Reciprocally Actuated Switch With Rotatable Contact Selector

1. Field of the Invention

This invention generally relates to electrical switches and more specifically to a rotary switch with reciprocating slider.

2. Description of the Prior Art

Presently known rotary switch usually includes a shaft rotatably mounted in a suitable housing, a plurality of circumferentially spaced stationary contacts, and a wiper associated with the shaft for wiping engagement with the contacts. Rotation of the shaft selectively makes and breaks electrical connections between the contacts in accordance with its rotary position.

Such rotary switch has a disadvantage in requiring a considerable rotary force to rotate it from one contacting position to another. Another disadvantage is in the necessity to connect and disconnect the contacts in the same sequence.

In a broad sense, it is the principal object of this invention to provide a new type of a rotary switch that is extremely simple in construction and efficient in operation.

It is another object of the invention to provide a rotary switch with reciprocating slider.

It is still another object of the invention to provide a rotary switch that can be rotated by exerting a relatively low rotary force.

It is still another object of the invention to provide a rotary switch in which the contacts may be connected and disconnected in any sequence.

The rotary switch of the present invention includes rotatably coupled stationary and rotary members. The rotary member includes a flexible U-shaped conducting bridging element having at its ends two integral jaws. By moving a slider axially arranged on the rotary member, the jaws may be brought into and out of electrical engagement with a contact pair in the aligned position on the stationary member. When the slider is away from its engaging position, the rotary member may be selectively rotated to bring the bridging element into aligned position with another contact pair.

Further objects of the invention wil become obvious from the accompanying drawings and their description.

In the drawings in which are shown the preferred embodiments of the invention,

FIG. 1 is a cross-sectional view revealing internal structure of a rotary switch of this invention in its disengaged condition.

FIG. 2 is a cross-sectional view of a like rotary switch in its engaged condition.

FIG. 3 is a perspective view of a rotary member of the rotary switch.

FIG. 4 is a cross-sectional view of the rotary switch of FIG. 2, taken along the line 4--4, showing the detail of engaged jaws in the first rotary position.

FIG. 5 is a cross-sectional view of the rotary switch of FIG. 1, taken along the line 5--5, showing the detail of jaws during the rotation.

FIG. 6 is a cross-sectional view similar to FIG. 4 showing the detail of engaged jaws in the second rotary position.

FIG. 7 is a bottom view of the rotary switch of FIG. 2 in its first rotary position.

FIG. 8 is a bottom view of the rotary switch of FIG. 1 showing the progress of rotation of the rotary member with respect to the stationary member.

FIG. 9 is a bottom view similar to FIG. 7 of the rotary switch in its second rotary position.

FIG. 10 is a perspective view of a stationary member of the rotary switch.

FIG. 11 is a cross-sectional view, taken along the line 11--11 in FIG. 13, revealing the engagement of flanges on the rotary member and grooves in the slider.

FIG. 12 is a cross-sectional view revealing internal structure of another embodiment of a rotary switch in its disengaged condition.

FIG. 13 is a cross-sectional view of a like rotary switch in its engaged condition.

Throughout the drawings, like characters indicate like parts.

Referring now, more particularly, to the drawings, in FIGS. 1 to 3 is shown a rotary switch of the invention which includes a rotary member 10 and stationary member 30. Generally, the rotary switch has two conditions: engaged one, illustrated in FIG. 2, in which rotary member 10 is in engagement with stationary member 30 and cannot be rotated, and disengaged one, illustrated in FIG. 1, in which rotary member 10 is out of engagement with stationary member 30 and may be rotated to another rotary position. As will be pointed out more specifically below, slider 40 serves to engage and disengage the rotary switch.

Elongated rotary member 10, extending along a vertical longitudinal axis, is comprised of a generally cylindrical insulating body 11, with top 12 and bottom 14, and a conductive U-shaped bridging element 20, secured in body 11 by having its U-bend portion 21 axially anchored, having at its ends symmetrically disposed integral gripping jaws 23a and 23b with resiliently flexible portions 25a and 25b, respectively, viewed in FIG. 3. Jaws 23a and 23b normally extend at an angle with respect to the vertical axis, as illustrated in FIG. 1. Respective jaws 23a and 23b have abutting surfaces 26a and 26b formed on their outer convex faces and contacting surfaces 27a and 27b formed on their inner concave faces.

