US2028176A

US2028176A - Brush rigging and end cap assembly for surgical motors and the like

Info

Publication number: US2028176A
Application number: US624739A
Authority: US
Inventors: Howard A Whiteside
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-07-26
Filing date: 1932-07-26
Publication date: 1936-01-21
Anticipated expiration: 1953-01-21

Description

H. A. WHTESEDE BRUSH RIOGNG AND END OAR ASSEMBLY ROR SURGICAL MOTORS AND THE Lm;

Original Filed July 26, 1932 2 SheetS-Sheez .gam 2l, 1936. H. A, WW1-55395 ZQSU@ BRUSH RIGGING AND END CAP ASSEMBLY FOR SURGICAL MOTORS AND THE LIKE Original Filed July 26, 1932 2 Sheets-Sheet 2 IN l/E/v Toa HOW/JED V//rES/oe Patented Jan. 21, 1936 UNITED STATES PATENT OFFICE Howard A. Whiteside, New York, N. Y.

Application July 26, 1932, Serial No. 624,739 Renewed March 23, 1935 56 Claims.

The present invention relates to brush rigging and end cap assemblies for surgical motors and the like, and is more particularly directed toward structures of a type suitable for employment in such commutator type motors wherein themotor shaft and spindle of the hand piece are hollow so that the yfastening and release of a tool may be controlled by a clutch rod which passes through the motor armature shaft and hand piece spindle, or wherein the shaft is solid.

Hand pieces wherein the coupling and uncoupling of the tool are under the control of the clutch rod passing through the spindle are generally known as Doriot hand pieces, and the present invention is more particularly directed toward the rear end of a motorized Doriot hand piece wherein the motor for operating the tool in the hand piece is directly connected to the hand piece so that the motor and hand piece form a single instrument capable of being held in the hand for surgical operations and wherein the adjustment of the clutch for the tool is performed by the clutch rod extending out through the rear of the motor. Certain features of the present invention, however, are capable of general application to small motors, whether of the type wherein a hollow armature shaft is employed or whether of the type wherein a solid armature shaft is used which does not protrude through the end cap of the motor. In such motors, a modified arrangement of bearings may be employed.

An object of the present invention is to provide a brush rigging for surgical motors in which radial spring-pressed brushes cooperative with a cylinder type commutator are carried in a ring made out of insulating material secured on the end of the motor housing. This brush rigging may be so arranged that the brush carrying disk is cut away to permit access to the commutator for purposes of cleaning or the brush boxes may be provided by radially drilling the disk and axially extending metallic inserts. The brushes may be removed for cleaning and replacement Without disturbing the neutral point adjustment of the brushes.

The present invention also contemplates the provision of end cap and brush rigging assembly more particularly for surgical motors and wherein the brush carrying disk secured to the motor housing carries the end cap. The end cap housing preferably has a long bearing on the outer surface of the brush rigging carrying disk and is clamped to the brush carrying disk by axially extending members secured to the brush carrying disk and extending through the wall of the end cap. The end cap may then cover the brush rigging and prevent entrance of dirt or moisture. The end cap carries terminals electrically connected with the current supply wires in a iexible cable, and in certain types of motor, it also provides the support for the rear bearing in the motorized hand piece.

The present invention relates to improvements in the form of combined brush rigging and end cap assemblies shown in my copending application 580,920, a division of Patent No. 1,836,350. Other and further objects of the invention will appear as the description proceeds.

The accompanying drawings show, for purposes of illustrating the present invention, several of the many possible embodiments in which it may take form, it being understood that the drawings are illustrative of the invention rather than limiting the same.

Figure 1 is an elevational view of a complete motorized hand piece;

Figure 2 is an enlarged longitudinal sectional view through the rear end of the motorized hand piece showing one form of brush rigging and end cap assembly;

Figure 3 is a section taken on the line 3 3 of Figure 2 and showing particularly the brush rigging and brush supporting disk;

Figure 4 is an elevational view taken in the direction of the arrow 4 of Figure 2 with parts omitted;

Figure 5 is an elevational View taken in the direction of the arrow 5 of Figure 3; parts being in section and other parts being broken away, this iigure more particularly showing the securing of the end cap on the brush rigging disk;

Figure 6 is a sectional View taken on the line 6 6 of Figure 2 looking in the direction of the arrow and illustrating the inside of the end cap;

Figure 7 is a sectional view similar to Figure 2 showing a different form of construction;

Figure 8 is an elevational view of the rear or left end of Figure 7, with the cover plate omitted and parts broken away to show sections at varying places along the axis of the motor;

Figure 9 is a sectional view through the brush rigging and end cap showing the method of fastening these parts together, parts being in elevation and the armature shaft and bearings omitted;

Figures 10 and l1 are longitudinal and transverse sectional views with a modified form' of motor adapted for use with a central, current supply cord and a disk type commutator, Figure slightly larger than the commutator I2.

11 being taken on the line lI-II of Figure 10, and Figure 10 being taken on the broken section line lll-l of Figure 11;

Figure 12 is a longitudinal sectional view taken on the broken line |2-l2 of Figures 13 and 14 and showing a further modied form of motor;

Figures 13 and 14 are respectively end. elevational views of the end cap and of the brush rigging and motor body, being taken in the directions of the arrows I3 and lnrespectively, of Figure 12;

Figure 15 is a sectional vieweon the line I5-l5 of Figures 13 and 14 to show the securement of the end cap to the brush rigging disk and the brush rigging disk to the casing; and

Figure 16 is a sectional view on the line llii6 or Figure 13 to show the off-center current supply cord.

The motorized tool unit which is illustrated in Figure 1 may be considered to consist of a motor A and a hand piece B. The hand piece is adapted to carry a tool such as a drill or grinding Wheel indicated at C. The motor portion A contains all of the parts ordinarily found in an electric motor and 'the speed and direction of rotation of the motor armature may be under the control of a foot controller, such as shown in my copending application, Serial Number 580,920.

