US3743270A

US3743270A - Holding device for testing electrical connection

Info

Publication number: US3743270A
Application number: US00170552A
Authority: US
Inventors: H Kaufman
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-08-10
Filing date: 1971-08-10
Publication date: 1973-07-03
Anticipated expiration: 1990-07-03

Abstract

A holding device for testing electrical connections of the solderless wrapped type is described. The holding device comprises a base member having a plurality of aligned spaced projections, a lid member adapted to close over the projections and clamp terminals mounted thereon, and means for ejecting the terminals from the holder. The terminals are preferably provided in the form of a strip having perforations for engaging the projections and extending narrow portions for receiving the wrapped connections.

Description

United States Patent [191 Kaufman 3,743,270 [451 July 3,1973

d n a h e n. h mmm m in n a m m d .H o. M mow M w t m 1 M E o m 9 2 m 3 n 2 23 P. e. um G h m 7 C wi h T m Rm OEM FNYHW EN ae COKN I mu mw mm C I NRn T o Dcm LE O HEM- 4 M h. H.

[22] Filed: Aug. 10, 1971 Attorney-Jack Oisher [57] ABSTRACT,

. A holding device for testing electrical connections of [21] Appl. No.: 170,552

' 4 9 69 49, [52] 269/1 2 R03 1 4 the solderless wrapped type IS described. The holding device comprises a base member havin aligned spaced projections, a lid mem f ow m m m mmm w find 5 Md mm pa now- 5M 09b M close over the projections and clamp te mounted thereon, and means for ejecting the terminals from the holder. The terminals are preferably provided in the form of a strip having perforati the projections and extending narro 4 M4 7 10 38 k 3 mi S i 4 4M5 T 1/ g4 m 4 an 2 u h B "S C MC H mm MT WW e v u 6 mh d MR4 nm "85 T "S9 .1 6 N 0 U d MM [F 1111 8 6 55 5 rtl.

633,893 9/1899 Olin 1,782,615 11/1930 Hopwood........... 2,128,758 8/1938 Patented July 3, 1973 2 Sheets-Sheet 1 i k Q IN V1:':\"l'()1\ HARRY KAUFMAN 'ATTORNEY Patented July 3, 1973 2 SheetsSheet 2 V 1' TOR. R AUFMAN ATTORNEY HOLDING DEVICE FOR TESTING ELECTRICAL CONNECTION This invention relates to a holding device, and in particular to a device useful in the testing of a solderless, wrapped electrical wire connection. It also relates to a terminal strip for use with the holding device.

A technique for attaching or connecting a wire to a terminal is known as solderless wrapped connections. See Bell Laboratories Record, August 1955, pages 281-284. In this technique, a tool, generally power driven, is provided which fits over the terminal and which wraps any inserted wire tightly around the terminal. Often the wrapping tool also automatically strips the insulation from the wire end. Excessive wear of parts of the wrapping tool after prolonged use results in a too loosely wrapped wire, which may be unsatisfactory as an electrical connection, or in a too tightly wrapped wire, exhibiting poor mechanical properties. To determine when these conditions arise, indicating replacement or repair of worn parts of the wrapping tool or of the tool itself, it is conventional to test periodically the wrapped connection by so-called unwrap and pull tests. In the latter test, for instance, a device with attached pull-measuring gauge is used to pull the wrapped wire off a terminal, and the measured amount of force required to remove the wire is an indication of the operation of and the wear of the wrapping tool. To this end, it is desirable to mount terminals in a separate holding device while the wrapped wire connections are made and tested thereon.

My prior U.S. Pat. No. 3,312,460 describes a suitable holding device for separate terminals, employing an assembly of movable blocks with means for urging the blocks toward one another to clamp separate test terminals inserted between the blocks. While this construction operates very satisfactorily and has been in commercial use for several years, it does have certain limitations mainly involving the speed with which the operator can insert the terminals during a testing program.

One object of the invention is a holding device for testing solderless wrapped wire connections to plural terminals, which device is simple to operate and enables the testing to be performed rapidly and efficiently.

Another object of the invention is a holding device for receiving and tightly holding a strip of plural terminals while solderless, wrapped wire connections are applied thereto and tested, and enabling the test terminals to be quickly and easily removed.

Still a further object of the invention is a strip of plural terminals adapted for rapid assembly on a holding device and for rapid removal after testing of wrapped wire connections on the terminal ends.

These and other objects of the invention are achieved by joining together the plural terminals to form a unitary strip having apertures adapted for mounting on aligned projections extending above a base memberprovided with a lid for closing over the projections to clamp the terminal strip in place with the terminal ends projecting in a row ready to receive the wrapped wire connections. When the testing is completed, means are provided to eject the entire terminal strip from the base leaving it in position to receive a new terminal strip for further testing.

