US3272938A - Control valve means for air operating electric switch - Google Patents

Description

p 1965 SEIZO NAKANO ETAL 3,272,938

CONTROL VALVE MEANS FOR AIR OPERATING ELECTRIC SWITCH Filed Jan. 14, 1964 INVENT RS 35120 N HKQNo HFIRUJI N ammo B9: QQQQ QA; ;,g.

ATTORNEY United States Patent 3,272,938 CONTROL VALVE MEANS FQR AIR OPERATING ELEtITRlC SWHTQH Seizo Nakano and Haruji Nakano, Hitaehi-shi, Japan, as-

signors to Hitachi, Ltd, Tokyo, Japan, a corporation of Japan Filed Ian. 14, 1964, Ser. No. 337,616 Claims priority, application Japan, Jan. 16, 1963, 38/1348 14 Claims. (Cl. 2tl82) This invention relates to an improved control valve means to supply compressed air into an air operating device in an electric switch which has an air operating device to drive the moving portion of the switch to the contact making position or to the contact breaking position by sending compressed air into the air operating device.

Generally, an electric switch has a pair of control valve means; namely one for controlling supply of air into the air operating device to make contact and the other for controlling supply of air into the air operating device to break contact. Both of them are of a same structure, operate in accordance with a contact making order or a contact breaking order from the switch to properly control the main valve which opens or closes an air passage to supply compressed air into the air operating device from an air reservoir. Conventional control valve means, however, were accompanied by inconvenience that when said orders were cut off after a short time, the main valve could not be completely controlled, and thereby the contact making and breaking operations of the switch could not be accurately performed.

The present invention provides a control valve means which has been improved in said point. The first object of the present invention is to provide a control valve means with a means to lock the control valve either in the open or in the closed position to make the control valve completely control the main valve when an order has been issued and the control valve has operated according to that even if the order has continued only a short time.

A further object of the present invention is to provide a control valve means in which, when the operation of the moving portion of the electric switch is completed, a can rotating in interlocked relation with said moving portion works to relieve the control valve from said locked state to its original position and simultaneously locks the means to operate the control valve in accordance with orders not to operate, and thereby such an order as issued repeatedly by mistake after any operation of the electric switch has been completed is made ineffective.

A still further object is to obtain a control valve means with a means to cut off a contact making or breaking order so that the control valve may not operate in case the pressure of compressed air within the air reservoir has been reduced to such a degree as is unsuitable to perform contact making or breaking operation of the switch.

As stated above, an air operating electric switch has a control valve means for contact making and a control valve means for contact breaking, both of which are of a same structure. For simplification, a control valve means used and shown in the accompanying drawings as a contact making control valve means will be mentioned to explain the structure and operation.

The accompanying drawings show a contact making control valve means for an air operating electric switch embodying the present invention.

FIG. 1 is a vertical section showing the control valve means when contact has been broken;

FIG. 2 is a evrtical section showing the same during the initial period of contact making operation;

FIG. 3 is a vertical section showing the same during the terminating period of contact making operation; and

FIG. 4 is a vertical section showing the same when contact has been made.

