US1686882A

US1686882A - Automatic limit stop

Info

Publication number: US1686882A
Application number: US212522A
Authority: US
Inventors: Walter C Swancott
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-08-12
Filing date: 1927-08-12
Publication date: 1928-10-09
Anticipated expiration: 1945-10-09

Description

Oct. 9, 1928.

W. C. SWANCOTT AUTOMATIC LIMIT STOP Filed Aug; 12, 1927 fie'tnesses jnuemr:

h'ffl TEE C Swan c077 and are adapted to be Patented Get. 9, 1928.

' WALTER c. swnncor'r, on CLEVELAND, onto.

I AUTOMATIC LIMIT STOP.

Application filed August 12, 1927. Serial No. 212,522. i

This'invention relates to motor limit stops and, while not limited thereto, relates more particularly to "a limit stop for crane motors and the like, and has for its object theprovision of a novel'stop construction which will be entirely free from all springs, weights, contact points and similar parts which ordinarily wear and break or fail to function when only slightly worn.

Another object is to provide a stop mechanism which is purely mechanical, and one in which the action is positive even though.

the parts be considerably worn.

In the drawings- Figure 1 is a diagrammatic plan View showing 'my invention applied toa crane operating mechanism. 1 v

Figure 2 is an end elevation thereof.

Referring more particularly to the drawings, the numeral 2 designates the cable drum ofa crane which has its shaft 3 journaled in suitable bearings l and 5. One end of the shaft 3 is extended and connected through a train of gearing 6 with a drive shaft 7, which shaft is connected by a coupling 8 with the power shaft of a motor 9, which may be of any desired form, but is shown as an air or fluid motor.

A controlling mechanism of any desired standard construction is indicated by the numeral 12 and is provided to control the operation of the motor 9. The control mechanism 12 is adapted to be operated by a reciting lever 13 secured on a shaft 14-. The lever 13 is provided with operating cables 15 which are secured to its opposite ends pulled to rock the lever 13 to provide for manual control of the motor. p

A stop shaft 16 having a square portion '7 and a threaded portion 18 is mounted above the motor 9 and control lever 13. The squared portion ably mounted in a bearing 20, and the threaded portion 18 of the shaft 16 has a threaded engagement with a nut 21 which nut 15 jourualed in bearings 22 and 23 and provided with a hub portion 24: adapted to bear against and deliver end thrust to'the bearings. I

A sprocket 25 is secured on the hub portion 24: of drive chain 26 to a sprocket 27 secured on the drum shaft 3, so that the nut 21 will be rotated when the drum 2 is rotated. Rotation of the nut 21, due to its fixed mounting justably secured on lever 31.

over the shaft 16 intermediate the 17 of the shaft 16 is slid-- the nut and is connected by a in the. bearings'22 and engagement with the shaft 16, will cause the shaft 16 to move longitudinally through the nut. i A pair of '

stop'collars

28 and 29 are adlilte, and are-adapted to engage a rocking Thelever 31 has'its lower end shaped to form a cle'vice 32 which is fitted stop collars 28 and. 29 and has its upper end secured to a roc shaft 33' journaled in bearings 34:.

Tillie shaft 33 also has a lever 35' secured thereto' and positioned substantially at right angles to the lever 31; The lever 35 has its other end connected to the upper end of a vertically disposed lever or link 36' which has its lower end pivotally connected to" one end of the rocking lever 13 of'thecontrol mechanism 12. i

In operation, the

stop collars

28 and 29 will be adjusted on the shaft 16 so as to be in position to engage and rock the lever 31 when the desired amount of travel is im-.

drum 2, which drum is directly parted to the When the limit connected to the nut 21.

23, and its threaded the shaft 16 at spaced 7 points by means of set screws 30or the of travel is reached in either direction, one

of the

collars

28 or 29 will engage the lever 31 and rock the lever 31 and shaft 33 which in turn will move the lever 35 and link 36 and thereby rock the control lever 13 into horizontal or off position so as to operate the control mechanism 12 and stop the motor 9 and drum 2.

lVhile I have shown and described one specific embodiment of my invention, it will be understood that I do not wish to be limited thereto, since various modifications may be made and the invention may be applied to many other apparatuses than cranes without departing from the scope of my in vention as defined in the appended claims.

I claim 1. The combination with a motor and a control element for said motor, of means being vadapted to compel ,a longitudinal movement of said screw shaft, stop elements on said shaft, and means operated by said stop elements adapted to operatesaid motor control element to move said element into off position.

2. The combination with a motor and a control element for said ,motor, of means operated by said motor for automatically operating said control element, said means ,oomp-rising a screw shaft mounted for longitudinal reoiprooatory movement and locked against rotary movement, a nut having threaded engagement with said shaft, said nut being flour-na led in fixed bearings, drive means oonneeting said nut with said anotor whereby said nut will be rotated when said motor ispperated, the rota-tionof said nut being ad p ed to cflmpel a longitudinal movemen-tof saidsorew shaft, stop collars adjustably mounted ;at ,spaced points on said shaft, and leve me hanism a apted t be engag d and operated by said collars when said shaft is reoiprooated, said lever mechanismbeing ,eonnected with and adapted :to operate said motor ,controlelement to move said element into fi m men- The s m nwtiqn wi a motor and a control element for said otor, of means motor is operated, the rotation of'said nut being adapted to compel a longitudinal movement of said screw shaft, stop collars adj ustably shaft, a lever having a fixed fulcrum point relative to said screw shaft, a clev-is on one end of said lever and fitted over said :shaft intermediate said stop collars .so as to be engaged byt-saidstop {collars when said shaft is caused to move longitudinally by the rotation of said nut, said lever being adapted to be rocked about its {fulcrum point when said clevis is engaged by said stop collars, and other levers operated by said first named lever ,and adapted to operate said motorcon trol element to move said element into {off position.

mounted at spaced points on said I In witness whereof, I have hereunto signed my name.

WALTER swanoorr.