US2399935A - Brush rigging - Google Patents

Description

W. J. MORRILL v BRUSH- RIGGING May 7, 1946.

Filed Dec. 25, 1942 Inventor- Wayne J. Mot-rill,

His Attorney.

Patented May 7, 1946 UNITED STATES PATENT OFFICE General Electric Com New York pany, a corporation of Application December 23, 1942, Serial No. 469,861

11 Claims.

My invention relates to brush riggings such as are used in connection with dynamo-electric machine current collectors.

An object of my invention is to provide an improved and simplified brush rigging.

Another object of my invention is to provide an improved brush rigging in which the brush and brush holder move as a unit relative to a current collector and the contact surface of the brush remains substantially the same for all conditions of wear of the brush.

Further objects and advantages of my invention will become apparent and my invention will be better understood from the following description referring to the accompanying drawing, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In the drawing, Fig. 1 is an exploded perspective view of an embodiment of my improved brush rigging; Fig. 2 is a side elevational view, partly in section, illustrating an assembly of the brush rigging shown in Fig. 1; Fig. 3 is an exploded perspective view of a brush rigging provided with another embodiment of my invention; Fig. 4 is an assembled perspective view of the brush rigging shown in Fig. 3; and Fig. 5 is a side elevational view, partly in section, of the brush rigging shown in Figs. 3 and 4.

Referring to the drawing, I have shown in Figs. 1 and 2 a brush rigging which includes a contact brush member formed of a graphitic element l having a Wearing contact lower portion with substantially parallel curved opposite sides H and I2 formed on the same center of curvature. The contact brush element in is formed with a brush holder engaging portion l3 having opposite sides, one of which is formed by the side H and the other of which is formed by a tapered side I 4 extending at an angle to the sides i l and I2 providing a substantially wedge shape to the end brush holder engaging brush portion i3. A metal sheath I is arranged over the brush holder engaging portion of the brush member and is secured to the graphitic portion of the brush ill by a suitable rivet Hi. This brush member is adapted to be supported by a brush holder and resiliently biased into contact with a current collector IT. The brush holder is provided with sides i8 which are held together by a transversely extending plate l9 having fastening tabs 20 which extend through openings formed in the sides 3 and which are upset to provide rivet heads securing together the sides l8 and the transverse plate I9.

Each of the sides [8 of the brush holder is formed with an inturned brush engaging end element 2i. These elements 2| are arranged to engage the brush at transversely spaced apart points on one side of the brush member metal sheath I5. The transverse plate IQ of the brush holder is formed with spaced apart projections 22 and 23 adjacent the upper and lower ends thereof respectively, and these projections are formed on the plate l9 transversely thereof intermediate the brush engaging elements 2! and are spaced longitudinally above and below the elements 21 to provide for engagement of the brush member sheath i5 on the side thereof opposite the side M to provide brush engaging points spaced apart longitudinally of the brush member and spaced transversely intermediate the points of engagement of the brush with the elements 2| for wedging the brush member between the engaging elements on the opposite sides thereof. This provides for a rigid support of the brush in the brush holder and prevents any relative movement therebetween. The brush member and the brush holder are adapted to be biased resiliently as a unit towards the current collector I! by a resilient coil spring 24 which is provided with an end portion 25 hooked over a stationary pin 26 and another end portion 21 in engagement with an inturned end portion 28 of the transverse plate [9. The brush holder is pivotally supported on a spindle 29 adapted to extend through holes 30 in the brush holder sides l8 and is provided with a head 3| for holding the brush holder on the spindle. The end of the spindle away from the head 3| is threaded to provide for securing it to a suitable bracket for-pivotally supporting the brush and brush holder about an axis 32 of the spindle 29 which lies in a plane indicated by the line 33 which is substantially tangent to the current collector I! at the center of the contact of the brush member with the current collector. The center of curvature of the sides II and 12 of the brush element l0 coincides substantially with the axis 32 of the pivotal support for the brush holder. With this construction, the curved contact face 34 of the brush element In remains substantially the same for all conditions of wear of the brush ID, This also minimizes the tendency for the brush ill to toe or heel with different directions of rotation of the current collector ll. It is desirable that the pressure on the brush element In should be substantially the same for both directions of rotation in order further to minimize the tendency to toe or heel under different directions of rotation of the current collector ll. Ihis uniform pressure can be further assured by arranging the points of engagement of the elements 2| with the metal sheath l5 nearer to the lower point of engagement 23 than to the upper point of engagement 22 of the plate l9. With this type construction, a pigtail connection can be made directly to the brush holder, if desired, or to the metal sheath l5, and the simple brush member construction minimizes breakage of these member which occurs with conventional constructions using screws or other pressure devices for securing the brush members to the brush holders.