In the figures numeral 1 refers to a valve chamber containing a main valve and a control valve; 2 refers to an air supply pipe to a means to make the moving portion of the switch operate contact making; R refers to an air pipe supplying air to the valve chamber from an air reservoir; 3 refers to said main valve to open or cut air communication between said air supply pipe 2 and said air pipe R; 4 refers to a spring holding the main valve in the closed position; 5 refers to a driving piston to operate said main valve 3; 6 refers to a connecting rod connecting said main valve 3 and said driving piston 5 in a body. Numerals 7 and 8 are air passages within the valve chamber, and the former communicates with said air pipe R. Numeral 9 is a control valve to open and cut air communication between the air passages 7 and 8; 10 is a valve rod; and 11 and 12 are air exhaust ports. 13 refers to a pressure chamber communicating with said air passage 7, and 14 refers to a bellows receiving the air pressure of said pressure chamber. 15 is a rod which operates in case the air pressure is unsuitably low to perform the contact making or breaking operation of the switch; 16 is the support axis of said rod 15, and 17 is a projection extending from the rod, facing said bellows 14 and always pushed up by the air pressure within the pressure chamber 13 to make the rod 15 rotate upwards around the support axis 16. Numeral 18 refers to a magnet coil excited by a contact making or breaking order; 19 is a movable rod made to operate upon excitation of said magnet coil; 20 means a lever which is made to move by the operation of the movable rod 19; and 21 is a support axis of the lever. 22 is a push rod which in interlocked relation with the lever 20 pushes the valve rod 10 of the control valve 9 and has a pushing step portion 23 and an engaging step portion P. 24 and 25 are engaging projections protruding from the push rod; 26 is a through pin jointing the lever 20 and the push rod 22; and 27 is a tension spring working on the lever 20. Numeral 28 is a locking piece to lock the push rod 22 in the pushing position; 29 is its engaging step portion, 30 is a push spring and 31 means a support axis of the locking piece. Numerial 32 is a lever fitted in parallel with the push rod 22 and having an engaging step portion 33 and a support axis 34. 35 refers to a stopper fixed to the rod 15 which operates in response to low pressure with its head facing the left end of the lever 32; 36 is a tension spring extended between the rod 15 operating in response to low pressure and the left end of the push rod 32. 37 is a strong tension spring extended between the end of the rod 15 and the fixed portion, and the spring force of said spring 37 working on the end of the projection 17 corresponds to the air pressure within the pressure chamber 13 through the bellow 14. As the spring force of the spring 37 is previously fitted in accordance with the value of air pressure required for the contact making or breaking operation of the switch, as far as the air pressure within the pressure chamber 13 is kept above the allowable pressure value, the rod 15 stays at the position shown in the figures and does not make any operation on the control valve means.

Numeral 38 refers to a cam shaft which rotates in accordance with the contact making operation of the moving portion of the switch, and 39 is a responsive cam facing the lever 32.

In FIG. 1 showing the control valve means when contact has been broken compresed air within the air reservoir is being supplied to the valve chamber through the air pipe R, whereby the pressure chamber 13 is always filled with compressed air.

The main valve 3 is closed to cut the communication between the air suply pipe 2 and the air pipe R, the control valve 9 breaks the communication between the air passages 7 and 8; and the flat face of the cam 39 faces the lever 32 through a narrow space.

Now, when a contact making order is issued and the magnet coil 18 is excited, the movable rod 19 operates and pushes the lower end of the lever 20 leftwards. Accordingly, the lever 20 rotates clockwise around the support axis 21 against the tension of the spring 27 and pushes the push rod 22 jointed to the lever '20 by means of the through pin 26 rightwards. Then the pushing step portion 23 of the push rod 22 pushes valve rod 10 rightwards to push the control valve 9 and thereby to communicate the air passages 7 and 8 with each other. When the control valve 9 is opened, the driving piston is pressed downwards, as shown in FIG. 2, to open the main valve 3, by which the air pipe R and the air supply pipe 2 are communicated with each other and compressed air with-in the air reservoir is supplied therethrough to the air operating device, whereby the moving portion of the switch is made to perform contact making operation. As known from FIG. 2 showing the control valve means during the initial period of the contact making operation, the instant when the push rod 22 pushes the valve rod rightwards the engaging projection 24 of the push rod 22 engages the engaging step portion 29 to lock the control Valve 9 in the open position. Therefore, even if the magnet coil 18 is excited only for a short period by the contact making order, the order once issued works to effectively lock the control valve 9 in the open position as long as necessary, properly controls the main valve 3 and thereby makes it possible to accurately and completely perform the contact making operation of the switch. Next, in the terminating period of the contact making operation the responsive cam 39, as shown in FIG. 3, rotates in accordance with the contact making operation of the moving portion pushing up the lever 32. Then the lever 32 pushes up the push rod 22 to relieve the engagement of the pushing step portion 23 and the valve rod 10. Thereby the control valve 9 returns to its closed position and cuts off communication between the air passages 7 and 8. Then the air within the passage 8 is exhausted from the air exhaust port 12, and the main valve 3 closes to cut off the supply of air from the air pipe R into the air supply pipe 2. When the push rod 22 is pushed up by the lever 32 as stated above, the engaging projection 25 also pushes up the locking piece 28 to relieve the engagement of the engaging projection 24 and the engaging step portion 29. When the contact making order is dissolved, the magnetic force of the magnet coil 18 is erased, and simultaneously the lever is made to rotate counterclockwise around the support axis 21 by the tension of the tension spring 27 and the push rod 22 moves leftwards to its original position, as shown in FIGURE 4. When the push rod 22 returns to its original position, the engaging step portion P engages the engaging step portion 33 of the lever 32 as shown in FIG. 4. The figure shows the control valve means after the contact making operation is completed. Because said two engaging step portions, when engaged, lock the push rod 22 to prevent it from reforming any operation upon the control valve 9, any contact making order issued repeatedly and by mistake after the contact making operation is finished has no eifect. On the other hand, when the electric switch has performed contact breaking operation in accordance with the contact breaking order given to the contact breaking control valve 4 means (not shown) which is separately fitted to the electric switch, the responsive cam 39 moving in accordance with the operation of the moving portion of the switch rotates back to its original position shown in FIG. 1 from the position in FIG. 4.

