Nov. A_12, 1946. w. A. l-:AToN' 2,410?,966 BRAKE MECHANISM Filed April 29, 1943 wigfred A. Eatøw. W* 71. „Q 62W 2,41`0,966 Patented Nov. 12, 1946 UNITED STATES PATENT OFFICE 2,410,966 BRAKE MECHANISM Wilfred A. Eaton, Elyria, Ohio, assignor to Bendix-Westinghouse Automotive Air Brake Company, Elyria, Ohio, a corporation of Dela Ware Application April 29, 1943, Serial No. 485,054 8 Claims. (Cl. 303-54) 1 . This invention relates to control mechanisms and more particularly to remotely controlled ?uid pressure operated mechanisms especially adaptable for use in connection with motor ve hicles. 2 o ence being had for this purpose to the appended claims. i ' In the drawing, a fluid pressure control system embodying the features of the present invention is illustrated as including a ?uid pressure reser voir 4, a fluid pressure actuator indicated gen It has heretofore been proposed to employ fluid erally as 5, and a control valve mechanism 6 of pressure operated, remotely controlled mecha the so-called self-lapping graduating type, which nism for controlling and actuating various of is preferably constructed in accordance with the the control elements of automotive Vehicles, and apparatus of this charaoter is especially suitable 10 principles set forth in the patent to W. J. Andres, and R. S. Sanford No. 2,133,275, dated October and adaptable to motor Vehicles of the type 18, 1938. The actuator 5 is provided with a cyl wherein the elements to be controlled are posi inder 'l and a piston 8 slidably mounted therein, tioned at a considerable distance from the opera the piston being providedwith a piston rod 9 tor of the vehicle. Dif?culty has been experi ada-pted to impart motion from the piston to a 15 enced in many of the mechanisms previously vehicle controlling element IO. proposed, however, in view of the fact that the The control valve mechanism 6 is provided time required to supply the required degree of with a casing l I provided with aninlet chamber ?uid pressure to the remotely positioned actua |2, an outlet Chamber 13 and a'diaphragm cham tor has 'been excessive, and it is accordingly one the inlet and outlet ehambers being sepa of the objects of the present invention to provide 20 ber'M, rated by means of a partition |5 provided with means for overcoming this diñiculty. a port IB therein, and the'outlet Chamber being A further object of the invention is to provide separated from the diaphrag'm chamber' by a control valve mechanism so constituted as to means of a partition ll, the only connection'be permit a substantially unrestrícted connection 25 Vtween the latter chambers being through the between the source of fluid pressure and the actu medium of a restricted passage or choke 18. The ator during substantially the entire period dur upper end of the chamber |4 is closed by means ing which the source and actuator are connected of a pressure responsive member or diaphragm by the operation of the control valve mecha |9 clamped 'between the upper end of the casing nism. Yet another object of the inventionris to pro Vide, in a self-lapping control valve mechanism, means for preventing lapping action of the valve from occurring until the pressure in the actua 'tor is substantially that for which the valve has been adjusted by the operator. . A still further object of the invention is to pro vide control valve mechanism of the so-called self-lapping and graduating type, so constituted | I and a closure member 20 suitably bolted there to, the upper portion of the closure member 20 being provided With a bore 2| and an operator controlled -plunger 22 slidably mounted therein. A valve Operating element 23 is slidably mounted ,in a bore 24 formed in partition Il, the valve op eratíng element being attached to the pressure responsive member l9 at its center, as shown, for movement therewith, a sealing device 25 posi tioned in the 'bore 24 serving toprevent com as to permit the establishment of a substantially 40 munication between the outlet Chamber |3 and the diaphragm chamber M between the outer unrestricted connection between the source of surface of the element 23 and the surface of the fluid pressure and the actuator without in any bore 24. The valve operating element 23 is way interfering with the operation of the self thus positioned by means of the bore 24 and the lapping and graduating features of the valve when the operation of the system requires the 45 pressure responsive member IS, and is adapted. v to be operated by movement of the plunger 22l satisfactory and normal operation of these fea through the medium 'of a graduating spring 25 tures. interposed between the upper face of a washer These and other objects and novel features ofŸ 21 mounted on the element and a washer 28 slid the invention will appear more fully hereinafter from the following detailed description when 50 ably mounted at the upper end of the valve op erating element and adapted to engage a shoul taken in connection with the accompanying der 23a formed on the plunger. In order that drawing. It is to be expressly understood, how the 'plunger 22 may Ibe readily controlled by the ever, that the drawing is forwarded for purpose vehicle operator, the