GB2272997A - Switch operating mechanism - Google Patents

Abstract

A switch operating mechanism includes a switch operating lever 33 movable with a first end of an actuating spring 35 which causes the operating lever to swing in a first direction from a neutral position to a first switch position or in a second direction from the neural position to a second switch position, a select lever 36 for selecting the swing direction of the operating lever, a holding arrangement 39 - 44 for holding the operating lever in each of the first, second and neutral positions and a device 29 for displacing the second end of the actuating spring 35 to store energy in the spring 35. <IMAGE>

Description

SWITCH OPERATING MECHANISM The present invention relates to a switch mechanism, and more specifically to a spring type switch operating mechanism for operating a switch having at least three different switch states.

One conventional type of a switch operating mechanism utilizes energy stored in a spring for obtaining rapid switch action and minimize damage due to arc.

A conventional mechanism 701 shown in Fig. 12 has a switch 702 and a mechanism 703 for operating the switch 702.

The mechanism 703 is installed immediate below the switch 702.

The mechanism 703 includes a compression coil spring 714 disposed between first and second spring levers 712 and 713 mounted on first and second pivot shafts 710 and 711, and an operating lever 715 which is swung by energy stored in the spring 714. The operating lever 715 has a first arm 715a which is connected with the first and second spring levers 712 and 723 by first and second links 718 and 721, and a second arm 715b which is connected with a movable contact 707 of the switch 702 by a mechanical linkage 708. Each of the spring levers 712 and 720 has a first arm supporting one end of the spring 714, and a second arm 717 or 720 pivotally joined with the right end of the link 718 or 721. Each link 718 or 721 has the left end formed with a slot 719 or 724 slidably receiving a pin 716 fixed to the first arm 715a of the operating lever 715.There are further provided stoppers 723, 726, 727 and 728 for limiting the swing motion of the first and second spring levers 712 and 713.

A counterclockwise rotational movement of the second spring lever 713 causes a switch action from an off state in which the movable contact.707 is in the position shown by a solid line in Fig. 12, to an on state in which the movable contact 707 connects a second terminal 706 with a ground terminal 705. In the counterclockwise rotation, the second spring lever 713 stores energy in the spring 714 by compressing the spring 714 while the slot 724 allows the second link 721 to move to the left without pushing the operating lever 715. As soon as the spring supporting arm of the second spring lever 713 further swings beyond a predetermined dead point 722, the spring 714 releases the stored energy and forces the second lever 713 to swing energetically until the stopper 723 stops as shown in Fig. 13.On the other hand, the right end of the slot 724 abuts on the pin 716 and swings the operating lever 715 abruptly and quickly to an angular position to bring the switch to the on state. The switch 702 is returned to the off state by a reverse process.

A counterclockwise rotation of the first spring lever 712 causes a switch action from the off state to the ground state in which the ground terminal 705 is connected with the second terminal 706. The first spring lever 712 stores energy in the spring 714 by rotating in the counterclockwise direction. During this, the pin 716 slides in the slot 719, and allows a rightward movement of the link 718 while the operating lever 715 remains motionless. When a predetermined dead point 725 is reached, the spring 714 release the stored energy and causes the first spring lever 712 to further swing hard up to the stopper 726, to jerk the operating lever 715 with one end of the slot 719 to an angular position to bring the switch to the ground state. The switch 702 can be switched off again by a reverse process.

In this conventional mechanism, however. it is required to reduce the angle between the slots 719 and 724 by making the first and second links 718 and 721 approximately parallel to each other in order to reduce the friction therebetween, and ensure smooth performance. Therefore. the angle between an imaginary plane containing both the axes of the main shaft 709 and the first pivot shaft 710 and another imaginary plane containing both the axes of the first and second pivot shafts 710 and 711 must be an obtuse angle (about 1300), and the distance between the main shaft 709 and the second pivot shaft 711 must be much greater than the distance between the main shaft 709 and the first pivot shaft 710. As a result, the second link 721 must be made long enough at the cost of compactness.

The second link 721 crosses the axis of the spring 714 as shown in Fig. 12. This conventional mechanism, therefore, requires the two large two-arm levers 712 and 713 at the two different positions in addition to the operating lever 715. This conventional mechanism cannot avoid complicating the structure, increasing the size, and increasing the number of the required component parts. Besides, the bar links 718 and 721 are both inclined. All these designs tend to make it difficult to determine the angular and spatial relationships among the component parts, and to assemble the parts together by accurately adjusting the strokes of the slotted bar links.

It is therefore an object of the present invention to provide a switch mechanism which is advantageous to downsizing; simple and reliable in construction; easy to assemble; and low in manufacturing cost.

A switch mechanism according to the present invention comprises: an operating lever which is linked with a switch so as to operate the switch, and which is swingable, on a main axis, in a first swing direction from a middle posture to a first swing position for holding the switch in a first switch state, and in a second swing direction from the middle posture to a second swing position for holding the switch in a second switch state. the operating lever holding the switch in a third switch state when the operating lever is in the middle posture; an actuating spring for causing the operating lever to swing in each of the first and second swing directions, the spring having a first spring end held by a swingable end of the operating lever, and a second spring end; a regulating means for displacing the second spring end of the actuating spring to store energy in the actuating spring;; a selecting means for selecting one of the first and second swing directions of the operating lever; and a holding means for holding the operating lever in each of the first and second swing positions and the middle posture.

In the accompanying drawings: Figs. 1A, 1B, 2A and 2B are schematic views showing a switch mechanism according to a first embodiment of the present invention in four different states.

Figs. 3A, 3B, 4A and 4B show a switch mechanism according to a second embodiment of the present invention in four different states.

Fig. 5 is a view showing a switch mechanism according to a third embodiment of the present invention.

Figs. 6A and 6B are views showing a switch mechanism according to a fourth embodiment of the present invention.

Figs. 7A and 7B are views showing a switch mechanism according to a fifth embodiment of the present invention.

