112 having a substantially hemispherical surface 114 which abuts the surface of a conical recess 115 in the end of an adjustment screw 116. Disposed about the

rods

110, 111 is a spring 117 which continually urges such rod 110 forward and thus results in the rollers 102 being positioned on the forward portion of transverse plate 101, as shown in FIGURE 2. This position of rollers 102 relative to transverse plate 101 corresponds to the downwardmost position of the latter, and to a clockwise positioning of

face plates

96, 97. The bolts 37, which fixedly interconnect the punch holder 27 to

such face plates

96, 97 are thus retained against the clockwise ends 119 of slotted apertures 20 in

side plates

14, 15 of handle 11.

In crimping a particular connector-conductor combination, the connector having been properly positioned in the crimping tool as explained above, and the conductor having been inserted into the connector barrel, the handle 11,

face plates

96, 97, and punch holder 27 are rotated clockwise relative to handle 12 and the punches 32 move inwardly and contact the outer surface of the connector barrel. Continued clockwise rotation of handle 11 causes the punches 32 to indent the connector barrel and the conductor contained therein. As the depth of indentation increases, the resistance to further indentation increases accordingly, such resistance being dependent upon the hardnesses of the connector and the conductor. If this resistance exceeds a certain amount, which is predetermined both by the constant of the spring 117, and by the initial axial compression thereof, the spring 117 will be compressed, the rollers 102 will move rearwardly on transverse plate 101, and the

face plates

96, 97 and punch holder 27 will cease clockwise rotation relative to handle 12, thereby stopping the inward movement of the punches 32. When this occurs, the punch holder 27 and

face plates

96, 97 are essentially in locked positions relative to handle 12. Upon continued clockwise rotation of handle 11 the bolts 37 are unseated from the clockwise ends 119 of slotted apertures 20 in

side plates

14, 15 of handle 11 and are moved toward the counterclockwise ends 120 of such apertures, thereby permitting continued handle closure to occur without further inward movement of punches 32.

The connectors which may be crimped with the present t3 crimping tool range from very small to relatively large sizes. The smaller size connectors are generally made of relatively soft material and have thin barrel wall sections. In order to prevent over-crimping such connectors a set screw is threadably engaged in an aperture 126 through the forward portion of body member 13 of hantile 11 and extends below the lower surface of such body member 13. A jam screw 127 tightened against the upper end of set screw 125 serves to prevent movement of the latter. As the

handles

11, 12 are closed, the raised portion 23 of handle 12 abuts the lower end of the set screw, as shown in FIGURE 3, thereby limiting the closure of

such handles

11, 12 and, hence, the inward movement of the punches 32. As may be readily seen the set screw 125 also servesas a means of adjusting the maximum depth of the crimp indentations. The larger size connectors, on the other hand, are usually made of harder materials and have relatively thick wall sections. In order to prevent under crimping the larger size connectors, another set screw 130 is threadably engaged in an aperture 131 which extends downwardly and forward through body member 13 at such a position that the lower end of the set screw 130 will abut the rear surface of linkage bar 105 as the latter rotates rearwardly and upwardly. Thus if the resistance to crimping offered by a connector is large enough to impede the inward movement of the punches 32 during the first few degrees of handle closure, thereby actuating the overload release mechanism, the

face plates

96, 97 and linkage bar 105 will rotate upwardly until the latter abuts the set screw 130. When this occurs, as shown in FIGURE 3, the

face plates

96, 97 can no longer rotate. Hence, contin ued closure of the

handles

11, 12 will result in further inward movement of the punches and thus a greater depth of identation in the connector barrel. A jam screw 132 is tightened against the upper end of set screw 130 to lock same in place. The set screw 130 may also be used as a means of adjusting the minimum depth of crimp indentation.

