US1220564A - Wear-compensating pawl-and-ratchet mechanism. - Google Patents

Description

J. SCHLAGEL.

WEAR COMPENSATING PAWL AND RATCHET MECHANISM.

APPLICATION FILED JUNE 27. i913.

1,220,564. Patented Mar. 27, 1917.

' 3 WITNESSES l/VVE/VTOR 4 ATTORNEY UNITED @TATES PATENT @EFlltlfi.

JACOB SOI-ILAGEL, OF BROOKLYN, NEW YORK, ASSIGNOR T0 CONRAD HUBERT, OF NEU YORK N. Y.

' WEAR-OOMPENSATING PAWL-AND-RATCHET MECHANISM.

and useful Improvement in Wear-Compensating Pawl-and- Ratchet Mechanism, of which the following is a specification, reference being had therein 0 the accompanying drawings forming part thereof.

My invention relates in a general way to wear compensators or self-adjusting devices for the operating connections of frictional restraining or looking devices such as brakes or clutches. More particularly, my invention is a self-adjusting pedal connection for spring operated engine starters. Examples of engine starters to which my invention is .tion, is released. as

applicable are he subject of patents to Clyde J. Coleman, N o. 867 ,7 95,0f October 8, 1907, No. 1,056,972, of March 25, 1913, and No. 1,102,322, of July 7, 1914.

' 11 these engine starters, starter engine, I spring-pressed to engaging or gripping posiby pressing a pedal. It has been found that wear at the brake shoe raws upon the brake-releasing connection such as the flexible connectors 70 and 21, re-

spectively, in the above mentioned first two patents, and such drawing causes the operatmg pedal to project to the inside of the car more and more as the wear goes on, and excessive projection of the pedal is undesirable. Also when the pedal has reached the limit of the projecting movement permitted or possible, the brake band of the starter can no longer be seated to lock the starter spring.

The object of the present invention is to overcome the above mentioned difficulty due to wear at the brake band and also to automatically compensate for any stretching which may take place in the flexible brakeor cable, should it stretch by reason of use.

I shall now describe the self-adjusting brake operating device embodying my invention illustrated in the accompanying drawings and shall thereafter point out my invention in claims.

Specification of Letters Patent. Application filed June 27, 1913.

Patented Mar. 27, 1917.

Serial No. 776,112.

Figure 1 is a side elevation, partly in section, of the complete device.

Fig. 2 is an enlarged vertical section on a plane indicated by the line 2-2 of Fig. l as viewed from the right.

Fig. 3 is a vertical section to Fig. 1 on a plane indicated by the line 3-3 of Fig. 9 as viewed from the right, the parts appearing in a different relative position and as seen from the rear in Fig. 1.

*ig. 1 is a rear elevation, partly in secti on, on a reduced scale of a spring engine starter illustrating the application of my invention.

In the construction illustrated in the drawings, flexible connector or the scale of a brake-releasing cable 1, shown as led Sheath 2, is anchored to a brake controlling disk or drum 3, as by means of an anchor pin 4, and is wound peripherally around a circular shoulder forming a winding space on the disk 3 and from which the cable 1 eX- tends tangentially.

he cable extending from the disk 3 is connected to a brake lever 5 of a spring-operated engine starter (Fig. 4). A spring 6, connected with the lever 5, holds a brake 7, connected with the lever 5 by'a chain 8, normally in action on a brake wheel or spring-locking disk 9. Drawing upon the cable 1 will release the brake and permit the starter spring to effect an engine-starting operation, and relief of restraint on the cable will permit the spring 6 to lock the starter spring. Any desired further information as to the engine starter may be obtained from the above mentioned patents.

Radially outward from the cable-receiving space the disk 3 is provided with peripheral ratchet teeth shown as sloping on one side The disk 3 is supporting stud 10 bracket 11 the car and through a protective lower end of the stem of apedal 17 .11 and shown as the brake-releasing cable 1 under the influence of the brake-applying spring, such The brake-releasing operation is effected through the ratchet teeth of the disk 3 by means of a spring-pressed pawl 14 pivoted at an intermediate poi t on a bent lever 15,, the latter being fulcrumed on the stud 10 outward from the star spring 13 and also outward from an intermediate collar or washer 16. The free end of the brake-releasing lever 15 is pivotally connected to the guided floor of the car so that the pedal normally projects a suitable distance above the floor, as appears in Fig. 1. The lever 15, carrying the pawl 14c and the pedal 17, is returned to normal position after each actuation or forward movement, by means of a retractile coiled spring 18 anchored to a lug on the supporting bracket attached to the lever 15 between the pivot stud 10 and the pawl 14.

Normally the pawl M is held out of engagement with the ratchet teeth of the disk 3 (Figs. 1 and 2) by means of a projecting cam lug, shown as provided at the upper end of the pawl 14, coming into contact with a cam-actuating surface provided on the contiguous portion of the supporting bracket 11. However, when the pedal 17 is depressed (Fig. 3), imparting a forward or downward movement to the lever 15, the awl 14: will come into engagement with the ratchet teeth of the disk 3, thereby rotating the disk 3 (Fig. 3) and drawing on the cable 1 to release the starter brake for effecting an engine-starting operation.

