US1438425A - Timer brush - Google Patents

Description

A. w. CAPS.

TIMER BRUSH.

APPLICATION FILED MAY 24, 1920.

1,4;38Q425, Patented Dec. 12,1922.

I '24 NAM- 4 A a lNVE/VTOR 7/7/1 Wap-s A TTORNE Y Patented Dec. 12, 1922.

UNITED STATES PATENT OFFICE.

ARTHUR W. CAPS, OF TOPEKA, KANSAS, ASSIGNQR, BY MESNE ASSIGNMENTS, TO 0. I).

COLLIS, OF CLINTON, IOWA. v

TIMER BRUSH.

Application filed May 24,

T all whom it may concern Be it known that I, ARTHUR IV. CAPS, a citizen of the United States, residin at Topeka, in the county of Shawnee and tate of Kansas, have invented certain new and useful Improvements in Timer Brushes; and

I do declare the following to be a full, clear,

and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to electric timers for the ignition system of an explosion engine and, specifically, it has reference to a novel construction of timer brush for use in a timer casing.

Electric timers usually consist generally of a casing provided with a commutator consisting of spaced and insulated contacts 00- operating with a rotatable brush to intermittently make and break the timer circuit. The insulation and contacts are usually constructed to form a ring-shaped commutator, over which a rotatable timer brush travels, and the interior of the casing isusually packed with grease in order to insure lubrication to assist in the smooth co-operation of the parts. Sometimes dust collects in the casing, or the grease dries out, and as a result the rotatable brush packs the dust and grease over the surface of the commutator, forming a hard, gummy film and thus seriously interfering with the perfect timing of the making and breaking of the circuit.

My invention contemplates the provision of .an electric timer in which the brush is in the form of a wiping contact, which passes over the commutator surface in such a manner that it will wipe off any accumulating grease or dirt, leaving the surface of the commutator bright and clean sothat a perfeet operation of the timer may be insured. I prefer to maintain the wiping cont-act or brush under tension so that it wili bear against the face of the commutator over which it travels to insure the removal of any accumulations and so that there will bean intimate contact between the brush and the commutators surface at all times.

The construction of the brush and commutator is such that the engine may back- 1920. Serial N0. 383,694.

fire and thereby reverse the direction of movement of the brush without danger.

The construction selected for illustrative purposes in order to exemplify the novel features of my invention constitutes only one form of the device, it being apparent that the specific construction may be varied without, departing from the generic conception thereof.

In the drawings:

Fig. I is a perspective view of a brush and its bracket, disassociated from the timer shaftQ Fig. II is a cross sectional view through the timer casing, the commutator, brush, bracket and shaft being shown in end elevation, and

Fig. III is a cross sectional view on the line III-III of Fig. II.

The particular construction of the timer casing and the commutator constitutes no part of this particular invention but I have shown a casing 1 provided with a commutator consisting of the insulation segments 2 and the inserted contacts 3, one for each spark plug of a four cylinder engine and. spaced equi-distantly about the commutator. The insulation segments 2 and the inserts 3 constitute a commutator of circular form so that the inner face 4 of the.

commutator over which the brush travels is annular. Concentric with the annular commutator is a timer shaft 5, which may be driven in any well known manner.

The timer shaft is adapted to receive a brush bracket consisting of a tubular memher 6, preferably of spring metal and normally of less diameter than the diameter of the shaft. The tube is slit longitudinally, as at 7, so that it may be expanded to embrace the shaft 5 and when released, will clamp upon the shaft 5 to be in intimate contact therewith:

In order to prevent rotative movement of the tube 6 with respect to the shaft 5, I have provided the tube with a longitudinal notch or slot 8, adapted to receive a pin or lug 9 on the shaft 5 when the tube is sleeved on said shaft. One edge of the tube at the slitted portion 7 is provided with an outstanding fiange 10, having perforations 11 and 12 to receive the hooked ends 13 and 14: of the spring arms 15 and 16 which carry the brush element, the arms being connected at their outer ends by a bar member 17, which passes through a bore 18 in the brush element 19. The brush element 19 is preferably grooved at its respective ends, as indicated at 20 and 21. to receive the arms 15 and 16, which hold it in non-rotative position so as to eliminate liability of the brush ele ment. 19 rotating on the bar or shaft 17, which it would otherwise do because the brush element 19 is shown as a cylinder.

The arms 15 and 16 pass through the openings 22 and 23 in the outstanding flange 24, struck up from the tube 6, the flange 2i and the flange 10 constituting eflicient anchorages for the brush supporting loop consisting of the arms 15 and 16 and the bar 17.

I prefer to form the arms 15 and 16 of the brush supporting loop upon arcs of greater radii than the radius of the commutator so that when the parts are assembled, as shown in Fig. II, the arms will be bent inwardly, but since they are of spring metal and will tend to spring back into their original shape, it will be apparent that the arms will be put under tension when the parts are assembled and, therefore, the brush 7 will be held in intimate contact with the commutator surface 4 at all times.

If the parts are in the position shown in Figs. II and III and the timer shaft 5 is rotating in a contra-clockwise direction the brush 19 will be under tension against the surface or face 4 of the commutator and serve as a wiping contact non-rotatable about its axis. Therefore, liability of a film of grease or dirt being packed upon the surface 4 of the commutator will be eliminated.

On the other hand, the surface will be kept free from accumulations and the ,eflicient performance of the timer insured.

Should the engine back-fire so as to drive the shaft 5 clockwise, the contact would sim ply reverse its direction of movement without imparing the mechanism of the timer in any way, this being a material advantage in timer construction.

It is also an important feature of my invention that the supporting loop consisting of the arms 15 and 16 is so curved that the timer may be operated in either direction if necessary. 7

hat I claim and desire to secure by Let" ters-Patent is:

1. In an electric timer, a shaft engaging sleeve. flexible arms mounted on the sleeve, and a brush carried by said arms and having transverse grooves at its ends, seating said arms to prevent rotation of the brush when in contactwith a commutator.

2. In an electric timer, a shaft engaging sleeve, a brush having a longitudinal bore and transverse end grooves, and flexible arms carried by the sleeve, and a member connecting the ends of said arms and extending through the longitudinal bore in the brush to support the brush, the end portions of the arms being seated in the brush grooves to hold the same against rotation.

In testimony whereof I affix my signature.

.ARTHUR W. CAPS.

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