In Figs. 3, 4, and 5, I have shown another embodiment of my invention wherein a brush memher is provided having a graphitic contact element with curved opposite sides 36 and 31 formed on substantially the same center of curvature. A metal sheath or cap 38 is secured to the upper end of the contact element 35 by a pair of rivets 39 and a pigtail 40 is secured to the cap 38 and adapted to provide an electrical connection to a suitable source of electrical power supply. The brush member is adapted to be biased towards a current collector 4| by a brush holder in which it is rigidly secured without the use of screws or similar pressure clamping devices. This brush holder includes a pair of elements adapted to engage opposite sides of the brush member at spaced apart points for holding the brush in the brush holder. One of these elements is formed as a sheet metal stamping having a side 42 with an enlarged pivotal supporting opening 43 in an end thereof integrally formed with a transverse face portion 44 and an opposite side portion 45. The face portion 44 is formed with a pair of transversely spaced apart inwardly projecting brush engaging sections 45 which are adapted to engage the outer curved side of the brush member cap 38 which extends over the side 31 of the brush contact element and is also formed with inturned end tabs 41 at the upper edge thereof which are arranged to engage the upper surface 48 of the brush member cap 38. The brush member is adapted to be held in the brush holder between the engaging sections 46 and another element formed of a sheet metal stamping having a transverse plate portion 49 with a brush engaging section 59 which extends longitudinally of the brush and projects outwardly from the plate 49 to engage the inner curved side of the brush cap 38 over the curved brush side 36 at a point transversely intermediate the point of engagement of the brush holder sections 46 and the brush for wedging the brush member between the engaging elements on the opposite sides thereof. The plate 49 is arranged between sides 51 and pivotally supported by a pivot pin 52 which extends through openings 53 in the sides 5| and also through the opening 43 of the side 42 of the other brush holder element. The two brush holder elements are connected together for guided limited relative movement by a pin 54 which extends through openings 55 formed in the sides 5| of one brush holder element and through slots 56 formed in the sides 42 and 45 of the other brush holder element. The slots 56 extend angularly relatively to a line drawn between the holes 53 and 55 in the sides 5| of the other brush holder element such that relative pivotal movement between the two elements causes their brush engaging surfaces 46 and 58 to move toward or away from each other. In order to provide for this relative movement, the opening 43 in the side 42 of one of the elements is formed larger than the pivotal supporting pin 52. The brush engaging surfaces of the two elements are adapted to be biased toward each other and the brush and brush holder biased toward the current collector 4| by a resilient coil spring 5'? arranged about the pivot pin 52 and provided with an end portion 58 hooked over a stationary pin 59 and another end portion thereof arranged in engagement with an upper plate portion BI and a tab 62 extending between the sides 51 of the outer brush holder element. As in the construction shown in Figs. 1 and 2, the axis of the supporting pin 52 for the brush holder lies in a plane indicated by the line 63 substantially tangent to the center of contact between the brush member 35 and the current collector 4! to insure substantially the same curvature of the brush contact face 64 for all conditions of wear of the brush element 35. With this arrangement, the biasing spring 51 provides for rigidly holding the brush member in the brush holder by a Wedging action between the transversely spaced apart engaging surfaces of the sections 46 and 50 of the brush holder with the cap 33 of the brush member and also for biasing of the brush holder and brush member as a unit towards the current collector M. A lifting tab is formed on the face 44 of the brush holder intermediate the tabs 41 for raising the brush holder to replace or inspect the brush member.

While I have illustrated and described par ticular embodiments of my invention, modifications thereof will occur to those skilled in the art. I desire it to be understood, therefore, that my invention is not to be limited to the particular arrangements disclosed, and I intend in the ap pended claims to cover all modifications which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A brush rigging for a brush member including means including a pivo-tally supported brush holder having elements adapted to engage one side of said brush adjacent opposite edges of said brush member at transversely spaced apart points for holding said brush member in said brush holder, means for engaging the opposite side of said brush intermediate said transversely spaced apart points, said last-mentioned means and said brush engaging elements of said brush holder and said opposite sides of said brush member being arranged relatively to each other to provide for wedging of said brush member between said engaging elements on opposite sides of said brush member, and resilient means for biasing said brush holder and brush member as a unit toward a current collector and thereby increasing said wedging action between said engaging elements and said brush member sides.

2. A brush rigging for a brush member including means including a pivotally supported brush holder having elements adapted to engage one side of said brush adjacent opposite edges of said brush member at transversely spaced apart points for holding said brush member in said brush holder, means for engaging the opposite side of said brush intermediate said transversely spaced apart points, said last-mentioned means and said brush engaging elements of said brush holder and said opposite sides of said brush member being arranged relatively to each other to provide for wedgin of said brush member between said engaging elements on opposite sides of said.

brush member, and means for biasing said brush holder and brush member toward a current collector.

3. A brush rigging for a brush member including means including a pivotally supported brush holder having elements adapted to engage one side of said brush member at transversely spaced apart points and the opposite side of said brush member at longitudinally spaced apart points intermediate said first-mentioned points for h'olding said brush member in said brush holder, said brush engaging elements of said brush holder and said opposite sides of said brush member being arranged relatively to each other to provide for wedging of said brush member between said engaging elements on opposite sides of said brush member, and means for biasing said brush holder and said brush member toward a current collector.

