US3432924A

US3432924A - Method of crimping a sleeve connector

Info

Publication number: US3432924A
Application number: US274869A
Authority: US
Inventors: Charles H Trimble
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1963-04-22
Filing date: 1963-04-22
Publication date: 1969-03-18
Anticipated expiration: 1986-03-18

Description

March 18, 1969 c. H. TRIMBLE METHOD OF CRIMPING A SLEEVE CONNECTOR Sheet of 2 Filed April 22, 1963 INVENTOR ATTORNEY March 18, 1969 c. H. TRIMBLE 3,432,924

METHOD OF CRIMPING A SLEEVE CONNECTOR Filed April 22, 1965 Sheet 2 of 2 TF T-T 1 Pi E I W V! R I .5.

wz dw ATTORNEY United States Patent 3 Claims ABSTRACT OF THE DISCLOSURE In crimping a sleeve connector onto the end of a pair of bare metallic leads, the leads are inserted into opposite ends of the connector after which the connector is sequentially crimped, first at innermost points located adjacent to the center of the connector and then at points spaced from the center. Crimping of the innermost points results in displacement of the lead material toward the center of the connector to improve contact between the leads. During the crimping operation, the material of the connector is confined to flow longitudinally from the points of crimping outward toward the ends of the connector.

This invention relates to a method of crimping a sleeve connector and more particularly to a method of joining leads within a sequentially crimped sleeve connector.

Electrical leads may be secured together by crimping a solderless sleeve connector about the leads. In securing leads in this manner, it is important that a permanent set be achieved between the connector and the leads; that is, the leads and connector should be distorted into locking engagement. This requires the use of a die or other similar instrument to press and deform the connector and leads. When the connector and leads are so pressed, the metal of the connector and leads tends to flow longitudinally from the point of pressing.

A prior art apparatus for joining leads within a sleeve connector provides mating dies having spaced crimping jaws for simultaneously crimping the connector at several places. The use of such apparatus in some applications produces unsatisfactory results; that is, cracked connectors, weak connections, or the like.

In making this invention, it has been discovered that these unsatisfactory results are caused by stresses set up in the connector. These stresses result from the flow of the material of the connector being impeded when the connector is simultaneously crimped at several places.

It has also been discovered in making this invention, that if a connector having leads therein to be joined together is crimped at or near each end, the material of the connector is forced to flow longitudinally from the ends of the connector toward the center. When the connector is subsequently crimped at the junction of the leads or crimped on each side of the junction, a fracture often results due to the stresses at the center portion of the connector.

When a lead is severed with cutting pliers or other like shearing instruments, a wedge-shaped or generally uneven lead end results. If two such leads are placed end to end within a sleeve connector, the ends of the leads do not make good surface to surface contact and a poor electrical connection results,

An object of this invention is to provide a new and improved method of crimping a sleeve connector.

Another object is to provide a method of joining leads within a sequentially crimped sleeve connector.

Another object is to provide a method of joining leads within a sequentially crimped sleeve connector wherein detrimental longitudinal stress in the connector is eliminated.

Another object is to provide a method of joining leads within a sequentially crimped sleeve connector and for eliminating longitudinal stress in the connector by sequentially crimping the connector at successive spaced points proceeding from the junction of the leads toward the extremities of the connector.

Another object is to provide a method of sequentially crimping a sleeve connector about abutting leads simultaneously on each side of the junction of the leads, and then simultaneously near the ends of the connector.

A further object is to provide a method of crimping a sleeve connector about abutting unevenly severed leads so that the leads are forced together to make good surface to surface contact.

With these and other objects in view, an apparatus illustrating certain features of the invention may include a pair of opposed carriers having facilities for gripping and crimping a sleeve connector, for example, a plurality of gripping members may be mounted on each carrier and interspaced between a plurality of crimping elements. Facilities are provided for first moving the gripping members to hold a sleeve connector containing abutting leads against displacement; then actuating certain crimping elements to crimp the connector on each side of the junction of the leads; and then actuating certain other crimping elements to crimp the connector at its ends.

