US1848000A - Power actuator - Google Patents

Description

March i, W32. c. s BRAGG ET AL POWER ACTUATOR Original Filed Jan. ,5, 1925 Ill/i 016i 55m M INVENTORS Va'clarW/Klggralk Patented Mar. 1, 1932 UNITED STATES, PATENT OFFICE CALEB s. 'BnAqG, or ran: .nmcn, rnonmnfnnnvro'ron w. xnmsna'rn, or soon:

BEND,

INDIANA, ASSIGNORS TO-BRAGGi-KLIESRATH CORPORATION, OF LONG- ISLAND CITY, NEW YORK, a conronnrron on NEW You I towns ac'run'ron.

Original application filed Our invention consists in the novel features hereinafter described, reference being had to the accompanying drawings which show one embodiment of the invention selected by us for purposes of illustration, and the said invention is fully disclosed in the following description and claims.

' This application is a division of our former application States filed January 5, 1925 and given Serial N o. 506. I

Our invention relates to a power actuator adapted especially for use in connection with automotive vehicles propelled by an internal l combustion engine, the actuator being most conveniently operated by suction from a suction passage of the engine between the throttle valve and the engine cylinder or cylinders, as for example by means 'of a connection with the intake manifold of the engine,

as the source of lower fluid pressure, and a connection with the atmosphere, as the source of higher fluid pressures. In our prior application for Letters Patent of the United States filed December 22, 1923,. Serial No. 682,346, we have disclosed a power actuator of this general type, an adjustable regulating valve or other restricting means, and a check valve being located in the suction connection with the manifold, and a storage space or tank being providedbetween the manifold and the power actuator, which comprises a cylinder, a double acting piston therein, and reversing valve mechanism operated by a foot lever or other operator operated part, the piston of the actuatorbeing connected with brake mechanism forthe vehicle.

The regulating valve or other restricting device prevents such large volumes of air being drawn intothe intake manifold as to be likely to dilute the explosive charges passing therethrough so as to stall the engine while idling,.while the storage space or vacuum tank provides a large space in which a partial vacuum is maintained at all times while-the engine is running. to insure the instantaneous withdrawal of the necessary amount of air from the actuator cylinder when the brakes are applied.

According to our present invention we disfor Letters Patent of the United January 5, 1925, Serial No. 506. Divided and this application filed September 1, 1928, Serial No. 308,412. Renewed July 16, 1931.

pense with any extraneous storage space or storage tank in the suction line extending to the intake manifold exterior to the actuator cylinder and maintain a condition of partial vacuum or rarefication within the actuator cylinder itself'on both sides of the piston, the cylinder itself supplying the necessary vacuum storage space.

According to our present invention this is accomplished without interfering with the normal operation of the valve mechanism, all the valves of which are permitted to seat in the released position of the parts, the actuator cylinder being provided with an auxiliary valve for controlling passages which when the valve is opened connect the actuator cylinder on both sides of the piston with the suc-' tion connection independently of the reversin valve mechanism, said auxiliary valve being normally held in the open position by the piston. I I

Referring to the accompanying drawings which illustrate an embodiment of our invention selected by us for purposes of illustration,

Fig. 1 is a diagrammatic view representing an installation of our improved actuator in connection with the internal combustion engine of an automotive vehicle for the,opera tion of the brake mechanism thereof. so

Fig. 2 is an enlarged sectional view of one form of our improved actuator having one form of ourpresent invention embodied therein.

Fig. 2a is a detail sectional view ofthe terminal portions of the piston rod and valve actuating sleeve omitted from Fig. 2.

I Fig. 3 isa partial sectional view illustratan internal combustion engine for propelling 3% the vehicle, provided with an intake manifold, 561, to which is connected a suction pipe, 562, in which are located preferably an adjustable regulating valve or restricting valve, 564, a check valve, 565, and a vent valve, 567 normally closed and opening outwardly. The construction of the check valve and vent valve forms no part of our present invention and will not be particularly desdribed or illustrated herein. The suction pipe, 562, communicates with one of our improved power actuators, the cylinder of which is indicated at 501, in Fig. 1, the said pipe having a flexible portion connected to a hollow valve actuating sleeve, 520, and communicating with the reversing valve mechanism. The sleeve, 520, is connected by a link, 585, with the foot lever, 588, which is provided with the usual retracting spring, 589, and the piston rod, 505, of the actuator is cgnnected by a link, 573, with the brake lever, 5 2.