4. A brush rigging for a brush member ineluding means including a pivotally supported brush h'older having elements adapted to engage one side of said brush member at transversely spaced apart points and the opposite side intermediate said first-mentioned points for holding said brush member in said brush holder, said brush engaging elements of said brush holder and said opposite sides of said brush member being arranged relatively to each other to provide for wedging of said brush member between said engaging elements on opposite sides of said brush member, and resilient means for biasing said brush holder and brush as a unit toward a current collector and thereby increasing said wedging action between said engaging elements and said brush member sides.

5. A brush rigging for a brush member including means including a pivotally supported brush holder having elements adapted to engage opposite sides of said brush member at transversely and longitudinally spaced apart points for holding said brush member in said brush holder, said brush engaging elements of said brush holder and said opposite sides of said brush member being arranged relatively to each other to provide for wedging of said brush member between said engaging elements on opposite sides of said brush member, and resilient spring means for biasing said brush holder and said brush member toward a current collector and thereby increasing said wedging action between said engaging elements and said brush member sides.

6. A brush rigging for a brush member including means including a pivotally supported brush holder having an element with a pair of projecting engaging sections adapted to enga e one side of said brush at transversely spaced apart points, a second element pivotally supported relatively to said first-mentioned element having a projecting engaging section adapted to engage the opposite side of said brush member intermediate said first-mentioned points, means for connecting together said brush engaging elements of said brush holder for guided relative movement for providing for varying the distance between said projecting engaging sections for wedging of said brush member between said engaging elements on opposite sides of said brush member, and means for biasing said second element relatively to said firstmentioned element into wedging engagement with said brush member.

7. A brush rigging for a dynamo-electric machine including a brush member, means including a pivotally supported brush holder having elements adapted to engage one side of said brush member at transversely spaced apart points and the opposite side of said brush member at longitudinally spaced apart points intermediate said first-mentioned points for holding said brush member in said brush holder with a current collector contact portion of said brush member projecting from one side of said brush holder, said transversely spaced points being arranged nearer one of said longitudinally spaced points adjacent said brush projecting side of said brush holder to provide substantially equal pressure on said brush member for both directions of rotation of the dynamo-electric machine, and means for biasing said brush holder and said brush member toward a current collector.

8. A brush rigging for a brush member including means including a pivotally supported brush holder having elements adapted to engage one side of said brush member at transversely spaced apart'points and the opposite side of said brush member at longitudinally spaced apart points intermediate said first-mentioned points and spaced longitudinall therefrom for holding said brush member in said brush holder with a current collector contact portion of said brush member projecting from one side of said brush holder, said brush engaging elements of said brush holder and said opposite sides of said brush member being arranged relatively to each other to provide for wedging of said brush member between said engaging elements on opposite sides of said brush member, and resilient spring means for biasing said brush holder and said brush member toward a current collector and thereby increasing said wedging action between said engaging elements and said brush member sides.

9. A brush rigging for a brush member including means including a pivotally supported brush holder having elements adapted to engage one side of said brush adjacent opposite edges of said brush member at spaced apart points for holding said brush member in said brush holder, means for engaging the opposite side of said brush intermediate said transversely spaced apart points, said last-mentioned means and said brush engaging elements of said brush holder and said opposite sides of said brush member being arranged relatively to each other to provide for wedging of said brush member between said engaging elements on opposite sides of said brush member, resilient means for biasing said brush holder and brush member as a unit toward a current collector and thereby increasing said wedging action between said engaging elements and said brush member sides, and means having the center line thereof in a plane tangent to the current collector at substantially the center of the contact of said brush member and the current collector for pivotally supporting said brush holder.

10. A brush rigging for a brush member including means including a pivotally supported brush holder having an element with a pair of projecting engaging sections adapted to engage one side of said brush at transversely spaced apart points and elements arranged to engage the top of the brush member, a second element pivotally supported relatively to said first-mentioned element having a projecting engaging section adapted to engage the opposite side of said brush member intermediate said first-mentioned points for holding said brush member in said brush holder, means for connecting together said brush engaging elements of said brush holder for guided limited relative movement for providing for varying the distance between said projecting engaging sections for wedging of said brush member between said engaging elements on opposite sides of said brush member, and resilient means for biasing said second element relatively to said first-mentioned element into wedging engagement with said brush member and for biasing said brush holder and brush member as a unit toward a current collector and thereby increasing said wedging action between said engaging elements and said brush member sides.

11. A brush rigging for a dynamo-electric machine including a brush member, means including a pivotally supported brush holder having elements adapted to engage one side of said brush member at transversely spaced apart points and the opposite side of said brush member at longitudinall spaced apart points intermediate said first-mentioned points and spaced longitudinally therefrom for holding said brush member in said brush holder with a current collector contact portion of said brush member projecting from one side of said brush holder, said transversely spaced points being arranged nearer one of said longitudinally spaced points adjacent said brush projecting side of said brush holder to provide substantially equal pressure on said brush memher for both directions of rotation of the dynamoelectric machine, said brush engaging elements of said brush holder and said opposite sides of said brush member being arranged relatively to each other to provide for wedging of said brush member between said engaging elements on opposite sides of said brush member, and resilient spring means for biasing said brush holder and said brush member toward a current collector and thereby increasing said Wedglng action between said engaging elements and said brush member sides.

WAYNE J. MORRILL.

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