Stationary member 30 is comprised of an insulating cylindrical body 31 having at its surface secured four axially extending stationary contacts 33a, 33b, 33c, and 33d arranged substantially equally spaced from each other to form diametrical contact pairs 33a, 33c and 33b, 33d. The other ends of contacts 33a, 33b, 33c, and 33d, adjacent bottom 37, are respectively provided with electrical terminals 35a, 35b (not shown but opposite to terminal 35d), 35c, and 35d with apertures 36a, 36b (not shown but similar to aperture 36d), 36c, and 36d for joining conductors thereto.

A shaft 50, integral with rotary body 11 and axially extending from its bottom 14, has its lower end 51 secured in inner race of a ball bearing 55 which has its outer race secured in a recess 39 formed in top 38 of stationary body 31. Rotary member 10 may be thus rotated with respect to stationary member 30, when the rotary switch is disengaged, by exerting a relatively low rotary force.

Tubular insulating slider 40 is arranged on rotary body 11 of rotary member 10 for reciprocating movement along the vertical axis to its engaging position towards jaws 23a and 23b, illustrated in FIG. 2, and to its disengaging position sufficiently away from jaws 23a and 23b, illustrated in FIG. 1. Slider 40 includes an overhanging portion 45, extending over spring stop 19 for internally defining annular spring cavity 46 and for limiting the travel of slider 40 over its engaging position. Annular abutting stop projection 48, adapted to engage stop projection 17 formed on bottom 14 of rotary body 11, is formed on slider 40 and serves to limit its travel away from its engaging position. Inwardly turned rim 47 is formed on slider 40 for allowing it to snugly slide to its engaging position on rotary body 11. A helical coil spring 18 surrounding rotary body 11 is anchored by its one end at annular spring stop 19 integrally formed on body 11 and has its other end applied to slider 40 for normally urging it to its engaging position.

Slider 40 has formed thereon annular abutting surfaces 43 sloped at an angle less than 30 degrees with respect to the vertical axis and adapted to engage complementary abutting surfaces 26a and 26b on jaws 23a and 23b and to transfer the force of spring 18 to jaws 23a and 23b and thence to contact pair 33a, 33c or 33b, 33d. When in its engaging position, slider 40 abuts jaws 23a and 23b, as illustrated in FIG. 2, to deflect same towards, and into intimate electrical engagement with, the contact pair 33a, 33c or 33b, 33d on stationary member 30, to complete the circuit continuity. When in its disengaging position, slider 40 disengages jaws 23a and 23b, as illustrated in FIG. 1, to release contact pair 33a, 33c or 33b, 33d. Consequently, to rotate the rotary switch to its another position, it is necessary to manually move slider 40 against the force of spring 18 and sufficient distance away from its engaging position, as indicated in FIG. 1 by arrows 1a and 1b.

It is contemplated that the best operating mode of the rotary switch is to rigidly secure stationary member 30, move slider 40 to its disengaging position, and rotate rotary member 10 to the desired rotary position. This can be accomplished either by holding slider 40 in its disengaging position with one hand and rotating rotary member 10 with the other hand, or by holding slider 40 and rotary member 10 together with three or four fingers and rotating them jointly.

FIGS. 4 to 6 show the details of engaged and disengaged contact pairs. In the first rotary position, viewed in FIG. 4, the contact pair 33a, 33c is electrically interconnected; in the second rotary position, viewed in FIG. 6, the contact pair 33b, 33d is interconnected. The portions of ball bearing 55 and shaft bottom 51 were omitted from FIGS. 4 to 6 so as not to obscure the drawings by unnecessary details.

As shown in FIG. 4, jaws 23a and 23b are in engagement with the contact pair 33a, 33c, and a continuous conducting path is established from terminal 35a, as viewed in FIG. 2, via contact 33a, jaw 23a, U-bend 21, jaw 23b, contact 33c, to terminal 35c. The contacts 33a, 33b, 33c, and 33d are physically separated by equiangularly spaced insulating ribs 32a, 32b, 32c, and 32d, respectively, best viewed in FIG. 10. There is a space between the sides of jaw 23a and sides of ribs 32a and 32d to allow jaw 23a to slightly slide sideways so as to provide a wiping action between jaw 23a and contact 33a, and, in a similar fashion between jaw 23b and contact 33c.

FIG. 5 illustrates the rotary switch in its disengaged condition showing how jaws 23a and 23b may be freely rotated from the first to second rotary position or vice versa.

As shown in FIG. 6, jaws 23a and 23b are in engagement with the contact pair 33b, 33d, and a continuous conducting path is established from terminal 35b, via contact 33b, jaw 23a, U-bend 21, jaw 23b, contact 33d, to terminal 35d.

