US2988808A - Spring-lifter tool for facilitating electrical brush maintenance - Google Patents

Description

June 20, 1961 L. P. MASON -LIFTER Toor. FOR FACILITATING SPRING ELECTRICAL BRUSH MAINTENANCE Filed Jan. 26, 1959 United States Patent l Y l 2,988,808 SPRING-LIFTER TOOL FOR FACILITATING ELECTRICAL BRUSH MAINTENANCE Lester P. Mason, 1830 Parleys Canyon Blvd.,

Salt Lake City, Utah Filed Jan. 26, 1959, Ser. No. 789,198 7 Claims. (Cl. 29-205) away from the respective brushes and held in lift position vk once the tool is set without necessitating continuation of hand pressure applied thereto, so that the user may have both hands free to substitute new brushes for old ones or to perform other maintenance duties,

The present invention has proven to be extremely usev Y ful in the maintenance of traction motor gear of diesel railroad engines to facilitate electrical brush maintenance of such gear. Conventional `armature housing for such gear normally provides three access ports (covered when in use) which enable maintenance personnel to obtain access to the four sets of armature brushes. Considerable Y distance exists between these access ports and the several brush sets so that in the past much diculty has been encountered in changing armature brushes. Where longhandled screw drivers are used to force the springs away fnom ltheir respective brushes, it has been found that there is much likelihood of damage by these screw drivers to the electrical gear. Furthermore, even though a screw driver is used, the operator must keep the screw driver against the spring with one hand while attempting to remove a brush from its holder with the other hand. This is an awkward and difficult operation. It would of course he highly desirable if there were such a tool as to keep the springs away from their brushes in a manner vso that the operator would have both of his hands free tov remove the armature brushes. l

Accordingly, an object of the present inventionis to provide a new and useful spring-lifter toolfor facilitating electrical brush maintenance of tractionmotors, generators and the like.

It is a further object of the present invention to provide a spring-lifter tool of the type described which may be mounted to and within the armature housings of conventional traction motors and the like so as to enable maximum access to the brush area while safely clamping the springs away from the brushes, and this without necessitating the operator continuing to hold the tool.

According to the present invention, the novel springlifter tool includes a rotatable adjustable, spring-engaging pocket retainer having an open, slant face adapted to engage the ends of the flat springs of traction motors and the like. A retainer spring enables axial displacement of the pocket retainer while frictionally securing the same to a hinged brace. Respective arms of the brace include respective shoulder clamps slideably mounted thereon, the shoulder clamps having respective shoulder flanges extending in opposite directions. A slide bolt is adapted for disposition over the hinge area of the brace so as to render the brace one sturdy long piece when desired.I As shall be seen hereinafter, the shoulder clamps, the posi- ICC tion of the hinge joining the arm to the brace, and the disposition of the slide clamp are such as to enable complete brush maintenance of conventional traction motors, this being accomplished by clamping the device to and between the armature housing and the respective brush spring in certain configurations as shall be hereinafter described. The shoulder clamps of the device are securedV to the respective arms of the brace by means of wing-head set screws or similar attachments.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as toits organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings in which:

FIGURE 1 is an elevation of the device of the present invention. f

FIGURE 2 is a view taken along the line 2-2 of FIG- URE 1.

FIGURE 3 is a partially sectioned elevation of a oonventional traction motor housing, illustrating schematically the manner of securing the device to and within the traction motor and against the respective springs so as to keep the springs in lift position as the respective brushes are replaced or otherwise maintained.