Fig. 8 is a front view of a switch mechanism according to a sixth embodiment of the present invention.

Fig. 9 is a sectional view taken across a line IX-IX of Fig. 8.

Fig. 10 is a view showing the switch mechanism as shown from a direction shown by an arrow X in Fig. 8.

Fig. 11 is a sectional view taken across a line XI-XI in Fig. 8.

Fig. 12 is a view showing a switch and a conventional mechanism for operating the switch.

Figs. 13 and 14 are views for illustrating the operations of the conventional mechanism.

Figs. 1A - 2B show a switch mechanism according to a first embodiment of the present invention.

A regulating arrangement (or regulating means) of the switch mechanism shown in Fig. 1A includes an electric motor 29; a small bevel gear 30 mounted on an output shaft of the motor 29; a large bevel gear 31 which is in engagement with the small bevel gear 30; and a movable regulating member. In this example, the regulating member is a screw rod 32 having an external (male) screw thread engaging with an internal (female) screw thread formed in a center hole of the large bevel gear 3 1.

The large bevel gear 31 is driven by the motor 29 through the small bevel gear 30, and causes the screw rod 32 to move axially.

up and down as viewed in Fig. 1A.

An operating lever 33 for operating a switch is mounted on a main shaft 9 (whose axis is a main axis). The operating lever 33 has a base end fixed to the main shaft 9, and a swingable end.

The operating lever 33 is linked with the switch so as to operate the switch, and which is swingable, about the main axis of the mains shaft 9, in a first swing direction (the clockwise direction as viewed in Figs. 1A and 1B) from a middle (or neutral) posture to a first swing position for holding the switch in a first switch state, and in a second swing direction (the counterclockwise direction in Figs. 1A and 1 B) from the middle posture to a second swing position for holding the switch in a second switch state. The operating lever 33 holds the switch in a third switch state when the operating lever 33 is in the middle posture.

An actuating spring 35 is designed to cause the operating lever 33 to swing about the (main) axis of the main shaft 9. The spring 35 is disposed between the regulating screw rod 32 and the operating lever 33. The spring 35 has a first (lower) spring end which is pivotally joined with the swingable end of the operating lever 33 through a pin 34 fixed to the swingable end of the operating lever 33; and a second (upper) spring end which is pivotally joined with one (lower) end of the screw rod 32 through a spring support pin 83 provided at the lower end of the screw rod 32.

A selecting arrangement is a means for selecting a swing direction of the operating lever 33. The selecting arrangement of this example comprises, as a main component, a select member, which, in this example, is a swingable lever 36. The select lever 36 is swingable between first and second select positions. The selector lever 36 has first and second recesses. A stopper pin 37 urged by a compression spring 38 holds the selector lever 36 in the first select position by being received snugly in the first recess, and in the second select position by being received in the second recess.

A holding arrangement (or holding means) is provided to hold the operating lever 33 in each of the first and second swing positions and in the middle posture. The holding arrangement may comprise detents (or holders or hooks) and stoppers to hold the operating lever 33 at four different angular positions.The holding arrangement of this example includes a first inner detent 39 for holding the operating lever 33 at a first middle (or neutral) position; a first outer detent 40 for holding the operating lever 33 at the first swing position; a first stopper 41 for limiting the swing movement of the operating lever 33 in the first swing direction; a second inner detent 42 for holding the operating lever 33 at a second middle (or neutral) position; a second outer detent 43 for holding the operating lever at the second swing position; and a second stopper 44 for limiting the swing movement of the operating lever 33 in the second swing direction. In this example, the first and second inner detents 39 and 42 constitutes a neutral holding means for holding the operating lever 33 in the middle (or neutral) posture.

In this embodiment, these detents and stoppers are arranged in such a manner of bilateral symmetry that the holding arrangement can be divided by an imaginary median (or center) plane into the first set of the first inner and outer detents 39 and 40 and the first stopper 41, and the second set of the second inner and outer detents 42 and 43 and the second stopper 44. Each of the first and second sets is substantially a mirror image of the other. In this example, the imaginary median plane passes through the axis of the main shaft 9, the swing axis of the select lever 36, and the axis of the screw rod 32. In the imaginary median plane, the swing axis of the selector lever 36 is parallel to the axis of the main shaft 9, and the axis of the screw rod is perpendicular to the axis of the main shaft 9.In the state shown in Fig. 1A, the first inner detent 39 holds the operating lever 33 in the first neutral position in which the pin 34 of the operating lever 33 is slightly deviated from the median plane, and located on the first side of the median plane (that is, the right side in Fig. 1A). In the state shown in Fig. 1B. the first outer detent 40 holds the operating lever 33 at the first swing position; and the first stopper 41 abuts on the operating lever 33 and prevents the operating lever 33 from further swing in the first swing direction which is the clockwise direction as viewed in Fig.

1B.

The switch of this example is substantially identical to the switch 702 shown in Fig. 12. That is, the switch includes a first terminal 704, a second terminal 706, a third terminal 705 such as a ground terminal, and a movable contact (switch element) 707.

This switch 701 assumes one of first and second switch (on) states and a third switch (off) state. In the third (off) state, the movable contact 707 is located at a middle between the first and third terminals 704 and 705, as shown in a solid line in Fig. 12, and the second terminal 706 is connected with neither the first terminal 704 nor the third terminal 705. In the first switch on state, the second terminal 706 is connected with the first terminal 704 by the movable contact 707 as shown by a one dot chain line in Fig. 12, and the second terminal 706 is disconnected from the third terminal 707. In the second switch state, the second terminal 706 is disconnected from the first terminal 704, and instead connected with the third terminal 705 by the movable contact 707 as shown by a two dot chain line in Fig. 12.

The movable contact 707 of this example is connected with a second arm 45 of the operating lever 33 shown in Fig. 1A by a mechanical linkage 708. In this example, the switch 701 is in the first switch state when the operating lever 33 is in the first swing position held by the first outer detent 40; in the second switch state when the operating lever 33 is in the second swing position held by the second outer detent 43; and in the off state when the operating lever 33 is in either the first or second middle (neutral) position.

