US2656178A - Return mechanism - Google Patents

Description

Oct. 20, 1953 AC. HUGHES, JR 2,656,178

, RETURN MECHANISM Filed March 14, 1946 2 Sheets-Sheet l FIGJ INVENTOR. ARTHUR C. HUGHES JR.

BY 2Z1 ATTORNEY 2 1953 A. c. HUGHES, JR 2,656, 78

RETURN MECHANISM Filed March 14, 1946 V 2 Sheets-Sheet 2 [N VEN TOR.

' Y ARTHUR- HUGHES JR.

ATTORNEY Patented Oct. 20, 1953 UNEIT STATES PATENT OFFICE RETURN MECHANISM,

Arthur 0. Hughes; Jr., Puente, Calif., assignor;

by mesneassignments, to the United States of'America as represented by the Secretary Application March 14, 1946, Serial No. 654,494

11 Claims;

This" invention pertains to mechanical 'means" for returning? to center from rotary displacement, and more particularly to such means" leased'. One example of such an operation is fbundin some constructions involving potenti ometers. The prior arthas included means for returning to center'from a rotary displacement. What is proposed here is a novel means for accomplishing this result, one which comprises a single power spring.

An objectof this invention is to provide a novel device for automatically returning a'shaft toa predetermined position upon" rotary displacement from such predetermined position.

Another objectof this invention is to provide a novel centering device for automatically returning to. a predetermined center position a shaft which has been subjected to rotary motion.-

Still" another object of this invention is to provide a novel centering device havingasingle springfor automatically returning to a predetermined'center position a shaft which'hasbeen subjected to. rotary motion, said spring being operable irrespective of the dir'ectionof rotation of said shaft. from said center position;

Other objects and advantages'of"this invention will be apparent from" theaccompanying' claims and description; taken in connection with the "drawings in which:

mantled to facilitate understanding; saidview showing all-of the essential features except the single power spring;

Fig. 2 is a perspective view of the interior elements assemb1edbut does not showthe case shaft 16" has fixedly securedto it a first discli, Inherent in shaped as shown in the drawings. p the shape of disc ii "areworkingsurfaces"30; 3|

and 32; the functions of which will be described below under the descriptionof operation. Also fixedly secured to shaft I6 is a bushing 24; the function of which is defined below. As is shown best in Fig. 4, shaft It is supported at one end by a'bearing 33 in such a manner that shafts l l and it are concentrically and rotatably mounted with respect to each other. The other end of shaft i6 is supported by abearing' 9 mounted in a cap 8 oncase l3.

Referring again to Fig. 1 there is shown a' lug l8 secured toshaft It foranchoring one end of a spiral spring is. Spring 19 appears in'Figs. 2, 3 and 4. Also shownin Fig. 1 are a stop 20-, fixedly mounted in case l3, and a seconddisc 2'! with a pin 22 for securing the second end of spring [9. Disc 2! has a centrally-located circular opening 23 to support disc 2i on aforementioned bushing 25 of shaft It. Inherent in the shape of disc 2| are working-surfaces 3 5', 35',

and 36, corresponding to' surfaces 30, 3| and 32 of disc ll.

Operation of this invention is best understood from a study of Fig. 2. pin [5- normally is held in its zero (or center) position by the combined restraining action of surface 34 of disc 2i and surface 30 of'd-isc l'l. These discs themselves are zero positioned by surfaces 36 and 32, of discs 2! and I! respective-' ly, bearing on stop 20 which is fixed with respect to case it. Discs ll and'zl and spring Iii are so installed that some stress exists in spring l9 when it is holding the discs intheir zero posi tion. If through application of an external from the input end) disc Ii will be rotated by the action of centering pin l5 bearing on surface Since one end of spring is is secured to lug I8 of shaft l6, which turns with disc l1, and the other end of spring [9 is secured to pin 22 on disc 2|, held fixed by surface 36 bearing'on stop 20, spring l9 consequently will be stressed during this operation. During the rotation, there fore, energy is stored in" spring is. This stored l1, and consequently is such as to cause rotation in a counterclockwise direction (as seen from the input end) disc Ii will remain without rotation because of sur face 32 bearing on stop Eli, but centering ltwill' act against surface 3i and cause rotation ofdisc 21 As-beiore; ener'gy'isstored in spring" In operation centering [9 during this rotary deflection, which energy will restore to the zero position disc 2i, centering pin 15 and main shaft ll upon removal of the external force.