In Fig. 2 we have shown one form of our improved actuator embodying our present invention. In this figure, 501 represents the actuator cylinder closed at both ends by heads, 502, connected by tubular bolts, 502 and nuts. 503 represents the double acting piston provided with oppositely disposed gaskets, 504. 505 represents a hollow piston rod which extends through the rear cylinder head andis connected at its inner end with the hub of the piston. The hub, 510, of the actuator piston is provided with two valve chambers, 511 and 512 respectively, each of which is provided with two valve seats, preferably conical and concentric to the axis of the piston. The valve chamber, 511, is shown as provided with conical valve seats, 513 and 514, and the valve chamber. 512, is similarly provided with valve seats, 515 and 516. The piston hub is provided in this instance with an outlet chamber or suction chamber, indicated at 517, which communicates with each of the valve chambers through the valve seats, 514 and 515. The piston hub is also provided with a higher pressure chamber, 518, in this instance communicating with the atmosphere, and-which communicates with the valve seat, 516, and by a lateral passage, 519, with the valve seat, 513, at the opposite end of the piston hub.

520 represents the valve actuating part, consisting in this instance of a valve sleeve passing through a stutiing box, 521, in the cylinder head at the opposite end from the piston rod, 505. said sleeve also extending longitudinally through the piston hub. the chambers thereof. and through the hollow piston rod, 505, and being movable longitudinally with respect thereto to effect the operation of the reversing valve. The valve sleeve is preferably made in two parts. 520 and 520" connected by threaded projections on a centrally located collar, 522, in the suction chamber, 517. The collar, 522, is provided with one or more lateral passages, 524, communicating with the interior of the sleeve section, 520, through a. longitudinal passage inone of the plugs, indicated in dotted lines in Fig. 2. The sleeve sections, 520 and 520, are thus connected for joint movement, but arenotincommunicationwitheach other. The valve sleeve section, 520, is provided adjacent to its outer end with a lateral passage, 526,

to which the suction pipe, 562, is connected, and the outer end of the sleeve section, 520, is provided with an attaching eye to which the link, 585, extending to the foot lever is connected. The sleeve section, 520, is provided with apertures, 527, communicating with the atmosphere or higher pressure chamber, 518, and the outer end of the sleeve section, 520*, which extends through the hollow piston rod, is opened and communicates with the interior of the piston rod, which is provided with means for admitting atmospheric air thereto. In this instance the piston rod, 505, is shown provided with a plug, 528, having lateral air inlet apertures, 529, communicating with a longitudinalaperture, 530, and the plug, 528, is also provided with an eye for enabling it to be attached to the connecting rod, 573.

The suction chamber, 517, is adapted to be connected with the cylinder on opposite sides of the piston by means of a port or ports, 534, in the valve seat, 514, and a port or ports, 535, in the valve seat, 515. The valve seat, 513, communicates with the cylinder forward of the piston through the annular passage, 533, and the valve seat, 516, is provided with a port or ports, 536, communicating with the cylinder in rear of the piston.

Each of the valve chambers, 511 and 512, is provided with a pair of oppositely disposed poppet valves, preferably conical, engaging the opposite valve seats, said valves being preferably formed of molded rubber and being loose on the valve actuating sleeve, although said valves may be formed of other material, if preferred. The valves are indicated at 540, 541, 542 and 543. Each of these valves is held seated by yielding'means, a rubber cushioning device, 550, being shown interposed between the valves of each pair and serving the combined purpose of retracting means and sealing means for the adjacent valves. The actuating sleeve is also provided with suitable means for opening one valve of each pair when the Valve sleeve is moved in either direction. As shown in Fig. 2, this function is performed by the collar, 522. and end collars, 531 and 532.