In order to prevent premature disengagement of the punches 32 from the connector conductor being crimped, as would occur if the handles were not fully closed before release, a ratchet mechanism is employed in the present crimping tool. Such ratchet mechanism includes a rack 135, having an arcuate front surface with notches 136 thereon, the lower end of which is pivotally positioned in a clevis 137 at the forward end of body member 13 by means of a pin 139. The notches 136 are engageable by a triangular pawl 140 formed on the outer surface of the enlarged end 21 portion of handle 12. Attached to the upper end of the rack 135, by means of pin 141, is one end of a rack positioning spring 142, the other end of which is fastened to the wall of clevis 137 in body member 13, by pin 144. The spring 142 is of the compression type and serves to urge rotation of the rack 135. The lower end of the front surface of such rack is sharply curved as indicated at 145 to form a forwardly extending protrusion 146. With the handles in the open position the pawl rides upon the sharply curved surface 145, thereby causing the rack to rotate to the counterclockwise position shown in FIGURE 2. With the rack 135 so disposed the spring 142 exerts a counterclockwise torque thereon, thus retaining the rack in a position such that the notches 136 will be engaged by the pawl 14.0 upon closure of the

handles

11, 12. And, since the lower surface of each of the notches 136 is essentiallyperpendicular to the curvature of the rack in the area of the notches, once the pawl 140 has engaged the lowermost notch, the

handles

11, 12 cannot be reopened without completing the crimping cycle. A few degrees before the

handles

11, 12 reach the fully closed position the raised portion 23 of handle 12 abuts the lower end of a small knob 147 which protrudes from the bottom surface of the rack 135. The knob 147 is located forward of pivot pin 139. The rack 135 will therefore be forcibly rotated to the clockwise position shown in FIGURE 3 when the handles are fully closed. It will be noted that the pawl 14%) is disengaged from notches 136. The spring 142 now exerts a clockwise torque on the rack 135, thereby retaining same in the clockwise position. Thus the handles Ill, 12 may be reopened without interference between pawl Mt? and rack 135. As the

handles

11, 12 approach the fully open position, the pawl 14% again contacts the curved surface 145, thereby causing the rack 135 to rotate counterclockwise into position for the next crimping cycle.

In order to prevent double crimping of a connection, as might occur if the

handles

11, 12 could be reclosed after being only partially opened, the ratchet mechanism is made double-acting by forming a plurality of transverse notches 148 immediately below pawl 14th on the surface of the enlarged end portion 21 of handle ll. The front surface of the forward protrusion 1% is ground fiat so that it will engage the notches 148. As may be observed from FIGURE 2, during closure of the handles Ill, 12 the forward protrusion 1% cannot interfere with notches 14-8, since the two are separated. However, at the fully closed position, the protrusion 14-6 is rotated forward and engages the lowermost of the notches M8 as shown in FIGURE 3. Since the lower surface of each of the notches M3 is approximately perpendicular to the curvature of the end portion 21 of handle 12, it may be readily seen that the handles ill, 12 must be fully opened before the crimping cycle can be repeated.

As thus described the present invention is characterized as an improved crimping tool for attaching a connector to the end of a conductor which includes means for locating the connector centrally between a set of punches ac tuated by the closure of a pair of pivotally interconnected handles, means for locating the connector in the proper axial relation to the punches, an overload release mechanism which permits continued closure of the handles without further punch movement when the resistance to crimping offered by the connector-conductor combination exceeds a certain predetermined amount, and a ratchet mechanism for preventing disengagement of the punches before a minimum crimping force has been applied.

Although only the preferred embodiment of the invention has been shown and described herein, it is not to be construed that the invention is limited thereto, as numerous modifications will be apparent to those skilled in the art; and the invention is to be given its broadest possible interpretation within the terms of the following claims.

r What we claim is:

1. A crimping tool adapted for attaching a connector to the end of a conductor and comprising in combination: a pair of handle members pivotally connected at one of their ends; punch means carried by one of said handle members for forming identifications in the barrel of said connector,

said punch means being adapted for radial movement in response to movement of said handle members;

locator means for positioning said connector in desired relation to said punch means,

said locator means including a plurality of connector locating elements for positioning connectors of dif ferent size diameters.

