US1706068A

US1706068A - Brush-lifting device

Info

Publication number: US1706068A
Application number: US215613A
Authority: US
Inventors: George H Leland
Original assignee: Leland Electric Co
Current assignee: Leland Electric Co
Priority date: 1927-08-26
Filing date: 1927-08-26
Publication date: 1929-03-19
Anticipated expiration: 1946-03-19

Description

March 19, 1929. G, H. LELAND BRUSH LIFTING DEVICE Filed Aug. 26, 1927 2 Sheets-Sheet //v v/v T0 R. 650965 H. L EL 4N0.

4 TT0/PNE Y March 19, 1929. G H L LAND 1,706,068

BRUSH LIF'fING DEVICE 7 Filed Aug. 26, 1927 2 Sheets-Sheet 2 //V Vf' N TOR 60R6 H. LEI. AND.

ATTOHNIE'Y Patented Mar. l9, 1929.

UNITED STATES A "1,706,068 PATENT OFFICE.

'enonen n. mun, .or nan-on, omo, assrenon or our-mum 'ro 'rnn Luann anaem c comm, or narrow, onto, a coarom'rron or 0310.

Barren-turtles nnvroa.

Application filed August 38, 1927. Serial No. 215,818.

This invention relates to a brush lifting device for use with electric motors and the ike. In certain types of electric motor it is desirable that the brush should be lifted out 6 of engagement with the commutator. For example, a repulsion induction motor starts as a repulsion motor and after it has attained also results in a noise which is objectionable.

One object of the invention is to provide a simple eflicient mechanism for automatically lifting the brushes out of contact with the commutator when the motor has attained a predetermined speed.

A further object of the invention is to provide such a mechanism in which the brushes will be permitted to have movement with relation to the lifting mechanism, asthey wear away, but willbe engaged by the lifting mechanism and moved out of contact with the commutator regardless of the positions which they have assumed with relation to the lifting mechanism.

Other objects of the invention will appear as the mechanism is described in detail.

In the accompanyin drawings Fig. I is a rear elevation of a rush lifting mechanism embodying my invention, and a portion of the commutator; Fi 2 is a bottom plan view of the brush lifting mechanism; Fig

3 is a transversesectional view taken on the line 3-3 of Fig.1; 'Fig. 4 is a section taken on the-line 44 of Fig. 1; Fig. 5 is a rear elevation, partly broken away of a modified 40 form of the brush lifting mechanism; and

Fig. 6 is a rear elevation of another modified form of the invention. I

In these drawings I have illustrated several embodimentsof the invention all of which embed the same essential features of construction ut which differ in certain details of the mechanism. It will beunderstood that these several forms of the apparatus have been chosen for the purposes of illus tration only and that the mechanism may take various forms and the several parts thereof may be arranged in 'various ways. In that form of the apparatus illustrated in Figs.'1 to 4- the brush lifting mechanism is shown in connection with a commutator cuiting device are divided into groups by 1 of a motor, which is of ordinary construction and is mounted on the motor shaft 2 and provided with the usual insulated commutator bars 3. Cooperating with the commutator is a short circuitin device consisting of a series of centrifugally operated contact weights 4 arran ed circumferentially of the motor shaft an confined between the face of the commutator and a retainin late 5. Extending about the outer edges 0% t e contact weights 4 is an annular contractile band or spring 6 which resists the outward movement of the weights by centrifu al force and returns the same to their norma or retracted positions when the centrifugal force decreases. Also mounted about the commutator shaft is a centrifugal device consisting of a series of weights 7 each having at its outer end a forwardly extending flange 8 the several flanges being so arranged that they will form a practically continuous annular flange on the centrifugaldevice as a whole. The several weights of the short cirmeans of separator plates 9 which have at their inner ends circumferentially arranged portions 10 upon which the weights of the respective groups are supported. These separator plates .9 have forwardly extending projections or lugs 11 which extend through slots in the respective weights 7 of the centrifugal device so that they are connected with and held against radial movement with relation to said centrifugal device and the spring 6 of the short circuiting device also serves to resist the outward movement of the weights of the centrifugal device. The short circuiting device and the centrifugal device do not in themselves form any part of the present invention and it is not necessary to describe the same in detail. It will be understood that when the motor is idle or running at low speed the spring 6 will hold'both devices in their retracted positions and when the motor attains a certain predetermined speed cen- 100 trifugal force will move both devices outwardly against the action of the spring 6,