In the figures the shape of discs I! and 2! and the position of stop 20 with respect to the zero position of centering pin l are such as to limit rotation of main shaft II to 90 degrees either side of its zero position. It is emphasized that this is for example only, and that the maximum rotation of main shaft Il may have any value within desirable predetermined limits without departing from the principles of this invention.

What is claimed is:

l. A centering device for returning a shaft to a predetermined center position, said device comprising a housing, a shaft rotatably mounted in said housing, an arm fixedly secured to said shaft, a second shaft rotatably mounted in said housing, a first disc fixedly mounted on said second shaft, a second disc rotatably mounted on said second shaft, means on said housing and said discs for limiting rotation of one of said discs in one direction and for limiting rotation of the other of said discs in the opposite direction, means on said arm and said first disc responsive to one direction of rotation of said arm for causing rotation of said first disc, means on said arm and said second disc responsive to the opposite direction of rotation of said arm for causing rotation of said second disc, and means operatively connecting said second-mentioned disc and said second-mentioned shaft for returning said first-mentioned shaft to a predetermined position upon displacement therefrom.

2. A centering device for returning shaft to a predetermined center position, said device comprising a housing, a shaft rotatably mounted in said housing, an arm fixedly secured to said shaft, a second shaft rotatably mounted within said housing, a first disc fixedly mounted on said second shaft, a second disc rotatably mounted on said second shaft, means on said housing and said discs for limiting rotation of said first-mentioned disc in one direction and for limiting rotation of said second-mentioned disc in the opposite direction, a pin mounted on said arm, means on said first disc to engage said pin for causing rotation of said first-mentioned disc in response to one direction of rotation of said first shaft, means on said second disc to engage said pin for causing rotation of said second-mentioned disc in response to the opposite direction of rotation of said first shaft, and a spring operatively connecting said second-mentioned disc and said second-mentioned shaft for returning said first-mentioned shaft to a predetermined center position upon displacement of said shaft from said position.

3. A centering device for returning a shaft to a predetermined center position, said device comprising a housing, a shaft rotatably mounted in said housing, an arm fixedly secured to said shaft, a second shaft rotatably mounted within said housing, a first disc fixedly mounted on said second shaft, a second disc rotatably mounted on said second shaft, a first pin mounted on said housing and means on said first-mentioned disc for engaging said first pin for limiting rotation of said first-mentioned disc in one direction and means on said second-mentioned disc for engaging said first pin for limiting rotation of said second-mentioned disc in the opposite direction,

a second pin mounted on said arm and means on said first-mentioned disc for engaging said second pin for rotating said first-mentioned disc in response to one direction of rotation of said first shaft and means on said second-mentioned disc for engaging said second pin for rotating said second-mentioned disc in response to the opposite direction of rotation of said first shaft, and a spring operatively connecting said secondmentioned disc and said second-mentioned shaft for returning said first-mentioned shaft to a predetermined center position upon angular displacement of said shaft from said position.

4. A centering device for returning a shaft to a predetermined center position Within a housing comprising, an arm fixedly attached to said shaft, a stop fixedly attached to said housing, a first member rotatable within said housing, disposed coaxially with said shaft and bearing upon said arm, a second member rotatable within said housing, disposed coaxially with said shaft and also bearing on said arm, a spring connected between said first and second members for urging said first member and said shaft in a clockwise direction, and for simultaneously urging said second member and said shaft in a counterclockwise direction, first means on said first and second members for engaging said stop to limit rotation of said members, second means on said first and second members for engaging said stop to determine the position of rest of said members and thereby said center position.

5. A centering device for returning a rotatable main shaft to a predetermined center position within a housing comprising, a stop fixedly attached within said housing, an arm fixedly attached to said shaft and extending radially therefrom within said housing, a first substantially disc shaped member rotatable within said housing and disposed coaxially with said shaft, an auxiliary shaft attached to said member and extending axially therefrom, a second substantially disc shaped member rotatably mounted upon said auxiliary shaft, a spiral spring mounted under stress between a point on said second disc shaped member and a point on said auxiliary shaft, said spring urging said first member in a clockwise direction and said second member in a counterclockwise direction, first surfaces on said members acting oppositely on said arm, and second surfaces on said members for engaging said stop from opposite sides.

