US3375696A - Tool for adjusting contact springs - Google Patents

Description

April 2, 1968 r A. N. A. LUSSIER 3,375,696 v TOOL FOR ADJUSTING CONTACT SPRINGS Filed Jan. 7, 1966 INVENTOR A. N. A. LUSSIER BY JW PATENT AGENTS United States Patent 3,375,696 TOOL FOR ADJUSTING CONTACT SPRINGS Antoine N. Andre Lussier, Chambly, Quebec, Canada, assignor to Northern Electric Company Limited, Montreal, Quebec, Canada Filed Jan. 7, 1966, Ser. No. 519,317 7 Claims. (Cl. 72400) This invention relates to a tool for adjusting resilient contact spring-s.

Contact springs are widely used in .the electrical industry. They are used extensively in the telephone field and more particularly in step-by-step switches. Such switches are mounted on shelves and electrical connection is achieved by the use of plugs adapted to engage the contact springs. Specifically, the plugs are inserted between pairs of contact springs, and because certain pairs of springs must make contact when the plugs are removed, the springs must be tensioned against each other. Furthermore, the springs must be so aligned that the associated plug will enter between them without snagging on the tips of the springs. At present, the pairs of springs are adjusted by hand with two pairs of pliers used simultaneously. The fixed portion of a pair of contact springs is grasped and held stationary with one pair of pliers while the contact portion of one spring is adjusted toward its mate with the other pair of pliers. The mating contact spring is adjusted in the same manner so that when adjustrnent is complete the point of contact of the two springs will be aligned with a point midway between the fixed ends of the springs.

There is a substantial amount of guesswork in this adjustment procedure with the result that the pressure between the contacts is often inadequate and furthermore that the springs are not always perfectly aligned.

The disadvantages of the prior art are overcome in accordance with the present invention by providing a plierlike tool for adjusting a pair of spaced resilient contact springs fixed at one end and having portions movable into contact with each other usually adjacent free ends of the springs. The tool comprises a pair of elongated members pivotally connected together intermediate their ends to form a pair of handles and a pair of jaws for embracing and deforming the springs into contact with each other. An anvil is pivotally connected to the elongated member and comprises spacing means in the form of a member which is offset from the plane of the jaws and adapted to be inserted between the contact springs intermediate the fixed ends and the movable portions. The anvil further comprises means for centering the spacing member between the jaws when the jaws are closed, and means for aligning the spacing member with the midpoint between the fixed ends of the springs. The novel anvil therefore ensures that the cont-act springs will always be deformed in a position such that the point of contact between the two movable ends of the springs are aligned with a point midway between the fixed ends of the springs.

With the above tool the adjustment is done in only one operation and all the guesswork to determine the pressure between the contacts is eliminated. The accuracy, quality and uniformity of adjustment is improved and also the time for adjustment is greatly reduced.

The invention will now be described with reference to a preferred embodiment of the invention in which:

FIGURE 1 illustrates a tool, in accordance with the invention, in position for adjusting the contact springs;

FIGURE 2 illustrates a number of contact springs mounted on a support, the center one being normally closed; 7

FIGURE 3 illustrates a plan view of the adjusting tool;

FIGURE 4 illustrates a side view of the adjusting tool;

FIGURE 5 illustrates a section view along line 5-5 in FIGURE 4 illustrating the .anvil and the spacing member in position before closure of the jaws on the contact springs;

FIGURE 6 illustrates the same section view as FIG- URE 5 after closure of the jaws.

FiGURES 1 and 2 illustrate a support m which are mounted a number of pairs of contact springs 11, 12 and 13 each having two contact springs 14 and 15 fixed at one end and separated by an insulator 16. Plugs (not shown) are adapted to be inserted between the movable ends of springs 14 and 15. As mentioned previously certain springs are required to make contact when the plugs are removed. This is exemplified in FIGURE 2 by switch 12 which is shown normally closed. Consequently the contact springs have to be .adjusted to make contact and the present invention is concerned with a tool generally shown in FIGURE 1 for effecting such adjustment.

Referring .now to FIGURES 3 and 4, "the contact adjusting tool of the present invention comprises a pair of elongated members 17 and 18 pivotally connected by a bolt 19 to form a pair of handles 20 and] 21 and a pair of jaws 22 and 23. An anvil 24 is pivotally connected to the elongated members by the bolt 19. Anvil 24 comprises a spacing member 25 which is offset from the plane of the jaws 22 and 23 and adapted. to be inserted between contact springs 14 and 15. Spacing member 25 is positioned in a slot 26 in the center of the top surface of anvil 24 and secured to the anvil by means of a screw 27 which protrudes through the anvil from the bottom surface thereof. Spacing member 25 has a pointed end 28 to facilitate entry between the contact springs. It is understood however, that spacing member 25 may be otherwise secured to anvil 24 and may even be integral therewith.

Screw 27 is provided with a smooth elongated extension 29 in the form of a pin which extends between jaws 22 and 23 to act as a centering means for centering spacing member 25 between the jaws. Centering means 29 may take various forms and it is only as a matter of convenience that it is shown as an extension of screw 27.

Pin 29 is also used to limit the amount of closure of the jaws to control the pressure of the jaws on the contact springs. By varying the size of the pin various amount of closure of the jaws may be obtained. The jaws 22 and 23 also have slots 30 to permit full closure of the jaws when it is required with a minimum size screw.