' 05 The brush lifting mechanism of Fi .lto

'4 comprises a supporting member or p ate 12;:

which is rigidly mounted on a fixed support; such as the motor casing, which is not here f /"f shown. Pivotally mounted on the supporting structure aretwo brush supporting members which are preferably in the form of arms 13 pivotally mounted upon the supporting structure and extending in opposite-directions circumferentially to the commutator. In the present instance, the two brush supporting arms are mounted on' separate studs 14 and each arm comprises parallel side members connected one to the other at their outer ends by a: transverse portion 15, thus forming at the outer end of the arm a guideway for the brush 16. If desired, each arm may be formed from a single piece of metal bent to the desired shape. lifting arms are actuating devices, which preferably consist of arms 17 pivotally mounted on the respective studs 14 and, as here shown, each actuating arm comprises parallel side members mounted at their inner ends on the studs 14 and connected at their outer ends by a transverse portion 18 which constitutes a clamping member to engage the brush and retain the same in a fixed position in the guideway. This clamping member or plate 18 is so arranged with relation to the guideway for the brush that when the actuating device is in its normal position the brush will be free to move with relation to the supporting arm 13 and the actuating device but when the actuating device is moved about its axis it will engage thebrush and clamp the same against the outer wall 15 of the guideway, thus not only holding the brush against movement with relation to the brush lifting arm but also connecting the actuating device with the brush lifting arm so that further movement of the actuating device will lift the arm and the brush. Any suitable means may be provided for pressing the brush against the commutator and for moving the brush supporting. arms toward the commutator, but this means preferably consists of a pressure device of such a character that the pressures on the two arms and on the two brushes will be respectively equalized and a predetermined ratio will be malntained between the pressure on each arm and the pressure on the brush carried by thatarm. As here shown, I have provided the two brush lifting arms with pressure members or bars 19 which are pivotally mounted at 20 on the respective arms near the inner ends thereof and which have their outer ends curved, as

shown at 21, and resting upon the upper ends of the respective brushes 16. A spring 22 is connected at its ends with the two pressure members 19. In the present instance, the ends of the spring are connected with lugs 23 struck from the respective pressure members and, bent inwardly. The points of connection between the spring and the pressure members are so arranged that the spring will tend to press the brushes into engagement with the commutator and to move the brush supporting arms about their axes, the arrangement Cooperating with the brush being such that the pressure is properly divided between the brushes and the arms, the pressure on the two arms being substantially equal and the pressure on the two brushes being substantially equal, and, further, the pressure on each arm having a predetermined ratio to the pressure on the brush carried by that arm. The pressure members 19 are provided with resilient fingers 24, preferably struck from the members and bent downwardly, to receive clips 25 by means of which conductors 26 are electrically connected with the pressure members, these conductors being connected at their other ends with the re spective brushes.

The actuating devices 17 may be operated in any suitable manner. In the device here shown, the two actuating arms 17 have inwardly extending portions 27 which are provided with opposed contact surfaces, these contact surfaces being,'in the present instance, in the form of rollers 28 mounted between the projections 27 on the two parts of the respective arms. A centrifugall actuated stud 29 is arranged normally be ow the contact surfaces of rollers 28 of the actuating devices and is preferably carried by a lever 30 which is pivotally mounted at 31 on a supportingstructure 12 and has its inner end turned downwardly and provided with a transverse channel 32 into which the flange 8 of the centrifugal device 7 projects. Conscquentlythe outward movement of the centrifugal device will impart outward movement to the stud 29, thus forcing the same between the opposed contact portions of the two actuating devices and imparting pivotal movement to those devices. The firstportion of this movement causes the clamping plates 18 to grip the brushes and to establish connection between the actuating devices and the brush supporting arms, and the further movement of the actuating devices lifts the arms and moves the brush out of contact with the commutator. When the stud 29 has been moved to its outermost position its horizontal diameter will lie beyond the plane passing through the axes of the two rollers and these rollers will support the stud in its outermost position and the stud while in this position will prevent the rollers from returning to their normal positions, thus retaining the brushes out of contact with the commutator. I

