US3711921A

US3711921A - Terminating tool for wires

Info

Publication number: US3711921A
Application number: US00179723A
Authority: US
Inventors: G Debortoli; H Lukas
Original assignee: Northern Electric Co Ltd
Current assignee: Nortel Networks Ltd
Priority date: 1971-09-13
Filing date: 1971-09-13
Publication date: 1973-01-23
Anticipated expiration: 1990-01-23

Abstract

Terminating tool for thin wires, for example as used in wiring terminal blocks in telephone systems, in which the wire is sheared by the cooperative relative sliding movement of two members. A first member is attached to a handle and the second member projects slightly from the bottom of the first member. A wire is positioned in a slot in the lower end of the second member and the wire is then pushed down between terminal clips. On meeting the surface of the terminal block the second member slides relative to the first member and shears the wire. Damage to the terminal block is avoided and the cut wire does not become imbedded in the terminal block - common occurrences with conventional tools which use the terminal block as an anvil to cut the wire.

Description

United States Patent 91 Debortoli et al.

m1 -3,7'1 1,921 [451' Jan. 23, 1973 TERMINATING TOOL FOR WIRES [73] Assignee: Northern Electric Company Limited,

Montreal, Quebec, Canada [22] Filed: Sept. 13, 1971 [21] Appl. No.: 179,723

[52] US. Cl. ..29/203 H [51] Int. Cl. ..H0 lr 43/00, H05k 13/04 [58] Field ol'search ..29/203 H, 203 RC, 203 HM,

[56] Reterences Cited UNITED STATES PATENTS 3,604,092 9/1971 Knickerbocker ..29/203 H Primary Examiner-Thomas l-l. Eager AnorneySidney T. Jelly [5 7] ABSTRACT Terminating tool for thin wires, for example as used in wiring terminal blocks in telephone systems, in which the wire is sheared by the cooperative relative sliding movement of two members. A first member is attached to a handle and the second member projects slightly from the bottom of the first member. A wire is positioned in a slot in the lower end of the second member and the wire is then pushed down between terminal clips. On meeting the surface of the terminal block the second member slides relative to the first member and shears the wire. Damage to the terminal block is avoided and the cut wire does not become imbedded in the terminal block common occurrences with conventional tools which use the terminal block as an anvil to cut the wire.

10 Claims, 1 1 Drawing Figures PATENIEUJAH 23 1915 13,71 1. 921

sum 1 0r 4 TERMINATING TOOL FOR WIRES The invention relates to terminating tools for terminating conductors on terminal blocks having terminal clips of the insulation slicing type.

With terminal clips of the insulation slicing type, a wire conductor is terminated by forcing the wire down between the pair of clips forming a terminal, the clips having edges which slice through the insulation to make contact with the conductor.

The present tool used for terminating conductors comprises a cutting edge at its lower extremity which cuts the wire by using the terminal block as an anvil. The pressure required to cut the wire will depend upon the sharpness of the cutting edge. As it becomes more difficult to cut the wire the user often resorts to hitting the tool, either with the hand or with some other item. This is liable to damage the block. Alternatively the user may pull the wire against the cutting edge in an attempt to break the wire and this can cause displacement of the wire in the terminal.

A further disadvantage is that as the terminal block acts as an anvil for the cutting edge it must be of material which can withstand this treatment. There is therefore some restriction as to material which can be used. Even with careful selection of material, a groove is formed in the block after several wire cut-offs. It is desired that considerable number of reconnections be possible but the deformation of the block by the cutting edge restricts the number of reconnections. Deformation of the block material can cause the terminal clip to become tight in its slot. Terminal clips are given a limited amount of free movement so that tracing of connections can be made readily by pulling lightly on the conductor and seeing which terminal moves. By preventing free movement of the terminal clip tracing of connections becomes difficult.

Another difficulty arises when it is desired to remove a wire from a terminal clip. As the wire is cut off by pressure against the block material, the cut end sits tight against the block, and can be pressed into the block when a groove has been formed by the cutting edge.