The switch mechanism according to the first embodiment of the present invention is operated as follows: In the state shown in Fig. 1A, the select lever 36 is held at the first select position by the stopper pin 37 urged into the first recess of the select lever 36 by the spring 38; and the operating lever 33 is held at the first neutral position by the first inner detent 39. The switch is held in the off state by the operating lever 33. In the first select position, the select lever 36 prevents the operating lever 33 from swinging in the second swing direction (i.e. the counterclockwise direction as viewed in Fig. 1A) from the first neutral position. The operating lever 33 is prevented from swinging in the first swing direction (or the clockwise direction) by the first inner detent 39.

When the first inner detent 39 is moved to release the operating lever 33, then the operating lever 33 rotates in the first swing (clockwise) direction by the force of the spring 35 until the operating lever 33 abuts on the first stopper 41 as shown in Fig. 1B.

In the state shown in Fig. 1B, the operating lever 33 is held at the first swing position for holding the switch 702 in the first switch state, by the first outer detent 40 and the first stopper 41.

In this state, the screw rod 32 is moved upwards as shown in Fig.

2A, and the spring 35 stores energy.

The switch 702 is turned from the first switch state in which the first terminal 704 is connected with the second terminal 706, to the off state by disengaging the first outer detent 40 from the operating lever 33. When the operating lever 33 is released, the operating lever 33 rotates in the second swing (counterclockwise) direction from the first swing position by the force of the spring 35 until the operating lever 33 abuts on the select lever 36. as shown in Fig. 2B. In the state in which the operating lever 33 is held in the first neutral position by the first inner detent 39, the screw rod 32 is moved downwards. and the spring 35 stores energy as shown in Fig. 1A.

To make and break the connection between the second terminal 706 and the third terminal 705 of the switch 702. the select lever 36 is swung in the counterclockwise direction from the first select position shown in Fig. lA to the second select position. The operating lever 33 is held at the second neutral position for holding the switch 702 in the off state, by the second inner detent 42. In the second select position. the select lever 36 prevents the operating lever 33 from swinging in the first swing (clockwise) direction from the second neutral position.

When the second inner detent 43 is swung to a position for releasing the operating lever 33, the operating lever 33 rotates in the second swing (counterclockwise) direction from the second neutral position until the second swing position is reached. In the second swing position, the second stopper 44 limits the further swing movement of the operating lever 33 in the second swing direction. The second outer detent 43 holds the operating lever 33 in the second swing position. The screw rod 32 is moved upwards, and causes the spring 35 to store energy by displacing the upper end of the spring 35 upwards.

The switch 701 is turned off by swinging the second outer detent 43 to a position to release the operating lever 33. The spring 35 causes the operating lever 33 to swing in the first swing (clockwise) direction from the second swing position. The operating lever 33 abuts on the select lever 36 in the second select position when the second neutral position is reached. The operating lever 33 is held in the second neutral position by the second inner detent 42, and the screw rod 32 is moved downwards to store energy again in the spring 35.

The switch mechanism of the first embodiment is significantly simiplified by eliminating the spring levers 712 and 713 and the links 718 and 721 of the conventional design. This embodiment makes it possible to reduce the size of the mechanism and the number of required components, and to facilitate the assembly process. The single motor 29 suffices for driving one end of the actuating spring 35 in all the operating states. By contrast, the conventional mechanism requires two motors for driving the first and second spring levers 712 and 713, and a special shaft coupling which transmits torque when energy is stored and which slips when the energy is released.

The first embodiment requires only one motor even if the electric driving force is required, and requires no special shaft coupling.

The select lever 36 makes the select operation very easy. The symmetrical arrangement of the detents can simiplify the structure, facilitate the operations and make the switch mechanism more reliable.

Figs. 3A - 4B show a switch mechanism according to a second embodiment of the present invention.

A regulating arrangement of the second embodiment is different from that of the first embodiment.

The regulating arrangement shown in Fig. 3A includes a movable regulating member in the form of a rotary disk (or rotary lever) 229 having a crank pin (sprng support pin) 283, a stopper 231, and a compression spring 232. The rotary disk 229 is adapted to be rotated manually or electrically. The rotary disk 229 is a circular disk having two recesses 229a formed in the outer circumference of the disk 229. The two recesses 229a are symmetrically arranged with respect to the axis of the rotary disk 229. As shown in Fig. 3A, the two recesses 229a are formed, respectively, at the two opposite ends of one diameter of the circle defining the outer circumference of the circular rotary disk 229. The stopper 231 is loaded by the spring 232, and arranged to hold the rotary disk 229 at a predetermined angular position by entering one of the recesses 229a.The crank pin 283 is parallel to the axis of the rotary disk 229, and spaced apart from the axis of the rotary disk 229. The regulating member 229 of the second embodiment can reduce the vertical dimension of the mechanism.

The mechanism shown in Fig. 3A includes an operating lever 233 and an actuating spring 235 which are substantially identical to the operating lever 33 and the actuating spring 35 shown in Fig. 1A, except that the upper (second) end of the actuating spring 235 is pivotally joined with the crank pin 283 of the rotary disk 229.

The switch mechanism shown in Fig. 3A also has a select lever 236 held by a stopper pin 237 loaded by a spring 237; and a holding arrangement of first inner and outer detents 239 and 240, a first stopper 241, second inner and outer detents 242 and 243, and a second stopper 244 . Theses members are constructed, and operated substantially in the same manner as in the mechanism shown in Fig. 1A.

The switch mechanism according to the second embodiment of the present invention is operated as follows: In the state shown in Fig. 3A, the select lever 236 is held at the first select position by the stopper pin 237 urged into the first recess of the select lever 236 by the spring 238; and the operating lever 323 is held at the first neutral position by the first inner detent 239. The switch is held in the off state by the operating lever 233.