These and other features and advantages of this invention will become more apparent by reference to the following detailed description of several embodiments of the invention, taken in conjunction with the accompanying drawing, wherein:

FIG. I is a perspective view of one form of holding device in accordance with the invention with regions broken away to show interior details and with the lid open;

FIG. 2 is a partial cross-sectional view along the line 2--2 through the center of the device illustrated in FIG. I with the terminals removed;

FIG. 3 is a perspective view of the same device illustrated in FIG. l with the lid closed;

' FIG. 4a is a perspective view of another form of terminal strip for use with the device illustrated in the preceding figures;

FIG. 4b is a partial cross-sectional view through the center of FIG. 4a along the line 4b4b.

Referring to FIG. 1, there is illustrated therein one form of holding device in accordance with this invention specifically adapted for testing the pull-off force or the unwrapping of a solderless, wrapped wire connection on a terminal, to indicate the effectiveness of the wire wrapping tool. Experience has shown that, for best results, a single test performed on a single connection is inadequatefA large number of connections must be made and all be able to survive the pulloff or unwrap test to ensure a high degree of probability that subsequent connections madeby the same wrapping tool will be satisfactory. To this end, the testing device of the invention is adapted to hold a large number of terminals.

The holding device of my aforementioned prior pa tent requires that separate terminals be inserted one at I a time between the blocks before the blocks are clamped together. This is time-consuming and cumbersome.

The holding device of my present invention is adapted to receive a single strip comprising a plurality of joined terminals, with the result that the single strip can be assembled on the holding device in a single time-saving operation. Several suitable forms of such a strip are depicted in FIGS. 1 and 4a.

Referring back to FIG. 1 the holding device comprises a generally H-shaped solid support frame, of metal for example, with side supports 10, 11 joined together by a base member 12. The base member 12, which has an L-shaped cross-section, has a front flat upper surface 13 containing a plurality of upstanding parallel spaced projections 14 aligned in a continuous row and adapted to engage correspondingly spaced apertures in the terminal strip. The rear top surface 15 of the horizontal base member 12 is recessed for clearance by the terminal portions which extend above it as shown.

Resting on top of the front top surface 13 of the horizontal base member 12 is an ejecting or knock-off member comprising a flat metal strip-shaped member 17 having apertures 18 which receive the projections 14 with some clearance. The ejecting member 117 is rigidly connected by metal rods or screws 19, which pass through clearance holes 20 in the horizontal base 12, to s depending horizontal bar 21 which is spaced a distance below the horizontal base 12 corresponding to the height of the projections 14.

The terminal strip, shown in FIG. 1 and designated 40, comprises a punched-out flat metal strip consisting of plural sectionsof double-ended terminal or connecting ends 41 joined by a generally rectangular widened center portion 42 having a front surface 43 and a center aperture 44 for engaging the projections 14. The plural terminal sections are joined together by thin connecting pieces 45.

The terminal strip 40 seats on the ejecting member 17 with its aligned apertures 44 engaging the aligned projections 14. The strip can be clamped in that position by a closing lid 30, shown in open position in FIG. 1. The lid 30 is journalled 31 in opposite side supports 10, ill and is fitted at its right end with a small extension 32 to which a tight extension spring 33 is secured, the other end of which spring 33 is anchored 34 in the side support 10. A groove 35 receives the lid extension 32 in the open position. The lid 30 has a bottom surface 36 containing a series of holes 37 aligned with the projections 14. When the lid is pivoted forward to its closed position, shown in FIG. 3, the lid holes 37 receive the projections 14 and the lid biased tightly by the spring 33, clamps the terminal strip 40 between its surface 36 and the ejecting member 17 which is supported by the underlying horizontal base 12. A second groove 38 is provided in the side support to accommodate the lid extension 32 in its closed position. The width of the widened center portions 42 of the sections of the.

terminal strip 40 is chosen wider than the corresponding width dimension of the lid closing surface 36 and the ejecting member 17, so that the front edge 43 projects frontwardly beyond the lid 30 and beyond the front surfaces of the ejecting member 17, the base 12, and the ejecting bar 21, as shown in FIG. 3.

In the closed lid position, with the terminal strip 40 tightly clamped the wrapping tool may be brought up against the surface 43 of each of the terminal sections in turn and proceed to wrap a wire connection around the projecting terminal ends 41, one of which is shown at 50 in FIG. 3. The conventional tool construction is such as to wrap the wire up against the front surface 43. This leaves a clearance between the wrapped wire 50 at the shoulder 43 and the front of the lid 30, sufficient to accommodate the claw of a conventional pull gauge tool while measuring the force required to pull off the wrapped connections during the testing program. As usual, wires are wrapped around each of the protruding terminal ends, and the pull-off force measured on all to obtain a more reliable indication of the performance of the wrapping tool.

