Joystick Operator For Pushbutton Switch

Abstract

A mechanism for actuating selected ones of a plurality of plungers comprising a plurality of levers each of which is rotatable in engagement with at least one corresponding plunger to actuate the plunger and a common operating member to selectively rotate said levers.

Description

BACKGROUND OF THE INVENTION

This invention relates to plunger actuating mechanisms and has for its primary object the provision of such a mechanism which will actuate a plurality of plungers one or more at a time under the control of a common operating member.

One aspect of the invention is a modification or improvement of the invention the subject of our British Pat. No. 958805.

SUMMARY OF THE INVENTION

The invention provides a mechanism for simultaneously actuating selected ones of a plurality of plungers comprising a plurality of levers each of which is rotatable in engagement with at least one corresponding plunger to actuate said plunger, an operating member, and linkage means displaceable by said operating member to rotate selected ones of said levers whereby to actuate respective ones of said plungers.

An object of the invention is to provide an improved plunger actuating mechanism capable of operating a plurality of plungers one or more at a time under the control of a common operating member.

A preferred form of the invention provides a so-called "joystick" manual actuating mechanism for a plurality of associated plunger-actuated electric switches. In one form of the invention, the actuating mechanism is particularly adapted to operate plunger switches of the kind described in the specification of our British Pat. No. 833435.

Further features and advantages of the invention will appear from the following description of an embodiment thereof, given by way of example, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electric switch including a plunger-actuating mechanism in accordance with the invention, and

FIG. 2 is an exploded perspective view, part in section of the switch.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The switch shown in the drawings comprises a mechanism for actuating a plurality of plungers one or more at a time, comprising a plurality of levers each of which is rotatable in engagement with a respective plunger or combination of plungers to actuate the plungers and linking members connected with said levers and with a common operating member, said operating member being displaceable between a plurality of different positions to produce respective displacements or combinations of displacements of said linking members and levers, so as to actuate respective plungers or combinations of plungers.

The operating member is preferably displaceable between five different positions for example to actuate respectively no plungers at all, and four different plungers or combinations of plungers.

Referring now to the drawings in more detail, the switch comprises two contact blocks S and T, disposed side by side, with respective pairs of plungers Sa, Sb and Ta, Tb, projecting from their lower faces (as seen in FIG. 2) which faces lie in a common plane. The plungers can be depressed in directions parallel to an axis X, the axis being perpendicular to the plane mentioned above, in order to operate respective contact pairs disposed in the contact blocks. The plungers comprise generally cone shaped heads, and shafts (not shown) which project through the contact block, so that if desired further contact blocks (not shown) may be stacked on the contact blocks shown, to be actuated by the shafts of the contact blocks shown.

The plunger actuating mechanism comprises a joystick having a shaft 1b, and a handle 1c, the shaft having a part-spherical enlargement 1a which is mounted in a bearing 1, so that the handle 1c can be moved from the neutral position shown, with the shaft 1b parallel to the axis X, in any of the directions marked N,S,E, and W in FIG. 1, which directions are generally perpendicular to the axis X, or in any intermediate direction. An indexing mechanism (described below) ensures that the handle has nine stable positions, corresponding to the neutral position, to displacement of the handle 1c in each of the directions N,S,E and W, and to displacement of the handle 1c in each of the four directions bisecting the directions N,S,E and W. In FIG. 1 the reference N,S,E and W also indicate the plungers which are actuated by movement of the handle in each of the directions N,S,E and W respectively. If the handle is moved in an intermediate direction, two of the plungers are actuated simultaneously.

The switch also comprises a linkage mechanism contained in covers 2 and 3 which form a housing for the linkage, the linkage connecting the ball-end 1d on the joystick to the plungers Sa, Sb, Ta and Tb. The bearing 1 is centered on the axis which passes through the center of the contact block S, and the cover 2 has an aperture 2a centered on the axis X, the ball-end 1b projecting through the aperture 2a. The cover 2 also has an internal pivot pin projecting along an axis Y parallel to the axis X, and passing through the center of the contact block T.

The linkage also comprises a bush 3a which fits over the ball-end 1d, and is mounted on a plate 3 at one end of the plate. The other end of the plate 3 has a slot 3b which fits over the pivot pin 2b. Accordingly, the bush 3a follows the movement of the ball-end 1b, but its axis is maintained parallel to the axis X, and its movement is guided by the slot 3b.