closure member 20 is pro of illustration only, and is not designed as a de?nition of the limits of the invention, refer 55 vided at its upper end with a suitable pivot pin ' › e i 2,410,966 3 4 ing a substantially unrestricted connection be tween the reservoir and the actuator. In valves control pedal 30, the latter having a connection of this general type, however, it is well known with the upper end of the plunger 22 through that during this type of operation, as the pres the medium of a roller 3| pivotally mounted on sure in the outlet chamber approaches that for the pedal by means of a pivot pin 32. which the graduating spring has been adjusted, In order that the valve mechanism may oper the upward pressure on the diaphragm increases, ate to control the flow of fluid pressure from with the result that the valve actuating element the reservoir 4 to the actuator 5 and from the moves upward to permit gradual closing of the actuator 5 to atmosphere, the inlet chamber |2` is connected with the reservoir through the me 10 inlet valve under the action of the Valve spring 42, the connection between the conduits 33 and dium of conduit 33, while the outlet chamber 34, gradually becoming more restricted until a l3 is connected with the actuator through the point is reached where the passage between the medium of a conduit 34, the outlet chamber in 29 on which is pivotally mounted an operator's inlet and outlet chambers is fully closed and turn being connected with atmosphere through the medium of a bore 35 formed in the element 15 further passage of ?uid pressure is prevented. This has resulted in a relatively slow applica 23, a port 36 formed in the wall of said bore, and tion of fluid pressure to the actuator, and a an exhaust outlet 31 which serves to connect with consequent delayed operation of the actuator in atmosphere a chamber 38 formed between the the past, and the present invention contemplates, upper surface of the pressure responsive mem ber |9 and the closure member 20. Communica 20 in connection with a control valve meohanism of the above type, the inclusion of means for tion between the chambers I 2 and I 3 through the maintaining the inlet valve in substantially wide port I 6 is normally prevented by means of an open'position until the pressure delivered to the inlet valve 39, an exhaust valve 40 connected actuator is substantially equal to that for which thereto by means of a Stem 4| being adapted to close the lower end of the bore 35 in the element 25 the graduating spring has been adjusted by the operator, and such means include, in the present 23 on downward movement of the latter. In instance, a permanent magnet 43, which may be order that the inlet valve may normally be main of the horse shoe type, preferably mounted on tained in closed position, a suitable spring 42 is the casing as shown by means of suitable screws interposed between the upper surface of the par tition |5 and the lower face of the exhaust valve 30 44 'and provided with a bore 44a to provide clear ance for the valve spring 42. The valve actuating 40. Thus it will be apparent that with the parts element 23 is also provided with a suitable arma in the positions shown, communication between reservoir 4 and the actuator 5 is prevented by ture 45 of magnetic metal, which may be means of nonnally closed inlet valve 39, while communication between the actuator and atmos threadedly mounted on the lower end of the ele ment as shown, the result being that on opera phere is permitted through the conduit 34, outlet tion of the control pedal to move the valve actuat ing element 23 downward to move the inlet valve chamber l3, bore 35, port 36, chamber 38 and ex to fully open-position, the armature 45 carried by the element approaches the poles 46 of the of the valve Operating element 23, the lower end of the bore 35 ?rstcontacts the exhaust valve 40 magnet, the armatura when in contact With the upper end of the poles tending to adhere thereto 40 to'prevent communication between the outlet and maintain the Valve Operating element in its chamber and atmosphere, further movement downward position so that the intake valve is opening the intake valve against the force ex fully open to permit the unrestricted flow of erted by the spring 42 to permit communication between conduits 33 and 34, thus allowing ?uid 45 fluid pressure between the inlet and outlet cham bers,V and thence to the actuator. It is desirable, pressure to be supplied from the reservoir to' the haust outlet 31, while on downward movement i actuator. It will be understood from the foregoing, and on reference to the above referred to patent, that on downward movement of the operatons pedal 50 30, the graduating spring 26 will be compressed however, that the valve be permitted to move to lapped position as soon as the pressure in the outlet chamber and in the actuator approaches that for which the graduating spring has been adjusted, and the magnet is accordingly so de signed in connection with the armature as to to exert a downward force on the valve Operating provide a holding force which will be overcome element 23 to close the exhaust valve and open by the fluid pressure acting on