to permit of this, I have provided a stop'to 112 extending rearwardly from the supporting plate 12 and arranged between the brush supporting arms so that*the inner edges of.

these arms will engage the lug before the outer ends of the arms can engage the commutator.

In Fig. 5 I have illustrated a modified form which differs from the form above described principally in the manner of applying the springs thereto. As shown in this figure the mechanism comprises a supporting"structure or plate 33 and the brush lifting membersare in the form of arms, 34 and 34, pivotally mounted on a single stud 35, carried by the supporting plz te, and extending in opposite directions circumferentially of the commutator 1. The arms are similar in construction to those above described and each is provided at its outer end with a guideway for the brush 36. The actuating devices 37 are in the form of arms pivotally mounted on the single stud 35 and having opposed contact surfaces or rollers 38 arranged to be engaged by a centrifugally operated stud 39, each arm having at its outer end a clamping member 40 to hold the brush against movement and to connect the actuating device with the lifting arm.

Each of the brush lifting arms has connected therewith and preferablyformed integral therewith, a supplemental arm,.41 and 41", which extends on that side of the stud 35 opposite the brush lifting arm, the supplemental arm 41 of the brush lifting arm 34 extending alongside of the brush lifting arm 34 and the supplemental arm 41 of the brush lifting arm 34 extends alongside, of the brush lifting arm 34. Mounted lupon the outer end of each of the supplemental arms.

is a spring 42 having that portion which is connected with the arm in the form of a coil and having its outer portion substantially flat and bearing upon the end of the adjacent brush. This arrangement is such that each of the springs 42- will tend to press the brush *of one supporting arm against the commutae tor and to move the other supporting arm about its axis. When the two brush supporting arms are moved about their axes by the actuating devices each supporting arm will be moved towardthe supplemental arm of the other supporting arm, thus increasing the tension on the springs42. I

In Fig. 6 I have shown a further slight modification of the mechanism. As there shown, the brush supporting arms 43 are pivotally mounted on separate studs 44 carried by a supporting structure or plate 45; In

this instance each arms consists of a single.

member, the outer end of which is bent laterally, as shown at 46, and then rearwardly,

as shown at 47, to form a guide for the brush 48. The transverse portion 46 of the guide projects some distance above the upper ed e of the arm and beyond the end'of the brus The actuating devices comprise arms 49 pivotally mounted on the respective studs 44 and each having its outer end bent laterally, as shown at 50, to provide a clamping plate which cooperates with a wall of the guideway to secure the brush against movement and to connect the actuating device with the arm. Each actuating arm has an inwardly extending portion 51 and these portions are provided with opposed contact surfaces but these contact surfaces are in the form of fixed beveled surfaces 52 instead of rollers and areacted upon by an operating member or stud 53 in the manner described in connection with the mechanism of Fig. 1. Connected with each stud 44 are two. flat springs, 54 and 55, these springs having those ends which are connected with the studs coiled about the studs and having their other ends bearing respectively upon the transverse outer portion of the arm and upon the end of the brush, the transverse portion of the arm being slotted, as shown at 56, topermit the inward movement of the spring 55. A stud or projection 57 extending rearwardly from the supporting structure 33 lies between the edges of the two brush supporting arms to limit their inward movement.