When the first inner detent 239 is moved to release the operating lever 233, then the operating lever 233 rotates in the first swing (clockwise) direction by the force of the actuating spring 235 until the operating lever 233 abuts on the first stopper 241 as shown in Fig. 3B.

In the state shown in Fig. 1B, the operating lever 233 is held at the first swing position for holding the switch 701 in the first switch state, by the first outer detent 240 and the first stopper 241. In this state, the stopper 231 is extracted, and the rotary disk 229 is rotated by 180 degrees, as shown in Fig. 4A, by a human operator or an electrical device. In the state shown in Fig. 3B, the crank pin 283 is in the lowest position closest to the main shaft 209 of the operating lever 233. After the half turn of the rotary disk 229, the crank pin 283 is located at the highest position most remote from the main shaft 209 as shown in Fig. 4B. In this way, the actuating spring 235 is stretched by the crank pin 283, and prepared for the next action by storing energy.

The switch 702 is turned from the first switch state, to the off switch state by disengaging the first outer detent 240 from the operating lever 233. When the operating lever 233 is released, the operating lever 233 returns from the first swing position shown in Fig. 4A by the force of the spring 235 until the operating lever 33 abuts on the select lever 236. as shown in Fig.

4B. In the state in which the operating lever 233 is held in the first neutral position by the first inner detent 239, the stopper 231 is pulled back to release the rotary disk 229, and the rotary disk 229 is rotated by a half turn to the angular position shown in Fig. 3A and the spring 235 is compressed to store energy for use in the next switching action.

The select lever 236 is swung from the first select position shown in Fig. 3A to the second select position to allow the swing movement toward the second swing position.

When the second inner detent 243 is swung to a position for releasing the operating lever 33, the operating lever 233 rotates in the second swing direction from the second neutral position until the second swing position is reached. The second outer detent 243 holds the operating lever 233 in the second swing position. The rotary disk 229 is rotated through 1 80C to cause the crank pin 283 to pull up the upper end of the actuating spring 235, and then held at the position by the stopper 231.

The switch 702 is turned off by swinging the second outer detent 243 to the position to release the operating lever 33. The actuating spring 235 causes the released operating lever 233 to swing in the first swing (clockwise) direction from the second swing position. The operating lever 233 stops by abutting on the select lever 236 in the second select position when the second neutral position is reached. The operating lever 233 is held in the second neutral position by the second inner detent 242, and then the actuating spring 235 is compressed again by a half turn of the rotary disk 229.

Fig. 5 shows a switch mechanism according to a third embodiment of the present invention.

The switch mechanism shown in Fig. 5 is almost the same as the mechanism shown in Figs. 3A - 4B. However, the mechanism according to the third embodiment further includes a releasing arrangment for releasing the operating lever 233. In the example shown in Fig. 5, the releasing arrangement includes four electromagnets, which are a first inner electromagnet 246 for swinging the first inner detent 239 to its releasing position, a first outer electromagnet 247 for swinging the first outer detent 240 to its releasing position a second inner electromagnet 248 for the second inner detent 242, and a second outer electromagnet 249 for the second outer detent 243. Each of the detents 239, 240, 242 and 243 is a lever which has a first arm for holding the operating lever 233, and a second arm confronting the corresponding electromagnet.Each detent is swung to the releasing position when the nearby electromagnet is energized to attract the second arm.

Figs. 6A and 6B show a switch mechanism according to a fourth embodiment of the present invention.

The switch mechanism shown in Figs. 6A and 6B is almost the same as that of the first embodiment shown in Figs. 1A and 1B. The switch mechanism shown in Figs. 6A and 6B further includes a releasing arrangement (or releasing means) for releasing the grip of the holding arrangement.

In the example shown in Figs. 6A and 6B, each of the four detents 339, 340, 342 and 343 corresponding to the detents 39, 40, 42 and 43 shown in Fig. 1A is in the form of a rocker lever having a first short arm for catching the swingable end of the operating lever 333, and a second long arm which meets the first arm at a pivot. In this example, each of the first inner detent lever 339 and the second inner detent lever 342 is substantially straight so that the first and second arms extends from the pivot in the opposite directions. Each of the first outer and second outer detent levers 340 and 343 is shaped like a bell crank. Each of the four detent levers 339, 340, 342 and 342 has a slider pin 361, 362, 370 or 371 fixed to the end of the second arm.

The releasing arrangement includes four releasing slotted bars (or links) 363, 364, 372 and 373 as schematically shown in Figs. 6A and 6B. Each bar has a first (lower) end and a second (upper) end. The second (upper) end of each slotted bar 363, 364, 372 or 373 is pivotally connected through a spring support pin (or rod) 383 with the lower end of the screw rod 332 corresponding to the screw rod 32 shown in Figs. lA and 1B. The first (lower) end of each bar 363, 364, 372 or 373 is formed with a slot (elongate hole) 365, 366, 374 or 371 extending in the longitudinal direction of the bar. These slots 365, 366, 374 and 371 receive, respectively, the slider pins 361, 362, 370 and 371 of the four detent levers 339, 340, 342 and 343 in a movable manner. In this way, the first inner detent lever 339 is connected with the screw rod 332 by the first inner releasing slotted bar 363.The first outer detent lever 340 is connected with the screw rod 332 by the first outer releasing slotted bar 364. The detent levers 342 and 343 on the second (left) side are connected with the screw rod 332 in such a symmetrical manner that the pair of the second inner detent lever 342 and the second inner releasing bar 372 is a mirror image of the pair of the first inner detent lever 339 and the first inner bar 363, and the pair of the second outer detent lever 343 and the second outer bar 373 is a mirror image of the pair of the first outer detent lever 340 and the first outer bar 364.