A method illustrative of the practice of the invention may include the following sequence of steps, holding a sleeve connector containing leads against displacement; crimping the connector simultaneously on each side of the junction of the leads; and crimping the connector at points separated by and spaced from the junction of the leads.

Other objects and advantages of the invention will become apparent from a consideration of the detailed spec ification and the accompanying drawings, wherein:

FIG. 1 is a side elevation view, partially broken away, of an apparatus for crimping a sleeve connector showing a pair of carriers in the closed position in accordance with the principles of the invention;

FIG. 2 is a plan view of FIG. 1 showing the pair of carriers in the closed position;

FIG. 3 is a detailed enlarged plan view of one of the carriers of FIG. 2;

FIG. 4 is a vertical section view, taken along line 44 of FIG. 1, showing the mounting arrangement of a plurality of cam followers on each of the carriers;

FIG. 5 -is a perspective view showing a plurality of straight cams at different horizontal levels mounted on a slide for engaging the cam followers;

FIG. 6 is a view showing a sleeve connector, containing abutting leads, held against displacement by opposed gripping members;

FIG. 7 is a view showing the sleeve connector of FIG. 6 after opposed inner pairs of crimping elements have acted upon the connector and leads;

FIG. 8 is a view showing the sleeve connector of FIG. 7 after opposed outer pairs of crimping elements have acted upon the connector and leads; and

FIG. 9 is a cross section view taken along the line 99 of FIG. 8 showing a cross section of the crimped connector and lead.

Referring to FIG. 6, there is shown a malleable or deformable sleeve connector 10 containing bare metallic abutting leads 11 and 12. The connector may be metal, plastic, or other suitably deformable material, and is of uniform cross section. The leads are representative of a class of members which may be joined in a sleeve connector, such as electrical wires, pluralities of wires, cables, strands, or the like. A junction 13 of abutting leads 11 and 12 is located approximately at the center of connector 10.

As seen in FIG. 6, the abutting ends of leads 11 and 12 are wedge-shaped as a result of being severed by shearing edges of cutting pliers or other common cutting implement. Whatever the means used to sever the leads, it is to be expected that a wedge-shaped, pointed, jagged, or othenwise uneven lead end will result.

Referring to FIG. 1, a pair of opposed identical carriers 16 are shown in the closed position. Since the carriers are identical, only one carrier will be described. Each carrier 16 is pivotally mounted about a shaft 17 secured to a frame 18. A compression spring 20 urges carriers 16 to a normally separated position. A cam assembly 19 and a rack 21 are mounted on a slide 22. Slide 22 is mounted for vertical movement within the frame and such movement may be accommodated in any suitable manner, for example, trackways may be provided as shown in FIG. 2.

Rack 21 is provided with teeth which engage a gear 23 which in turn engages a gear 24. A handle 26 is attached to gear 24 which is mounted for pivotal movement about a shaft 27 secured to frame 18. Gear 24 engages a gear 28 which, in turn, engages a gear 29 which engages a rack 31. Rack 31 and a cam assembly 32 are mounted on a slide 33. Rack 31, cam assembly 32, and slide 33 are identical to rack 21, cam assembly 19, and slide 22.

Referring to FIGS. 1 and 2, and particularly to FIG. 3, a plurality of gripping members or jaws 40-44 are fixedly mounted to carrier 16. A plurality of crimping elements or jaws 46-49 are slidably mounted within carrier 16 and are interspaced between gripping jaws 40-44. Crimping

jaws

47 and 48 comprise an inner pair of crimping jaws and crimping

jaws

46 and 49 comprise an outer pair of crimping aws.

Crimping jaws 46-49 are engaged by slide pins 51-54 which, in turn, engage blocks 56-58 of cam followers 61-63. Block 62 engages two slide pins 52 and 53. Each cam follower 61-63 includes a roller 64 rotatably mounted about a shaft 66 mounted in each block 56-58 which is secured to an arm 67 (FIGS. 1 and 4). Each of cam followers 61-63 and its arm 67 are pivotally mounted about a shaft 68 (FIGS. 1 and 4) secured to carrier 16.

