US 3382733 A
Description (OCR text may contain errors)
May 14, 1968 P. J- MILLER ET AL SPRING RETURN FOR SELECTOR VALVES Filed April 22, 1966 mm 6 w; 262 5/ V 0 7 i ZYM United States Patent 3,382,733 SPRING RETURN FOR SELECTOR VALVES Paul J. Miller, Maple Heights, and James R. Jeromsou, Jr., Willoughby, Ohio, pssignors to The Weatherhead Company, a corporation of Ohio Filed Apr. 22, 1966, Ser. No. 544,551 Claims. (Cl. 74-543) ABSTRACT OF THE DISCLOSURE A valve has a rotating shaft for actuating the valve extending outward from the valve housing and surrounded by a projecting boss. The boss has an arcuate slot to allow movement of the shaft by a handle connected to the shaft and extending radially outward through the slotrln one position of the handle, it is in alignment With a pair of projections on the boss axially on each side of the handle with respect to the shaft. A C-shaped spring surrounds the boss and abuts the projections to hold the handle in the centered position, so that movement of the handle to rotate the shaft in either direction engages an end of the spring which provides a restoring force for the handle.
The present invention relates generally to return spring arrangements for intermittently actuated control mechanisms and more particularly to return spring arrangements for rotary selector valves.
Many intermittently actuated control mechanisms are provided with some form of a selector element or actuating means which is moved from a centered or neutral first position to a second position to actuate the control mechanism. Particularly when the operation of the control mechanism is intermittent, the selector element need remain in the second position for a short period of time only, and it should automatically return to the first position by a spring return arrangement upon the release of the selector element or other actuating means.
In many uses, it is important that the return spring arrangement hold the zero position accurately so as to prevent play in the selector element, and there must be a minimum of binding or other interference with the operation of the control mechanism. Also, the arrangement should permit bi-directional movement of the selector element from the centered or neutral position so as to provide a plurality of operating settings. Furthermore, the arrangement should be easily replaceable and interchangeable with other units and of such a design that the spring tension may be varied easily, while being compact and durable with a long service life.
The present invention provides a novel arangement having a slotted yoke fixed relative to the selector or actuating means of the control mechanism and an element within the yoke slot which is movable in response to the movement of the actuating means. The return biasing force is provided by an arcuate spring having an end engaging the yoke body across the width of the yoke slot so as to be engaged by the movable element upon movement of the actuating means. The width of the movable element and the length of the yoke slot allow the end of the arcuate spring to rest against the yoke when the movable element is in the centered or neutral position so that this position is accurately maintained by the fixed yoke rather than by the spring.
Since the spring does not engage the actuating means directly, it does not bind or interfere with its movement except by the desired force tending to return it to its centered or neutral position. The arcuate spring may be arranged about the other elements of the control mechanism and may be relatively wide as compared to its thickness to be both compact and durable. Bi-directional "Ice movement of the actuating means can be provided by the use of a substantially C-shaped spring having its ends engaging opposite sides of the yoke body to be engageable by the movable element when moved in either direction from the centered or neutral position.
The spring is easily removable from the control mechanism for replacement, and the spring tension can be varied easily either by substituting a heavier or lighter spring or by adding or substracting spring leaves from the arrangement.
Further features and advantages of the invention will readily appear to those skilled in the art upon a more I complete understanding of the preferred embodiment of the invention as applied to a rotary hydraulic selector valve as shown and described in the following description and drawings, wherein:
FIGURE 1 is an elevational view of a rotary hydraulic selector valve partially cross sectioned through the return spring arrangement;
FIGURE 2 is a cross sectional view taken on line 2-2 of FIGURE 1 showing the return spring arrangement in the centered or neutral position;
FIGURE 3 is a cross sectional view taken on line 3-3 of FIGURE 1 but with the selector member moved to one side of the centered or neutral position; and,
FIGURE 4 is a perspective view of the valve body and yoke arrangement.
While the present invention is shown and described as applied to a rotary hydraulic selector valve, this is done for purposes of illustration only and it is also applicable to any intermittently actuated control mechanism. Referring to FIGURE 1, the control mechanism comprises a rotary hydraulic selector valve indicated generally by the numeral 10. The internal operating mechanism of the selector valve forms no part of the present invention and, therefore, has not been shown in further detail. The selector valve 10 comprises a valve body 11 having an integral boss generally indicated by the numeral 12 formed upon one end thereof. A bore 13 leading to the internal operating mechanism of the selector valve 10 extends through the valve body 11 and the boss 12.
The boss 12 includes a radially outwardly extending neck-like yoke portion 17 having a slot 18 extending transversely of and opening into the bore 13. The slot is defined by parallel sides 15 and 16 and end surfaces 22 and 23 extending generally radially of the boss 12. Spaced stop surfaces 20 and 21 defining curved recesses are formed on opposite sides of the exterior of the yoke portion 17 and extend axially on both sides of the yoke slot 18.
Rotatably mounted within the bore 13 is an axially extending actuating means or control shaft 25 adapted to be connected at its inner end to the rotary selector valve mechanism (not shown). A handle 27 threaded in the outer end of the control shaft 25 at 28 projects radially outwardly from the shaft 25 through the yoke slot 18 and beyond the stop surfaces 20 and 21. The handle 27 forms a selector element movable relative to the yoke portion 17 and is adapted to be hand manipulated by an operator from the exterior of the selector valve. The diameter or width of the handle 27 is substantially equal to the width of the yoke portion 17 between the stop surfaces 20 and 21 so that the handle may be centered within the yoke slot.