The motor A has a rigid self-supporting unitary casing l0 of generally cylindrical shape forming a structural part of the motor and directly supporting the field structure. Further details of construction o the motor and hand piece and the operation of assembling the motorized hand piece are set forth in my application for Surgical motors and hand pieces i'iled on even date herewith as Serial No. 624,738. So far as the parts described in detail herein are concerned, it is suicient to say that the motor A has a field structure H and cylindrical type commutator l2 and hollow or tubular armature shaft i3 which extends out to the left or rear end of the motor. The hollow armature shaft is provided so as to accommodate a clutch rod I4 employed in Doriot type hand pieces.

The motor is provided with a two pole brush rigging carried by an insulating disk 20, one form of which is shown more in detail in Figures 2, 3 and 5. This disk has a slightly reduced portion 2| which extends'inside the open left or rear end of the motor casing I0 to which it can be secured by screws 22 after adjustment. The brush holding disk may be considered to consist of a round annulus having a central hole or aperture 24 The disk is transversely drilled on a diameter as indicated at 25 to accommodate the brushes.

Tubular metal sleeves

26 and 21 are pressed into the drilling 25 and each of these tubular sleeves is adapted to support a brush 28, a brush spring 29 and a headless screw 30, the latter being carried in threads tapped into the metal sleeve.

In order to reduce the weight of the parts and permit access to the side of the commutator for cleaning, the disk is cut away in the sides of the brush boxes asappears more clearly in Figure 5. To further lighten the disk and provide for the passage of armature wires, and to maintainV the balance of the motor, four holes are drilled into the disk as indicated at 3 I. The disk 20 may also be provided with a bridging member of about the width of the brush boxes or the aperture 24 may extend all the way through the disk. This bridging member is apertured in the center to accommodate the shaft and may form a bearing for the shaft when the end cap is removed. If it is to form a bearing it is reamed at the same time as the bearing in the end cap, and to the proper size.

The brush carrying disk also carries a pair of field connection studs 32 and a pair of brush rigging connection studs 34. These studs may conveniently be in the form of long screws passing through tapped holes in the insulating material of the brush disk. The

brush boxes

26 and 21 are inserted in place in the brush carrying disk before the holes for the screws 34 are drilled so that each screw will pass through the wall of the brush box, as indicated in Figure 3 thereby locking the brush box in place and electrically connecting it with the screw. The screws 32 and 34 are securely locked in place by nuts 35 and 36, respectively, having heads as indicated for cooperation with a wrench. Two or all of these nuts may have long tubular extensions 35a and 35a chamfered on the edge as indicated. The eld wires are passed through the holes 3| and clamped under the nuts 35 so that these studs 32 are connected to the eld wires. These four studs are asymmetrically located and extend rearwardly to provide means for securing the end cap above referred to onto the motor and at the same time to provide current connections for themotor armature and field.

In the form of construction shown in Figures 2 and 6, inclusive, the end cap 40 is in the form of a cup-like member adapted to telescope over the outside of the brush carrying disk 2li and abut against the end of the motor casing l0. This end cap carries an adjustable bearing 4I which may include, as shown in Figure 2, a metal sleeve 4Z threaded into the end cap di! and an arguto wood sleeve carried in the metal sleeve. This arguto wood sleeve forms an oilless bearing and cooperates with the ring 4 abutting against a shoulder M on the armature shaft to take the thrust of the tool. It is adjustable toward this shoulder on the armature shaft by threading the metal part l in the casing and clamping it in place by a lock nut 455. The armature shaft i3 is hollow and extends out to the left as indicated. It carries a knurled iinger grip 41 so that the operator can grip the armature shaft while adjusting the clutch rod, all of which appears more in detail in the application Serial No. 624,738, referred to above.

The end cap 4Q is drilled and tapped as indicated in Figure so as to receive four metal inserts 50. Each insert passes down into an annular recess 5l in the end cap and on the inner end is provided with slots 52 for cooperation with a special wrench so that it can be secured tightly in place. The threaded end of the insert extends beyond the inner face 53 of the end cap and nuts 54 having slotted heads 55 are threaded on the exposed ends of theseinserts.

These nuts are employed for clamping the wires 56, 51, 58 and 59 in place as indicated in Figure 6. These wires are brought to the motor by a cable 6G whichY passes through a hole 6l in the wall of the end cap. The cable employed is preierably a rubber covered four conductor cable which fits close to the hole 5| in the end cap and the wires and cable are sealed in place by a quick drying varnish.

The end cap carrying the four inserts, the bearing and the cord, may be inserted in place on the armature and armature shaft by merely passing the bushing 44 along the armature shaft, then aligning the inserts 5B and screws32 and 35 and passing the forward end of the end cap over the brush rigging disk 2i). In order that the end cap cannot be placed in the improper position, the screws 32 and 34 are arranged in asymmetric manner. As indicated in the drawings, they are all on the same radius but not on the quadrant.

In assembling the end cap, the tubular portions a and a oi the nuts 35 and Se pass into the metal inserts this being facilitated by chamfering the nuts as indicated. This arrange ment provides for accurately centering the screws or studs 32 or 35i in the metal inserts. Flanged nuts 62 are threaded on the exposed ends of the screws 32 and Sii. These iianged nuts have slots 63 to receive a screw driver and when they are threaded down tightly as indicated in Figure 5, the iianges overlie the ends of the inserts and the end cap and brush carrying disk are secured together. In order that the electrical connections on the rear of the motor will not be exposed, a cover plate 64 may be employed. This cover plate is fastened on by screws 55. The cover plate is notched to accommodate the cord Si?.