When the pedal 17 is released, the return spring 18 will restore the lever 15, pedal 17 and pawl 14' to the position shown in Figs. 1 and 2, the pawl 14 being thrown out of engagement with the ratchet teeth of the disk 3, permitting this disk to continue to rotate under the stress exerted upon the cable 1 by the starter brake-applying spring, such as 6, until the brake band is firmly seated, regardless of any wear upon the latter or upon the braking surface of the spring-locking disk. When the wear upon the starter brake has become sufficient to thus move the disk ratchet tooth, the pawl 14 will then engage the next following tooth in the brake-releasing operation, and so on. The wear of the starter brake is thus compensated for and the pedal 17 will always project to the same extent within the car. The return spring 18 may be omitted if the brake-applying spring 6 be made sufliciently strong to return the ratchet and lift the pedal lever 15. Then when the brake wear has become sufiicient,

in an opening in the this return movement will engage the heel or cam lug of the pawl 14; with the surface of Fig. 1, that the stem 3 a distance equal to one.

and permit the pedal lever to drop slightly until the pawl is seated against the next f tooth below. a

The wearing of the braking surfaces is what has given trouble prior to this invention, but, on the other hand, should the cable 1 stretch by use'to a greater extent than the wear of the brake, my invention willcompensate also for this stretching of the cable. In that case the stretched cable'will fail'to return the disk 3 to itsinitial position and the pawl 14: will to that extent ride over the ratchet teeth in the final portion of the return movement of the lever 15. cable has stretched to the extent of one ratchet tooth, the pawl will engage the next tooth in advance, and so on.

It is to be noted, as clearly appears in of the pedal 17 is made in two loosely telescoping parts, permitting the upper projecting pedal part to be readily removed and carried away by the chauffeur, to prevent tampering.

It is obvious that various modifications may be made in the construction shown in the drawings and above particularly described within the principle and scope of my invention.

I claim z- 1. A self-adjusting brake-releasing pawl and ratchet mechanism for brakes having a normal tendency to the applied condition, such mechanism comprising a pawl. two relatively movable parts one of which carries the pawl and the other of which is a ratchet cooperative with the pawl, one of the said parts being part adapted to be connected to the brake to release the same and to be returned by the brake to the normal position and the other of the said parts being an operating member for the. pawl and ratchet, means operative to disengage the pawl and ratchet upon the return of the operating member to a predetermined normal position, an yieldable movement-restraining means for the brake-controlling part for stopping and holding such part in correct adjusted position relatively to theoperating member in the normal position of the latter.

2. A self-adjusting brake-releasingpawl for brakes having and ratchet mechanism a normal tendency to the applied condition,

the brake to the normal position and the other of the said parts being an operating.

member for the pawl andratchet, position- When the a brake-controllin g restoring means for the operating member for returning the latter to a predetermined normal position, means operative to disengage the pawl and ratchet upon the return the operating member to the normal position by the position restoring means, and frictional stopping and holding means engaging the brake-controlling part for automatically adjusting the normal position of such part relatively to the normal position of the operating member.

3. A self-adjusting brake-releasing pawl and ratchet mechanism for brakes having a normal tendency to the applied position, such mechanism comprising a brake-controlling drum disk provided with ratchet teeth and having a peripheral winding space providing for flexibly connecting the brake-controlling drum to a brake for releasing the brake, a friction stop for yieldingly holding the disk at the position to which it is returned by the applied brake, a disk-operating manual lever pivoted con centrically with the disk, a pawl carried by the lever and engageable with the ratchet teeth of the disk to operate the brake during the forward movement of the lever, an abutment adapted to effect the disengagement of the pawl upon the the reverse or return movement of the lever der continued stress of the brake as the rake moves to the applled position until such disk is stopped by the friction stop at the correct adjusted position relatively to Copies of this patent may be obtained for five cents each, by Washington, D. G.

the pawl carried by the operating lever in the returned position of the latter and a spring arranged to effect the return movement of the lever.

4. Brake mechanism comprising a brakeand brake-releasing means including: an operative member adapted to receive operative energy, an operated member connected with the brake, means for maintaining a fixed connection between the operative and operated members during the actuation of he operative member in one direction to release the brake and during a reverse movement of both members as the brake is brake-setting movement.

5. Brake mechanism comprising a brake and brake-releasing means including: a manually operative member, a ratchet connected with the brake, a pawl carried by the manually operative member and arranged to maintain connectlon with a single tooth of the ratchet during its actuation of the ratchet to release the brake and during the reverse brake-setting movement, and a detent arranged to disconnect the pawl from said tooth at the end of said reverse or brake-setting movement.

In testimony whereof I have afiiXed my signature in presence of two witnesses.

JACOB SCHLAGEL. Witnesses HARRY G. Lewis, JOSEPH T. LEYDEN.

addressing the Commissioner of Patents

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