After completion of the testing, the lid 30 is lifted up and pivoted to its open position, using the front projecting edge 52 as a handle, and then the operator merely pushes the ejecting bar 21 upwardly. This pushes up the ejecting member 17 ejecting the used terminal strip 40 as a unit from the holder. When the ejecting bar 21 is released, it falls downward to its resting position rendering the holder ready to receive the ejected terminal strip reversed in position to expose the unused terminal side, or a new terminal strip 40 for further testing.

The side supports 10, 11 are provided with suitable clamps 53 for convenient mounting of the holder onto a suitable support surface, such as a work bench 54 the device can be readily adapted to receive a lesser or a greater number. Also other suitable means can be employed for mounting of the holding device to a suitable support surface, as for example at right angles.

FIG. ll has depicted a terminal strip of metal comprising plural sections joined together by metal connecting pieces. FIGS. 4a and 4b illustrate another embodiment employing metal end portions joined together by a plastic resin. As shown, the metal portions comprise straight wire sections with a generally rectangular cross section at their protruding ends 60, and with an enlarged center section 61 formed, for example, by flattening the center, to form opposite wings 62. A suitable plastic 63 is then molded around the centers of the plu ral wire sections properly arranged as shown. Any strong rigid plastic can be used for this purpose, for example, such as a polycarbonate. Simultaneously or thereafter spaced holes 64 are formed in the plastic between the embedded terminal sections. The wings 62 improve anchoring of the wire sections and prevent turning in the molded plastic. The spacing and size of the holes 64 correspond to that of the holes 44 in the terminal strip 40 so that the holes 64 can engage the projections 14. The position of the front surface 65 of the resin 63 corresponds to the position of the edge surface 43 of the strip 40 and serves the same purpose. The wire sections 60 can be of relatively fine wire, such as, for example, number 30 gauge.

While I have described my invention in connection with specific embodiments and applications, other modifications thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is: v

1. A holding device for testing wrapped wire connections comprising a support member having a plurality of upwardly extending spaced projections aligned in a row and adapted to receive and engage an apertured strip of terminals, lid means adapted to close over the support member and having portions for receiving the upwardly extending projections and clamping the terminal strip between it and the support, and means on the support for ejecting the terminal strip after opening of the lid means.

2. A holding device for testing wrapped wire connections as set forth in claim 1 wherein means are provided for biasing the lid in its closed position.

3. A holding device as set forth in claim 2 wherein the support comprises vertical side support members supporting a horizontal base member comprising the upwardly extending projections, means journalling the lid on the side support members, and the lid biasing means include a spring which also biases the lid in its open position, said lid receiving portions-comprising a row of apertures aligned with and adapted to receive the row of upwardly extending projections.

4. A holding device as set forth in claim 1 wherein the terminal strip ejecting means comprises a horizontal member having a row'of apertures and mounted on the support member with its apertures loosely receiving the upwardly extending projections and adapted for vertical movement to lift the terminal strip up and over the projections.

5. A holding device as setforth in claim 4 wherein means are provided below the upwardly extending proapertured strip of terminals comprises plural thin metal ends projecting frontwardly from a front surface thereof, and the lid and support are dimensioned such that the front surface of the terminal strip projects frontwardly beyond the lid and support when the terminal strip is clamped in the device.

Claims

3. A holding device as set forth in claim 2 wherein the support comprises vertical side support members supporting a horizontal base member comprising the upwardly extending projections, means journalling the lid on the side support members, and the lid biasing means include a spring which also biases the lid in its open position, said lid receiving portions comprising a row of apertures aligned with and adapted to receive the row of upwardly extending projections.

4. A holding device as set forth in claim 1 wherein the terminal strip ejecting means comprises a horizontal member having a row of apertures and mounted on the support member with its apertures loosely receiving the upwardly extending projections and adapted for vertical movement to lift the terminal strip up and over the projections.

5. A holding device as set forth in claim 4 wherein means are provided below the upwardly extending projections support and connected to the ejecting means for operating same.

6. A holding device as set forth in claim 5 wherein the operating means comprises a horizontal bar rigidly connected to the ejecting means horizontal member through apertures in the support and being spaced below the latter.

7. A holding device as set forth in claim 1 wherein the apertured strip of terminals comprises plural thin metal ends projecting frontwardly from a front surface thereof, and the lid and support are dimensioned such that the front surface of the terminal strip projects frontwardly beyond the lid and support when the terminal strip is clamped in the device.