When assembling a motor cf the type which has been described, the armature and iield are placed in position in the motor casing with the field wires projecting out of the casing. The brush rigging disk 2u is placed in position on the end of the motor casing, Field wires passed through the holes in the disk and secured to the binding posts provided by the nut on the screws 32. The brushes and springs are placed in the brush boxes and in adjusting the brush rigging to the neutral point, the motor is run with temporary connection to the screws 32 and 34, or a dummy end cap is employed. rlhis end cap may be the same as the regular cap except that it is provided with holes to permit observation 0f the action of the brushes on the commutator, and is also provided with parts to engage with the brush carrying disk to permit turning the latter relative to the casing. The holes for the screws 32 are then drilled and tapped and the screws inserted.

In Figure 7 the motor casing 'iii may be the same as that shown in Figures 1 and 2. The motor may be provided with the same type of commutator l2 and tubular armature shaft I3 which has been described in detail with respect to Figure 2. The motor is also adapted to carry the knurled nger grip il and clutch rod I d which has been before set forth. The rear end of the armature shaft may be supported in an adjustable bearing 4l.

The brush rigging disk Ti has a slightly reduced. end portion 'i2 adapte-d to be inserted into the open end of the motor casing and to fit tightly in place therein. The brush rigging disk is provided with a central aperture indicated at 'I3 to accommodate the commutator and is drilled and tapped as indicated at I to receive four studs. These studs are arranged in pairs, l5, 'i5 and l5, i6 and are disposed asymmetrically in somewhat the saine manner as the screws 32 and 34. These studs are threaded into the brush rigging plate from the front or inner face and are clamped in place by lock nuts 'il which enter recesses counterbored into the rear or outer face of the brush rigging disk. The exposed ends of the studs may be smooth as indicated.

After the studs i5, have been secured in place, the brush rigging disk is drilled on a diameter so as to provide brush boxes i3 which eX- tend directly through the center of the studs l5,

as indicated. These drillings form brush boxes and are adapted to receive a brush "i9, brush spring 33, and screw 8|. The screws are threadn ed into the outer ends of the drillings suitable threads having been cut into the material so that the screws may pass below the surface of the brush rigging disk.

The wires irorn the motor field may be carried out through holes 32 drilled through the brush rigging disk and these :Field wires are placed underneath the nuts 'il carried on the studs 16 before these nuts are tightened in place.

The brush rigging is adjusted to the neutral point in the same manner that has been described and the brush rigging and motor casing fastened together by screws 85 as before described.

The end cap 85 in the construction shown in Figure 7 is somewhat similar to the end cap that has been described previously. It has a skirted portion S7 which overlies the brush rigging disk and which abuts the end of the motor casing. The end cap is threaded at sil to receive an adjustable bearing di and is provided with four asyinmetrically arranged holes iig threaded and receive a cable '32 similar to the cable above described and the wires extending from this cable are passed across the inner face of the end cap and secured underneath nuts 23 threaded onto the metal inserts Sil. These wires and the cable are cemented in place by a quick drying varnisand in this manner the end cap with its inserts, bearing and attached cable may be assembled as a unit.

The end cap may be laced on the armature shaft and brush rigging disk of the motor in an obvious manner and then the outer ends of the studs i5 and l5 will be carried within the inserts rThese studs are internally threaded as indicated at S4 to receive screws having heads which are adapted to down into the counterbored holes in the end cap and against the outer end of the metal inserts. In this manner the screws S5 are employed for securing good electrical connection between the parts. To cover the screws 95, an end plate may be fastened on in the same manner as the end plate till in the construction shown in 1Figure 2.

The arrangement shown in Figures l0 and ll is designed for a motor with an end type commutator, solid shaft and current supply cord in the center. The casing lili), brush rigging disk i9 l, and end cap im are made of insulating material. tral bearing m3, made for example of oilless wood, for the armature shaft luft. rIhe disk is provided with two comparatively large tapped holes le for brush boxes i and two comparatively small tapped holes ier held connection studs IiiS, these holes being asymmetrically arranged as indicated in Figure li. The disk lili is secured to the motor casing iliii, after adjustment oi the brushes to the neutral position, as above described, by means oi screws 2&9.

The brush boxes have slotted heads 65 and are xedly secured to the disk by lock washers HQ. Each is drilled to receive a brush lll, a brush spring H2, and tapped to receive a screw iii?. The field connection studs it are in the form of long screws, and locked to the disk by lock nuts i i5 which also secure the iield leads I i8 in place.

The end cap m2 is received over the brush disk in thD manner above described. It has a central The brush rigging disk ii carries a cenopening for a four conductor current supply cord i8 which is suitably connected in place. It is drilled, tapped, and counterbored as indicated so as to receive two large inserts |29 to receive the brush boxes H35 and two smaller inserts |2|l to receive the eld connection studs |58. These inserts are locked in place by threaded washers |2| and 22 which also bind the ap-propriate wires of the cord to the proper insert.

The end cap, with attached cord, may be placed on the rearwardly projecting brush boxes and -studs in the same manner as the cap of Figures 1 9. Nuts |23 are threaded onto the studs |93, and the brushes and brush springs inserted into the brush Aboxes ISB and screws |2l threaded into the tapped ends of the brush boxes. The screws |24 and nuts secure the end cap in place. A cover plate 25, similar to the cover plate 55d, is threaded onto the rear end of the end cap, as shown, so as to cover the exposed conducting elements.

The form shown in Figures i2-l6, inclusive, is designed more particularly for a Doriot type motor having a disk type commutator. The rear or open end of the motor casing is indicated at |30. This motor casing carries the eld and front armature bearing in any suitable manner. The tubular armature shaft is indicated at |3| and the disk type commutator at |32. The tubular armature shaft ESE is adapted to receive the Doriot clutch rod indicated at |33. The brush rigging disk is indicated at E36 and the end cap at |35.