The switch mechanism according to the fourth embodiment of the present invention is operated as follows: In the state shown in Fig. 6A, the select lever 336 is held at the first select position by the stopper pin 337 urged into the first recess of the select lever 336 by the spring 338; and the operating lever 333 is held at the first neutral position by the first inner detent 339. The switch 702 is held in the off state by the operating lever 333. The screw rod 332 is in the upper position.

From the state shown in Fig. 6A, the screw rod 332 is lowered to store energy in the actuating spring 335. By this downward movement of the screw rod 332, the actuating spring 335 is compressed until the upper end of the slot 365 of the first inner releasing bar 363 abuts against the slider pin 361 of the first inner detent lever 339. and the first inner releasing bar 363 disengages the first inner detent lever 339 from the operating lever 333 by pushing down the slider pin 361. On release from the first inner detent lever 339, the operating lever 333 swings rapidly by receiving the force of the compressed actuating spring 335 to the first swing position shown by a solid line in Fig. 6B.

In the state shown in Fig. 6B, the operating lever 333 is held at the first swing position for holding the switch 702 in the first switch state, by the first outer detent lever 340 and the first stopper 341. In this state, the screw rod 332 is moved upwards to store energy in the spring 335 by expanding the spring 335.

When the energy is stored in the spring 335, the lower end of the slot 366 of the first outer release bar 364 pulls up the slider pin 362 of the first outer detent lever 340, and accordingly the first outer detent lever 340 releases the operating lever 333. No sooner has the operating lever 33 been set free than the actuating spring 335 causes the operating lever 335 to swing to the first neutral position shown by a solid line in Fig. 6A by pulling the pin 334 of the operating lever 335.

To rotate the operating lever 335 toward the second swing position, the select lever 336 is swung in the counterclockwise direction from the first select position to the second select position. The operating lever 333 is held at the second neutral position for holding the switch 702 in the off state, by the second inner detent lever 342.

When the screw rod 332 is lowered toward the main shaft 309, the actuating spring stores energy therein. Then, the upper end of the slot 374 of the second inner release bar 372 pushes down the slider pin 370, and the second inner detent lever 342 allows the operating lever 333 to swing in the second (counterclockwise) direction to the second swing position.

Then, the screw rod 332 is moved upwards away from the main shaft 309 of the operating lever 333, and the spring 335 stores energy until the lower end of the slot 375 pulls up the slider pin 371, and the second outer detent lever 343 allows the operating lever 333 to return to the second neutral position.

In the fourth embodiment, the regulating member in the form of the screw rod 332 is used not only for displacing the upper end of the actuating spring 335 but also for operating the releasing arrangement. The single motor 329 provides driving force to both the actuating spring 335 and the releasing arragement. The fourth embodiment can reduce the number of required components and simplify the structure.

Figs. 7A and 7B show a switch mechanism according to a fifth embodiment of the present invention.

The switch mechanism shown in Figs. 7A and 7B is almost the same as the mechanism shown in Figs. 6A and 6B. Unlike the fourth embodiment, the switch mechanism of the fifth embodiment includes four position detectors (or position detecting switches) 378, 379, 380 and 381, which are operated by a piece 382 fixed to the lower end of the screw rod 332. The detector 378 is placed at a highest position to detect an upper limit position of the lower end piece 382 of the screw rod 332.

The detector 379 is placed at a lowest position to detect a lower limit position of the lower end piece 382 of the screw rod 332.

The detectors 380 and 381 are intermediate in height between the detectors 378 and 379. The detector 380 is positioned to detect a tension position in which the storage of energy has been completed in the spring 335 in tension, and the detector 381 is to detect a compression position in which the storage of energy has been completed in the spring 335 in compression. The tension position detector 380 is located above the compression position detector (switch) 381.

In the state shown in Fig. 7A, the screw rod 332 is in the compression position, and therefore, the lower end piece 382 of the screw rod 332 holds the compression position detector (switch) 381 in an on state, and causes the motor 329 to stop.

From this state, the electric motor 329 further lowers the screw rod 332 in response to a first switch on signal to bring the switch 702 to the first switch state. This further downward movement of the screw rod 332 causes the upper end of the slot 365 of the first inner bar 363 to push down the slider pin 361 and to disengage the first inner detent lever 339 from the operating lever 333. Therefore, the operating lever 333 rotates in the clockwise direction abruptly and rapidly until the first swing position is reached. When, on the other hand. the screw rod 332 reaches the lower limit position, the lower limit position detector 379 is operated, and the motor 229 is rotated in the reverse direction to move up the screw rod 332.Therefore, the spring stores energy, and the motor 229 stops when the screw rod 332 reaches the tension position and the tension position detector 380 turns on, as shown in Fig. 7B.

From the state shown in Fig. 7B, the motor 329 rotates to cause the screw rod 332 to move up further in response to a first switch off signal. Therefore, the first outer releasing bar 364 pulls up the slider pin 362 with the lower end of the slot 366, disengages the first outer detent lever 340 from the operating lever 333, and allows the actuating spring 335 to rotate the operating lever in the counterclockwise direction to the first neutral position. When the screw rod 332 moves up to the upper limit position, the upper limit position detector 378 is operated and causes the motor 329 to rotate in the reverse direction to lower the screw rod 332. The screw rod 332 descends, and the spring 335 stores energy under compression until the compression position detector 381 turns on, the motor 229 comes to a stop, and the state shown in Fig. 7A is reached.

The position detectors and the motor 329 are operated in the same manner when the selector lever 336 is in the second select position to allow the swing motion of the operating lever only on the second side.

In the fifth embodiment, the actuating spring can be automaticaly brought to a standby state in which energy is stored sufficiently. Therefore, the next switching action can be started immediately.

Figs. 8 - 11 show a switch mechanism according to a sixth embodiment of the present invention.

A frame structure shown in Fig. 9 includes an upper support member 564, and first (rear) and second (front) link frame members 565 and 566 which are fixed to the underside of the upper support member 564 and which extends downwards in parallel to each other.

An actuating spring 435 and a screw rod 432 are placed between the first and second link frame members 565 and 566.

