Patent Publication Number: US-6037856-A

Title: Rotating electrical component having rotary lock mechanism of operating shaft

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a rotating electrical component, such as a variable resistor, rotary encoder, etc., suitable for use in such an electric cooking appliance as an electric range. 
     2. Description of Related Art 
     In a conventional portable electronic equipment such as a radio receiver, a transceiver, etc., if the power switch is carelessly pressed to on and the user does not notice it, battery power will be wasted. To obviate the above-described disadvantage, a switch described below has been disclosed in Japanese Utility Model Publication No. Sho 63-18095. 
     In the switch disclosed in Japanese Utility Model Publication No. Sho 63-18095, as shown in FIGS. 12 and 13, a cylindrical support member 31 is comprised of a projecting piece 32 mounted on the outer peripheral portion for operating the switch, a projection-recess portion 33, a flange 34 formed on the inside surface, and a pair of recesses 35 mutually facing on both sides of the shaft hole and formed in the lower surface of the flange so as to be positioned on the circumference of the same diameter. 
     The sliding member 36 has a small-diameter shaft 37, a large-diameter shaft 38, a flange 39 located between the small-diameter shaft 37 and the large-diameter shaft 38, and a pair of projections 40 formed on the upper surface of the flange 39 in opposite positions on both sides of the small-diameter shaft 37. 
     The sliding member 36 is inserted in the support member 31. In this state the sliding member 36 thus installed is rotatable and axially movable. And the pair of projections 40 can be engaged with, and disengaged from, the pair of recesses 35. 
     Furthermore the sliding member 36 thus installed is pressed against the flange 34 of the support member 31 by the force of a spring 42 interposed between a bottom member 41 and the flange 39. 
     Above the sliding member 36 are mounted a knob 43 and a push member 44, and furthermore a ball 46 loaded with a spring 45 is placed oppositely to the projection-recess portion 33 of the support member 31, thereby constituting a click mechanism. 
     The switch operation stated above first presses the push member 44 against the force of the spring 42 to move the slide member 36 in the axial direction, disengaging the projection 40 from the recess 35, and thereafter the knob 43 is turned to turn the slide member 36 to thereby rotate the support member 31. 
     Then, the support member 31 is operated with a click by the click mechanism and the projecting piece 32 rotates to change over the contact of the switch not shown. 
     As the knob 43 is turned back to the original position, the slide member 36 also moves back to engage the projection 40 with the recess 35. 
     That is, the switch is first pushed and then turned so as not to be carelessly operated to on. 
     The above-described conventional switch has such a disadvantage that because the pair of recesses 35 and the projections 40 are formed on a circumference of the same diameter, the projection 40 is engaged with the recess 35 within the 180-degree range of rotation of the slide member 36; and accordingly the slide member 36 has a narrow operation range. 
     The bottom member 41 is needed beside the slide member 36 to install the spring 42, which increases components count and cost, resulting in low productivity. 
     Furthermore, there is such a drawback that the support member 31, being designed to be rotated, needs a member for supporting itself, thereby increasing the components count; and moreover on the outer periphery of the support member 31 the projecting piece 32 is formed for switch operation or the projection-recess portion 33 is provided as the click mechanism, making the structure large and complicated. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide, as a first means for obviating the above-described drawback, a rotating electrical component which has a support member having a flange, an operating shaft rotatably and axially movably mounted on the support member and having a flange, and a spring member for pressing the operating shaft to the flange side of the support member. On mating surface sides of the flange of the support member and the flange of the operating shaft, and on both sides of the center of rotation on the line which passes through the center of rotation of the operating shaft, there are provided projections and recesses which differ in diameter measured from the center of rotation of the operating shaft and can be engaged and disengaged in positions where they will not overlap each other in the circumferential direction, so that the projections will be disengaged from the recesses when the operating shaft is moved axially against the force of the spring member, thereby enabling rotation of the operating shaft. 
     It is another object of the present invention to provide, as a second means for obviating the above-described drawback, a rotating electrical component in which either one of the flange of the support member and the flange of the operating shaft is provided with recesses on both sides of the center of rotation of the operating shaft and in positions where the diameter from the center of rotation of the operating shaft differs, and the other flange is provided with projections which engage with, and disengage from, the recesses. 