While I have shown and described certain embodiments of my invention I wish it to be understood that I do not desire to be'limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent, is: 1

1. In a brush lifting mechanism for an electric motor or the like, a supporting structure, a brush supporting member pivotally mounted on said structure, extending circumferentially of the commutator of said motor, and having at its outer end a guideway for a brush, abrush in said guideway, an actuating device associated with said brush supportingmember and havinga part movable with relation thereto to clamp the brush in a contact portion, and an operating member" to engage said contact portion and cause said actuating device to first clamp the brush in said guideway and to.tl1en impart movement to said brush supporting member to lift the brush.-

2. In a brush lifting mechanism for'an electric motor or the like, a supporting structure, a brush supporting arm pivotally mounted on saidstructure, extending circumguideway, an actuating arm associated with said brush supporting arm, mounted 'for movement about the axis of said arm and having a part forming a clamping member to engage the brush in said guideway, yieldable means for moving said arm and said brush toward said commutator, and an operating member arranged to engage said actuating arm and first move said arm with relation to said brush supporting arm and then cause said actuating arm to impart movement to said brush supporting arm.

3. In a brush lifting mechanism for an electric motor or the like, a supporting structure, a brush supporting arm arranged circumferentially of the commutator of said motor and comprising parallel members spaced :1 art and pivotally mounted at their inner ends on said "supporting structure and connected at their outer ends by a transverse portion to form a guideway for a brush, a

- brush in said guideway, an actuating arm piv- Gil otally mounted on said supporting structure, arranged between the two members of said brush supporting arm and having at its outer end a part spaced from the transverse portion I of said brush supporting arm andadapted to clamp the brush in said guideway, and an operating member to engage said actuatin arm and move the same with relation to said brush supporting arm to cause the brush to be clamped in said guideway and to then impart movement-to said brush supporting arm.

4. In a brush lifting mechanism for an electric motor or the like, a supporting structure, brush supporting members pivotally mounted on said structure and each-having a guideway for a brush, a brush in said guideway, actuating devices associated with the respective brush supporting members and each having a part movable with relation to the adjacent brush supporting member to clamp the brush in the guideway of said member, said actuating devices having opposed contact parts, and an operating member to engage said opposed contact parts and cause said actuating devices to first clamp the brushes in the respective guideways and to then impartmovement to said brush sup porting members to liftsaid brushes.

5. 'In a 'brush lifting mechanism for an electric motor or thelike, a supporting structure, brush supporting arms pivotally mounted on said structure and each having a art shaped to form a guideway for a brush, a brush in said guideway, actuating arms associated with the respective brush lifting arms and mountedfor movement about the axes of the respective arms, each actuating arm having a part forming a clamping member to engage the brush in said guideway, yieldable means for moving said arms and said brushes toward said commutator, said actuating arms having opposed contact parts, and an operating member arranged to engage the opposed contact parts of said actuating arms and first move said arms with relation to the support-v ing arms and then cause said actuating arms to impart movement to the brush supporting arms.

6. In a brush lifting mechanism for an electric motor or the like, a supporting. structure, brush supporting arms pivotally mounted on said structure and each having a art shaped to form a guideway for a brus a .brush in said guideway, actuating arms associated with the respective brush lifting arms and mounted for movement about the axes of the supporting arms, each actuating arm having a part forming a clamping memberto engage the brush in said guideway, yieldable means for moving said arms and said brushes toward said commutator, said actuating arms having inwardly extending projections provided with contact surfaces, an operating stud to engage said contact surfaces and impart movement to said actuating arms, and 'cen trifugally operated means for actuating said stud.

7 i In a brush lifting mechanism for an electric motor or the like, a supporting structure, brush supporting arms each comprising parallel members spaced apart and pivotally mounted at their inner ends on said supporting structure and connected at their outer ends by a transverse portion to form aguideway for a brush, a brush in said guideway, actuating arms pivotally mounted on said supporting structure, arranged between the two members of the respective brush supporting arms and each having at its outer end a transverse-portion spaced from the-transverse portion of said brush su porting arm and adapted to clamp the brus between the same an the transverse portion of said supporting arm, said actuating arms having opposed contact surfaces, and an operating member toengage said opposed contact surfaces and impart movement to said actuating devices.