It would be obvious to those skilled in the art that rotary switches having more than two contact pairs may be readily designed in accordance with the principles of the invention. It would be further obvious that such rotary switches may be so rotated as to interconnect the pairs of contacts in any desired sequence, without regard to their physical arrangement.

FIGS. 7 to 9 are bottom views of the rotary switch of FIGS. 1 and 2 showing the progress of rotation of jaws 23a and 23b. The details of electrical terminals 35a, 35b, 35c, and 35d were omitted to render the illustration less complex.

In FIG. 7 is shown the rotary switch in the first rotary position. Ribs 32a and 32d define therebetween recess 34a for assuring the correct position of jaw 23a. In a similar fashion, ribs 32b and 32c define therebetween recess 34c for assuring the correct position of jaw 23b.

In FIG. 8 is shown the rotary switch in its intermediate position. When slider 40 is moved to its disengaging position, viewed in FIG. 1, its abutting surfaces 43 release jaws 23a and 23b to allow them to extend angularly to provide sufficient clearance from ribs 32a, 32b, 32c, and 32d. Rotary member 10 may be then rotated without obstruction to the second rotary position. During the rotation, bottom 14 of rotary member 10, with jaws 23a and 23b resiliently extending therefrom, rotates counterclockwise with respect to bottom 37 of stationary member 30.

When jaws 23a and 23b reach the aligned position with recesses 34b and 34d in the second rotary position, slider 40 may be released to its engaging position. Ribs 32a and 32b define therebetween recess 34b for assuring the correct position of jaw 23b. In a similar fashion, ribs 32c and 32d define therebetween recess 34d for assuring the correct position of jaw 23a.

In FIG. 10 is shown a perspective view of stationary member 30. Four insulating longitudinal ribs 32a, 32b, 32c, and 32d are axially secured on cylindrical surface of stationary body 31 and substantially equally spaced from each other. Ribs 32a and 32b define therebetween recess 34b, ribs 32b and 32c define therebetween recess 34c, ribs 32c and 32d define therebetween recess 34d (not shown but opposite to recess 34b), and ribs 32d and 32a define therebetween recess 34a. Contacts 33a, 33b, 33c, and 33d (not shown but similar to contact 33b) are respectively secured in recesses 34a, 34b, 34c, and 34d and provided with terminals 35a, 35b, 35c, and 35d, of which only terminal 35d is shown so as not to obscure the details of ribs 32a, 32b, 32c, and 32 d.

In FIGS. 11 to 13 is shown a modified embodiment of the rotary switch of the invention in which rotary member 10 is constrained to rotate with slider 40. Since the bottom portion of the rotary switch is substantially same as viewed in FIGS. 1 and 2, it will be described only briefly. Rotary member 10 has on the opposite sides of its top portion 12 formed two flanges 15a and 15b, extending along the vertical axis for respectively slidably engaging vertical grooves 16a and 16b formed in the inner surface of slider 40. Slider 40 has its top portion 45a modified to completely overhang rotary member 10. To operate the rotary switch, slider 40 may be grasped wtih a thumb and forefinger and pulled up, as indicated by arrows 1a and 1b in FIG. 12. As previously mentioned, the upward movement of slider 40 is limited by stop projection 48. Slider 40 may be then rotated, constraining by means of engagement of flanges 15a and 15b with grooves 16a and 16b, as viewed in FIG. 11, rotary member 10 to rotate therewith to the second rotary position. When the second rotary position is reached, slider 40 may be released to its engaging position viewed in FIG. 13. It would be obvious that markings may be placed on the top 45a to indicate the positions of jaws 23a and 23b. Slider 40 and rotary member 10 may be otherwise shaped to constrain them to rotate jointly.

In summary, the invention describes a rotary switch comprising a stationary and rotary members and a reciprocating slider. The rotary member includes an insulating body and a flexible conducting bridging element secured thereto. The stationary member includes an insulating body having a plurality of stationary contact pairs angularly arranged thereon. The rotary and stationary members are coupled for rotating the bridging element to one of a plurality of angular rotary positions aligned with a selective one of the contact pairs. A slider member is arranged on the rotary member for reciprocating movement to its engaging position, for deflecting the bridging element into electrical engagement with the aligned contact pair on the stationary member, and to its disengaging position, for releasing the bridging element from the aligned contact pair. In another embodiment is disclosed a rotary switch having a slider capable of rotation about an axis and a rotary member constrained to rotate with the slider.

It would be obvious that persons skilled in the art may resort to numerous modifications in the construction of the preferred embodiments shown herein, without departing from the spirit of the invention as defined in the appended claims.