2. A crimping tool adapted for attaching a connector to the end of a conductor and comprising in combination:

at first handle member;

a second handle member;

said first and second handle members being pivotally interconnected at one of their ends;

a punch holder afiixed to said first handle member,

said first handle member and said punch holder having aligned apertures extending therethrough at the pivotal axis of said handle members for receiving said connector;

a set of punches carried by said punch holder for forming indentations in the barrel of said connector,

said punches be symmetrically disposed in radial directions about said connector receiving apertures and adapted for inward movement upon closure of said to the end of a conductor and comprising in combination:

first and second handle members,

said first and second handle members being pivotally interconnected at one of their ends,

a punch holder attached to said first handle member,

said first handle member and said punch holder hav ing aligned apertures extending therethrough at the pivotal axis of said handle members for receiving said connector, a set of punches carried by said punch holder for forming indentations in the barrel of said connector, said punches symmetrically disposed in radial directions about said connector receiving apertures and adapted for inward movement upon closure of said handle members,

locator means for positioning said connector in desired relation to said punches,

said locator means including a housing member fixedly attached to said first handle member adjacent said connector receiving apertures,

a rotatable, axially movable turret member disposed in said housing member,

a plurality of connector locating element means carried by said turret member for positioning connectors having different diameters,

each of said locating element means being limited to the maximum size connector the element means can receive and each element means being capable of receiving a diiferent maximum size connector,

each of said connector locating elements being capable of being individually aligned with said connector receiving apertures by rotating said turret member,

and means for retaining the one of said locating elements individually aligned with said connector receiving apparatus in abutment with said punch holder.

4. The crimping tool of claim 3 in which the individual locating element means are individually biased away from said turret member and into abutment with said punch holder when aligned with said connector receiving apertures.

5. A crimping tool adapted for attaching a connector to the end of a conductor comprising in combination:

a first handle member, a second handle member, said first and second handle members being pivotally interconnected at one of their ends, punch means carried by said first handle member for forming indentations in the barrel of said connector, said punch means being adapted for radial movement in response to movement of said handle members, means for permitting continued closure of said handle members without further movement of said punch means, double acting ratchet means associated with said handle members for preventing opening of said handle members until said handle members have been fully closed 9 and for preventing closure of said handle members until said handle members have been fully opened, said ratchet means including a pall carried by said second handle member,

a rack pivotally carried by said first handle member adjacent said pall having two normal positions,

said rack having a forwardly protruding lower end engageable by said pall when said handle members are in the fully opened position to rotate said rack from a first position to a second position wherein said rack will be engaged by said pall upon closure of said handles thereby to prevent reopening of said handle members until same have been fully closed,

a rack positioning spring to retain said rack in said first or second positions,

said rack being capable of engaging said second handle member when said handle members are in said closed position and thereby being moved to said first position,

said second handle member having a plurality of transverse notches adjacent said pall for engaging said lower end of said rack when in said first position for preventing closing of said handle members until said handle members are in a substantially 'fully opened position.

6. A crimping tool for securing a connector to a conductor inserted therein comprising a pair of pivotally conected handles each having enlarged portions at their pivotal ends,

a rotatable punch holder connected to one or" said handles and having punches mounted therein adapted for inward radial movement upon closing movement between said handles,

overload release means for permitting continued closing movement between said handles without further movement of. said punches when pressure exerted on said punches exceeds a predetermined limit,

said overload release means comprising a release plate secured to said punch holder and rotatable therewith,

resilient compression means engaging said release plate for rotation with one of said handles until force applied to said handle exceeds the force of said resilient compression means,

and means for selectively varying the force of said resilient compression means.

7. A crimping tool of claim 6 in which a stop means is utilized to prevent under crimping of said connector, said stop means being aflixed to said handles and being so positioned to contact said resilient compression means to prevent further movement of said release plate upon said release plate being moved a pre determined distance upon closure of said handles.

8. A crimping tool of claim 6 in which a stop means is utilized to prevent over crimping of said connector,

said stop means being adjustably positioned between said handles for selectively establishing a predetermined distance between said handles when said handles are in the fully closed position.

9. A crimping tool of claim 6 in which a pair of stop means are utilized to prevent under and over crimping of said connector,

one of said stop means being afiixed to said handles and being so positioned to contact said resilient compression means to prevent further movement of said release plate upon said release plate being moved a predetermined distance upon closure of said handles,

a second stop means being adjustably positioned between said handles for selectively establishing a predetermined distance between said handles when said handles are in the fully closed position.

