US1884895A - Engine starter - Google Patents

Description

R. E. SLAYTON ENGINE STARTER Oct. 25, 1932a Filed May 28, 1932 INVENTOR w/zzwj Patented Oct. 25, 1932 srArEs ArEr FFHCE ROBERT E. SLAYTON, OF ELMIRA, NEW YORK, ASSIGNOR TO ECLIPSE MACHINE COM- PANY, OI ELMIRA, NEW YORK, A CORPORATION OF NEW YORK ENGINE STARTER Application filed May 28, 1932. Serial No. 614,240.

This invention relates to engine starters and more particularly to starters of thetype in which a driving member such as a pinion is automatically traversed into and out of driving engagement with a member such as a flywheel gear of the engine to be started.

In starters of this type in whlch the disengagement of the pinion is brought about by the overrunning action of the flywheel gear, the driving member may be thrown back to idle position with considerable veloc1t when the engine becomes self-operative. '1 1s ve locity of the pinion may cause 1t to rebound from its idle position and the rebounding action is sometlmes of sufiicient magnitude to carry the pinion back against the flywheel.

' Since the flywheel is rotating more rapidly than the pinion at such times, unnecessary noise and wear of the parts may be caused by the rebounding action of the pinion.

It is an object of the present invention to rovide a novel and efiicient device for checkmg the driving member of an engine starter when thrown back to its idle position and preventing rebounding thereof toward the engine member.

It is a further object of thls invention to provide such a device in connection w th a weighted starter pinion in which certam elements thereof are constructed as components of the pinion weight and are in effect parts thereof.

Another object of the invention isto provide such a device which is easily adaptable to commercial types of engine starters.

Another object is to provide such a device which is readily manufactured by economical machine operations and which is compact, self-contained and enclosed when in normal idle position so as to be protected from dirt and grease.

A still further object is to provide such a device in which the checking action is automatically increased as the violence of the throw-out increases. I

Further objects and advantages will be apparent to those skilled in this art from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation partly in section of a starter embodying this invention;

Fig. 2 is a cross-section of the starter taken substantially on the line 2-2 of Fig. 1 showing the parts of the rebound check 1n normal idle position; and

Fig. 3 is a cross-section similar to Fig. 2 showing the parts of the rebound check in operative position.

In Fig. 1 of the drawing there is illustrated a power member in the form of a shaft 1 which may be the extended armature shaft of an electric motor, not shown, on which is rigidly mounted a driving head 2 as by means of a key 3 and cap screw 4. An operating member in the form ofa hollow screw shaft 5 is loosely mounted on the power shaft -1 and is yieldably connected to the driving head 2 as by means of a spring 6 which is rigidly connected at its ends to shaft 5 and driving head 2 as by means of cap screws 7 and 4 respectively. A drivin member in the form of a pinion 8 is mounte for rotation and traversal on a threaded portion 9 of the operating shaft 5 whereby rotation of the shaft relative to the pinion in the direction of the arrow traverses said pinion into mesh with a member of the engine to be started such as a flywheel gear indicated at 12. A stop 11 fixed to the shaft 5 is the meshing position of the pinion 8 whereby further rotation of shaft 5 after the pinion engages said stop causes the pinion to rotate and drive the flywheel gear 12 in a direction to crank the engine.

Anti-drift means are provided for maintaining the pinion in idle position. Such means is here shown in the form of a spring 13 hearing at one end on a collar 14 slidably mounted on shaft 5 in contact with a pinion 8, and at the other end against stop 11.