On the plate 3 is disposed a plate 4, whose side edges engage flanges on the cover 2, so that the plate 4 is restrained from movement in the directions E and W, but can slide rectilinearly in the directions N and S. The plate 4 has an elongate aperture 4a whose length extends parallel to the directions E and W, and the width of the slot 4a is such as to accommodate the bush 3a, over which the slot fits, so as to transmit movement of the bush in the directions N and S to the plate 4, but not movement in the directions E and W. The plate 4 also has a slot 4b which fits over the pivot pin 2b, to locate the opposite end of the plate 4, and a projection 4c and a notch 4d which cooperates with subsequent parts of the mechanism.

A plate 5 is disposed on the plate 4, and is pivoted about the pivoted pin 2b by an aperture 5a. A pin 5b projects from the underside (as seen in FIG. 2) of the plate 5, and engages in the notch 4d so that movement of the plate 4 rotates the plate 5 about the pivot pin 2b. The plate 5 is also formed with a finger 5d, so that with the pin 5b and the finger 5d, the plate 5 acts as a bell crank. The end of the finger 5d is arranged to move generally parallel to, but in the opposite sense to, the plate 4. Indentations are cut in the side of the plate 5 to form part of an indexing mechanism (described below).

A plate 8 is disposed on the plate 5, and is pivoted about the pivot pin 2b by an aperture 8b which fits on the pivot pin. The plate 8 also has an elongate slot 8a whose length extends parallel to the directions N, S, and whose width accommodated to the bush 3a, so that movement of the bush parallel to the directions E and W is transmitted to the plate 8 to rotate the plate about the pivot pin 2b, while movement of the bush parallel to the directions N, S, is not transmitted to the plate 8. The plate also has apertures 8d which cooperate with the later parts of the mechanism, and indentations 8c cut into its end to form part of the indexing mechanism (described below).

A partition plate 11 is disposed above (as seen in FIG. 2) the plates 3, 4, 5, and 8, and is fixed to the cover 2 to maintain the parts of the mechanism described above in operating relationship. The plate 11 has openings through which the projection 4c, the finger 5d and the slots 8d can be engaged by subsequent parts of the mechanism. The plate 11 has a slot 11c serves to locate a projection 12a on a bridging piece 12, the bridging piece 12 being located also in the cover 13, so as to extend parallel to the directions E, W. A notch 13c in the cover 13, and a notch 12c in the bridging piece 12, cooperate with the plate 11 to form pivot points for two bell crank levers 14 and 15, so that the levers can picot about an axis parallel to the directions N,S. The levers 14 and 15 have projections 14a and 15a respectively, which project through the plate 11, and engage in the apertures 8d. The apertures are arranged so that the plate 8 engages the projection 14a to rotate the lever 14 in response to movement of the handle 1c in the direction W (corresponding to movement of ball-end 1d in the direction E), but does not engage the projection 15a. Similarly, movement of the handle 1c in the opposite direction E, causes the plate 8 to engage the projection 15a to rotate the lever 15, and to disengage the projection 14a. The lever 14 has a finger 14b which engages the plunger Sb, and lever 15 has a finger 15b which engages the plunger Sa. Accordingly, rotation of the lever 14 in a clockwise direction as shown in FIG. 2 depresses the plunger Sb, while rotation of the lever 15 in an anti-clockwise direction as shown in FIG. 2 depresses the plunger Sa.

The cover 13 also has notches 13b which cooperate with a plate 11 to form pivot points for bell crank levers 16 and 17, with projections 16a and 17a respectively extending through the plate 11 to engage the projection 4c and the finger 5d. The lever 16 has a finger 16b, and the lever 17 a finger 17b, which engage the plungers Tb and Ta respectively. Movement of the handle 1c in the direction N causes the finger 5d engaging the projection 16a to rotate the lever 17 in an anti-clockwise direction as seen in FIG. 2, and depress the plunger Tb; movement of the handle 1c in the direction S causes the projection 4c to rotate the lever 17 and depress the plunger Ta.

In the absence of an indexing mechanism, the return springs in the contact blocks S and T would tend to return the joystick to its neutral position as shown in FIGS. 1 and 2 when released. Accordingly, it is usually preferred to provide an indexing mechanism, which comprises levers 6 and 9 in this embodiment.