8. In a brush lifting mechanism for an electric motor or the like, a brush, a movable brush supporting member having means for supporting said brush thereon for movement relatively thereto during the operation of said motor, a device to act on said supporting member and said brush to press the same yieldably toward the commutator of said motor, said device comprising means to main tain a predetermined ratio between the pressure on said brush supporting member and the pressure on said brush.

9. In a brush lifting mechanism for an electric motor or .the like, a brush, a movable brush supporting member having means for supporting said brush thereon for movement relatively thereto. during the operation of said motor, a pressure device having diiferent ing a predetermined ratio to the moaooa tained at a predetermined ratio to the pressure on said brush.

10. In a brush lifting mechanism for an electric motor or the like, a brush, a movable brush supporting member having means for supporting said brush thereon for movement re atively thereto, and a pressure device comprising a member having parts spaced one from the other and arranged to act respectively on said brush supporting member and a said brush, and a spring acting on said member at a 'point so arranged with relation to said parts thereof that the pressure on said supporting member will have a predetermined ratio to the pressure on said brush.

11. In a brush lifting mechanism for an electric motor or the like, movable brush supporting members each having means for supporting a brush thereon for movement with relation thereto during the operation of said motor, brushes carried by said supporting members, and means for causing said brushes to bear upon the commutator of said motor with equalized pressure and to cause said supporting members to be pressedtoward said commutator with equalized pressure havpressare on said brushes. I a

12. In a brush lifting mechanism for an electric motor or the like, movable brush sup? porting members each having means for sup porting a brush thereon for movement withrelation thereto during the operation of said motor, brushes carried by said supporting members, and a pressure device having parts to act on said supporting members and on said brushes to press the same toward the commutator of said motor and comprising means for equalizing the pressure ofsaid supporting members and for equalizing the pressure on said brushes, and for maintaining the pressure on said supporting members at a predetermined ratio to the pressure on said brushes. v I

13. In a brush lifting mechanism for an electric motor or the like, movable brush supporting members each having means'for supporting a brush thereon for movement withrelation thereto during the operation of said motor, brushes carried by said supporting members, pressure members to when the respective supporting members and the brushes carried thereby and ress the same toward the commutator of sai motor, and a yieidable device acting on said pressure members to cause the same to exert equal pressure on said supporting members and to exert equal pressure on said brushes thepressure on said brushes having a predetermined ratio to the pressure on said su porting members.

14. In a brush iftin mechanism for an electric motor or the li a, a pair of pivoted brush supporting arms each having mea,ns

being spaced a greater for supporting a brush thereon for movement with relation thereto, brushes carried b said supporting arms, pressure members eac connected near one end with one of said arms and having its other end arranged to act on the brush carried by thatarm, and an expan-.

sion spring connected at its ends with the respective pressu gemembers, the points of connection of the sprin with said pressure members being arranged to cause the pressure on said arms to bear a predetermined v ratio to the pressure on said brushes.

- 15. In a brush lifting mechanism for an electric motor orthe like, a pair of ivoted supporting arms each having means or supporting a brush thereon for movement with relation thereto, brushes carried by said supporting arms, pressure members each ivotally connected at one end with one 0 said arms near the axis of said arm and having its other end arranged to'bear on the brush carried by that arm, and a coiled spring connected at its ends with the respective pressure members, the point of connection of said spring with each of said ressure members istance from the brush engaging part of said member than it is spaced from the axis of said member.

16. In a brush. lifting mechanism for an electric motor or the like, a supporting structure, brush supporting arms pivotally mounted at their inner ends on said supporting structure and each having at its outer end a guideway for a brush, a brushin each guide- Way, actuating arms prvotally mounted on said supporting structure and having at their ends portions to clamp the brushes in the guideways of said supportin actuating arms having oppose contact surfaces, an operating member to engage said opposed contact surfaces and impart movement to said actuating devices, a bar pivotally mounted on each brush supporting arm near the inner end of said arm and having its outer portion bearing upon the brush supported by that arm, and a spring acting upon the bars of the twoarms to move said brush supportarms, said ing arms about their axis and to exert pres sure on said brushes.

