US1406580A - Pawl and ratchet device - Google Patents

Description

UNlTED STATES fATENT OFFICE.

MARTIN NYSTROM, or cnroneo, ILLINOIS, Assmnon To run BnUNswIoK-nALKnoonnnnnnn COMIPANY, or cnrcneo, ILLINOIS, n oonronn'rron or DELAWARE.

PA'WL AND RATCHET DEVICE.

Specification of Letters Patent.

Patented Feb. 14, 1922.

Original application filed. August 16, 1919, Serial No. 317,885. Divided and this application filed March 22, 1920. Serial No. 367,740.

T 0 all whom it may concern Be it known that I, MARTIN Nrs'rnon, a citizen of the United States, residing at Chicago, in the county of Cool: and State of Illinois, have invented certain new and useful Improvements in Pawl and Ratchet Dcvices, of which the following is a specification.

This application is a division of my application, Serial No. 317,885, filed August 16, 1919, upon which Patent No. 1,861,176 was granted December 7 1920.

The object of this invention is to provide a pawl and ratchet mechanism which Wlll operate noisclessly and which is, therefore,

especially adapted for locking the winding shaft of a phonograph spring motor.

The invention also has for its object to provide a pawl and ratchet device comprising but few parts which can be easily manufactured and assembled at comparatively low cost, which possess high efficiency in use as a locking device and which may last 1ndefinitely without getting out of order. In the accompanying drawings illustrating a selected embodiment of the invention- Fig. 1 is a sectional view showing the invention applied to the winding shaft of a phonograph motor, a part of which is shown.

Fig. 2 is a side elevation, partly broken away, of the pawl and ratchet.

Fig. 3 is a top plan view.

Referring to the drawings, 4: is a winding shaft mounted in the frame 5 of a phonograph motor and isprovided with worms 6 which mesh with worm gears 7 for winding the springs on the shafts 8. The usual winding crank is applied to the end 4- of the winding shaft.

The toothed locking pawl 9 is pivoted at 9 to the motor frame 5 and it is arranged to engage the teeth of the ratchet wheel 10 to lock the winding shaft against reverse movement. Spring fingers 11, 12 are piv; otally connected by a pin 13 to the free end of the pawl and project laterally in parallel relation on opposite sides of the ratchetwheel and yieldingly engage the same. These spring fingers preferably constitute parts of a clamping member 14: which is secured by the pin 13 on the pawl and consists of a metal strip bent upon itself to embrace the pawl and ratchet and cut away to accommodate the winding shaft and facilitate assembly of the parts. The fingers are provided with indentations 11', 12 to insure frictional engagement with the ratchet wheel, and one of the fingers, as 12, is provided with a projection 15 to engage the stop 16 on the motor frame.

From the foregoing description it will be noted that the spring finger clamping member 14. is suspended by the pin 13 from'the free end of the pawl and the teeth of the pawl are normally engaged with the teeth of the ratchet wheel. Then the winding shaft is turned in the direction of the arrow (Fig? 2) to wind the springs, the ratchet will revolve with the shaft and, by reason of the frictional engagement of the spring fingers with the ratchet wheel, the clamping member will be carried to the right and thereby disengage the pawl from the ratchet wheel. The movement of the clamping member and the pawl is limited by the stop 16 on the motor frame and therefore when the projection 15 on the clamping member engages this stop, the ratchet wheel will continue to turn freely between the spring fingers of the clamping frame and be free from engagement with the pawl throughout the winding operation. When the springs have been wound sufiiciently or at any time the winding operation is stopped, a slight reverse movement of the winding shaft ratchet wheel will carry the clamping member to the left (Fig. 2) by reason of the frictional engagement of the fingers with the sides of the wheel until the pawl is again engaged with the ratchet wheel. It will thus be noted that throughout the winding operation the pawl is free from engagement with the ratchet wheel and hence the noise common to ratchet devices occasioned by the pawl riding over the ratchet teeth during the winding operation is entirely eliminated.

I have illustrated the invention embodied in a phonograph motor because I have used it in this way and have found that it operates efliciently and noiselessly in the manner set forth and for the desired purpose. The invention consists of very few parts which can be easily made and assembled and which are not liable to get out of order or to wear materially in actual use. The invention may he used for other purposes than to look a spring winding shaft of a phonograph motor, and I do not desire or intend to limit the invention to this particular embodiment.

I am aware that changes in the form and proportion and details of the construction may be made to adapt the invention for different embodiments and for different associations without departing from the spirit of the invention, and I reserve the right to make all changes which fairly fall within the scope of the following claims.

I claim:

1. The combination of a rotary shaft, a ratchet wheel rigid on said shaft, a pawl engaging said'ratchet wheel to lock the shaft against reverse movement, and spring fingers pivotally connected to the pawland frictionally engaging the sides of the ratchet wheel to be operated by the ratchet wheel. to shift the pawl out of engagement with the ratchet wheel on the forward movement of the shaft and ratchet wheel and to return the pawl into operative engagement with the ratchet wheel upon reverse movement of the shaft and ratchet wheel.

2. The combination of a rotary shaft, a ratchet wheel rigid on said shaft, a pawl engaging said ratchet wheel to lock the shaft against reverse movement spring fin gers pivotally connected to the free end of the pawl and frictionally engaging the sides of the ratchet wheel to be operated to shift the pawl out of contact with the ratchet wheel on the forward movement of the shaft and ratchet wheel and to return the pawl into operative engagement with the ratchet wheel upon reverse movement of the shaft and ratchet wheel, and a stop for limiting the movement of the pawl.

3. The combination of a rotary shaft, a ratchet wheel rigid on said. shaft, a pawl 4 engaging said ratchet wheel to lock the shaft against reverse movement, and a clan1ping device pivotally connected to the free end of the pawl and comprising spring fingers frietionally engaging the sides of the 4 ratchet wheel to be operated by the ratchet wheel to shift the pawl out of engagement with the ratchet wheel on the forward movement of the shaft and ratchet wheel andto return the pawl into operative engagement 5 with the ratchet wheel upon reverse movement of the shaft and ratchet wheel.

4-. The combination of a rotary shaft, a ratchet wheel rigid on said shaft, a pivoted pawl engaging said ratchet wheel to prevent reverse movement of the shaft and ratchet wheel, and a clamping member carried by the free end of the pawl and frictionally engaging the sides of said wheel to be operated to shift the pawl out of en- 6 gagement with the ratchet wheel on the forward movement of the shaft and ratchet wheel and to return the pawl into operative engagement with the ratchet wheel upon reverse movement of the shaft and ratchet wheel, a projection on said clamp ing member, and a fixed stop to beengaged by said projection to limit the dis engaging movement of said pawl and clamping member.

MARTIN NYSTROM.

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