A tool in accordance with the present invention has a retractable cutting member which cuts the wire by a shearing action between the cutting member and a seating member. The seating member is used to push the conductor into the terminal clip. The cutting member is normally held in a retracted position by a spring and is extended for insertion of a wire conductor. Initial movement of the tool on a terminal clip forces the wire down between the two clip members, while continued movement causes relative sliding between the cutting member and the seating member shearing the wire.

The invention will be readily understood by the following description of one form of tool, by way of example, in conjunction with the accompanying drawings, in which:

FIG. I is a front view of a complete tool, in accordance with the invention;

FIG. 2 is a cross-section on the line llll of FIG. 1;

FIG. 3 is a front view of the seating member;

FIGS. 4 and 5 are top and bottom end views respectively of the seating member;

FIG. 6 is a cross-section of the line VI-Vl of FIG. 3;

FIG. 7 is a front view of the cutting member;

FIG. 8 is a side view of the cutting member;

FIG. 9 is a view of the lower part of a tool in use;

FIG. 10 is a cross-section of the upper portion of a tool similar to FIG. 1, illustrating a modification embodying a wire removal tool; and

FIG. 11 is a view of the tool of FIG. 10, showing the wire removal tool extended.

As seen in FIGS. 1 and 2 the tool comprises a handle portion 10 formed from two

hollow halves

11 and 12. The

halves

11 and 12 are held together at the top, or hand engaging, portion by a rivet 13, or other suitable fastener, situated in recesses 14. At the lower end of the handle, the two halves 1 1 and 12 define an enclosed slot or channel 15 in which are positioned a seating member 16 and a cutting member 17. The two halves l1 and 12 are also held together at the lower end by a bolt and nut 18, the bolt also passing through the seating member 16 and cutting member 17.

FIGS. 3, 4, 5 and 6 illustrate the seating member 16 to a larger scale and in more detail. The seating member is elongated in form having a bottom edge 20 at its lower end and an upper end 21. The member is generally of rectangular cross-section of varying form along its length. For a major portion of its length it is of a width equal to the width of the slot or channel 15 (FIG. 2). At the lower end there is a portion 22 of slightly reduced width. On each side of the portion 22, and extending partway up the remainder of the seating member, is formed a rib 23. The ribs 23 are on one face of the seating member only and have small flanges 24 facing toward each other. The ribs 23 and flanges 24 defined a guiding channel within which slides the cutting member 17. It will be seen that the distance between the ribs 23 at the lower portion 22 is slightly less than the width between the ribs 23 nearer the upper end. This variation cooperates with a similar variation in width of the cutting member, as will be described later, to limit downward movement of the cutting member 16.

Formed in the lower portion of the seating member and extending upwardly from the bottom edge 20, is a slot 25. The slot 25 is of a length sufficient to accept the terminal clips and is seen more readily in FIG. 9. Formed in the bottom end of the seating member is a groove 26 extending normal to the slot 25. Approximately midway along the length of the member is a hole 27 through which passes the bolt 28 (FIG. 2). Bolt 18 holds the seating member firmly and fixedly in the slot or channel 15 in the handle portion 10 (FIG. 1). Toward the upper end 21 of the seating member is formed a groove 28. This is for reception of a compression spring, indicated at 29 in FIG. 2. Spring 29 cooperates with the cutting member 17 as will be described.

FIGS. 7 and 8 illustrate the cutting member 17, which is of T formation, as shown. The cross-bar portion 35 has pads 36 formed on each end and as seen in FIG. 1 these pads project from each side of the handle 10 and can be engaged by a thumb of the user. The stem portion 37 has a bottom edge 38 and spaced a short distance up from the bottom edge is a slot 39 extending in from one edge of the stem portion. Theslot 39 is inclined downwardly from the edge, as shown. As will be explained, slot 39 receives a wire and the lower edge of the slot cooperates with the bottom edge 20 of the seating member to shear the wire.