Cam followers

71 and 72 are secured to carrier 16 and include blocks 73 and 74, respectively. Each of these blocks has a roller 64 mounted for rotatable movement about shaft 66 mounted in the blocks.

Referring to FIGS. 1 and 2, and particularly to FIG. 5, cam assembly 19 is mounted on slide 22. Cam assembly 19 includes a plurality of flat angularly disposed, cam surfaces 81-85 mounted adjacent to one another on the cam assembly. Cam surfaces 81 and 85 are mounted at a common high horizontal level, cam surface 83 is mounted at an intermediate horizontal level, and cam surfaces 82 and 84 are mounted at a common low horizontal level. It is noted that each cam surface "81-85 itself extends from an upper horizontal level to a lower horizontal level, for example, cam surface 81 extends from an upper horizontal level 86 to a lower horizontal level 87.

OPERATION Referring to FIGS. 1, 2, and 3, the starting position for operating the apparatus is attained when handle 26 is revolved clockwise so that slides 22 and 33 and

cam assemblies

19 and 32 are at their lowermost position and rollers 64 engage the uppermost portion 89 of the cam assemblies. Compression spring 20 acts to urge carriers 16 to a normally separated position.

Sleeve connector (FIG. 6) is placed between the opposed crimping jaws 46-49 and gripping jaws 40-44. Handle 26 is partially revolved counterclockwise to operate

gears

23, 24, 28, and 29, and racks 21 and 31 to raise

slides

22 and 33 and cam assemblies 19' and 32. Cam surfaces 81 and 85 engage rollers 64 of

cam followers

71 and 72 to move the opposed carriers 16 and opposed gripping jaws 40-44 into engagement with the connector 10 to hold the connector against displacement. Leads 11 and 12 are placed into abutting relation within connector 10 to form a junction 13 at approximately the center of the connector (FIG. 6).

Handle 26 is further revolved counterclockwise to raise slides 21 and 31 further. Cam surfaces 83 engage rollers 64 of cam followers 62 to drive slide pins 52 and 53 and inner crimping

jaws

47 and 48 to crimp connector 11) and leads 11 and 12 at opposed pairs of inner points.

Referring to FIG. 7, inner pairs of opposed crimping

jaws

47 and 48 are shown after they have been driven to crimp connector 10 into leads 11 and 12. During this operation, gripping jaws 42 confine connector 10 so that the displaced metal of leads 11 and 12 is forced to flow toward the junction 13. Thus, the leads which were formerly wedge-shaped (FIG. 6) now make good surface to surface contact at junction 13. Also, gripping jaws 41- 43 and crimping

jaws

47 and 48 constrain the connector 11) so that the displaced metal of the connector is forced to How longitudinally from the points of crimping outwardly toward the ends of the connector.

Handle 26 is revolved counterclockwise still further to raise

slides

22 and 33. Cam surfaces 82 and 84 engage rollers 64 of

cam followers

61 and 63 to drive slide pins 51 and 54 and outer crimping

jaws

46 and 49 to crimp connector 10 and leads 11 and 12 at opposed pairs of outer points.

Referring to FIG. 8, the crimping

jaws

46 and 49 are shown after they have been driven to crimp connector 10 into leads 11 and 12. Crimping

jaws

47 and 48, and gripping jaws 41-4-3, prevent the material of connector 10 from flowing toward the center of the connector. As a result, the displaced material of connector 10 is forced to flow longitudinally from the points of crimping by crimping

jaws

46 and 49 outwardly toward the ends of the connector. Also, the displaced metal of leads 11 and 12 cannot flow toward the junction 13 of the leads due to the constraining action of all of the gripping and crimping jaws. As a result, the displaced metal of the leads is forced to flow away from junction 13.

Referring to FIG. 9, a cross section view is shown taken through a reduced portion of crimped connector 18 and lead 12. Crimping jaws 48 are shown engaging a reduced portion 91 of the connector which is concentric about a reduced portion 92 of the lead.