The specific details of the poppet valve mechanism herein shown and described forms no part of our present invention as the same is illustrated. described and claimed in our fornierapplication for Letters Patent of the United States, filed November 22, 1924,

gage the pins,

and given Serial No. 751,481. From the foregoing it will be noted that when the actuating sleeve is moved in either direction, one of the centrally located valves, 541 or 542, and one of the end valves, 540 or 543, will be opened simultaneously, thereby placing one end ofthe cylinder in communication with the suction chamber, 517,'and the other end of the cylinder. in communication with the atmosphere, and causing a corresponding movement of the piston in the same direction as that in which the valve actuating sleeve is moved. Conversely the movement of the valve sleeve in the opposite direction reverses the valve mechanism and effects the movement of the piston in the op osite direction.

ccording to our present invention in which no suction tank is employed, the interior of the actuator cylinder is. maintained in a state of rarefication on both sides of the piston when the parts are in the released osition and the engine is running, and this is accomplished without interfering with the normal operation of the valve mechanism, that is to say, in which all four of the valves of the reversing valve mechanism are permitted to firmly seatwhen the parts are in the released or normal position.

As shown in Fig. 2, the head, 502, of the cylinder is provided with a passage or .passages, 542 communicating with a recess, 542", in which is located a valve seat, 542, engaged by a movable valve, 542, which valve during the application of, the brakes closes communication between the recess, 542", and the interior of the cylinder on both'sides of the piston. The valve is in this instance operated by a ring, 542,provided with one or more projections, 542, extending into the cylinder far enough to be struck by the piston hub when the piston returns to its normal position, so as to insure the opening of the valve, 542. The valve seat, 542, is connected by a flexible pipe or tube, 542, with the suction pipe, 562, independently of the connection of the suction pipe with the reversing valve mechanism through the hollow valve sleeve, 520. Thevalve seat, 542, is also connected by a pipe, 542 with the cylinder on the forward side-of the piston,as shown in Fig. 2.

From this construction 'it wilLbe noted that when the piston moves forward, the valve, 542, isseated by its frictional engagement with the piston rod which it surrounds, and the valve may be maintained on its seat by a light spring, 542. When the piston returns to its normal position, right in Fig. 2, the hub of the piston will en- 542", and open the valve,l 542 thereby establishing communication between the auxiliary suction pipe, 542, and 'both ends of the cylinder, exhausting the air from the cylinder on the forward side of thepisually to the intake manifold moving to the ton and also maintaining the partial vacuum duced in returning the piston to its normal position.

It follows from this construction that as soon as the engine is started, the suction produced in the intake manifold will exhaust the air in the cylinder, 501, of the actuator, (the parts being in released position and the valve, 542, opened, and the reversing valves closed) on both sides of the piston through the auxiliary suction pipe, 542, the passages, 542, and the pipe, 542 If now it is desired to apply the brakes, the ,foot lever is actuated so as to move the valve sleeve, 520, in the direction of the arrow in Fig. 2, thereby opening the suction valve, 541, and thehigh pressure inlet valve, 543. This connects the cylinder forward of the piston directly with the suction pipe, 562, and admits atmospheric air in rear of the piston, moving the piston forward in a direction to apply the brakes and immediately eflecting the close of the auxiliary valve, 542. The forward movement of the piston will follow any extent of the forward movement of the brake lever and will apply the brakes to the desired extent without, however, admitting any appreciable amount of air into the intake manifold through the pipe, 562, as the portion of the cylinder forward of the piston is already exhausted. When the movement of the foot lever stops, the piston will continue to move forwardly until the and brakes as applied.