The actuating spring 435 is disposed between upper and lower spring retainers (or spring bearings) 483 and 591. The upper spring retainer 483 is in the form of a support pin (or rod) which is slidably received in vertical slots 567 and 568 formed, respectively, in the first and second frame members 565 and 566. The spring retaining support pin 483 is slidable up and down in the vertical slots 567 and 568.

An operating lever 433 is fixedly mounted on a front section of a main shaft 409 which is rotatably supported by the first and second link frame members 565 and 566. The front section of the main shaft 409 projects forwardly (left as viewed in Fig. 9) from the second (front) link frame member 566. As viewed in Fig. 9, the second (front) frame member 566 is between the operating lever 433 and the first (rear) frame member 565. A roller follower 434' is mounted on a pin 434 which is fixed to the swingable end of the operating lever 433 and which is parallel to the main shaft 409.

A select lever 436 is rotatably mounted on the front section of the main shaft 409. That is, the pivot axes of the operating lever 433 and select lever 436 are coincident in this example.

The select lever 436 can rotate relative to the main shaft 409.

The select lever 436 is between the operating lever 433 and the second (front) frame member 566 as viewed in Fig. 9. The select lever 436 has an outer periphery having a first recess 436a and a second recess 436b, a convex arc section 436c extending like an arc between the first and second recesses 436a and 436b, and first and second outer sections 436d and 436e for operating limit switches.

A stopper pin (or rod) 437 for retaining the select lever 436 is supported on the first and second frame members 565 and 566 in such a slidable manner that the stopper pin 437 can slide axially back and forth (right and left as viewed in Fig. 9). The stopper pin 437 has a large diameter section 437 a. A return spring 438 is mounted on the stopper pin 437, and disposed between the second frame member 566 and the stopper pin 437 to urge the stopper pin 437 in a rearward direction (the right in Fig. 9). In the state shown in Fig. 8, the large diameter section 437a of the stopper pin 437 is fit in the second recess 436b to hold the select lever 436 in the second select position.In order to rotate the select lever 436 to the first select position. -the stopper pin 437 is pulled forwards (left in Fig. 9) to remove the large diameter section 437a from the second recess 436b as shown in two dot chain lines in Fig. 9. Then, a handle 596 is attached to the main shaft 409, as shown in Fig. 11, and is rotated to rotate the main shaft 409 and the select lever 436 in the clockwise direction in Fig. 8 until the first recess 436b of the select lever 436 reaches the position just above the stopper pin 437. In this position, the large diameter section 437a fits in the first recess 436a and holds the select lever 436 in the first select position.

A releasing arrangement includes four slotted bars (or slotted links) 463, 464, 472 and 473. The spring retaining support pin 468 has a rear section supporting the upper end of the actuating spring 435, and a front section pivotally supporting the upper ends of the slotted bars 463, 464, 472 and 473.

Each of four detent levers 439, 440, 442 and 443 has a slider pin 461, 462, 470 or 471 which is slidably received in the slot of a corresponding one of the four slotted bars 463, 464, 472 and 473 in the same manner as the detent levers 339, 340, 342 and 343 shown in Figs. 6A - 7B. In this example, the first side detent levers 439 and 440 are pivotally mounted on a pivot pin 569 fixed to the frame member 566. The second side detent levers 442 and 443 are pivotally mounted on a pivot pin 571 fixed to the frame member 566. Alternatively. it is possible to provide four of the pivot pins and mount the four detent levers 439, 440, 442 and 443, respectively and independently. on the four pivot pins. Each detent lever is urged in a predetermined direction (toward its detent position, for example) by a return spring 573 mounted on one of the pivot pins 569 and 571.

A regulating arrangement shown in Figs. 8, 9 and 10 includes a driven spur gear 574. an internal screw member 575.

a pinion 577, a handle shaft 578, an electric motor 529. a speed reducer 579, and a driving spur gear 580 as well as the vertically extending screw rod 432. The driven spur gear 574 is supported on the supporting member 464 in such a manner that the driven spur gear 574 is rotatable, but immovable in the vertical direction. The internal screw member 575 is fixed to the driven spur gear 474 so that they rotate together on the same axis. The internal screw member 575 has a center hole which is formed with an internal screw thread. The screw rod 432 having an external screw thread is screwed into the internal screw member 575. The driven spur gear 574 is in mesh with the driving spur gear 580, which is, in turn, connected with the motor 579 through the speed reducer 579. The internal screw member 575 has a bevel gear 576, which is in mesh with a pinion (or small bevel gear) 577.The pinion 577 is fixedly mounted on one end of the horizontally extending handle shaft 578 adapted to be operated manually. Therefore, it is possible to move the screw rod 432 up and down by turning the handle shaft 578 manually with a handle, or controlling the electric motor 529.

There is further provided an auxiliary switch 581 which is operated in accordance with the rotational movement of the main shaft 409. When the screw rod 432 is moved up or down, the auxiliary switch 581 detects the end of an operation, and delivers a stop signal to stop the motor 529.

In the illustrated example, the motor 529 is placed on the right side of the screw rod 432 as viewed in Figs. 8 and 10. It is possible, however, to place the motor 529 on the left side. Each of the first and second frame members 565 and 566 of this example has an upper portion which has left and right flanges for mounting the motor 529 and the speed reducer 579. In this example, the motor 529 and the speed reducer 579 are placed under the driving spur gear 580, and below the upper support member 564. The structure shown in Fig. 9 further includes an outer frame member 482, a cover member 583 and an on-off indicator 584.

In this ebmodiment, the spring retainer 591 can be regarded as part of the operating lever 433. In this case, the operating lever includes the main shaft 409. the operating arm 433 fixedly mounted on the outside front section of the main shaft 409, and the spring retaining arm 591 which is fixedly mounted on the inside rear section of the main shaft 409 and which has a swingable end supporting the lower end of the actuating spring 435.