In FIGURES l and 2 brace 10 is composed of two elongated arms 11 and 12 which are hinged together at A by means of hinge 13, this hinge being secured to the adjacent ends of the arms 11 and 12 by means of rivets 14. Shoulder clamp 15 includes shoulder flange 16 (which extends in direction B as shown in FIGURE 2) and aV slide body 17 integral therewith and having slide aperture 18 cooperating with the yarm 11. The slide body is pivoted with a threaded bore 19 which threadedly receives wing-head set screw 20, the end of the same coming into set engagement with arm 11. Shoulder clamp 15', mounted upon arm 12 as is shown in FIGURE 2, may be exactly the same in construction as shoulder clamp 15. However, shoulder clamp 15' is oriented in a direction reversed fto that of shoulder clamp 15 so that shoulder ange 16 is pointed in direction C, a direction opposite to direction B associated with shoulder clamp 15. Wing-head set screw 20 threads through threaded bore 19' of slide body 17 so as to come in contact with arm 12. A bolt means 21 is disposed laterally across the hinge area A of brace 10 and includes a slide bolt 22, bolt end keeper 23 (aixed by rivets or other means to the innermost end of arm 12), bolt body keeper 24 (afxed by rivets or other means to the innermost end of arm 11) and a friction spring 25, the same being seated in recess 26 of bolt body keeper 24 and having an end 27 cooperating with an internal recessed shoulder 28 of the slide bolt 22. Thus, the bolt actuating knob 22 prevents the bolt from sliding beyond the bolts right extremity of travel whereas recess Ishoulder 28 of bolt 22 and its coacu'on with end 27 of spring 25 prevents the bolt from sliding beyond its left extremity of travel.

The outermost end of arm 12 is provided with a hollow bore 29 which receives shank 30 of the spring engaging pocket retainer 31. A shank head 3'2 is disposed on one end of shank 30 whereas the pocket retainer 31 is disposed on the other end. A spring engages at its ends the arm 12 and the pocket retainer 31 so as to keep the same 5 separated but frictionally related.

It will, be noted with reference to FIGURES 1 and 2 that the spring-engaging pocket retainer is. cup-shaped; this to say, one end of the retainer is closed whereas the other is opened. It should be noted, furthermore, that the open end has a slant face. This is for the purpose of providing a large opening so as to facilitate the engagement of the cup retainer with each electrical brush retaining spring. Additionally, and as will be illustrated in FIGURE 3, the long-and-short side feature of the retainer enables the user to urge a conventional coil-base flat spring away from physical contact with its associated armature brush. The shank 30within bore 29 enables the axial displacement of the pocket retainer so as to facilitate easy brush spring engagement thereby. At the same time, the spring 33, while permitting Jdie rotational displacement of the pocket retainer unit (including shank 30) will nonetheless temporarily fix the disposition of the same by means of the friction of the spring ends against the end of arm 12 and retainer 31, so that a particular placement of the retainer, pivotal about transverse axis A, may be maintained while the device is inserted within the housing to engage a brush spring; the retainer 31 will properly adjust its orientation (rotationally speaking) as the device is clamped in place.

In' certain applications it will be found advisable to include in arm 11 a series of detent depressions 34, shown in FIGURE 1. These detent depressions are for the purpose of locating appropriate dispositions for the shoulder clamp upon its arm 12. Detent depressions might also be provided on arm 11 for clamp 15.

FIGURE 3 illustrates the operation of the device. In FIGURE 3 the armature housing 300 includes access ports 301, 302 and 303, these being Vshow-n in open and uncovered condition. The 3 oclock, 6 oclock, 9 oclock and 12 oclock positions of the armature brushes and their associated spring sets are indicated in FIGURE 3. To retain the respective brush springs away from the 3 oclock brushes, the operator merely inserts the unbolted device through access port 303 until the pocket retainer 31 engages the spring and forces it outwardly. When proper spring lift is achieved, then the clamp 15 is merely tightened against the internal shoulder 304 of housing 300I so as to secure this spring away from its associated brush. Subsequently, the operator may replace or otherwise maintain the brush. Other brushes in this position may be maintained in a similar operation.l

To accomplish the maintenance of the 6 oclock brushes, the operator need only bolt the two arms together by bolt means 21 and insert the device through access port 303 in a manner such that the pocket retainer 31 engages the respective spring and forces it outwardly, with the shoulder clamp 15 being tightened in place on arm 11 when disposed securely against the shoulder l305. The operator may thus use either one or both hands for brush replacement and devote his full attention to the same.

To replace -the 9 oclock armature brushes the operator n'eedonly take the unbolted device and'insert the same through access port 301 and' clamp shoulder clamp 1S against housing shoulder 306, clamping shoulder clamp 15 against the opposite side 3070i access port 301. This second clamping has been found to be necessary for traction motor housings of conventional design so that the device may be made secure for this 9 oclock replacement.