As seen in FIGURES 2 and 3, the preferred form of return spring comprises an arcuate C-shaped leaf spring 30 which surrounds the boss 12. Generally, the return spring 30 may be any configuration of an open curve, the ends of which are arcuately displaced from one another by at least and which is mounted so that one end is fixed relatively to the yoke when the other is displaced by flexing of the spring. Bearing caps 31 and 32 which may be in the form of a slotted tube of sufiicient axial length to extend across the yoke slot 18 are secured to the opposite ends of the return spring 30 and bear against the stop surfaces 20 and 21 respectively. Since the diameter or width of the handle 27 is substantially equal to the width of the yoke portion 17, the bearing caps 31 and 32 rest against the machined stop surfaces 20 and 21 on the yoke 17 rather than directly against the handle 27 to accurately position the handle 27 in a centered or neutral position within the yoke slot 18.
The use of the substantially C-shaped return spring permits bi-directional movement of the handle 27 from the neutral or zero position with only a single return spring. With the handle centered within the yoke slot 18 as shown in FIGURE 2, movement of the handle 27 to the right rotates the control shaft 25 and causes the side of the handle to engage the bearing cap 31 and flex the return spring 30 by increasing its radius of curvature as shown in FIGURE 3. Although this causes the one end of the spring to move outwardly relative to the stop surface 20, the other end of the spring bears firmly against the other stop surface 21 and resists rotation of the spring around the boss 12. Thus the other end of the spring 30 is elfectively fixed relative to the yoke 17 and the spring exerts an inward force upon the handle 27 tending to return it to a centered position within the yoke slot 18. The dotted line 27a in FIGURE 3 represents the position of the handle 27 when it is rotated to the left against the other bearing cap 32.
The spring tension may be increased either by adding additional and similarly shaped leaves 35, 36 and 37 to overlie the same return spring 30 or by replacing the original return spring 30 with a heavier spring if it is so desired.
To protect the return spring arrangement from environmental abuse, a cup-shaped housing 40 is secured to the end of the control shaft 25 by a screw 41 in such a manner that the housing 40 will rotate along with the control shaft 25 and the handle 27. The housing 40 also serves as a safety feature to contain the return spring in case of breakage under tension.
Although the preferred embodiment of the invention has been shown and described in detail, it is recognized that various modifications and other arrangements will occur to those skilled in the art and will be within the scope of the invention as disclosed in the claims.
What is claimed is:
1. A mechanism comprising a body member, boss means on said body member, said body member and said boss means defining a bore coaxial with said boss means, shaft means rotatably journalled within said bore, said boss means including a yoke portion extending radially therefrom with respect to said bore, said boss means defining a slot through said yoke portion extending generally transversely of and opening into said bore, external stop surfaces on opposite radial sides of said yoke portion defining curved recesses extending axially on both sides of said slot, handle means secured to said shaft means and extending radially therefrom through said slot, C- shaped leaf spring means having an arcuate extent of more than 180, bearing caps secured to the ends of 4 said spring means, said spring means extending substantially around said boss means with said bearing caps being adapted to engage said stop surfaces, the spacing between said stop surfaces and the corresponding width of said handle means being substantially equal so that said bearing caps rest adjacent said stop surfaces and said handle means when said control shaft is centered within said yoke slot, whereby movement of said handle means away from said yoke portion engage the adjacent bearing cap to fiex said spring means and provide a biasing force tending to restore said handle means to its position within said yoke portion.
2. A mechanism as set forth in claim 1 wherein a housing means is provided surrounding said spring means, and boss means, said housing means being secured to said shaft means so as to rotate therewith and having an opening therethrough through which said handle means projects.
3. A return spring arrangement comprising slotted yoke means, a shaft rotatable relative to said yoke means, a handle projecting into the slot of said yoke means and connected to said shaft so as to cause rotation thereof, and arcuate spring means having one end adapted to engage said yoke means and being e-ngageable 'by said handle upon its movement from a neutral position within said slot, said spring means being arranged so that a portion of said spring is fixed relative to said yoke means when an end is engaged and flexed by said handle.
4. In a rotary selector valve, a valve body, a projecting boss on said valve body, a bore extending axially through said boss into said valve body, a rotatable actuating shaft in said bore, said boss having an arcuate slot thereon axially intermediate the ends thereof opening into said bore, a handle secured to said shaft and extending radially outward through said arcuate slot, said boss having a pair of radial projections, one on each side of said slot in axial alignment therealong and projecting outward beyond the remainder of said boss, said projections defining a neck of reduced width and having a portion of greater width radially outward of said neck, a C-shaped spring member extending around said boss and having free ends adjacent said projections, a bearing member secured to each end of said spring and having a portion engageable with the necks on both projections and arranged to engage said handle when said handle is moved out of a center position in alignment with said projections to provide a biasing force tending to return said handle and said shaft to a neutral position.
5. A device as set forth in claim 4 including at least one additional C-shaped spring overlying said spring member, said additional spring extending over less than the full circumferential extent of said spring member.
References Cited UNITED STATES PATENTS 2/1951 Jeffrey 74-470 5/1961 Johnson 74-523