     Another object of the present invention is to provide, as a third means for obviating the above-described drawback, a rotating electrical component in which the flange of the support member is provided, on both sides of the center of rotation of the operating shaft, with a recess in either one of positions where diameter from the center of rotation of the operating shaft differs, and with a projection in the other position; also the flange of the operating shaft is provided with a projection which can engage with the recess of the flange and a recess in which the projection of the flange engages. 
     Another object of the present invention is to provide, as a fourth means for obviating the above-described drawback, a rotating electrical component in which the operating shaft and the flange are unitarily formed by molding a synthetic resin. 
     Another object of the present invention is to provide, as a fifth means for obviating the above-described drawback, a rotating electrical component in which a rotating body holding a contact member is provided; the rotating body and the operating shaft being splined, so that the rotating body can be rotated by turning the operating shaft; and furthermore the spring member is interposed between the operating shaft and the rotating body. 
     Another object of the present invention is to provide, as a sixth means for obviating the above-described drawback, a rotating electrical component in which a spring for clicking disposed between the rotating body and the support member is attached to the rotating body or to the support member, so that the operating shaft will rotate with a click. 
     Another object of the present invention is to provide, as a seventh means for obviating the above-described drawback, a rotating electrical component in which a rotatable coding member comprising a magnet and others is provided; the coding member being splined to the operating shaft to rotate the coding member with the rotation of the operating shaft. Furthermore, a spring member is interposed between the operating shaft and the coding member. 
     Further another object of the present invention is to provide, as an eighth means for obviating the above-described drawback, a rotating electrical component in which the spring for clicking disposed between the coding member and the support member is attached to the coding member or to the support member, to thereby provide the rotation of the operating shaft with a click motion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features and advantages of the present invention will be clear from the following description with reference to the accompanying drawings in which: 
     FIG. 1 is a plan view of the first embodiment; 
     FIG. 2 is a sectional view thereof; 
     FIG. 3 is a sectional view taken along line 3--3 of FIG. 2; 
     FIG. 4 is a lower surface of a support member according to the first embodiment; 
     FIG. 5 is a plan view of an operating shaft according to the first embodiment; 
     FIG. 6 is an explanatory view showing the assembly of the support member and the operating shaft according to the first embodiment; 
     FIGS. 7A-C, are views explaining operation of the first embodiment; 
     FIG. 8 is a sectional view of the second embodiment; 
     FIG. 9 is a sectional view taken along line 9--9 of FIG. 8; 
     FIG. 10 is a sectional view of the third embodiment; and 
     FIG. 11 is a sectional view taken along line 11--11 of FIG. 10. 
     FIG. 12 is a sectional view of a prior art switch 
     FIG. 13 is an expanded view of the switch of FIG. 12. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The rotating electrical component of the first embodiment according to the present invention will be described with reference to FIG. 1 to FIG. 7. A support member 1 of a rectangular box type produced of a synthetic resin molding has a plate-like flange 1a, a hole 1b provided at the center of the flange 1a, a side wall 1c extending downwardly from the periphery of the flange 1a, a depressed portion 1e having a projection 1d formed on the inner peripheral surface on the hole 1b side of the inside surface of the flange 1a, a depressed portion 1g positioned in the outer periphery of the depressed portion 1e and having a projection 1f, and a flat portion 1k positioned further in the outer periphery of the depressed portion 1g and having a projection-recess portion 1h. 
     The projections 1d and 1f, as shown in FIG. 4, differ in diameter from the center P of the hole 1b on both sides (180 degrees apart) of the center P of the line S1 passing through the center P of the hole 1b, and are so formed as not to overlap in the circumferential direction. Furthermore, the projection-recess portion 1h is formed within the range of about 180 degrees of the flat portion 1k. 
     The projection-recess portion 1h may be formed throughout the range of 360 degrees. 
     The operating shaft produced of a synthetic resin molding is provided with a shaft portion 2a, a flange 2b formed unitarily with the shaft portion 2a in a stepped form, a pair of recesses 2c and 2d provided at the flange 2b, a depressed portion 2e provided around the shaft portion 2a, and a projection 2f formed on the underside of the flange 2b. 
     The recesses 2c and 2d, as shown in FIG. 5, are formed on both sides (180 degrees apart) of the center P of rotation of the line S1 passing through the center P of rotation of the operating shaft 2, different in diameter from the center P of rotation of the operating shaft 2, in positions in which they will not overlap in the circumferential direction. 
