US2275338A - Brake mechanism - Google Patents

Description

March 3, 1942. w. J. ANDRES rm.

B MEGHMISH Filed oet. 6, 1939 mwy/ a Patenfed M'a'r. 3, 1942 BRAKE MECHANISM William J. Andres and Frederick E. Strohm,

Pittsburgh, Pa., assignors to Bendix-Westinghouse Automotive Air Brake Company,Pittsburgh, Pa., a corporation of Delaware Application October 6, 1939, Serial No. 298,324

(ci. aos-54) 12 Claims.

This invention relates to iluid pressure control mechanism and more particularly to a valve device for controlling fluid pressure systems.

One of the objects of the present invention is to provide a novel fluid pressure control valve mechanism of the self-lapping type wherein a simplied construction is achieved by combining a portion of the valve assembly with the man ually-operable member.

Another object is to provide, in a device of the foregoing type, a combined pedal and valve mechanism wherein the valve-graduating spring is' mounted on and carried by the pedal, this arrangement facilitating assembly of the apparatus as well as inspection and repair procedures.

Still another object is to provide a novel control valve mechanism constituted in such a manner as to materially decrease valve vibration and chatter during operation thereof.

A further object comprehends a novel and compact arrangement of parts in a mechanism of the foregoing type, which will be unusually eilicient in operation and capable of economical manufacture.

vOther objects and novel features of the invention will appear more fully hereinafter from the 'following detailed description when taken in connection with the accompanying drawing illustrative of one form of the invention. It is to be expressly understood, however, that the drawing is utilized for purposes of illustration only and is not designed as a definition of the limits of the invention, referencebeing had for this purpose to the appended claims.

In the drawing, wherein similar reference characters refer to like parts throughout the several views:

, Fig.` 1 is an axial sectional view of a control valve mechanism constructed in accordance with the principles of the present invention, and

Fig. 2 is a sectional view taken along lines 2-2 of Fig. l.

Referring more particularly to Fig. 1, the invention is disclosed therein as embodying a. selflapping valvular mechanism including a casing 3 formed of upper and lower sections tand 5 respectively. The casing may be secured to a support, such as the iioorboards of the vehicle, in any suitable manner so as to be readily accessible to the vehicle operator. AAs shown, the casing is divided into a plurality of chambers, a partition i being provided and forming in said-casingan outlet chamber I and an exhaust chamber 8, the latter being connected to the atmosphere through an opening .9. The 'lower casing section 5 is so formed as to receive an inlet housing member i0 forming with said. casing section 5 an intake Y chamber I I, an intake valve seat member I2 being securely maintained in the position shown b the housing member I 0.

Valve means are provided for controlling the flow of fluid pressure from the intake chamber I i to the outlet chamber 'l and from the latter to the exhaust chamber 8, and, in accordance lwith the present invention, such valve mechanism is so constituted as to be self-aligning and to allow substantially unimpeded flow yof fluid lpast the intake valve portin thereof. As illustrated, such means are constituted by exhaust and intake valves I3 and I4 respectively, said valves being I of spherical form and rigidly interconnected as Vby means of arod I5. A single spring I6 seated upon the intake valve seat member I2 is employed as the sole support for the valves I3 and I4, and.

as shown, such spring normally tends to urge the valves upwardly in order tov eiect a closure of the intake valve. It will be perceived that, with the valve constructed as above described, an exceed ingly simple structure is provided and one wherein tight.closure of the intake valve will be insured irrespective oflateral misalignment of the valve. The construction, moreover, avoids the use of complicated guide structures for the intake valve which would otherwise impede the ow of fluid pressure to the outlet chamber.

Invorder to actuate the valves I3 and I4 for purposes of controlling the now of nuid pressure to the outlet chamber and also in order to control the communication between the outlet chamber and the exhaust chamber, a valve-actuating plunger l1 is utilized which is provided with an axial bore I8 forming an exhaust passage. This plunger is threadedly received by the lower end o! a tubular member I9 which serves to lock the plunger in the position shown, and which isprovided with exhaust openings I9a.

Secured to the valve plunger Il is a pressureresponsive element constituted by a diaphragm 20, clamped Abetween the two casing portions I and 5 and separating the. exhaust chamber 8 from the partition 6. This diaphragm is se- Y curely maintained in position upon the plunger Il as by being interposed between an annular shoulder 2| formed on the plunger and a plate 22, the latter being maintained in iirm engagement with the diaphragm as by means of a collar 23 threadedlyreceived -by the upper'portion of the plunger I'I.

Novel means are provided by the present invention for effecting operation of the valve mech- Yoi spring leaves 253, till and 3i.

pedal member 2t is pivotally mounted on the upl per casing section 4 as by means of a pair of ears depending from the rear portion of the pedal member, one of said ears being indicated at 2B. The ears carried by the pedal member cooperate with ears 2 formed on or secured to the casing section t, a rod or pin 253 serving to interconnect the cooperating ears to provide the pivotal mounting for the pedal.