Claims (38)

CLAIMS:

1. A switch mechanism comprising: a switch; an operating lever which is linked with the switch so as to operate the switch, and which is swingable, on a main axis, in a first swing direction from a middle posture to a first swing position for holding the switch in a first switch state, and in a second swing direction from the middle posture to a second swing position for holding the switch in a second switch state, the operating lever holding the switch in a third switch state when the operating lever is in the middle posture; an actuating spring for causing the operating lever to swing in each of the first and second swing directions, the spring having a first spring end held by a swingable end of the operating lever, and a second spring end;; a regulating means for displacing the second spring end of the actuating spring to store energy in the actuating spring; a selecting means for selecting one of the first and second swing directions of the operating lever; and a holding means for holding the operating lever in each of the first and second swing positions and the middle posture.

2. A switch mechanism as claimed,Claim 1, wherein the regulating means comprises a movable regulating member which moves in one of a compressing direction for compressing the actuating spring and an extending direction for extending the actuating spring to store energy in the actuating spring when the operating lever is held in the middle posture, and in the other of the compressing and extending directions to store energy in the actuating spring when the operating lever is held in the first or second swing position.

3. A switch mechanism as claimed in Claim 2, wherein the actuating spring is a coil spring which is compressed to store energy by the regulating means when the operating lever is in the middle posture and which is extended by the regulating means to store energy when the operating lever is in the first or second swing position.

4. A switch mechanism as claimed in any of Claims 1 to 3, wherein the regulating means comprises a spring support rod which supports the second spring end of the actuating spring and which is movable between a remote position remote from the main axis of the operating lever and a close position which is closer to the main axis than the remote position; the selecting means comprises a select member which is movable between a first select position for allowing the operating lever to swing from the middle posture only in the first swing direction, and a second select position for allowing the operating lever to swing from the middle posture only in the second swing direction; and the holding means comprises a first outer detent member which is movable between a first outer detent position for holding the operating lever in the first swing position, and a first outer release position for allowing the actuating spring to swing the operating lever from the first swing position to the middle posture by releasing energy stored in the actuating spring in tension, a second outer detent member which is movable between a second outer detent position for holding the operating lever in the second swing position, and a second outer release position for allowing the actuating spring to swing the operating lever from the second swing position to the middle posture by releasing energy stored in the actuating spring in tension. and a neutral holding means which is movable between a neutral detent position for holding the operating lever in the middle posture and a neutral release position for allowing the actuating spring to release energy stored in the actuating spring in compression and thereby to swing the operating lever from the middle posture in the first swing direction when the select member is in the first select position and in the second swing direction when the select member is in the second select position.

5. A switch mechanism as claimed in any of Claims 1 to 4, wherein the operating lever is linked with a movable switch element which is in a first switch-on position to connect first and second terminals of the switch together when the operating lever is in the first swing position, a second switch-on position to connect the second terminal with a third terminal of the switch when the operating lever is in the second swing position, and in a switch-off position to disconnect each of the first and third terminals from the second terminal when the operating lever is in the middle posture.

6. A switch mechanism as claimed in Claim 4 or 5, wherein the neutral holding means of the holding means comprises a first inner detent member which is movable between a first inner detent position for holding the operating lever in a first middle position, and a first inner release position for allowing the actuating spring to swing the operating lever from the first middle position to the first swing position by releasing energy stored in the actuating spring in compression, and a second inner detent member which is movable between a second inner detent position for holding the operating lever in a second middle position, and a second inner release position for allowing the actuating spring to swing the operating lever from the second middle position to the second swing position by releasing energy stored in the actuating spring in compression, the middle posture comprising the first and second middle positions so that the operating lever is in the middle posture both when the operating lever is in the first middle position and when the operating lever is in the second middle position.

7. A switch mechanism as claimed in Claim 6, wherein the holding means is substantially symmetrical with respect to an imaginary median plane passing through the main axis of the operating lever so that the first inner and outer detent members are substantially mirror images of the second inner and outer detent members, respectively.

8. A switch mechanism as claimed in any of Claims 2 to 7, wherein the movable regulating member of the regulating means comprises a screw rod which has one end pivotally connected with the second spring end of the actuating spring and the regulating means further comprises an internal screw gear member which has an internal screw thread meshing with the screw rod and which causes the screw rod to move axially by receiving rotational motion.

9. A switch mechanism as claimed in Claim 8, wherein the axis of the screw rod is contained in the imaginary median plane and substantially perpendicular to the main axis of the operating lever in the median plane.

10. A switch mechanism as claimed in any of Claims 2 to 7, wherein the movable regulating member of the regulating means comprises a rotary disk comprising an outer portion which is apart from an axis of the rotary disk and which pivotally supports the second spring end of the actuating spring, and the regulating means further comprises a stopper for holding the rotary disk at a predetermined angular position.

11. A switch mechanism as claimed in Claim 10, wherein the axis of the rotary disk is substantially parallel to the main axis of the operating lever.

12. A switch mechanism as claimed in any of Claims 1 to Ii, wherein the regulating means comprises at least one of an electric motor for electrically moving the second spring end of the actuating spring, and a handle member for manually moving the second spring end of the actuating spring.

13. A switch mechanism as claimed in any of Claims 4 to 12, wherein the select member is a select lever which is swingable on a swing axis parallel to the main axis of the operating lever. and the selecting means further comprises a stopper pin for holding the select lever in each of the first and second select positions.

14. A switch mechanism as claimed in any of Claims 1 to 13, wherein the switch mechanism further comprises a releasing means for causing the holding means to release the operating lever.

15. A switch mechanism as claimed in Claim 14, wherein the releasing means comprises a first inner release member for moving the first inner detent member to the first inner release position, a first outer release member for moving the first outer detent member to the first outer release position, a second inner release member for moving the second inner detent member to the second inner release position, and a second outer release member for moving the second outer detent member to the second outer release position.