     The operating shaft 2, with its shaft portion 2a inserted in the hole 1b of the support member 1, is rotatably and axially movably installed to the support member 1; when the operating shaft 2 is installed, the recess 2c can be engaged with the projection 1d, while the recess 2d can be engaged with the projection 1f. 
     In the present embodiment, the support member 1 is provided with the projections 1d and 1f, and the operating shaft 2 with the recesses 2c and 2d. The support member 1 may be provided with recesses, and the operating shaft 2 with projections. 
     The rotating body 3 comprising an insulating material has a noncircular hole 3a provided at a central part, a projection 3b provided on the upper surface, and a depressed portion 3c provided also on the upper surface. 
     The rotating body 3 is housed in the support member 1 and the operating shaft 2 is inserted in the hole 3a; in this state the rotating body 3 and the operating shaft 2 are splined, so that with the rotation of the operating shaft 2 the rotating body 3 will rotate simultaneously. Furthermore the rotating body 3 is assembled with the depressed portion 3c opposite to the projection 2f of the operating shaft 2. 
     The circular spring 4 for clicking which is a metal plate spring has a base portion 4d provided with holes 4a, 4b and 4c, an engagement portion 4e, and an arm portion 4f extending from the base portion 4d as shown in FIG. 3. 
     The spring 4 for clicking is mounted on the upper surface of the rotating body 3, with the projection 3b inserted in the hole 4a, and then attached to the rotating body 3 with the forward end of the projection 3b pressed down. Also when the spring 4 for clicking is mounted in the support member 1, the operating shaft 2 is mounted through in the hole 4c as shown in FIG. 2, and is disposed between the support member 1 and the rotating body 3. In this state, the hole 4b faces the projection 2f of the operating shaft 2, and the engagement portion 4e is engaged with the projection-recess portion 1h of the support member 1. 
     The spring 4 for clicking in the present embodiment is attached to the rotating body 3, but may be attached to the support member 1. In this case, the projection-recess portion in engagement with the spring 4 for clicking is required only to be provided on the rotating body 3 side. 
     The insulating base plate 5 has a hole 5a formed at the central part, and is provided with an embedded contact portion or a conductor 6 such as a resistor, and with a terminal 7 connected to the conductor 6. 
     Then, with the rotating body 3 partly inserted in the hole 5a, the insulating base plate 5 is mounted under the side wall 1c of the support member 1, and is attached to the support member 1 by a mounting plate 8. 
     A coil-shaped spring member 9 is inserted onto the operating shaft 2 for mounting between the operating shaft 2 and the rotating body 3. Thus the spring member 9 presses the operating shaft 2 towards the support member 1 side, and the rotating body 3 against the insulating base plate 5. 
     A contact member 10 comprising a metal plate spring is mounted on the underside of the rotating body 3, and the contact member 10 rotates together with the rotating member 3, thereby contacting, and releasing from, the conductor 6 such as a contact portion, or sliding on the conductor 6 such as the resistor. 
     Next, operation of the rotating electrical component will be described with reference to FIG. 7. FIG. 7A shows the projections 1d and 1f of the support member 1 are engaged with the recesses 2c and 2d of the operating shaft 2. In this state, when the operating shaft 2 is pressed axially against the force of the spring member 9, the projections 1d and 1f come off from the recesses 2c and 2d as shown in FIG. 7B; in this state the operating shaft 2 is rotatable and the projection 2f of the operating shaft 2 fits in the depressed portion 3c of the rotating body 3. 
     As the operating shaft 2 is turned in this state, the rotating body 3 rotates together with the operating shaft 2, to make the contact member 10 slide on the conductor 6, thereby adjusting the electrical component. Also with the rotation of the rotating body 3, the spring 4 for clicking moves up and down on the projection-recess portion 1h of the support member 1, thereby actuating the operating shaft 2 with a click motion. 
     When the operating shaft 2 is turned a little, the flange 2b of the operating shaft 2 rides on the projections 1d and 1f of the support member 1 as shown in FIG. 7C, releasing the push of the operating shaft 2 to allow the operating shaft 2 to rotate. 
     The projections 1d and 1f and the recesses 2c and 2d, so arranged as not to mutually overlap in the circumferential direction if the operating shaft 2 is turned through 180 degrees, will not be engaged. The operating shaft 2, when turned through 360 degrees, is pushed by the spring member 9 to engage the projections 1d and 1f with the recesses 2c and 2d respectively. 
