US1615117A

US1615117A - Device for gauging and adjusting springs

Info

Publication number: US1615117A
Application number: US667150A
Authority: US
Inventors: Emery Charles Brevet
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1923-10-08
Filing date: 1923-10-08
Publication date: 1927-01-18
Anticipated expiration: 1944-01-18

Description

C. B. EMERY DEVICE] FOR GAUGING AND ADJUSTING SPRINGS Jan. 18, 1927. f1,615,117

Filed Oct. 1923 45 47 v u {QM C fi 2 v 5 36 1 if Inventor clzczfldfli'mely Patented Jan. 18, 1927.

UNITED STATES PATENT OFFICE.

CHARLES BREVET EMERY, 0F RIVER FOREST, ILLINOIS, ASSIGNOR TO WESTERN ELEC- TBIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

Application filed. October 8, 1923. Serial No. 667,150.

This invention relates to devices for gauging and adjusting springs, and more particularly to devices for gauging and adjusting the contact pressure of electrical contact springs.

An object of the invention is the provision of a device for gauging and adjusting the contact pressure of contact springs such as are used on multi-contact brushes of telephone exchange apparatus of the machine switching type.

Another object of the invention is to provide a device of'the above mentioned type, which comprises a leaf spring adapted to be adjusted to provide different resilient values.

A further object of the invention is to provide a device combining means closely associated upon a common support for rapidly gauging and adjusting the contact pressure of a plurality of closely spaced contact springs.

In telephone exchange apparatus of the machine switching type, the mechanism is compactly arranged to conserve space and includes multi-contact brushes, each mounting a plurality of contact springs which are moved over a plurality of contact surfaces in the operation of the mechanism. In mechanism of this type it is essential that the contact pressure of each spring should be sufiicient to insure proper contact with the contact surface over which it moves Without causing an undue wear thereon or consumption of power in moving the same.

A device made in accordance with theinvention may comprise a support or hand grip having adjustably mounted thereona leaf spring having a resiliency equal 1n value to the desired contact pressure of the springs to be gauged and adjusted. The free end of the leaf spring is equipped with a plurality of engaging portions for successively and selectively engaging a plurality of closely spaced springs mounted in the same plane. The support or hand grip is provided with a plurality of recesses forming fixed jaws for engaging the springs to adjust them when found to exert a force which is more or less than the desired contact pressure.

These and other features of the invention not specifically mentioned will clearly appear from the following description and the accompanying drawings, in wh1ch'- Fig. 1 is a fragmentary plan view of the device mounted in one of its adjusting positions upon one of the contact springs of a multi-contact brush which is shown positioned on the commutator of a machine switching telephone exchange system;

Fig. 2 is a fragmentary side View of the brush member and the commutator with the device shown in several of its adjusting positions;

Fig. 3 is a section taken on the line 3-3 of Fig. 2 with the device shown in several different gauging and adjusting positions;

Fig. 41 is a fragmentary side view of the device shown engaged with a spring under test, and

Fig. 5 is a fragmentary plan view of the device.

Referring to the drawings in detail, in which similar reference characters are employed to denote similar parts throughout the various views, 10 indicates a commutator of a type frequently employed in telephone exchange apparatus of the machine switching type. A multi-contact brush 11 attached to a brush rod 12 by means of a clamping device 13 is adapted, in the opera tion of the telephone exchange system, to move resilient spring contact members 14:, 14 over the commutator 10, which may consist of metal contacting strips, such as 24, 24, embedded in a block of insulating material 28. Although in the use of such a commu tator and the associated apparatus the brush and supporting rod are mounted upon a suitable frame work and the contact surfaces may be suitably connected to the operating circuits of the exchange, such features are not essential to a complete understanding of the invention and have therefore been omitted from the drawings.

In the preferred embodiment of the invention which is devised for gauging and adjusting the contact pressure or resiliency of the springs 141, 1 1, a metal bar 30, square in cross section'is bent substantially midway along its length, as shown, to form a hand grip 31 for conveniently holding the tool in position in the hand without danger of it turning in the operators hand while operating it. Upon one face of the bar 30 and near one end, a leaf spring 33 is secured with plates 35 positioned at either side thereof by screws 34: which are threaded into the bar 30. The plates 35 and spring 33 are provided with elongated slots 36, whereby the resiliency of the spring may be adjusted to have various predetermined values.

The free end of the spring 33 is formed with an offset portion 38 terminating in a U shaped hook 39, which forms a pocket 40 between the spring which normally rests with a predetermined pressure against the bar 30 and the end ll thereof. (See Fig. 3.) The end ll of the bar is formed with a short right angle arm l2 extending in the opposite direction as the offset portion of the spring 33, and provided upon opposite faces thereof with slots and 4A, which form fixed jaws, the width of the openings therein being substantially the thickness of the springs to be adjusted. The opposite end of the bar 30 is also formed with a short right angle arm 47, disposed oppositely to the arm .l2 and provided upon its outside face with a slot a8, the opposing faces of which form a fixed jaw, the depth of which is substantially the width of the contacting portion 50, and the width of the opening therein being substantially the thickness of the spring to be adjusted.