Further, when the contact making operation is started under broken contact condition in accordance with a contact making order and the magnet coil 18 remains not relieved of excitation, the pushing step portion 23 of the push rod 22 is kept mounted on the valve rod 10. If a contact breaking order is issued under such a condition and'the moving portion of the switch operates, the responsive cam 39 returns to its original position shown in FIG. 1 leaving the push rod 22 as it is. If the magnet coil 18 is relieved of the excitation at such a. time, the push rod 22 is made to move back leftwards through the tension of the tension spring 27. In said leftward movement of the rod 22 the engaging step portion 29 of the locking piece 28 may engage the engaging projection 24 of the push rod 22 and lock the rod 22 in that place. Therefore, it may possibly impede the contact making operation thereafter. But such a trouble can be avoided by properly designing the shape of the lower end face of the locking piece 28 to engages the engaging projection 25.

The controlling function of the control valve means in the contact making operation in case of air pressure is above the allowable value required for switching operation has been stated in the foregoing explanation. Next, explanation will be made regarding the case the air pressure is unproperly :low. In that case, as the air pressure within the pressure chamber is insufficient, the equilibrium between the air pressure and the spring force of the tension spring 37 is lost. Accordingly, the rod 15 is made to rotate downwards from the position shown in FIG. 1 around the support axis 16 through the spring force of the spring 37, thereby the lower end of the stopper 35 pushes down the left end of the lever 32. Then the lever 32 rotates counterclockwise around the support axis 34 to make the engaging step portion 33 engage the engaging step portion P of the push rod 22, and thereby to lock the push rod 22 not to work on the valve rod 10 of the control valve 9. Thus, in the device of this invention, even if a contact making order is issued under insufficient air pressure, the control valve means does not perform control operation. Therefore, if the air pressure for operation is improperly low, contact making operation is not carried out. Additionally, burning of contact portions and other troubles caused by imperfect contact making can be prevented.

What is claimed is:

-1. Control valve means for a fluid operated electric switch and a fluid pressure source, comprising: main valve means controlling the flow of fluid from the fluid pressure source to the electric switch; control valve means controlling the operation of said main valve means; operating means responsive to a first electric switching signal for operating said control valve means to a control position; means for maintaining said control valve means at said control position until the operation of the electric switch corresponding to said switching signal has been completed; and means for rendering said operating means ineffective to operate said control valve means in response to any electric signal after the completion of the operation of the electric switch corresponding to said switching signal. 7

2. The control valve means according to claim 1, further comprising means for rendering said operating means ineffective to operate said control valve means when the pressure of the fluid pressure source decreases lower than a predetermined rated pressure.

3. A control valve, comprising: a fluid valve; actuating means mounted for reciprocation in one direction and operable to operate said valve when reciprocated in said one direction; pusher means operable to reciprocate in said one direction to a reciprocated position and push said actuating means in said one direction for operating said valve, when said pusher means is aligned with said actuating means; and control means operable to move said pusher means and said actuating means relative to each other to non-aligned positions, where reciprocation of said pusher means is ineffective to push said actuating means.

4. The device of claim 3, including, lock means to lock said pusher means in its reciprocated position corresponding to operation of said fluid valve.

5. The device of claim 3, wherein said control means is responsive to the pressure of the fluid being controlled by the valve, that is lower than a predetermined pressure and operable upon sensing the lower pressure.