reversed by the release of the foot lever, 588, the valves, 540 and 542, will be opened, eflecting the withdrawal of the air in rear piston and admitting air forward of the piston. The air exhausted from the cylinder in rear of the piston can be delivered gradby properly regulating the restricting valve, 564, in the pipe, 562, so that the operation of the engine shall not be interfered with and the eduction of air may be retarded as much as desired, as the first movement of the piston rearwardly will relieve the pressure of' the brakes, and it is not important that the piston move rearwardly as quickly as it moves forwardly to apply the brakes. When the piston is restored to normal position, the piston hub will enga the end of the cylinder, after engagin t e pins, 542, and opening the auxiliary va ve, 542, and the valve actuatin sleeve willbe" arrested by the engagement 0 the fitting, 526, with the adjustable follower which the stuifing box, 521, is provided, returning valves, 543, 542 and 540 to closed positionl The opening of the auxiliary valve, 542, places both ends of the cylinder in comof the with munication with each other and with the suotion e an equalization of-pressures on opposite sides of the piston followed by the evacuation of the air admitted to return the piston, from both ends of the cylinder, which air will be delivered to the suction passage of the engine under the control of the restricting valve. This produces rarefication on both sides of the piston, leaving the piston submerged in vacuum and in condition for immediate and eflective operation to apply the brakes at any moment. We prefer to connect the valve, actuating sleeve, 520, with the piston by means providing for a limited amount of lost motion suflicient to permit the operation of the valves, so that after this lost motion is taken up the physical power of the operator can be directly applied to the piston and the brake mechanism connected therewith, to' enable the operator to add his physi- 1 shown in Fig. 2a, the section, 520, of the valve sleeve is provided with a recessed portion, 520", and the collar, 520, and the piston rod, 505, is in this instance provided with set screws, 505, extending into said recess or recesses, 520", so, that when the sleeve is moyed forward by the foot lever to apply the brakes and the piston has followed, applying the brakes to the full capacity of the actuator, the o rator may, by pushing the foot lever, 588, orward until the rear edges of the recess, 520", engages the screws, 505, apply his physical force to the piston and brake mechanism in addition to the power of the actuator. It also follows from this construction that should the power fail, the operator may apply the brakes directly by his physical force, the first forward movement of the valve actuatin sleeve setting the valves so as to vent the cy inder forward of the piston and admit air in rear of the piston to permit this movement. On the release of the foot lever, the retracting spring, 589, will shift the valve sleeve rearwardly so as to vent the cylinder in case of failure of power, and the forward end of the recess, 520, will engage the set screws and assist in moving the piston rearwardly to release the brakes and restore the parts to the off or released position.

In Fig. 3 we have shown a slight modification of the auxiliary valve mechanism illustrated in Fig. 2, Fig. 3 being a partial sectional view in which the parts illustrated in Fig. 2 are given the corresponding numerals with the addition of 100. In this construction the auxiliar valve instead of bein located centrally o the cylinder head practically within the stuffing box as illustrated in F ig. 2, is located in a separate fitting indicated at 644, provided with a threaded portion, 645, which is screwed into an aperture Lseaooo Fig. 2, and the fitting is also provided with a pipe, 642*, which communicates with the 7 other end of the cylinder on the opposite side of the piston, all of said passages being closed when the valve is seated and being placed in communication by the opening of the valve. The auxiliary valve, 642, is provided with a valve stem, 642*, which projects into the cylinder in position to be engaged by the piston when the latter returns to its normal or released position, so as to open the auxiliary valve and establish communication between the vacuum pipe or suction pipe leading to the manifold of the engine and both ends of the cylinder which are placed in communica tion with each other, and thereby permitting an equalization of pressures on opposite sides of the piston when it returns to its normal or released position and exhausting air from both ends of the cylinder, and maintaining a partial vacuum within the cylinder on both sides of the piston in exactly the same manner as previously described with reference to Fig. 2. t

- t will be noted that in both forms of apparatus herein shown, a vacuum is continuously maintainedin the actuator cylinder on both sides of the piston when it is in its normal or released position and the engine is in operation so that the cylinder itself acts as a storage space, and no additional tank or other extraneous storage space is required.

The check valve, 565, shown in Fig. 1 and interposed in the suction pipe, insures the exhaustion of the cylinder on both sides of thepiston permitted at any time by the operation of the engine under the control of the throttle valve, while the vent valve, 567

provides for the venting of the cylinder should the motor stop or the suction fail at any time and it becomes necessary for the operator to apply the brakes by physical power.

It will be understood that the brake mechanism is provided with the usual retracting means represented. in the drawings by a spring, 574.

What we claimand desire to secure by Letters Patent is 1. In a power actuator for automotive vehicles having an internal combustion engine for driving the same and provided with a throttle controlled suction passage, the combination with a part to be actuated, an actuator for said part including a cylinder closed for admitting a higher fluid pressure to the held in open position when the pistonjis in its retracted position.