The novel graduating spring contemplated by the present invention is preferably formed as e. plurality of springleaves 29, St and ti, one end oi said leaves being rigidly secured to the forward portion of the pedal fiiibetween portions 2d' thereof as by means of a screw 32. Intermediate this last named connection and the pivotal mounting 25B, the pedal 25 is provided with a bracket :it having a rod or pin 35 against which the lower leaf spring il@ is maintained with a certain pressure as determined by the tension If desired, this tension may be varied by inserting or removing one or more shims it between the pedal 25 ,and

the upper leai spring 3i It will be readily understood-from the foregoing description that the graduating spring assembly 2d ls carried by and movable with the pedal and has its lower end resiliently maintained in contact with the pin 3ft with a certain predetermined degree of loading or tension.

Means are provided for operatively connecting the lower end oi the graduating spring 26 with the tubular member it, and, as shown, such means include la pin Streceivable in a recess 3l provided in the member id, the lower end 38 oi the spring leaf 29 being so formed as to conform to the upper portion of the pin 3B. The foregoing connection is such that movement o! th'e pedal 25 will be eilclently imparted to the member I9 through the graduating spring 24 as the pedal moves about` the pivotal mounting 28.

In order to maintain the parts in the normal position shown in Fig. 1 and with the pin 36 in' contact with the graduating spring, resilient means, such as spring 39, is interposed between an abutment 40 formed on the casing section 4 and an annular shoulder 4I formed on member I9. rI'here is also preferably provided an adjustable pedal stop 42 cooperable with a pin 43 secured to the lower end of the pedal 25, such stop being adjustable for the purpose of positioning l the pedal and its associatedv graduating spring 24 in proper cooperative relationship with the pin 33 in -member I9 irrespective of \the variations in tension of the graduating spring caused by the addition or removal of the adjusting shims y In utilizing the valve structure heretofore provided with a remote operation of vehicle controlling elements, tl'ie intake chamber I I is connected with a fluid pressure reservoir 44 as by conduit Actuator 46 may be connected to any spring 24. Such downward movement of member I9 will be accompanied by movement of the diaphragm zand plunger II carried thereby. the lower end of the latter contacting the exhaust valve I3 and thus interrupting communication between the outlet chamber I and the exhaust chamber 8. Further movement of the pedal 25 will eil'ect opening of intake valve I4, whereuponl such an arrangement, the rate of pressure buildup within the actuator d6 supplied from chamber l will be materially greater than the rate of pressure build-up within chamber 9 beneatl'i'the diaphragm 20, and the actuator will be promptly actuated notwithstanding the fact that it is positioned remotely as regards the controlling valve mechanism. It will also be noted that this action will be reversed when the valve is moved to ex.

haust position and hence the exhausting phase of the actuator will likewise take place rapidly.

It will be understood that, after the first initial movement of the pedal 25, assuming that the same remains in this position, suiiicient pressure must be built up beneath the element 2! in order to overcome the precompression force existing in spring 2li before the element 2t can edect upward movement of the plunger il in order to permit closing of the intake valve it. Thus, with a slight initial pressure on the pedal 25, a substantial pressure may be promptly created within the actuator 46 connected with chamber I before the valve mechanism laps. Preferably, the initial increment of pressure supplied by the valvular mechanism is such as to overcome the starting friction and any biasing forces residing in the actuator and the vehicle controlling elements connected thereto. In order to secure this desirable result, the graduating spring 24 is initially precompressed or tensloned by means of shims 35 to such a value that the initial operation of thevvalvular mechanism will yield this desirable pressure. Y Following successive movements of the pedal 25 1n order to secure increases in the pressure o! the fluid supplied the actuator 46 by the valvular mechanism, should it be desired to convey full reservoir pressure to the actuator, itis only necessary to depress the pedal 25 to such a position that a boss 5I carried by the pedal engages the end 38 of the leaf spring 29. It will be readily understood that further movement of the pedal 25 after such contact takes place will positively move the member I9 and parts carried thereby downwardly, as viewed in Fig. 1, in order to positively maintain the intake valve I4 in open posi- In order to prevent leakage of exhaust air into the drlvers compartment, a sealing washer 52 is interposed between member I9 and an upstanding flange 53 formed on the top of casing section 4. such construction also preventing dirt and dust from entering the valve mechanism.

' There is thus provided by the present invention a novel self-lapping valvular mechanism for controlling the now of'pressur'e fluid. The use of a graduating spring of the leaf-spring type enables a unitary and compact assembly to be achieved and one which may be readily and elllciently mounted upon the actuating pedal for the valve mechanism. It is, moreover, to be pointed p out that, in utilizing a graduatingspring of this type, a certain amount of friction exists between the leaves of the spring and this serves to elli-- ciently avoid any tendency of the valve parts to vibrate or chatter. The combined pedal and spring construction also facilitates assembly of the parts as well as rendering them more accessin the art. Reference will, therefore, be had tc the appended claims forv a definition of the limits of the invention.