An elongated slot 40 permits passage of bolt 18, while permitting sliding of the cutting member 17 in the channel in the seating member 16. The lower portion of the stem 37 is slightly reduced in width and fits in the channel defined by the ribs 23 on the seating member, the cutting member retained in the channel by the flanges 24. The upper portion of the stem 37 is greater than the width of the lower portion, a step 41 formed at the junction between the upper and lower portions. The step 41 engages with the upper ends of the ribs 23 on the seating member and limits downward movement of the cutting member. At the top of the member, at midpoint of the crossbar portion 35 is formed a small protrusion 42. The protrusion 42 engages the upper end of the spring 29. Normally the spring urges the cutting member upward, the spring acting on the protrusion 42 on the cutting member 17 and on the lower end 43 of the groove 28 in the seating member 16.

Use of the tool will be understood from FIG. 9. To position and cut a wire, the cutting member 17 is first pushed down, by pressing on one of the pads 36 with the thumb. This extends the lower end of the cutting member below the lower end of the seating member, against the action of the spring at 29. The slot 39 in the lower portion of the cutting member is uncovered. A wire 50 is positioned in the slot 39 and the cutting member allowed to retract. The wire is then gripped between the bottom edge of the slot 39 and the bottom edge of the seating member the wire fitting the groove 26.

The seating member is then pushed over an opposed pair of terminal clips 51, in such a position that the wire is aligned with a gap 52 between the clips, the clips in the slot 25 in the seating member. The tool is then pushed down, by hand, pushing the wire 50 down between the clips 51. The wire is pushed down to the bottom between the clips, the clips cutting through the insulation of the wire to make contact with the conductor. As the wire approaches the bottom of the clips, the lower end 38 of the cutting member engages the upper surface 53 of the terminal block 54. Further movement of the tool pushes the cutting member upwards relative to the seating member and the wire is sheared. Further movement of the seating member occurs after the wire is sheared, the wire finally being positioned at the bottom of the gap between two clips, as seen at 55 in FIG. 9.

Thus, although the tool relies on contact between the bottom end of the cutting member 17 with the block 54, for shearing of the wire, the bottom end of the cutting member is flat and does not cut into, or distort, the surface 53 of the block 54. Therefore the block can be of material selected for its efficiency and effectiveness as a terminal block without the restriction of needing to be able to resist deformation and also acting as an anvil for the cutting edge as with the conventional tool. The provision of the groove 26 also ensures that the wire is not forced down against the surface 53 of the block and also ensures correct alignment of the wire with the gap 52. By making groove 26 deeper than the diameter of the wire, it can be ensured that a gap will be left between the wire and the surface 53 of the block.

The clips 51 remain free in that they retain a degree of movement enabling connections to be traced by pulling on a conductor and seeing which terminal clips move. This assists in tracing faults and also makes disconnection quicker and easier.

A wire removal tool can be embodied with the terminating tool extending the usefulness of the tool. Conveniently a wire removal tool can be housed in the handle 10, being extended for use. Such an arrangement is illustrated in FIGS. 10 and 11.

As seen in FIG. 10, the handle is modified, as compared with the tool of FIGS. 1 and 2, by the use of a hollow bush 60, which has an enlarged head 61 at one end and internally threaded portion 62 at the other end. A screw 63 screws into the threaded portion 62 and the two parts -bush 60 and screw 63 hold the two handle

halves

11 and 12 together. The hollow bush 60 also acts as a pivotal mounting for a removal tool 65. A slot 66 is formed in the enlarged head 61 of the bush 60 and the wire removal tool is pivotally mounted in this slot by means of a pin 67, passing through the end 68 of the tool 65. The end 68 has two opposed indents 69 and mounted in the bore of the hollow bush is a ball 70 spring loaded by a compression spring 71.

In itsretracted position the tool 65 lies in the groove 72 formed in the handle half 1 1, being held in this position by engagement of the ball 70 with the appropriate indent 69. A depression 73 is formed in the handle half 11 so that the tool 65 can readily be extracted by the operator. In its extended position the tool is held in this position by engagement of the ball 70 with the other indent 69. The tool 65 in its extended position is shown in FIG. 11. The end of the tool remote from the pivotal mounting is provided with a hook 75 which can be inserted under the wire to be recovered. I

The terminal tool according to the invention provides several advantages. Among the advantages are:

a. the amount of pressure required to shear the wire is approximately 30% less than the conventional tool;

b. the terminal block surface is not damage, or distorted;

c. the number of wire cuts per terminal is unlimited damage to or distortion of the terminal block limits the number of wire cuts with conventional tools;

d. the terminal remains floating in its mounting in the block as the terminated wire is clear of the block surface; permitting easy terminal identification during 50 jumper tracing operations;

e. the conductor wire can be removed quickly and easily as there is sufficient clearance between the wire and the terminal block surface for insertion of the wire removal tool,

f. the cutting blade does not require sharpening;

g. the cutting blade remains protected when not in use;

h. the tool can be used for both seating and shearing a wire, or only seating a wire;

i. the same high quality of connection is attained independent of the user.