2. In a power actuator for automotive vehicles having an internal combustion engine for driving the same and provided with a throttle controlled suction passage, the com-- bination with a part to be actuated, an actuator for said part including a cylinder closed at both ends and a piston movable therein connected to said part to be actuated, normally closed controlling valve mechanism for connecting the said source of suction to the cylinder on either side of the piston, and

cylinder on one side of the piston to-actuate said part, auxiliary passages for connecting the portions of the cylinder on opposite sides of the piston with each other and with the said source of suction independently of the controlling valve mechanism and valve.

means for closing said passages held in open position when the piston is in its retracted position.

3.-'In a power actuator for automotive vehicles having an internal combustion engine for driving the same and provided with a throttle controlled suction passage, the combination with a part to be actuated, an actuator for said part including a cylinder closed at both ends and a piston movable therein connected to said part to be actuated, normally closed controlling valve mechanism for connecting .the said source of suction to the cylinder on either side of the piston, and for admitting a higher fluid pressure to the cyl-s ind er on one side of the piston to actuate said part, auxiliary passages for connecting the portions of the cylinder on opposite sides of the piston with each other and with said source of suction independently'of said controlling valve-mechanism, auxiliary valve mechanism for closing said auxiliary passages, and means for moving said auxiliary valve mechanism into and holding it "in open position when the piston is in retracted p9- sition, to permit equalization of pressures in the cylinder on opposite sides of the piston and maintain the piston submerged 'in' vacuum.

4. Ina power actuator for automotive vehicles having an internal combustion engine for driving the same and provided with a throttle controlled suction passage, the combination with a partto be actuated, an actuator for said part including a cylinder closed at both ends, a double acting piston movable therein and connected to said part to be actuated, normally closed controlling valve mechanism for connecting the cylinder on either side of the piston with said suction source and for simultaneously connecting the cylinder on the other side of the piston with a source of higher fluid pressure, to effect a power stroke of the piston, and to return it to retracted position, and auxiliary passages independent of said controlling valve mechanism for connecting the cylinder on both sides .of the piston with the said source of suction and valve mechanism for closing said passages held in open position by the piston when the piston is in retracted position.

5. In a power actuator for automotive vehicles having an internal combustion, engine for driving the same and provided with a throttle controlled suction passage, the combination with a part to be actuated, an actuator for said part including a cylinder closed at both ends, a double acting plston movable therein and connected to said part to be actuated, normally closed controlling valve mechanism for connecting the cylinder on either side of the piston with said suction source and for simultaneously connecting the cylinder on the other side of the piston with a source of higher fluid pressure, to efiect a power stroke of the piston, and to return it to retracted position, auxiliary passages independent of said controlling valve mechanism for connecting the cylinder on both sides of the piston with each other and with said source of suction When the piston is in retracted position, and means for closing said passages held in open position when the piston is in its retracted position.

6. In combination, an automotive vehicle having a power plant capable of driving the vehicle and producing a source of suction, a part to be actuated, an actuator for said part including a cylinder closed at both ends, a double acting piston movable therein and connected to said part to be actuated, controlling valve mechanism for connecting the cylinder on either side of the piston with said suction source and for simultaneously connecting the cylinder on the other side of -of the piston to retracted position formovanism, means for placing said valve mecha-v nism in position to close communication with both of said sources when the piston is in a retracted position, said cylinder being pro vided with passages independent of the passages controlled by the said controlling valve mechanism, for connecting the portions of the cylinder on opposite sides of the piston with each other and with the source of suction, and auxiliary valve mechanism for controlling said passages, provided with a part for engaging the piston when in its retracted poisition to effect the opening of said auxiliary va ve.

8. In a power actuator, the combination of a cylinder closed at both ends, a piston in said cylinder, reversing valve mechanism, means for connecting the cylinder with a source 0 vacuum and with a sourceof higher fluid pressure under the control of said valve mechanism, means for placing said valve mechanism in position to close communication with both of said sources when the piston is in retracted position, an auxiliary valve mechanism located on the cylinder at one end thereof, andprovided with an auxiliary passage communicating with the suction source and passages communicating with the cylinder on opposite sides of the piston, a movable valve for closing said passages, provided with parts extending into the cylinder and engaged by the piston when in retracted position, to effect the opening of the auxiliary valve and placing the portions of the cylinder on opposite sides of the piston in communication with each other and with the source of suction.