What is claimed is: K

l. lluid pressure control valve mechanism comprising a casing, a partition therein formed with an intake valve seat, said partition dividing the casing into intake and outlet chambers, a spherical exhaust valve in the outlet chamber, a spherical intake valve in the intake chamber, means rigidly vinterconnecting said valves, a spring interposed between said exhaust valve and partition for supporting said valves, a valve-actuating member formed with an exhaust passage, a pressure-responsive element carried by said valve-actuating member and adapted to be sub-.- jected to the pressure of the fluid in the outlet chamber, and means for actuating said last member comprising a pedal pivotally mounted on said casing together with a graduating spring mounted on and carried by the pedal and having a part thereof operatively connected with said member.

2. A control valve for fluid pressure mechanism comprising a casing, a pressure-responsive member forming a pressure chamber in said casing, inlet and exhaust valves in said casing for controlling the ilow of pressure fluid into and out of said chamber, means for operatively connecting said valves and member,v a precom pressed leaf graduating spring associated with said member, and a .pivotally-mounted manually,- operable device carrying said spring and having a portion thereof rigidly mounted thereon and movable to operate said member through said spring.

3. In combination with a fluid motor, means including a remotely-positioned self-lapping vaivular mechanism for controlling the flow of fluid to and from the motor, said mechanism including exhaust and intake'valves, an actuating .as-

sembly for said valves including a pressure-re sponsive member, a manually-operable element, and a precompressed leaf graduating spring having a portion rigidly attached. to said element and carried by and movable with said element.

said spring being operatively connected with said pressure-responsive member. 4. A control valve for uid pressure-mechanism comprising a casing, a pressure-responsive member forming a pressure chamber in said casing,

and having one end thereof rigidly connected with said pedal and having the other end operatively'connected with said member. 5. A self-lapping control valve for fluid pressure mechanism comprising a casing, a diaphragm in said'casing dividing the same into outlet and exhaust chambers, inlet and exhaust valves in said casing for controlling the flow of pressure uid into the outlet chamber and from the outlet chamber into the exhaust chamber, means within the casing for operating said valves upon movement of said diaphragm, and means for moving the diaphragm comprising a manuallyoperable member having a leaf spring rigidly carried thereby,-one end of said leaf spring being operatively connected with 'the diaphragm` whereby movement of the manually-operable member will cause movement of the diaphragm through said leaf spring. v

6. A control valve for fluid pressure mechanism comprising a casing, a pressure-responsive member forming a pressure chamber in said casing,

inlet and exhaust valves in said casing for controlling the ilow of pressure fluid into and out of said chamber, means for: operatively connecting said valves and member, means for moving said valves in said casing for controlling the flow of pressure fluid into and out of said chamber, means for operatively connecting said valves and member, means for moving said member .to operate said valves, said iast named meansl including a pedal mounted on said casing, a leaf spring having one end thereof rigidly secured to said pedal, a. diaphragm-actuating element carried by the diaphragm, and means operatively connecting the other end of said spring with said element.

8. A self-lappingcontrol valve for fluid pressure mechanism comprising a casing having inlet and exhaust valves mounted therein, means for operating said valves including a pedal pivotally mounted on the casing and having a supporting memberV connected thereto, a leaf spring having ing one end connected to the pedal and bearing against said element for maintaining the other end of said element in engagement with said supporting member with a predetermined degree of pressure, and means operatively connecting said other end with said valves. l

10. A self-lapping control valve for fluid pressure mechanism comprising a casing having inlet and exhaust valves therein, means for operating said valvesincluding a pivotally-mounted pedal,

' and means for adjusting the normal position of a the pedal.

11. A control valve for, fluid pressuremechanism comprising a casing, a pressure-responsive member forming a pressure chamber in said casingfinlet and exhaust valves in said casing for 10 controlling the flow of pressure fluid into and out of said chamber, means for operatively connecting said valves and member, means for moving said member to operate said valves, said last named means including a pedal mounted on said 15' casing, a leaf spring having one end thereof secured to said pedal, a diaphragm-actuating element carried by the diaphragm, sealing means interposed between said casing and element, and

means operatively Aconnecting the other end o1' said spring with said element.

12. The combination with a uid pressure control valve mechanism having a casing, inlet and exhaust valves, and a. member for actuating said valves, of means for operating said member including a. pedal pivotally mounted in relation to said casing and a resilient member carried by and solely positioned by said pedal in operative relationship with said member for actuating said valves in response to movement of said pedal.

WILLIAM J. ANDRES. FREDERICK E. STROHM.

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