17. In a brush lifting mechanism for an electric motor or the like, a supporting strucends by a transverse portion to form a ideway for a brush, a brush in each 1 eway, actuating arms pivotally mounte onsaidsupporting structure, arranged between the two members of the respective brush supporting arms and each having at its'outer end a transverse portion spaced from the transverse portion of said brush supporting arm and adapted to clamp the brush between the same and the transverse portion of said supporting arm, said actuating arms having opposed contact surfaces, an operating memher to engage said opposed contact surfaces and im art movement to said actuating devices, a ar pivotally mounted on each brush supportin arm near the inner end of said arm and aving its outer portion bearing u on the brush supported by that arm, each 0 said bars havin near its pivoted end an in lparallel members spaced apart and pivotally mounted at their inner ends on said support structure and connected at their outer ing1 on s by a transverse portion to form a guideway for a brush, a brush in each guideway, actuating arms pivotally mounted on said supporting structure, arranged between the two members of the respective brush supporting arms and each having at its outer end a transverse portion spaced from the transverse portion of said brush supporting arm and adapted to clamp the brush between the same and the transverse portion of said supporting arm, said actuating arms having opposed contact surfaces, an operating member to engage said opposed contact surfaces and impart movement to said actuating devices, a bar pivotally mounted on each brush supporting arm near the inner end of said arm and having its outer portion bearing upon the brush supported by that arm, a spring acting upon the bars of the two arms to move sald brush supporting arms about their axes and to exert ressure on said brush, and means for electrica ly connecting said brushes with the respective bars.

19. In a brush lifting mechanism for an electricmotor or the like, a supportingstructure, brush supporting arms each comprising parallel members spaced apart and pivotally mounted at their inner ends on said supportin structure and connected at their outer en s by a transverse portion to form a guideway for a brush, a brush in each guideway, actuating arms pivotally mounted on said supporting structure, arranged between the two members of the respective brush supporting arms and each having at its outer end a transverse portion spaced from the transverse portion of said brush supporting arm and adapted to clamp the brush between the same and the transverse portion of said supporting arm, said actuating arms having opposed contact surfaces, an operating member to engage said opposed contact surfaces and impart movement to said actuating devices, a bar pivotally mounted on each brush supporting arm near the inner end of said arm and having its outer portion bearing upon the brush supported by that arm, a spring acting on the bars of the two arms to move, sai brush supporting arms about their axes and to exert pressure on said brush, each of said bars having a resilient finger spaced fromone surface thereof, conductors connected with the respective brushes, and clips secured to the respective conductors and having parts adapted to be confined between the resilient fingers and the body portions of the respective bars.

20. In a brush lifting mechanism for an electric motor or the like, a supporting structure, brush supporting arms pivotally mounted on said structure, extending in opposite directions about the commutator of said motor and each having a guideway for a brush, a brush in each guideway: actuating devices associated with the respective brush supporting arms and each having a part movable with relation to the adjacent brush supporting member to clamp the brush in the guideway of said member, an operating device to impart operative movement to said actuating devices, a spring acting on said brush supporting arms to move the same, toward said commutator, and a part carried by said supporting structure and arranged between the adjacent edges of said brush supporting arms to limit the inward movement thereof.

21. In a brush lifting mechanism for an electric motor or the like, a supporting structure, brush supporting arms pivotally mounted in separate axes on said supporting structure, and each having near its outer end a guideway for a brush, a brush in each guideway, actuating arms extending parallel with the respective brush supporting arms and" pivotally mounted for movement about the axes of said arms,\each actuating arm having at its outer end a part to engage the brush and clamp the same in a guideway of the brush lifting arm and thereby connect said actuating device with said arm, yieldable means tending to move said brush supporting arms and said brushes toward said commutator, said actuatingarms having opposed contact parts, and an operating member arranged to engage said contact parts and impart operative movement to said actuating devices.

In testimony whereof, I afiix my signature hereto GEORGE H. LELAND.