The wire removal tool. if provided, provides further advantages, as follows:

a. the handle of basic terminating tool ensures a positive grip;

b. only one tool is required for two distinct operations seating of a wire and removal of a wire;

c. the removal tool is part of the terminating tool and is not easily misplaced;

d. access time to locate the wire removal tool is decreased.

What is claimed is:

1. A terminal tool for terminating conductors on terminal blocks having terminal clips in opposed pairs, comprising:

a seating member for positioning over a pair of terminal clips, and including a bottom edge for pushing the conductor down between the terminal clips;

a cutting member slidable in face-to-face contact with said seating member normal to said bottom edge, and including a laterally extending slot adjacent its lower end, said slot arranged to be exposed beyond said bottom edge of the seating member in an extended position and shielded by the seating member in a retracted position;

a spring urging the cutting member to the retracted position; and

means for urging the cutting member to the extended position; so constructed and arranged that a conductor wire can be inserted in the laterally extending slot in the cutting member when extended, the lower end of the cutting member engaging with the terminal block to cause sliding of the cutting member relative to the seating member, to shear the conductor wire, said seating member pushing the conductor wire between the terminal clips.

2. A terminating tool as claimed in claim 1, said seating tool having opposed formations on one face to form a channel for the reception of said cutting member.

3. A terminating tool as claimed in claim 2, said formations including opposed flanges for engagement over the side edges of the cutting member to hold said cutting member in face-to-face contact with said seating member.

4. A terminal tool as claimed in claim 1, including a groove in the bottom edge of the seating member, said groove extending normal to the direction of the slot in the cutting member, for positioning the conductor wire on said bottom edge.

5. A terminating tool as claimed in claim 1 including a slot extending transversely of said seating member at the lower end thereof for positioning over said terminal clips, said slot extending in a plane parallel to the plane of said laterally extending slot in said cutting member.

6. A terminating tool as claimed in claim 1 said too] including a handle portion two opposed halves, said halves forming a channel for the reception of said seating member and said cutting member.

7. A terminating tool as claimed in claim 6 said seating member fixedly connected to said handle portion.

8. A terminating tool as claimed in claim 6 including a wire removal tool attached to said handle portion.

9. A terminating tool as claimed in claim 8, said wire removal tool pivotally attached to said handle portion, and adapted to pivot from a retracted position enclosed in a groove in the handle portion to an extended position.

10. A terminating tool as claimed in claim 9, including spring loaded means for retaining said wire removal tool in each of said rstra cteg an d e ttended positions.

Claims

1. A terminal tool for terminating conductors on terminal blocks having terminal clips in opposed pairs, comprising: a seating member for positioning over a pair of terminal clips, and including a bottom edge for pushing the conductor down between the terminal clips; a cutting member slidable in face-to-face contact with said seating member normal to said bottom edge, and including a laterally extending slot adjacent its lower end, said slot arranged to be exposed beyond said bottom edge of the seating member in an extended position and shielded by the seating member in a retracted position; a spring urging the cutting member to the retracted position; and means for urging the cutting member to the extended position; so constructed and arranged that a conductor wire can be inserted in the laterally extending slot in the cutting member when extended, the lower end of the cutting member engaging with the terminal block to cause sliding of the cutting member relative to the seating member, to shear the conductor wire, said seating member pushing the conductor wire between the terminal clips.

6. A terminating tool as claimed in claim 1 said tool including a handle portion comprising two opposed halves, said halves forming a channel for the reception of said seating member and said cutting member.

10. A terminating tool as claimed in claim 9, including spring loaded means for retaining said wire removal tool in each of said retracted and extended positions.