6. A centering device for returning a shaft to a predetermined center position of rotation comprising, first and second members rotatably mounted about an axis coincident with the rotational axis of said shaft, a spring member connecting said first and second members and urging relative rotation between said first and second members, a stop fixed in position relative to said center position of said shaft, each of said first and second members being formed with at least one stop engaging means for limiting rotation of said first and second members by engagement with said stop, a third member secured to said shaft and rotatable therewith, said first member being formed with means engaging said third member upon rotation of said shaft in a first direction from said center position to cause said first member to rotate with said shaft in said first direction, said second member being formed with means engaging said third member upon rotation of said shaft in the opposite direction from said center position to cause said second member to rotate with said shaft in said second direction.

7. A centering device for returning a shaft to a predetermined center position of rotation comprising, first and second members rotatably mounted about an axis coincident with the rotational axis of said shaft, a spring member connecting said first and second members and urging relative rotation between said first and second members, said first member being urged in a clockwise direction and said second member being urged in a counterclockwise direction, a stop fixed in position relative to said center position of said shaft, each of said first and second members being formed with a stop engaging means for limiting rotation of said first and second members in clockwise and counterclockwise directions, respectively, by engagement with said stop thereby to determine the position of rest of said first and second members, a third member secured to said shaft and rotatable therewith, said first member being formed with means engaging said third member upon rotation of said shaft in a counterclockwise direction from said center position to cause said first member to rotate with said shaft in said counterclockwise direction, said second member being formed with means engaging said third member upon rotation of said shaft in a clockwise direction from said center position to cause said second member to rotate with said shaft in said second direction.

8. A centering device as in claim 7 wherein said means on said first and second members engaging said third member simultaneously engage said third member When said shaft is in said center position and said first and second members are in their respective rest positions.

9. A centering device for returning a shaft to a predetermined center position of rotation and for limiting the rotation of said shaft from said center position comprising, first and second members rotatably mounted about an axis coincident with the rotational axis of said shaft, a spring member acting between said first and. second members and urging relative rotation of said first and second members, said first member being urged in a clockwise direction relative to said second member, said first and second members each being formed with an arcuate way of predetermined length, a stop member fixed in position relative to said center position of said shaft and disposed in said ways of said first and second members, rotation of said first and second members being limited by engagement of said stop member with the ends of said ways, a third member secured to said shaft and rotatable therewith, said first member being formed with means engaging said third member upon rotation of said shaft in a counterclockwise direction from said center position, said second member being formed with means engaging said third member upon rotation of said shaft in a clockwise direction from said center position.

10. A centering device for returning a shaft journaled in a housing to a predetermined center position with respect to said housing com-- prising, a stop fixed to said housing, a first means adapted to urge the shaft in a clockwise direction relative to the housing, a second means adapted to urge the shaft in a counterclockwise direction relative to the housing, spring means acting between said first and second means and urging relative rotation of said first and second means, and means on said first and second means for engaging said stop to determine said center position.

11. A centering device for returning a shaft journaled in a housing to a predetermined center position with respect to said housing comprising, an arm fixedly attached to said shaft, a stop fixedly attached to said housing, a first member adapted to bear upon said arm to urge the shaft in a clockwise direction relative to said housing, a second member adapted to bear upon said arm to urge the shaft in a counterclockwise direction relative to said housing, spring means acting between said first and second members and urging relative rotation of said first and second members, means on said first and second members for engaging said stop to limit the rotation of said members, and additional means on said first and second members for engaging said stop to determine said center position.

ARTHUR C. HUGHES, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,192,731 Batchelder July 25, 1916 1,795,149 Shivers Mar. 3, 1931 2,023,235 Le Count Dec. 3, 1935 2,195,084 Eklund Mar. 26, 1940 2,336,307 Slye Dec. 7, 1943 2,408,274 Schleicher Sept. 24, 1946 2,429,313 Gilbert Oct. 21, 1947

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