9. In a power actuator for automotive vehicles having an internal combustion engine for driving the same and provided with a throttle controlled suction passage, the combination with a part to be actuated, a power actuator comprising among its members a cylinder closed at both ends, a piston in said cylinder provided with means for connecting it with brake mechanism for the vehicle, normally closed reversing valve mechanism, means for connecting the cylinder with said suction passage and with a source of higher fluid pressure under the control of said reversing valve mechanism, means for holding said valve mechanism in closed position when the piston is in released position, an auxiliary valve casing carried by the cylinder adjacent to the released position of the piston, said casing being provided with an auxiliary suction connection with the said suction passage of the engine .and with passages connecting it with the cylinder on opposite sides of the piston, and auxiliary valve mechanism in said casing for closing all of said passages, provided with parts extending into the cylinder and adapted to engage the piston when in its released position, for opening said auxiliary valve and placing the portions of the cylinder on opposite sides of the piston in communication with each other and with the suction passage of the engine independently of said controlling valve mechanism.

10. In a power actuator for automotive vehicles having an internal combustion engine for driving the same and provided with a throttle controlled suction passage, the combination with a part ti) be actuated, a power actuator comprising among its members a cyliiider closed at both ends, a double acting piston in said cylinder, normally closed re versing valve mechanism provided with passages for connecting the suction passages of the engine with the cylinder on both sides of the piston, and air inlet passages for connecting the cylinder on both sides of the piston with the atmosphere, controlling suction and inlet valves for said passages, yielding means for normally holding said valves seated, an operator operated part operatively connected with said valves, and means for holding said operator operated art in position to permit the seating of all 0 said valves when the pis ton is in released position, an auxiliary valve casing located at one end of the cylinder adjacent to the released position of the piston, and provided with a passage for connecting it with the suction passage of the engine independently of the controlling valve mechanism and with passages for connecting it with the cylinder on opposite sides of the piston independently of the passages controlled by said controlling valve mechanism, valve mechanism in said casing for closing all of said passages thereof, and means operated by the movement of the piston to its released position for o ening said valve mechanism and placing t e portions of the cylinder on opposite sides of the piston in communication with each other and with the suction passage of the engine.

11. In vacuum brake mechanism for automotive vehicles, providedvwith an internal combustion engine having a throttle controlled suction passage, the combination with a power actuator including a cylinder, a piston therein connected to said brake mechanism, passages for connecting the source of suction and a source of high pressure to said cylinder on each side of the piston, valves for controlling said passage, means for holding said valves closed when the piston is in retracted position, and means operable upon the retraction of the piston to its normal position to connect the source of suction to said cylinder on opposite sides of the piston.

12. In a vacuum brake mechanism for automotive vehicles provided with an internal combustion engine having a throttle controlled suction passage, the combination with a power actuator including a cylinder and a piston movable therein, brake mechanism for 1 the vehicle, passages in said actuator for connecting the suction passage and a source of higher pressure to the cylinder on each side of said piston, valves for controlling said passages, means for holding said valves closed when the piston is in retracted position, and extraneous means operable upon the retraction of the piston to normal position to connect the source of suction to said cylinder on opposite sides of the piston.

13. In a vacuum brake mechanism for auto motive vehicles provided with an internal combustion engine having a throttle controlled suction passage, the combination with a power actuator including a cylinder and a piston movable therein, brake mechanism for the vehicle, passages in said actuator for connecting the suction passage and a source of higher pressure to the cylinder on each side of said piston, valves for controlling said passages, means for holding said valves closed when the piston is in retracted position, and means operated by the piston upon the retraction thereof to normal position to connect the suction passage with said cylinder on opposite sides of the piston to submerge the piston in vacuum.

In testimony whereof, we aflix our signatures.

CALEB S. BRAGG. v VICTOR W. KLIESRATH.

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