The brush rigging disk has two small tapped holes as indicated at |36 for eld connection members i3?. These members are threaded as indicated and are provided with heads which enter counter sunk areas in the inner face of the brush disk. The outer ends of these iield terminals are split as indicated at |33.

Field connection leads |39 are passed through holes |49 drilled in the disk and are soldered to washers threaded on to the members |375.

The brush rigging disk is also provided with two larger tapped holes |52 adapted to receive tubular brush boxes |43 as shown. These tubular brush boxes carry brmhes ilii, brush springs |45, and screws M5. The brushes bear on the commutator in the usual well known manner. The brush disk telescopes into the casing |39, as illustrat-ed at |l, and these parts are secured together after adjusting the brush rigging to neutral position by means of screws |58.

In order to keep lubricant away from the commutator, the motor is provided with an oil thrower in the form or" a ange metal sleeve |659 which snugly ts the shaft and is out of contact with the brush disk.

The end cap is secured to the brush carrying disk by means of two screws |51 which pass through drilled and counter sunk holes |53 in the end cap, and into tapped holes |59 in the brush disk. These screws act to hold the end cap securely against the end of the motor casing and keep all the parts in proper position.

The brush springs act to press the armature toward the front end of the motor so that the thrust is normally on the front bearing, not shown. The oil thrower N9 is designed so as to just fill the space between the bushing |50 and the commutator, so that the weight of the armature is kept orf the brushes when the motor is operated with the rear or brush end down.

The form of construction shown in Figures i2-16 has the advantage of completely enclosing the eld and brush connections so that no cover plate is necessary. It is, however, possible to readily replace the brushes when necessary. This motor may, if desired, be enclosed in a metal shield or casing lli.

While the drawings show motors having four current carrying studs, thereby separating the eld and armature circuits, it is entirely possible to omit the eld connection studs and associated parts where a non-reversible motor is to be constructed, and the speed is controlled by varying the applied voltage.

I claim:

l. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising an adjustable brush rigging xedly secured in adjusted position across the open end of the motor casing and including a brush carrying disk located to hold brushes carried thereby on the commutator, said disk also carrying rearwardly extending current carrying members, an end cap carrying a current supply cable having wires connected to terminals disposed on the inner face of the end cap and spaced to cooperate with the current carrying members, a bearing carried by one of said parts for supporting one end of the armature shaft, and means including the current carrying members and independent of the bearing for securing the end cap in position.

2. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising an adjustable brush rigging fixedly secured in adjusted position across the open end of the motor casing and including a brush carrying disk located to hold brushes carried thereby on the commutator, said ydisk also carrying four rearwardly extending current carrying members, two of which are connected to the brushes and two of which provide eld connections, an end cap carrying a current supply cable having wires connected to each of four terminals disposed on the inner face of-the end cap and spaced to cooperate with the current carrying members, a bearing carried by one of said parts for supporting one end of the armature shaft, and screw threaded devices associated with the current carrying members and the terminals for securing the end cap in position.

3. in a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a commutator, ci a combined brush rigging and end cap assembly, comprising an adjustable brush rigging fixedly secured in adjusted position across the open end or" the motor casing and including a brush carrying disk located to hold brushes carried thereby on the commutator, said disk also carrying rearwardly extending current carrying members, an end cap carrying a current supply cable having Wires connected to terminals disposed on the inner face of the end cap and spaced to cooperate with the current carrying members, the end cap being cup-shaped, bearing on the brush disk and abutting against the end of the motor casing, a bearing carried by one of said parts for supporting one end of the armature shaft, and means to secure the end cap in position, said current carrying members and terminals being male and female so as to slide relatively when the end cap is moved in an axial direction.

4. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising an adjustable brush rigging xedly secured in adjusted position across the open end of the motor casing and including a brush carrying disk located to hold brushes carried thereby on the commutator, said disk also carrying rearwardly extending current carrying members, an end cap carrying a current supply cable having Wires connected to terminals disposed on the inner face of the end cap and spaced to cooperate Withthe current carrying members, an axially adjustable bearing carried by the end cap for supporting one end of the armature shaft, and means to secure the end cap to the brush carrying disk.

5. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising an adjustable brush rigging fixedly secured in adjusted position across the open end of the motor casing and including a brush carrying disk located to hold brushes carried thereby on the commutator, said disk also carrying rearwardly extending current carrying members, an end cap` carrying an eccentrically located current supply cable having wires connected to terminals disposed on the inner face of the end cap and spaced to cooperate with the current carrying members, an axially adjustable bearing carried by the end cap for supporting one end of the armature shaft, and means to secure the end cap to the brush carrying disk, the end cap with cable and bearing being removable as a unit to expose the brushes and commutator.

6. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising an adjustable brush rigging fixedly secured in ad-Y justed position across the open end of the motor casing and including a brush carrying disk located to hold brushes carried thereby on the commutator, said disk also carrying rearwardly extending threaded current carrying members, an end cap carrying a current supply cable having Wires connected to tubular terminals, passing through the end wall of the end cap and spaced to receive the current carrying members, a bearing carried by one of said parts for supporting one end of the armature shaft, and threaded members cooperative with the threaded current carrying members for securing the end cap in position beyond the brush carrying disk.

'7. In a miniature motor, the combination with a stationary' motor casing having an open end at the rear, and a revolvable armature-shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising an adjustable brush rigging xedly secured in adjusted position across the open end of the motor casing and including a brush carrying disk located to hold brushes carried thereby on the commutator, said disk also carrying rearwardly eX- tending threaded current carrying members, an end cap carrying a current supply cable having wires connected to tubular terminals, passing through the end wall of the end cap and spaced to receive the current carrying members, the end cap being cup-shaped, bearing on the brush disk, and abutting against the end of the motor casing, a bearing carried by one of said parts for supporting one end of the armature shaft, and threaded members cooperative with the threaded current carrying members for securing the end cap in position beyond the brush carrying disk.