According to the present invention speedresponsive retarding means are provided for checking the rebound of the pinion 8 comprising a pair of centrifugally-operated arcuate brake shoes 15 pivoted at 16 to a flange or weight member 17 fixed to said pinion; and a brake drum 18 fixedly mounted on shaft 5 in position to be engaged by the shoes 15 when the pinion is in idle position provided for defining as illustrated in Fig. 1. Ihe inner surfaces of the brake members 15 are preferably formed with inwardly extending projections 19 roughly conforming to the outline or the pinion teeth in order to provide additional weight without increasing the diameter thereof. The ends 20 of the brake members 15 are normally held in contact with each other as b means of a spring 21 interposed between t e opposite ends 22 of the brake members. As shown in Fig. 3 the projections 19 are spaced sufiiciently to clear the surfaces of the pinion teeth in all operative positions. Means for guiding the free ends of the brake shoes 15, and for limiting the outward move ment thereof is provided in the form of pins 23 fixed in flange 17 of the pinion and having a sliding fit in areuate slots 2a of the brake shoes. The brake drum 18 is chamfered at its edge as shown at 25, or may if desired be flared outwardly sufiiciently to encompass the brake shoes in their expanded positions, as limited by the pins 23, and guide them into the drum during the demeshing movement of the pinion.

In operation and starting with the parts in the positions shown in Figs. 1 and 2, rotation of the operating shaft 5 in the direction of the arrow traverses pinion 8 into mesh with flywheel gear 12 and against stop 11 whereupon the pinion is constrained to rotate with shaft 5 to crank the engine. During this traversal of the pinion, prior to rotation thereof, the centrifugal brake members 15 are maintained in retracted position by the spring 21 out of engagement with the brake drum 18 as shown in Fig. 2. The brake members 15 during said traversing action are in elfect a part of the pinion weight 17 and augment the inertia of the pinion thus assisting in the traversal thereof.

When the engine starts, the acceleration of the flywheel gear causes the pinion to overrun the shaft 5 whereby the threads 9 throw the inion back to idle position with considerable velocity. During this return traversal of the pinion the brake members 15 are moved outwardly by centrifugal force against the pins 23 which limit their expansion to an Outer radius substantially less than that of the leading edge of chamfer 25 so that the brake members may engage on the chamfer 25 and be guided into the drum 18. As the pinion and its depending members continue to move to idle position, the brake members 15 make frictional contact with the drum 18 due to centrifugal force whereby the rotation of pinion 8 relative to shaft 5 is so checked that rebounding of the pinion from its idle position is effectively prevented. When the starting motor comes to rest, the spring 21 acts to move brake members 15 to their retracted positions out of contact with the drum 18.

It will thus be seen that there is here provided a rebound check which is positive and automatic in action, is substantially self-contained and enclosed, is readily installed on commercial drives without requiring remodeling or expensive operations.

Although but one embodiment of this invention has been shown and described in detail, it will be understood that this embodiment is not exclusive and other embodiments are possible and changes may be made in the details and construction of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an engine starter, an operating memher, a driving member mounted for rotation thereon and therewith and for movement into and out of engagement with a member of the engine to be started, centrifugal elements mounted on said driving member and means mounted on said operating membei cooperating therewith to oppose relative rotation between the operating member and driving member during the disengaging movement of said driving member.

2. In an engine starter, an operating memher, a driving member mounted for rotation thereon and therewith and for movement into and out of engagement with a member of the engine to be started, and cooperating centrifugal brake members mounted on said operating member and driving member for opposing relative rotation therebetween during the disengaging movement of said driving member.

3. In an engine starter, an operating member, a pinion mounted for rotation thereon and therewith and for movement into and out of engagement with a member of the engine to be started, and a centrifugal brake effective to hinder relative rotation between said operating member and pinion, and including a drum mounted on said operating member and arcuate members surrounding said pinion and pivoted thereto and adapted when rotated to frictionally engage said drum.

4.. In an engine starter, an operating memher, a pinion mounted for rotation thereon and therewith and for movement into and out of engagement with a member of the engine to be started, a weight member fixed to said pinion, speed-responsive means mounted on and forming a part of said weight member and means on said operating member coopcrating with said speed-responsive means for retarding relative rotation between said operating member and pinion when the pinion ]is thrown out of mesh with the engine mem- 5. In an engine starter, an operating member, a pinion mounted for rotation thereon and therewith and for movement into and out of engagement with a member of the engine to be started, and means for opposing relative rotation between the operating member and pinion when the pinion is thrown out of mesh with the engine member, said means including centrifugally-operated brake members mounted on said pinlon and a drum mounted on said operating member and extending over and enclosing said brake members when the latter are in idle position.

In testimony whereof, I have hereunto signed my name.

ROBERT E. SLAYTON.

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