     When the projections 1d and 1f are engaged with the recesses 2c and 2d, the electrical component is in the state shown in FIG. 7A. In this state, the operating shaft 2 will not turn if a force is applied to turn because the projections 1d and 1f are in engagement with the recesses 2c and 2d. 
     In the present embodiment, the operating shaft 2 makes a click motion from the projection 1d as the original point within the range of 90 degrees in the clockwise or counterclockwise direction. 
     The operating shaft 2 can properly turn without tilting because the projections 1d and 1f are provided on both sides of the center P of rotation. 
     In the present embodiment, since the recesses 2c and 2d are open on the outer peripheral side, it is unnecessary to allow a large amount of radial deviation for the purpose of proper engagement, and accordingly it is possible to decrease a radial dimension. 
     Further in the present embodiment, the projections 1d and 1f are connected with the depressed portion 1g and the flat portion 1k surface, thereby providing a greater strength. 
     FIG. 8 and FIG. 9 show the second embodiment of the rotating electrical component according to the present invention. The present embodiment is the embodiment applied to the rotary encoder, in which the flange 1a of the support member 1, similarly to the aforesaid embodiment, differs in diameter from the center P of rotation of the operating shaft 2, on both sides (in positions 180 degrees apart) of the center P of rotation of the line S1 passing through the center P of rotation of the operating shaft 2, and the projections 1d and 1f are formed in positions not overlapping in the circumferential direction. 
     The flange 2b of the operating shaft 2 is provided with the recesses 2c and 2d, which differ in diameter from the center P of rotation of the operating shaft 2, on both sides (in positions 180 degrees apart) of the center P of rotation of the line S1 passing through the center P of rotation of the operating shaft 2, and are not overlapped in the circumferential direction. 
     The recesses 2c and 2d can be engaged with the projections 1d and 1f. 
     The coding member 11 consisting of a magnet and others is splined to the operating shaft 2, and mounted rotatable together with the operating shaft 2. Between the coding member 11 and the operating shaft 2 the spring member 9 is disposed to constantly press the operating shaft 2 towards the flange 1a side. 
     Oppositely to the coding member 11 a detecting sensor 12 is disposed to detect the magnet. The detecting sensor 12 is designed to detect the rotation of the coding member 11. 
     The operation of the rotary encoder mentioned above is similar to the aforesaid embodiment. The projections 1d and 1f of the support member fit in the recesses 2c and 2d of the operating shaft 2; in this state of engagement of the projections in the recesses, when the operating shaft 2 is pushed axially against the force of the spring member 9, the projections 1d and 1f come off from the recesses 2c and 2d, thereby allowing the operating shaft 2 to rotate. 
     When the operating shaft is turned in this state, the coding member 11 turns together with the operating shaft 2, detecting the code by the detecting sensor 12. 
     When the operating shaft 2 is turned a little, the flange 2b of the operating shaft 2 rides on the projections 1d and 1f of the support member 1, thereby releasing the push of the operating shaft to allow the rotation of the operating shaft 2. 
     The projections 1d and 1f and the recesses 2c and 2d, so arranged not to be mutually overlapped in the circumferential direction, will not be engaged if the operating shaft 1 is turned through 180 degrees. The operating shaft 2 is pushed by the spring member 9 when turned through 360 degrees, where the projections 1d and 1f are engaged with the recesses 2c and 2d. 
     When the projections 1d and 1f are in engagement with the recesses 2c and 2d as shown in FIG. 8, the operating shaft 2 in this state will be checked from turning if forced to turn. 
     In the present embodiment, the click mechanism like in the above-described embodiment may be formed by interposing the spring for clicking between the operating shaft 2 and the coding member 11 and mounting the spring for clicking on the coding member 11 or on the operating shaft 2. 
     FIG. 10 and FIG. 11 show the third embodiment of the rotating electrical component of the present invention. In the present embodiment, the rotary encoder is applied, in which the flange 1a of the support member 1 differs in diameter from the center P of rotation of the operating shaft 2, on both sides (in positions 180 degrees apart) of the center P of rotation of the line S1 passing through the center P of rotation of the operating shaft 2, and the projections in are formed in positions not overlapping the recesses 1m in the circumferential direction. 