8.A In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising an adjustable brush rigging fixedly secured in adjusted position across the open end of the motor casing and including a brush carrying disk 10- cated to hold brushes carried thereby on the commutator, said disk also carrying rearwardly extending threaded current carrying members, an end cap carrying a current supply cable having wires connected to tubular terminals, passing through the end Wall of the end cap and spaced to receive the current carrying members, a bearing carried by one of said parts for supporting onev end of the armature shaft, threaded members cooperative with the threaded current carrying members for securing the end cap in position beyond the brush carrying disk, and a cover plate of insulating material secured to the outer face of the end cap and covering the last mentioned threaded members.

9. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armatureshaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising an adjustable brush rigging xedly secured in adjusted position across the open end of the motor casing and including a brush carrying disk located to hold brushes carried thereby on the commutator, said disk also carrying rearwardly extending current carrying members, an end cap carrying a current supply cable having wires connected to terminals disposed on the inner face of the end capand spaced to cooperate with the current carrying members, the end cap being cup-shaped, bearing on the brush disk and abutting against the end of the motor casing, an axially adjustable bearing carried by the end cap for supporting one end of the armature shaft, and means including the current carrying members and independent of the bearing for securing the end cap in position beyond the brush carrying disk.

l0. In a miniature motor, the combination with a stationary motor casing made of frangible insulating material, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising a brush carrying disk made of frangible insulating material and having a reduced portion slidably received within the motor casing and fixedlysecured to the motor casing across the end thereof and'in position to hold brushes caricd thereby on the commutator, a cup-shaped end cap, also made of frangible insulating material and slidably received about-the periphery of the disk, means to secure the end cap on the brush rcarrying disk with the end cap surrounding the disk and having its edge abutting the end of the casing, the inner surfaces of the end cap and casing adjacent the edges being in contact Vwith and reinforced by the disk, and a bearing carried by one of said parts for supporting one end of the armature shaft. Y

-11. In a miniature motor, the combination with a stationary motor casing, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising a brush carrying disk adapted to be xedly secured to the motor casing across the end thereof and in position to hold brushes carried thereby on the commutator, an end cap, disk-supported axially extending current carrying members arranged in pairs, two for the armature leads and i two for Vthe eld leads, said members extending through the end cap, means cooperative with these members to secure the end cap on the brush carrying disk, the end cap having a peripheral wall surrounding the disk and having its edge abutting the end of the casing, and a bearing carried by one of said parts for supporting one end of the armature shaft.

12. In a miniature motor, the combination with a stationary motor casing, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising a brush carrying disk adapted to be xedly secured to the motor casing across the end thereof and in position `to hold brushes carried thereby on the commutator, an end cap, a plurality of disk-supported threaded members extending through the end cap, threaded members cooperating therewith for securing the end cap on the brush carrying disk with the end cap surrounding the disk and having its edge abutting the end of the casing, and a bearing carried by one of said parts for supporting one end of the armature shaft.

13. In a miniature motor, the combination with a stationary motor casing, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and end cap assembly, comprising a brush carrying disk adapted to be fixedly secured to the motor casing across the end thereof and in position to hold brushes carried thereby on the commutator, an end cap supporting the armature shaft outside the brush rigging disk, and means to secure the end cap on the brush carrying disk with the end cap surrounding the disk and having its edge abutting the end of the casing.

14. In a miniature motor, the combination with a stationary motor casing, and a revolvable armature shaft carrying a commutator, of a combined f vbrush rigging and end cap assembly, comprising a brush carrying disk adapted to be iixedly secured to the motor casing across the end thereof and in position to hold brushes carried thereby on the commutator, an end cap carrying current supply terminals, supporting the armature shaft outside the disk and having its edge abutting the end of the casing, and dually functioning axially extending threaded members carried by the brush carrying disk and extending through the termilnals on the end cap for clamping the end cap in place and conducting current to the brushes and motor field.

15. In a miniature motor, a motor casing open at the rear end, a motor eld carried in the casing, amotor armature shaft carrying a commutator, and a combined end cap and brush rigging assembly which provides a bearing for the armature shaft and includes an end cap and a brush rigging disk secured to the casing and carrying brushes for the commutator, brush terminals and field terminals, said terminals extending axially into corresponding terminals carried by the end cap, and securing means cooperative with the terminals for securing the end cap to the disk.

16. In a miniature motor, a motor casing open at the rear end, a motor eld carried in the casing, a motor armature shaft carrying a commutator, and a combined end cap and brush rigging assembly which includes an end cap and a brush rigging disk secured to the casing and carrying brushes for the commutator, brush terminals and field terminals, said terminals extending axially into corresponding terminals carried by the end cap, securing means cooperative with the terminals for securing the end cap to the disk, and an axially adjustable thrust bearing carried by the end cap.

17. In a miniature motor, a motor casing open at the rear end, a motor field carried in the casing, a motor armature shaft carrying a commutator, and a combined end cap and brush rigging assembly which provides a bearing for the armature shaft and includes an end cap and a brush rigging disk secured to the casing and carrying brushes for the commutator, brush terminals and field terminals, said terminals extending axially into corresponding terminals carried by the end cap, the end cap telescopically fitting the disk and having its end engaging the open end of the casing, and securing means cooperative with the terminals for securing the end cap to the disk.

. 18. In a miniature electric motor, in combination, a cup-shaped end cap, a brush rigging disk telescopically fitting inside the end cap and carrying a pair of brush lead studs and a pan' of field lead studs, all the studs extending rearwardly and passing through metal inserts in the end cap, and threaded members cooperative with the outside of the end cap and the studs for securing the end cap to the brush rigging disk.