Anvil 24 has a projection 31 which acts as a means for aligning the spacing member 25 with the midpoint between the fixed ends of the springs. Projection 3'1 has a recess portion 32 wide enough to receive the fixed ends of the contact springs. The sides of the recess 31 may be sloped outwardly approximately 5 degrees to facilitate entry of the springs therein.

Also shown in FIGURES 3 and 4 of the drawings is a pin 33 mounted on the anvil 24 and siidable to a position with one end between the open jaws 22 and 23 to maintain the anvil centrally located between the jaws when the latter are open. Pin 33 protrudes through the anvil 24 and is biased in position by a spring 34 secured under the fastening nut of bolt 19. The end of the pin which lies between the open jaws is cone shaped such that the jaws engage said cone shaped end on closing to urge the pin out of its position between the jaws.

It is to be understood equivalent means may be used to perform the functions of each of the elements of the tool disclosed. A preferred embodiment has been described by way of illustration only and applicant does not intend to be limited by such description.

The operation of the adjusting tool is shown schematically in FIGURES 5 and 6. As shown in FIGURE 5, the fixed ends of the contact springs are placed in groove 32 of anvil 24 and spacing member 25 is inserted be- When the jaws are fully closed about pin 29, the point of contact of the mating springs will be in alignment with the midpoint between the fixed ends because the aligning means 31 provides for proper alignment of the spacing member 25 and centering means 29 with the midpoint between the fixed ends of the springs.

It is seen therefore, that with the above described adjusting tool the operation is performed in only one move and that all guesswork to determine the amount of deformation of the springs, the pressure between the contact springs and the alignment of the springs is eliminated. The accuracy, quality and uniformity of adjustment is greatly improved and also the time required for adjusting the springs is greatly reduced.

What is claimed is:

1. A plier-like tool for adjusting a pair of spaced resilient contact springs fixed at one end and having portions movable toward each other, said tool comprising a pair of elongated members pivotally connected together intermediate their ends to form a pair of handles and a pair of jaws for embracing and deforming said movable portions of the springs into contact with each other, and an anvil pivotally connected to said members, said anvil including spacing means offset from the plane of the jaws for insertion between the contact springs intermediate the fixed ends and said movable portions, centering means rigidly connected to the anvil for centering the spacing means between the jaws when the jaws are closed, and aligning means rigidly connected to the anvil and adapted to engage the fixed ends of the contact springs for aligning the spacing means with the midpoint between the fixed ends whereby the movable portions are deformed into contact in alignment with said midpoint.

2. A tool as defined in claim 1 wherein the pivotal connection of the anvil to said members coincides with the pivotal connection between said members.

3. A tool as defined in claim 2 including means for positioning the anvil between the jaws when the latter are open.

4. A tool as defined in claim 3 wherein said positioning means comprises a pin mounted on the anvil and slidable to a position with one end between the open jaws, spring means biasing the pin to said position, said one end of the pin being substantially cone-shaped such that the jaws engage said one end on closing to urge the pin from said position between the jaws.

5. A tool as defined in claim 1 including means for limiting the distance between the jaws when the latter are closed to control the pressure of the jaws on the contact springs.

6. A tool as defined in claim 5 wherein said limiting means comprises a portion of said centering means projecting between the jaws.

7. A tool as defined in claim 1 wherein said aligning means comprises a projection of said anvil having a recess therein for receiving the fixed ends of the contact springs.

References Cited UNITED STATES PATENTS 2,810,312 10/1957 Mueller '72409 RICHARD J. HERBST, Primary Examiner.

R. D. GREFE, Examiner.

Claims (1)

1. A PLIER-LIKE TOOL FOR ADJUSTING A PAIR OF SPACED RESILIENT CONTACT SPRINGS FIXED AT ONE END AND HAVING PORTIONS MOVABLE TOWARD EACH OTHER, SAID TOOL COMPRISING A PAIR OF ELONGATED MEMBERS PIVOTALLY CONNECTED TOGETHER INTERMEDIATE THEIR ENDS TO FORM A PAIR OF HANDLES AND A PAIR OF JAWS FOR EMBRACING AND DEFORMING SAID MOVABLE PORTIONS OF THE SPRINGS INTO CONTACT WITH EACH OTHER, AND AN ANVIL PIVOTALLY CONNECTED TO SAID MEMBERS, SAID ANVIL INCLUDING SPACING MEANS OFFSET FROM THE PLANE OF THE JAWS FOR INSERTION BETWEEN THE CONTACT SPRINGS INTERMEDIATE THE FIXED ENDS AND SAID MOVABLE PORTIONS, CENTERING MEANS RIGIDLY CONNECTED TO THE ANVIL FOR CENTERING THE SPACING MEANS BETWEEN THE JAWS WHEN THE JAWS ARE CLOSED, AND ALIGNING MEANS RIGIDLY CONNECTED TO THE ANVIL AND ADAPTED TO ENGAGE THE FIXED ENDS OF THE CONTACT SPRINGS FOR ALIGNING THE SPACING MEANS WITH THE MIDPOINT BETWEEN THE FIXED ENDS WHEREBY THE MOVABLE PORTIONS ARE DEFORMED INTO CONTACT IN ALIGNMENT WITH SAID MIDPOINT.

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