In the use of the tool, after the multicontact brush 11 has been properly secured to the brush rod 12, the contacting portion 50 of the spring to be gauged and adjusted is first adjusted to form a substantially right angle bend with the contacting edge thereof lying flat against the contacting metal strip of the commutator. This adjustment is made by entering the portion 50 of the spring near the point where it joins the longer portion thereof within the depression 18 of the arm 47 as clearly shown in Figs. 1 and 2, and then twisting the bar 30 so as tobend the portion 50 either up or down until it forms substantially a right angle bend with its end face resting flat against the contact strip. To adjust the portion 50 of the adjacent spring, the tool is engaged therewith from the opposite edge as clearly shown in dotted outline in Fig. 2.

After the adjustment of the portion 50 of the spring, the next step is to gauge the contact pressure of the spring. This is done by entering the long portion of the spring to be gauged and near the upper end thereof into the U shaped hook 39 or within the pocket 40 between the end of the leaf spring 33 and the bar 30 as shown in full and dotted outline respectively in Fig. 3. In this position it will be observed that the leaf spring 33 rests against the bar 30. The

operator'now slowly moves the bar 30 forward, away from the spring 14 being gauged, and if the contacting end of the portion 50 of the spring 1e breaks contact with the contacting metal strip at simultaneously with the disengagement of the leaf spring 33 from the bar 30 as clearly shown in Fig. 4;, it is an indication that the contact pres sure of the spring 1-l is normal. If the contacting end of the portion 50 breaks contact with the strip 27 before the leaf spring 33 breaks engagement with the bar 30, it is an indication that the pressure of the spring is below normal, and if the re verse, that it is above normal. The adjacent spring is similarly gauged by merely moving the tool to the left and slightly rearward as viewed in F 3, with the exception that the spring is entered within the pocket 40 between the end of the leaf spring 33 and the bar 30 as clearly shown in dotted outline in Fig. 3. The next adjacent spring is similarly gauged, with the exception that the tool is engaged therewith from the opposite edge thereof by entering it within the U shaped hook 39 of the leaf spring 33 as clearly shown in dotted outline in Fig. 3. W' hen the contact pressure of the spring let is found to be under or over the required pressure, the tool is positioned adjacent the upper end of the long portion thereof, which is entered within either the

slots

43 or 44, depending upon what spring is to be adjusted. The tool is then lowered to engage the spring near its lower or supporting end (see Figs. 2 and 3), and by twisting the bar 30 so as to bend the spring either toward or away from the contacting strips 27, the contact pressure will be increased or decreased respectively.

What is claimed is:

1. In a device for gauging the resiliency exertedby springs, a support, a member of predetermined resiliency having a portion at its free end normally contacting therewith, and another portion adapted to engage springs to be tested, and means for securing the member in a plurality of adjusted positions upon the support.

2. In a device for successively gauging the contact pressure exerted by closely spaced adjacent springs mounted in the same plane, a member of predetermined resiliency having a U shaped free end forming a plurality of parallel disposed surfaces for engaging springs from the opposite edges thereof.

3. In a device for successively gauging the contact pressure exerted by closely spaced adjacent springs, a support, a member of predetermined resiliency adjustably mountet. thereon, having a portion shaped t? engage springs from opposite edges there- 0 4:. In a. device for successively gauging and adjusting the contact pressure exerted by closely spaced adjacent springs, a support, and a member of predetermined resiliency mounted thereon, having a portion shaped to engage springs from opposite edges thereof, said support having means formed therein for adjusting the contact pressure of the springs under test.

5. In a device for successively gauging and adjusting the contact pressure exerted by closely spaced adjacent springs, a support having jaws formed thereon for adjusting the contact pressure of springs under test, a leaf spring of predetermined resiliency mounted thereon, having a plurality of parallel disposed portions for engaging springs from opposite edges thereof.

6. In a device for successively gauging and adjusting the contact pressure exerted by closely spaced adjacent springs of the leaf type, a support having jaws formed at opposite ends thereof for adjusting the contact pressure of springs under test, a leaf spring of predetermined resiliency mounted thereon, having an offset U shaped free end normally contacting with the support at one point to form a pocket between one arm of the U shaped end and the adjacent surface of the support, and another within the U shaped end thereof for engaging springs from opposite edges thereof,

7. In a device for successively gauging the contact pressure exerted by closely spaced adjacent springs, a support, a member of predetermined resiliency mounted thereon and normally contacting therewith at its free end and having a portion adapted to engage springs to be tested, the resilient member having such a degree of resiliency that it disengages the support at the instant the spring under test disengages the associated contact, thereby indicating that the contact pressure of the spring under test is normal.

8. In a device for successively gaugin the contact pressure exerted by closely space adjacent springs, a support, a leaf spring of predetermined resiliency adjustably mounted thereon and normally contacting therewith near its free end, and having a plurality of parallel disposed portions at its free end for engaging springs to be tested, the leaf spring having such a degree of resiliency that it disengages the support at the instant the spring under test disengages the associated contact, thereby indieating that the contact pressure of the spring under test is normal.

In witness whereof, I hereunto subscribe my name this 21st day of September A. D.,

CHARLES BREVET EMERY.