19. In a miniature electric motor, in combination, a cup-shaped end cap, a brush rigging disk telescopically tting inside the end cap and carrying a pair of brush lead studs and a pair of field lead studs, al1 the studs extending rearwardly and passing through metal inserts in the end cap, threaded members cooperative with the outside of the end cap and the studs for securing the end cap to the brush rigging disk, and a shaft bearing carried by one of said parts for the armature shaft.

20. In a miniature electric motor, in combination, a cup-shaped end cap, a brush rigging disk telescopically fitting inside the end cap and carrying a pair of brush lead studs and a pair of eld lead studs, all the studs extending rearwardly and passing through metal inserts in the end cap, threaded members cooperative with the outside of the end cap and they studs for securing the end cap to the brush rigging disk, and an axially adjustable armature shaft bearing carrie by the end cap. 21. The combination with a cylindrical motor casing of rigid self-sustaining insulating material and having its open end in a plane normal to the cylinder axis, of a brush rigging disk of insulatingmaterial telescopically tting inside and secured to the casing, and having a shoulder in a plane normal to the disk axis and abutting against the inner margin of the end wall of the casing to limit the movement oi the disk along the casing axis and to insure that the axis oi the disk coincides with the axis of the casing, and an end cap telescopically itting the outside of the brush rigging disk and coaxial therewith, the edge of the end cap being normal to the plane of the cap axis and abutting against the end wall of the motor casing whereby the disk and cap may be adjusted about the casing axis.

22. The combination with a cylindrical motor casing of rigid self-sustaining insulating material and having its open end in a plane normal to the cylinder axis, of a brush rigging disk of insulating material telesccpically fitting inside and secured to the casing, and having a shoulder in a plane normal to the disk axis and abutting against the inner margin oi the end of the casing to limit the movement of the disk along the casing axis and to insure that the axis of the disk coincides with the axis of the casing, and an end cap telescopically tting the outside of the brush rigging disk and coaxial therewith, the edge of the end cap being normal to the plane of the cap axis and abutting against the end wall of the motor casing whereby the disk and cap may be adjusted about the casing axis, the disk having radial brush boxes which are covered by the end cap.

23. The combination with a cylindrical motor casing of rigid selfesustaining insulating material, of a brush rigging disk of insulating material telescopically tting inside and secured to the casing, and having a shoulder abutting against the inner margin of the end of the casing, an end cap telescopically fitting the outside of the brush rigging disk and abutting against the end wall of the motor casing, pairs of studs attached to the disk for supplying current to the armature and field., said studs passing through the end cap, and devices threaded on the exposed ends of the studs for securing the end cap in place.

24. In an electric motor, a brush rigging disk, a pair of rearwardly extending armature lead studs carried by the disk and connected with brushes for cooperation with the motor. commutator, a pair of rearwardly extending ield connection studs carried by the disk, an end cap having four metal sleeves each connected to a current supply wire, and adapted to receive one of the studs, and means cooperative with the studs for securing the end cap in place.

25. In an electric motor, a brush rigging disk, a pair of rearwardly extending armature lead studs carried by the disk and connected with brushes for cooperation with the motor cornmutator, a pair of rearwardly extending field Connection studs carried by the disk, an end cap having four metal sleeves each connected to a current supply wire and adapted to receive one of the studs, the end cap also having a peripheral skirt which surrounds the disk, and means cooperative with the studs for securing the end cap in place.

26. In an electric motor, a brush rigging disk, a pair of rearwardly extending armature lead studs carried by the disk and radially drilled to provide boxes for brushes for cooperation with the motor commutator, a pair of rearwardly extending eld connection studs carried by the disk, an end cap having tour metal sleeves each connected to a current supply wire and adapted to receive one of the studs, and threaded mem- ,ca-l, flanged metal tubular bers carried by the studs for securing the end cap in place.

27. An end cap for miniature motors comning cup-shaped body of insulating ina having a plurality of threaded holes exten nig through. the end wall of the end cap, flanged metal tubular inserts threaded into the holes, the outer face of the end cap being recessed to receive the anges, the inserts extending beyond the inner face of the end wall or the cap, and a cable passing through the end wall and having wires, each of which is secured to the exposed end of an insert.

28. .An end cap tor miniature motors comprising a rigid seit-sustaining cup-shaped body of insulating material having a plurality of threaded holes extending through the end wall of the end inserts threaded into the holes, the outer face of the end cap being recessed to receive the flanges, the inserts extending beyond the inner face ci' the end wall of the cap and being slotted to receive a screw driver to permit tightening there from the inside, nuts threaded onto the ends or the inserts, and a cable passing through the end wall and having wires, each oit which is secured underneath a nut.

29. In a miniature electric motor of the type wherein a shaft driven tool connected to the motor casing and driven from the front end of the motor. an end cap for the rear end of the motor in the iorrn oi a rigid self-sustaining cupsnaped body or" insulating material carrying a plurality or tubular metal inserts spaced about the motor axis, and extending through its end wall, and a cable passing through a hole in said end wall and having a wire secured to each insert.

3i). In a miniature electric motor of the type wherein a shaft driven tool is connected to the rector casing and driven from the iront end of the motor, an end cap for the rear end of the motor in the form of a rigid self-sustaining cupshaped body or" insulatinsr material carrying a plurality of tubular inetal inserts spaced about the motor axis, and extending through its end wall, the outer face oi the end cap being recessed to receive hanged heads on the inserts, and a cable passing through a hole in said end wall and having a wire secured to each insert.

3l. In a miniature electric motor of the type wherein a shaft driven tool is connected to the motor casing and driven from the front end of the motor, an end cap for the rear end of the motor in the rorrn oi a rigid self-sustaining cupshaped body of insulating material carrying a plurality of tubular metal inserts spaced about the motor axis, and threaded through its end wall, each insert having a anged outer end, and a cable passing through a hole in said end wall and having a wire secured to each insert.