16. A switch mechanism as claimed in Claim 15, wherein each of the release members comprises an electromagnet.

17. A switch mechanism as claimed in Claim 15, wherein each of the release members is a slotted bar having a first end formed with a slot and a second end pivotally connected with the movable regulating member of the regulating means. and each of the detent member is a detent lever having a first arm for holding the operating lever and a second arm having a slider pin which is slidably received in the slot of a corresponding one of the release members.

18. A switch mechanism as claimed in Claim 17, wherein the slot of each slotted bar extends longitudinally of the slotted bar from a first slot end to a second slot end which is closer to the second end of the slotted bar. each of the first and second inner release member being arranged to push the second arm of the associated one of the first and second inner detent lever with the second slot end when the movable regulating member of the regulating means moves axially from a predetermined close energy storage position to a predetermined close limit position in the compressing direction toward the main axis of the operating lever, and each of the first and second outer release members being arranged to pull the second arm of the associated one of the first and second outer detent levers with the first slot end when the movable regulating member of the regulating means moves axially from a predetermined remote energy storage position to a predetermined remote limit position in the extending direction away the main axis of the operating lever.

19. A switch mechanism as claimed in Claim 18, wherein the switch mechanism further comprises a position sensing means for sensing the position of the movable regulating member of the regulating means.

20. A switch mechanism as claimed in Claim 19, wherein the regulating means reverses the motor when the movable regulating member reaches each of the close and remote limit positions, and stops the motor when the movable regulating member reaches the close energy storage position by moving in the compressing direction, or when the movable member reaches the remote energy storage position by moving in the extending direction.

2 1. A switch mechanism as claimed in any of Claims 4 to 20, wherein the select member is swingable on the main axis of the operating lever, and formed with first and second recesses and the selecting means further comprises a stopper for holding the select member in the first or second select position by engaging with the first or second recess of the select member.

22. A switch mechanism as claimed in Claim 21, wherein the stopper of the selecting means is a stopper rod which is substantially parallel to, and movable along. the main axis of the operating lever1 and which comprises a large diameter section adapted to fit in each of the first and second recesses of the select member.

23. A switch mechanism as claimed in any of Claims 1 to 22, wherein the switch mechanism further comprises a frame structure comprising first and second frame members between which the actuating spring and the regulating member are placed.

24. A switch mechanism as claimed in Claim 23, wherein the operating lever comprises a main shaft which is rotatably supported by the first and second frame members and which comprises an inside shaft section placed between the first and second frame members and an outside shaft section projecting outward from one of the first and second frame members. a first arm which is fixed to the outside section of the main shaft and which is engageable with each of the detent members. a spring retaining portion which supports the first end of the actuating spring and which is fixed to the inside section of the main shaft.

25. A switch mechanism as claimed in Claim 24, wherein the spring support rod for supporting the second end of the actuating spring is supported on the regulating member. and received in two parallel slots formed. respectively, in the first and second frame members, and the spring support rod comprises an inside rod section which is placed between the first and second frame members and which supports the second end of the actuating spring and an outside rod section which projects outwardly from one of the first and second frame member and which pivotally supports the release members.

26. A switch mechanism as claimed in any of Claims 23 to 25, wherein each of the release members is pivotally supported on one of pivot pins which are fixed to one of the first and second frame members and which projects outwardly from one of the first and second frame members in parallel to the main shaft, and each of the release members is urged by a return spring in a predetermined rotational direction.

27. A switch mechanism as claimed in Claim 26, wherein the pivot pins consists only of first and second pivot pins which are both fixed to the second frame member, the first inner and outer release levers are mounted, respectively, on first and second sections of the first pivot pin, and the second inner and outer release members are mounted, respectively, on first and second sections of the second pivot pin.

28. A switch mechanism as claimed in any of Claims 23 to 27, wherein the first and second frame members extend vertically.

the main shaft extends horizontally, and the regulating member of the regulating means is placed above the main shaft, and arranged to move vertically to compress and extend the actuating spring.

29. A switch mechanism as claimed in any of Claims 23 to 28, wherein the frame structure further comprises an upper support member which is fixed to top ends of the first and second frame members, and the motor of the regulating means is mounted on the upper support member.

30. A switch mechanism as claimed in any of Claims 1 to 29.

wherein the regulating means further comprises a gear system which connects the regulating member with the electric motor of the regulating means to transmit rotation from the motor to the regulating member.

3 1. A switch mechanism as claimed in Claim 30, wherein the gear system comprises the internal screw member comprising a portion having the internal screw thread meshing with an external screw tread of the screw rod, and a portion defining a driven spur gear, and a driving spur gear which is driven by the motor and which is in engagement with the driven spur gear.

32. A switch mechanism as claimed in Claim 31, wherein the internal screw member and the driving spur gears are both mounted on the upper support member of the frame structure.

33. A switch mechanism as claimed in Claims 31 or 32, wherein the motor is placed under the driving spur gear, and fixed to one of left and right sides of each of the first and second frame members.

34. A switch mechanism as claimed in any of Claims 23 to 33, wherein each of the first and second frame members comprises a left upper flanged portion and a right upper flanged portion each of which is adapted to support the motor so that the motor can be fixed to either the right side or the left side of the first and second frame members.

35. A switch mechanism as claimed in any of Claims 31 to 34, wherein the regulating means further comprises the handle member in the form of a handle shaft which is not parallel to the screw rod, which is drivingly connected with the internal screw member through bevel gears, and which is adapted to be turned manually.

36. A switch mechanism as claimed in Claim 35, wherein the handle shaft is placed above the upper support member and extends substantially in parallel to the main shaft.

37. A switch mechanism as claimed in any of Claims 24 to 36, wherein the operating lever comprises at least one roller follower mounted on a pin fixed to the swingable end of the first arm ol the operating lever.

38. A switch mechanism substantially as described with reference to, and as shown in, Figures 1A to 2B, Figures 3A to 4B, Figure 5, Figures 6A and 6B, Figures 7A and 7B, or Figures 8 to 11 of the accompanying drawings.