Toreplace the 12 oclock brushes the operator need only insert the device through access port 301 in its bolted condition, clamping shoulder clamp 15 securely against side 308 of access pont 301 of the armature housing 300.

It will be seen from the various maintenance coniigurations that to'accommodate all of the brush replacement positions both clamps are needed to clamp the device within the housing and against the brushv retainer springs; further, the shoulder flanges of the clamps must extend in opposite directions. In the case of the 9 oclock adjustment it has been seen that, since both clamps are here necessary, the presence of the hinge feature in the device becomes imperative.l Where the device is to be used in the straight fashion, as is true in the 6 oclock and l2 oclock positions, the device is made straight by the use of the bolt means 21. The device will be in its unbolted, hinged condition for the 3 oclock and 9 oclock positions.

If desired, the anges 16 and 16' of the device may include coatings or covers V to increase the coeflicient of friction of the working surfaces of the anges and also to protect them and the housing from inadvertent scratches which might be caused by their inter-cooperation. A vinyl plastic will serve.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled inthe art that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

l. A spring-lifter tool for facilitating electrical brush maintenance of an electric motor, generator or the like having an armature, a housing at least one access port therein, a plurality of electrical brushes, and a plurality of vsprings respective ones of which normally contact said brushes to urge the same inwardly against said armature, said tool including, in combination: means for releaseably engaging the end of one of said brush springs and lifting` the same away from said brush, and brace means for maintaining said spring away from said brush, said brace means including adjustable shoulder clamp means engageable with said housing, and said brace means laterally journalling said engaging means for enabling pivotal displacement of the latter about an axis transverse with respect to the former so as to ensure optimum retention of the engaged spring for various dispositions thereof.

2. A tool according to claim l wherein said engaging means includes a shank rotatably and laterally aixed to said brace means at one end thereof and a spring engaging pocket retainer affixed to said shank.

3. A tool according to claim `l wherein said engaging means includes a shank rotatably aiiixed to said brace means at one end thereof, a spring engaging pocket retainer atlixed to said shank, and a spiral compression spring disposed about said shank and in engagement with said brace means and said pocket retainer.

4. A tool according to claim 1 wherein said engaging means includes a shank rotatable aflixed to said brace means at one end thereof and a spring engaging pocket retainer aixed to said shank, said pocket retainer having an open face which is angulated.

5. A tool according to claim l wherein said brace means comprises a pair of elongated arms, hinge means connecting adjacent ends of said arms, selectively actuatable bolt means atiixed to said arm across said hinge means, and wherein said adjustable shoulder clamp means comprising a first shoulder clamp slideably mounted on one of said arms, a second shoulder clamp slideably mounted on the remaining arm, each of said shoulder clamps having a laterally extending shoulder ange, the flanges of the two clamps extending in opposite directions and manually operable set screw means for releaseably securing each of said clamps to its respective arm at a selected point.

`6. A tool according to claim 5 wherein at least one of said arms is provided with detent means to accommodate said set screw means.

7. A spring-lifter tool for facilitating electrical brush maintenance of an electric motor, generator or the like having an armature, a housing, a plurality of access ports therein, a plurality of electrical brushes, and a plurality of springs respective ones of which normally contact said brushes to urge the same inwardly against said armature, said tool including, in combination: means for releaseably engaging the end of one of said brush springs and lifting the same' away from said brush, said means including a rotationally displaceable, spring engaging pocket retainer having an angulated open face for receiving said spring;

5 6 i and brace means laterally and frictionally mounted to References Cited in the le of this patent said engaging means and having a pair of elongated arms, means hnging together said arms at adjacent ends thereof, UNITED STATES PATENTS selectively actuatable bolt means aixed to said arms 1,614,426 Rosiers Ian. 11, 1927 across said hinge means, and a pair of shoulder clamps 5 1,986,093 Abernathy Jan. 1, 1935 slideably mounted on said arms, said shoulder clamps 2,301,984 'Turnbull Nov. 17, 1942 having shoulder flanges laterally extending in opposite 2,331,920 McMaster Oct. 19,11943 directions, and set screw means for securing said shoulder 2,492,741 Goodman Dec. 27, 1949 clamps at desired points along said arms. 2,567,181V Bye Sept. 11, 1951

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