32. In a miniature electric motor of the type wherein a shaft driven tool is connected to the motor casing and driven from the front end o f the motor, an end cap for the rear end of the motor in the form of a rigid self-sustaining cupshaped body of insulating material carrying a plurality of tubular metal inserts spaced about the motor axis, and extending through its end wall, a threaded shaft bearing carried in the center of the end wall, and a cable passing through a hole in said end wall having a wire secured to each insert.

33. A brush rigging for miniature motors comprising an annulus of insulating material having a central opening for a commutator, and a plurainy of axially extending threaded holes arranged in pairs, a pair of metallic studs secured in said holes and extending rearwardly from the annulus, there being a radially extending drilling extending through the annulus and each stud, brushes and brush springs disposed in said drillings, and plugs in the outer ends of the drillings to retain the brushes and springs in place.

34. A brush rigging for miniature motors comprising an annulus of insulating material having a central opening for a commutator, a forwardly extending peripheral skirt adapted to be received in a motor casing and a plurality of axially extending threaded holes arranged in pairs, a pair of metallic studs threaded through said holes extending rearwardly from the annulus and locked therein, there being a radially extending drilling extending through the annulus and each stud, brushes and brush springs disposed in said drillings, and plugs in the outer ends of the drillings to retain the brushes and springs in place.

35. A brush rigging for miniature motors comprising an annulus of insulating material having a central opening for a commutator, a forwardly extending peripheral skirt adapted to be received in a motor casing, and a plurality of axially extending threaded holes arranged in pairs, a pair of metallic studs threaded through said holes extending rearwardly from the annulus and locked therein, there being a radially extending drilling extending through the annulus and each stud to provide a brush box, and a pair of field connection studs secured in the other pair of threaded holes and extending rearwardly from the annulus, all said studs having tapped holes at their rear ends to receive end cap supporting screws.`

36. A brush rigging for miniature motors comprising an annulus of insulating material having a central opening for a commutator, a forwardly extending peripheral skirt adapted to be received in a motor casing and a plurality of axially extending threaded holes arranged in pairs, a pair of metallic studs threaded through said holes extending rearwardly from the annulus and locked therein, there being a radially extending drilling extending through the annulus and each stud, brushes and brush springs disposed in said drillings, plugs in the outer ends of the drillings to retain the brushes and springs in place, and a pair of eld connection studs secured in the other pair of threaded holes and extending rearwardly from the annulus, the annulus having apertures to allow passing field wires through it for securing to the last mentioned studs, all said studs having tapped holes at their rear ends to receive end cap supporting screws.

37. A brush rigging for miniature electric motors comprising an annular disk of insulating material having an opening to receive a commutator, and a pair of metallic members axially extending through the disk and secured to it, there being a radial drilling through the disk and members to provide brush boxes.

38. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a commutator, of a combined brush rigging and endcap assembly comprising an adjustable brush rigging fixedly secured in adjusted position across the open end of the motor casing and including a brush carrying disk located to hold brushes carried therein on the commutator, said disk also carrying rearwardly extending current carrying pins and a central bearing for the armature shaft, an end cap carrying a current supply cable extending out through the center of the end cap, tubular terminals disposed on the inner face of the end cap, connected to the wires of the cable, and spaced to cooperate with the current carrying pins, and means to secure the end cap in position beyond the brush carrying disk.

39. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying disk type commutator, of a combined brush rigging and end cap assembly comprising an adjustable brush rigging iixedly secured in adjusted position across the open end of the motor casing and including a brush carrying disk having radially extending brush boxes so located to hold brushes carried therein on the commutator, said disk also carrying rearwardly extending current carrying pins and a central bearing for the armature shaft, an end cap carrying a current supply cable extending out through the center of the end cap, tubular terminals disposed on the inner face of the end cap connected to the wires of the cable, and spaced to cooperate with the current carrying pins, and means to secure the end cap in position beyond the brush carrying disk.

40. In a miniature motor, a motor casing open at the rear end, a motor iield carried in the casing, a motor armature carrying a cylindrical commutator, and a combined end cap and brush rigging assembly which includes a brush rigging disk secured to the casing and carrying brushes disposed in radial brush boxes and cooperative with the commutator, brush terminals and field terminals, and a bearing for the armature shaft, and an end cap having tubular terminals into which the first terminals axially extend and means cooperative with the terminals for securing the end cap to the disk.

.41. In a miniature electric motor, in combination, a cup-shaped end cap, a brush rigging disk telescopically fitting inside the end cap and carrying a pair of brush lead studs and a pair of field lead studs, all the studs extending rearwardly and passing through metal inserts in the end cap, threaded members cooperative with the outside of the end cap and the studs for securing the end cap to the brush rigging disk, a bearing for the armature shaft mounted in the disk, and a current supply cable passing through the center of the end cap and having wires secured to the inserts.

42. An end cap for miniature motors made of insulating material and having axially extending radially disposed metallic inserts, the end cap being recessed so that the inserts are below the surface of the end cap, the end cap having a threaded boss, and an insulating cover plate threaded on the boss.

43. An end cap for miniature motors made of insulating material and having axially extending radially disposed metallic inserts, the end cap being recessed so that the inserts are below the surface of the en-d cap, the end cap having a threaded boss, and an insulating cover plate threaded on the boss, the boss being tubular to accommodate a current supply cable.

44. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a disk type commutator, of a combined brush rigging and end cap assembly comprising an adjustable brush rigging xedly secured in adjusted position across the open end of the casing and including a brush carrying disk having tubularbrush boxes axially disposed therein on opposite sides of the bearing, and an end cap carrying a current supply cable connected to tubular terminals disposed on the inner race of the end cap and spaced to receive the brush boxes.