It is noted, with respect to FIGS. 6-9, that connector 10 and leads 11 and 12 are deformed into interlocking engagement at the points of crimping; and also that connector 10 is constrained by all gripping members -43 during the crimping operations so that the displaced metal of the connector is forced to flow outward toward the ends thereof.

From the foregoing, it will be understood that a method of practicing the invention includes the following steps: A pair of leads 11 and 12 are placed from each end into a sleeve connector 10 so that the leads attain an abutting relationship at a junction 13 approximately at the center of the connector (FIG. 6).

Connector 10 is simultaneously crimped at opposed pairs of points on either side of junction 13 of leads 11 and 12 (FIG. 7). Connector 10 is then crimped at opposed pairs of points separated by and spaced from the inner pair of opposed points (FIG. 8).

Apparatus other than the apparatus of the instant invention may be used to practice the method of the invention, for example, hand-operated crimping pliers similar to those shown in U.S. Patent 376,493 may be used. These pliers have a pair of opposed crimping elements mounted on each jaw. A first pair of these pliers having a pair of crimping elements separated by a first given distance on each jaw may be used to simultaneously crimp a sleeve connector at a pair of opposed inner points near the center of the connector. A second pair of pliers having a pair of crimping elements separated on each jaw further apart then the crimping elements of the first pair of pliers may then be used to simultaneoulsy crimp 5 the connector at a pair of opposed outer points separated by and spaced from the inner pair of points.

It will be understood that the apparatus of the invention could easily be arranged to operate automatically and that the apparatus and method of the invention described are merely illustrative of its principles and other embodiments may be devised without departing from the scope of the invention. What is claimed is: 1. A method of connecting a pair of leads which comprises the steps of inserting the ends of the leads into a sleeve connector to bring the ends of the leads into abutting relation,

crimping the connector simultaneously at points removed from and on both sides of the juncture of the abutting leads to displace the metal of the leads and force the ends of the leads together while confining the outer surface of the connector surrounding the ends of the leads to constrain the material of the connector to flow longitudinally outward from the points of crimping, and

then crimping the connector at second points spaced outwardly from and separated by the first crimps to force the displaced material of the connector to flow longitudinally outward toward the ends of the connector while confining the outer surface of the connector between the second points to constrain the material of the connector to flow longitudinally outward from said second points.

2. A method of joining leads within a sleeve connector, the leads being in abutting relation therein, comprising the steps of crimping the connetcor simultaneously at a first pair of spaced points on both sides of the junction of the leads while confining the outer surface of the connector between the first pair of points to force the crimped material of the connector to flow longitudinally toward the ends of the connector, and

Cir

crimping the connector at a second pair of points spaced 40 outwardly from and separated by the first pair of points while confining the outer surface of the connector between the second pair of points to force the crimped material of the connector to flow longitudinally toward the ends of the connector. 3. A method of joining leads within a sleeve connector, the leads being in abutting relation therein, comprising the steps of crimping the connector simultaneously at a first pair of spaced points on opposite sides of the junction of the abutting leads to displace the metal of the leads and force the ends of the leads together while confining the outer surface of the connector between the first pair of points to force the crimped material of the connector to flow longitudinally toward the ends of the connector, and crimping the conector at a second pair of points spaced outwardly from and on opposite sides of the first pair of points to displace the metal of the leads longitudinally away from the junction of the leads while confining the outer surface of the connector between the second pair of points to force the crimped material of the connector to flow longitudinally toward the ends of the connector.

References Cited UNITED STATES PATENTS 1,834,436 12/ 193- 1 Straley 29-517 X 2,375,480 5/1945 Lee.

2,375,741 5/1945 Dibner 29-517 2,587,095 2/ 1952 Bergan.

2,622,314 12/1952 Bergan 29-517 2,799,721 7/ 1957 Floyd 29-630 2,601,462 6/1952 Streader 29-5119 2,272,244 2/ 1942 Klein 29-517 2,639,754 5/1953 Macy 153-1 3,055,412 9/1962 Dibner 153-1 CHARLIE T. MOON, Primary Examiner.

US. Cl. X.'R. 29-517; 174-84; 287-109