It). A crimping tool adapted for attaching a connector to the end of a conductor and comprising in combination;

a first handle member,

a second handle member,

a punch holder attached to said first handle member,

said first handle member and said punch holder having aligned apertures extending therethrough at the pivotal axis of said handle members for receiving said connector,

a set of punches carried by said punch holder for forming indentations in the barrel of said connector upon closure of said handle members,

overload release means for permitting continued closing movement between said first and second handles without further movement of said punches when pressure exerted on said punches in crimping said connector exceeds a predetermined limit,

resilient compression means attached to said first handle member for engaging said release plate and rotating with said second handle until the force applied to said second handle in its movement toward said first handle exceeds the force of said resilient compression means,

means attached to said first handle member for selectively varying the force of said resilient compression means,

first stop means connected to said first handle member and being adjustably positioned to contact said resilient compression means for preventing further release of said overload release means beyond a given movement of said handle members toward each other,

and second stop means for adjustably varying the positive spacing between said first and second handle movements at the point of fully closed position.

11. A crimping tool adapted for attaching a connector to the end of a conductor and comprising in combination:

first and second handle members,

a punch holder attached to said first handle member,

said punches being symmetrically disposed in radial directions about said connector receiving apertures and adapted for inward movement upon closure of said handle members,

a rotatable, axially movable turret member disposed in said housing member,

a plurality of connector locating element means carried by said turret member for positioning connectors having different size diameters,

each of said locating element means being limited to the maximum size connector the element means can receive and each element means being capable of receiving a different maximum size connector,

and means for retaining one of said locating elements in a biased position away from said turret member ll and into abutment with said punch holder when aligned with said connector receiving apertures, double acting ratchet means associated with said handle members for preventing opening of said handle members until said handle members have been fully closed and for preventing closure of said handle members until said handle members have been fully opened, said ratchet means including a pall carried by said second handle member, a rack pivotally carried by said first handle member adjacent said pall having two normal positions, said rack having a forwardly protuding lower end engageable by said pall when said handle members are in the fully opened position to rotate said rack from a first position to a second position wherein said rack will be engaged by said pall upon closure of said handles thereby to prevent reopening of said handle members until same have been fully closed,

said second handle member having a plurality of transverse notches adjacent said pall for engaging said lower end of said rack when in said first position for preventing closing of said handle members until said handle members are in a substantially fully opened position,

overload release means for permitting continued closing movement between said handles without further movement or said punches when pressure ere erted on said punches exceeds a predetermined limit,

means for selectively varying the force of said resilient compression means,

stop means aflixed to said handles and being so positioned to contact said resilient compression means to prevent further movement of said release plate upon said release plate being moved a predetermined distance upon closure of said handles,

and a second stop means being adjustably positioned between said handles for selectively establishing a predetermined distance between said handles when said handles are in the fully closed position.

References (lited by the Examiner UNITED STATES PATENTS 1,072,742 9/ 13 Kortick.

2,079,498 5/37 Douglas.

2,524,343 10/50 Diener 74 470 2,572,013 10/51 Cushrnan 33-181 2,577,199 12/51 Klopner 74-475 2,753,742 7/56 Buchanan.

3,059,511 10/62 Morris.

WILLIAM FELDMAN, Primary Examiner.

WALTER A. SCHEEL, Examiner.

Claims

1. A CRIMPING TOOL ADAPTED FOR ATTACHING A CONNECTOR TO THE END OF A CONDUCTOR AND COMPRISING IN COMBINATION: A PAIR OF HANDLE MEMBERS PIVOTALLY CONNECTED AT ONE OF THEIR ENDS; PUNCH MEANS CARRIED BY ONE OF SAID HANDLE MEMBERS FOR FORMING IDENTIFICATIONS IN THE BARREL OF SAID CONNECTOR, SAID PUNCH MEANS BEING ADAPTED FOR RADIAL MOVEMENT IN RESPONSE TO MOVEMENT OF SAID HANDLE MEMBERS; LOCATOR MEANS FOR POSITIONING SAID CONNECTOR IN DESIRED RELATION TO SAID PUNCH MEANS, SAID LOCATOR MEANS INCLUDING A PLURALITY OF CONNECTOR LOCATING ELEMENTS FOR POSITIONING CONNECTORS OF DIFFERENT SIZE DIAMETERS.