In a miniature motor, the combination with a stationary motor oassg having an open end at the rear, and a revoivable armature shaft carrying a disk type coinmutator, ci a combined brush rigging and end cap assembly comprising an adjustable brush rigging fixedly secured in adjusted position across the open end of the casing and including a brush carrying disk having outwardly opening tubular brush boxes axially disposed thereon on opposite sides of the shaft axis,

an end cap carrying a current supply cable connected to tubular terminals disposed on the inner face of the end cap and spaced to receive the brush boxes, and means for securing the end cap on the disk and against the end ofthe casing, said means being in addition to the brush boxes whereby the brushes r .y be removed for inspecion without removing he end In a miniature motor, the combination with a stationary motor casing haring an open end at the rear, and a revolvable arr ature shaft carrying a disk type oorjznutator, of combined brush rigging and end cap assembly comprising an adjustable brush rigging fixedly secured in adjusted position across the open end of the casing and including a brush carrying disk having tubular brush boxes axially disposed therein on opposite sides of the shaft axis, an end cap carrying a current supply cable connected to tubular terminals disposed on the inn-cr iace of the end cap and spaced to receive the boxes, and screws threaded into the brush boxes and cooperative with the end cap for securing the end cap in position and holding the brushes in the brush boxes.

47. In a miniature motor, the combination with a stationary motor casing having an open end at the rear, and a revolvable armature shaft carrying a disk type commutator, of a combined brush rigging and end cap assembly comprising an adjustable brush rigging ixedly secured in adjusted position across the open end of the casing and including a brush carrying disk having axially disposed threaded openings on opposite sides of the shaft axis, tubular brush boxes threaded into the openings and projecting rearwardly, an end cap carrying a current supply cable connected to tubular terminals disposed on the inner face of the end cap and spaced to receive the brush boxes, and screws threaded into the brush boxes and cooperative with the end cap for securing the end cap in position and holding the brushes in the brush boxes.

48. In a miniature motor, a motor casing open at the rear end, a motor eld carried in the casing, a motor armature shaft carrying a disk typ-e commutator, and a combined end cap and brush rigging assembly vvhich provides a bearing for the armature shaft and includes an end cap and brush rigging disk secured to the casing and carrying axially extending tubular terminals for brushes for the commutator, and field terminals, said terminals extending axially into corresponding terminals carried by the end cap, and means ror securing the end cap to the disk.

a9. In a miniature motor, a motor casing open at the rear end, a motor field carried in the casing, a motor armature shaft carrying a disk type commutator, and a combined end cap and brush rigging assembly which provides a bearing for the armature shaft and includes an end cap and brush rigging disk secured to the casing and carrying axially extending tubular terminals ici' brushes for the commutator, and field terminals, said terminals extending axially into corresponding terminals carried by the end cap, nuts threaded on the eld terminals for securing the end cap to the disk.

50. In a miniature motor, a motor casing open at the rear end, a motor field carried in the casing, a motor armature shaft carrying a disk type commutator, and a combined end cap and brush rigging assembly which provides a bearing for the armature shaft and includes an end cap and brush rigging disk secured to the casing and carrying axially extending tubular terminals for brushes for the commutator, and field terminals, said terminals extending axially into corresponding terminals carried by the end cap, and screws threaded to the tubular terminals for holding brushes therein.

l. In a miniature electric motor, in combination, a cup-shaped end cap, a brush rigging disk telescopically tting inside the end cap and carrying a pair of eld connection studs and a pair of tubular brush boxes, the studs and boxes extending rearwardly and passing through metal inserts in the end cap, and threaded members cooperative With the outside of the end cap and the ends of the studs and boxes for securing the end cap to the disk, the brush box securing members also securing brushes in the brush boxes.

52. The combination with a cylindrical motor casing of rigid self-sustaining insulating material, of a brush rigging disk of insulating material telescopically fitting inside and secured to the casing, and having a shoulder abutting against the inner margin of the end of the casing, and an end cap telescopically fitting the outside of the brush rigging disk and abutting against the end wall oi the motor casing, the disk having axially extending brush boxes extending into inserts in the end cap.

53. In a miniature motor, the combination with a stationary motor casing and a revolvable armature shaft carrying a disk type commutator, of a brush carrying disk secured across the end of the casing, a pair of tubular brush boxes carried by the disk and projecting rearwardly from the disk, brushes and brush springs in each brush box, a retaining screw for holding the brushes and springs in place, a cup-shaped end cap having tubular metal inserts adapted to frictionally receive the ends of the brush boxes, a current supply Wire secured to each insert, and screws passing through the end cap and threaded into the brush disk for securing the end cap against the end of the motor casing.

54. A miniature motor as claimed in claim 44, characterized in that the end cap covers and conceals the inserts so that current carrying parts are absent from the rear face of the end cap, and wherein the end cap is secured to the brush rigging disk by axially extending screws threaded into the disk.

55. In a miniature motor, a brush rigging disk made of insulating material and adapted to be secured across the open end oi a motor casing, and two tubular metallic brush boxes secured to the disk and adapted to hold brushes against a disk type commutator disposed within the casing, said brush boxes extending rearwardly from the disk, threaded members carried by the boxes for holding brushes therein, and an end cap made of insulating material and telescopically received by the disk and having tubular inserts carried in sockets for frietionally receiving the brush boxes.

56. In a miniature motor, a motor casing open at the rear end, a motorreld carried in the casing, a motor armature shaft carrying a disk type commutator, and a combined end cap and brush rigging assembly which provides a bearing for the armature shaft and includes an end cap and brush rigging disk secured to the casing and carrying axially extending tubular terminals for brushes for the eommutator, and field terminals, said terminals extending axially into corresponding terminals carried by the end cap, and means independent of the conducting parts for securing the end cap to the disk.

HOWARD A. WHITESIDE.