     The flange 2b of the operating shaft 2 is provided with projection 2g and the recess 2h, which differ in diameter from the center P of rotation of the operating shaft 2, on both sides (in positions 180 degrees apart) of the center P of rotation of the line S1 passing through the center P of rotation of the operating shaft 2, and are not overlapped in the circumferential direction. 
     The projection 2g of the operating shaft 2 can be engaged with, and released from, the recess 1m of the support member 1; and also the projection in of the support member 1 can be engaged with, and released from, the recess 2h of the operating shaft 2. The electrical component is the same in other points of constitution as the second embodiment; therefore the same members are designated with the same reference numerals and will not be described. 
     In the present third embodiment, when the operating shaft 2 is axially pushed, the projection 2g and the recess 2h of the operating shaft 2 are disengaged from the recess 1m and the projection in of the support member 1 respectively, to thereby permit rotation of the operating shaft 2. As the operating shaft 2 is turned through 360 degrees, the projection 2g and the recess 2h of the operating shaft 2 engage with the recess 1m and the projection in of the support member 1 respectively; consequently the operating shaft is checked from turning. Other operations are done similarly to the second embodiment and therefore will not be described. 
     In the second and third embodiments, the electrical component can be made thinner as compared with that of the first embodiment. 
     In the first to third embodiments, the projections and recesses are provided in two places at intervals of 180 degrees, and may be provided in three places at intervals of 120 degrees not overlapping in the radial direction. 
     The present invention can provide a rotating electrical component in which the operating shaft is turned after axially moved, and therefore the electrical component will never carelessly be operated. 
     It is, therefore, possible to provide a rotating electrical component in which the operating shaft 2 is adjustable within a wide range of rotation because of the formation of the projections 1d and 1f and the recesses 2c and 2d which differ in diameter from the center P of rotation of the operating shaft 2 and can be mutually engaged and disengaged, on the mating surface sides of the flange 1a of the support member 1 and the flange 2b of the operating shaft 2, on both sides of the center P of rotation of the line S1 passing through the center P of rotation of the operating shaft 2, and in such positions where the projections and recesses are not overlapped in the circumferential direction. 
     It is also possible to provide a rotating electrical component in which the operating shaft 2 is adjustable within a wide range of rotation, is simple in constitution and of good productivity, and besides will not tilt during rotation because of the formation of the recesses 2c and 2d which differ in diameter from the center P of rotation of the operating shaft 2, on either one of the flange 1a of the support member 1 and the flange 2b of the operating shaft 2, on both sides of the center P of rotation of the line S1 passing through the center P of rotation of the operating shaft 2, and the formation of the projections 1d and 1f, on the other, which can be engaged with, and disengaged from, the recesses 2c and 2d. 
     Furthermore it is possible to provide a rotating electrical component in which the operating shaft 2 is adjustable within a wide range of rotation and will not tilt during rotation because of the formation of the recess 1m in one of the positions and the projection in in the other position which differ in diameter from the center P of rotation of the operating shaft 2, on both sides of the center P of rotation of the operating shaft 2, and further the formation, on the flange 2b of the operating shaft, of the projections 2g which can be engaged with, and disengaged from, the recess 1m of the flange 1a, and the recess 2h which can be engaged with, and disengaged from, the projection 1n of the flange 1a. 
     Furthermore it is possible to provide a low-cost rotating electrical component of simple constitution and high productivity because of the unitary formation of the operating shaft 2 and the flange 2b. 
     Furthermore it is possible to provide a rotating electrical component, such as a low-cost variable resistor, switch, etc., which comprises a small components count and accordingly ensures efficient assembling because the spring member 9 for actuating the operating shaft 2 is interposed between the rotating body 3 holding the contact member 10 and the operating shaft 2. 
     Furthermore it is possible to provide a rotating electrical component with a small click mechanism which has a good space factor because the spring 4 for clicking is interposed between the rotating body 3 and the operating shaft 2. 
     Furthermore it is possible to provide a rotating electrical component having a small components count which allows efficient assembling, and comprising a low-cost rotary encoder because of the interposition of the spring member 9, for actuating the operating shaft 2, between the coding member 11 and the operating shaft 2. 
     Furthermore it is possible to provide a rotating electrical component with a small clicking mechanism which has a good space factor because of the disposition of the spring 4 for clicking between the coding member 11 and the operating shaft 2.