6. The device of claim 4, wherein said control means is responsive to a pressure of the fluid being controlled by said fluid valve that is lower than a predetermined pressure and operable upon sensing the lower pressure.

7. A control valve for controlling the operation of a fluid operated device, comprising: a fluid valve; actuating means mounted for reciprocation in one direction and operable to operate said fluid valve when reciprocated in said one direction to a reciprocated position; pusher means operable to reciprocate in said one direction from a retracted position to a reciprocated position and push said actuating means in said one direction for operating said fluid valve, when said pusher means is aligned with said actuating means; lock means operable to lock said pusher means in its said reciprocated position corresponding to operation of said fluid valve; means responsive to the operation of said fluid operated device and operable upon sensing the completed operation of said fluid operated device to render said lock means ineffective to lock said push-er means.

'8. The device of claim 7, including means responsive to a pressure being controlled by said fluid valve that is lower than a predetermined pressure and operable upon sensing the lower pressure to move said pusher means and said actuating means relative to each other to non-aligned positions Where reciprocation of said pusher means is ineffestive to push said actuating means.

9. The device of claim 7, including means responsive to the operation of the fluid operated device and operable upon sensing the completed operation of said fluid ooera-ted device to lock said pusher means in its retracted position away from said actuating means.

10. The device of claim 9, including means responsive to a pressure of the fluid being controlled by said fluid valve that is lower than a predetermined pressure and operable upon sensing the lower pressure to move said pusher means and said actuating means relative to each other to non-aligned positions where reciprocation of said pusher means is ineffective to push said actuating means.

11. A control valve for controlling the operation of a fluid operated device, comprising; a fluid valve means operable to be connected to a source of fluid pressure for controlling the operation of the fluid operated device by the fluid pressure source; actuating means mounted for reciprocation in one direction and operable to operate said fluid valve when forwardly reciprocated in said one direction; pusher means operable to reciprocate in said one direction from a rearward position to a reciprocated position and push said actuating means forward in said one direction for operating said fluid valve, when said pusher means is aligned with said actuating means; cam means operable to rotate in response to the operation of the fluid operated device; and lock means actuated by said cam means operable to lock said pusher means in its rearward position where it is ineflective to push said actuating means.

12. The device of claim 11, including means operably connected to the fluid pressure source and responsive to a pressure of the fluid being controlled by said fluid valve that is lower than a predetermined pressure and operable upon sensing the lower pressure to move said pusher means and said actuating means relative to each other to non-aligned positions where reciprocation of said pusher means is ineffective to push said actuating means when the pressure is lower than said predetermined pressure.

13. The device of claim 11, including lock means operable to lock said pusher means in its reciprocated position corresponding to operation of said fluid valve.

14. The device of claim 12, including lock means operable to lock said pusher means in its reciprocated position corresponding to operation of said fluid valve.

References Cited by the Examiner UNITED STATES PATENTS 3,133,475 5/1964 Barkan 200-82 X BERNARD A. GILHEANY, Primary Examiner. H. M. F-LECK, Assistant Examiner.

Claims (1)

1. CONTROL VALVE MEANS FOR A FLUID OPERATED ELECTRIC SWITCH AND A FLUID PRESSURE SOURCE, COMPRISING: MAIN VALVE MEANS CONTROLLING THE FLOW OF FLUID FROM THE FLUID PRESSURE SOURCE TO THE ELECTRIC SWITCH; CONTROL VALVE MEANS CONTROLLING THE OPERATION OF SAID MAIN VALVE MEANS; OPERATING MEANS RESPONSIVE TO A FIRST ELECTRIC SWITCHING SIGNAL FOR OPERATING SAID CONTROL VALVE MEANS TO A CONTROL POSITION; MEANS FOR MAINTAINING SAID CONTROL VALVE MEANS AT SAID CONTROL POSITION UNTIL SAID CONTROL VALVE MEANS AT SAID CORRESPONDING TO SAID SWITCHING SIGNAL HAS BEEN COMPLETED; AND MEANS FOR RENDERING SAID OPERATING MEANS INEFFECTIVE TO OPERATE SAID CONTROL VALVE MEANS IN RESPONSE TO ANY ELECTRIC SIGNAL AFTER THE COMPLETE OF THE OPERATION OF THE ELECTRTIC SWITCH CORRESPONDING TO SAID SWITCHING SIGNAL.

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