The lever 6 is pivoted on a shouldered pin 7 engaging between an aperture 2c in the cover 2 and an aperture 11a in the plate 11, the lever 6 having a roller 6a which engages the indentations 5c on the plate 5. A compression spring 6b (FIG. 1) is located between a pin 6c on the lever 6 and a lug 2e on the cover 2, and biases the roller 6a into engagement with the notches 5c, so that the plate 5 is maintained in any one of the three positions against the bias of the return springs in the contact block T. Similarly, a lever 9 pivoted on a shouldered pin 10 mounted between apertures 2d and 11b has a roller 9a biased into engagement with the indentations 8c on the plate 8 by a compression spring 9b. Accordingly, the plate 8 is maintained in any one of three stable positions against the bias of the return springs in the contact block S. Since the plates 4 and 8 between them govern the position of the ball end 1b on the joystick, it will be seen that the movement of the handle 1c is correspondingly indexed.

If desired a small fill-in piece (not shown) may be attached in any of the indentations 5c or 8c by a screw, so that the indentation is blocked out, disabling the indexing action at the corresponding position of the handle 1c.

The movement of the handle 1 could be restricted by a gate (not shown). The gate can be simple cross, having arms parallel to the directions N,S,E and W in which case the plungers S a, Sb, Ta and Tb will be operated singly. Alternatively, the cross could have arms bisecting the directions N,S,E and W in which case the plungers Sa, Sb, Ta and Tb will be operated two at a time. Alternatively the gate may have an H-shaped aperture, in which case movement of the handle 1c corresponding to movement of the ball end 1d to one end of the H will actuate first one contact alone, then that contact, together with another one. Other suitable gate shapes will occur to those skilled in the art.

Claims

I claim:

1. A mechanism for simultaneously actuating selected ones of a plurality of plungers comprising, in combination, a plurality of levers comprising first and second pairs of first and second levers each of which is rotatable for engagement with at least one corresponding plunger to actuate such plunger, an operating member, and a plurality of linkage members operable by movement of said operating member between a plurality of different positions to rotate a selected one of said levers of said first pair of levers and one of said levers of said second pair of levers.

2. A mechanism as claimed in claim 1 wherein said plurality of linkage members comprises first and second linkage members, said first linkage member being disposed for rectilinear displacement in first and second opposite directions to rotate the respective first and second levers of said first pair.

3. A mechanism as claimed in claim 2 wherein said second linkage member is mounted for pivotal displacement in first and second opposite directions to rotate the respective first and second levers of said second pair.

4. A mechanism as claimed in claim 3 wherein said first and second levers of said second pair each comprise first and second arms, said respective first arms being adapted for engagement by said second linkage member to rotate said respective first and second levers of said second pair and said second arms being engageable with corresponding plungers whereby to actuate the plungers.

5. A mechanism as claimed in claim 4 wherein said plurality of linkage members comprises a third linkage member being a bell-crank, pivot means for said bell-crank and means connecting said bell-crank to said first linkage member to pivot said bell-crank about said pivot means in response to said rectilinear displacement of said first linkage member, and said first and second levers of said first pair each comprise first and second arms, said first arms being adapted for engagement by said first linkage member and said bell-crank respectively whereby to rotate said respective first and second levers of said first pair and said second arms being engageable with corresponding plungers whereby to actuate the plungers.

6. A mechanism as claimed in claim 5 comprising operating member pivot means wherein said operating member comprises an elongate joystick connected to said operating member pivot means between its ends, a bush movable with one end of said joystick, first and second elongate slots formed in said first and second linkage members respectively, the major ones of said slots being disposed substantially at right angles in a plane substantially perpendicular to the major axis of said joystick, said bush being slidably engaged with said slots whereby pivotal movement of said joystick about an axis parallel with the major axis of said first slot produces said rectilinear displacement of said first linkage member and pivotal movement of said joystick about an axis parallel with the major axis of said second slot produces said pivotal displacement of said second linkage member.

7. A mechanism as claimed in claim 2 comprising index means to index said respective displacements and combinations of displacements of said linkage members wherein said first and second linkage members are provided with respective notches or pluralities of notches and said index means comprises first and second bias springs and first and second index members biased by the respective said bias springs into engagement with said first and second linkage members respectively so as to engage with said respective notches or pluralities of notches.

8. A mechanism as claimed in claim 1 comprising operating member pivot means wherein said operating member comprises an elongate joystick connected to said operating member pivot means between its ends, one end of said joystick being adapted to engage said linkage members so that pivotal movement of said joystick about said operating member pivot means between said plurality of different positions produces said respective displacements or combinations of displacements of said linkage members.