the diaphragm the intake valve, and that as the pressure builds up in the outlet chamber |3 and in the actuator 55 E9, when the force resulting from this pressure exceeds that exerted in a downward direction 5, this pressure will also be supplied to the dia phragm chamber |4 through the restricted port |8,› with the result that the upward force on the by the graduating spring by a small predeter mined amount, the strength of the magnet being preferably so chosen as to exert a force somewhat diaphragm due to the pressure in the chamber |4 will eventually overbalance the downward force 60 on the order of the force necessary to compress exerted by the spring and permit the element 23 the graduating spring by an amount necessary to permit the inlet valve to move from fully open to move upward to a point where both the inlet to fully closed position. Thus with the inlet valve and exhaust valves are in closed position, this held in open position by means of the magnet being considered as the lapped position in the valve, as will be readily understood by those 65 as above described, andrwith the pressure build ing up in the outlet chamber of the valve and skilled in the art. It is to be pointed out, how ever, that on initial operation of the pedal 30 to the chamber below the diaphragm IS, it will be adjust the valve mechanism to deliver a substan understood that the pressure acting on the dia phragm can increase su??ciently to overcome the tially high pressure to the actuator 5, the fluid in the chamber |4 will be substantially at atmos 70 lforce exerted by the graduating spring and the pheric pressure, and consequently no pressure will force exerted by the magnet and start upward initially be exerted on the member |9 to oppose movement of the valve Operating element to downward movement of the valve actuating ele move the valve to closed position, and that if ment, the result being that the inlet valve 39 will the force of the magnet is chosen as described, be moved to its fully open position, thus establish 75 this additional force exerted on the diaphragm 5 willbe'substantially dissípated, or, in other Words, absorbed by compression of the graduating spring 26, with the result that there will be no tendency for the diaphragm to'exert` an over-Controlling. action on the element 23,`with 'a resultant se tion between said chambers, a valve Operating element for moving said valve in one direction to open the valve and establishl a connection be tween said chambers, a member responsive to the ressure in': the outletV Chamber and 'associated with said'element for moving'the element in the quential closing of the inlet valve and opening other ldirection to permit closing ofv the valve, of the exhaust valve to Åunnecessarily exhaust and means including a magnet Vcooperating with ?uid pressure from the outlet Chamber l3 and said valve 'Operating element and effective when from the aotuator 5. It will also be clearly under stood that the magnet force Chos'encan be any de 10 the latter is moved to valve-opening position for maintaining said element in said position, until sired amount less than that .above described, and the f force exerted by the pressure responsive that under certain circumstances of operation, member/'to move the valve Operating element to it may also be desirable' to usev a magnet exert valve-Closing position exceeds the force tending ing a larger force, it being understood that the to move said valve Operating element to valve foregoing description is merely illustrative of the opening position by a predetermined amount.` preferred mode of operation. As soon as the force 2. The combination in a fluid pressure control exerted in an upward direction by the diaphragm HQ exceeds the force exerted in a downward direc valve mechanism having an inlet Chamber, an outlet Chamber, and a valve for controlling the tion by the graduating spring 25 by an amount equal to or slightly greater than that exerted by 20 ?ow of'fluid between said chambers, of means the magnet, it will be readily understood that for moving said valve to one position to permit the element 2-3 will be movedrapidly upward > the ?ow of fluid from said inlet Chamber to said outlet Chamber, means for moving said valve to in an upward direction by the ?uid pressure force a second position to prevent the ?ow fluid be acting upward on the diaph-ragm, and that the tween said chambers, and means including a Valve spring 42 will then move the valve assembly magnet for maintaining the valve in said one upward to move the valve 39 to Closed position position in vopposition to the action of said last and prevent further communication between the named means. inlet and outlet chambers. 3. The combination in a fluid pressure control With reference to the mode of operation de 30 valve mechanism having an inlet Chamber, an scribed in the preceding paragraph, this type of outlet Chamber and a valve for ,Controlling the operation is particularly desirable under condi ?ow of ?uid from said inlet Chamber to said tions such that the operator wishes to supply a outlet Chamber, of means for applying a force to the valve to move it to one position to estab predetermined degree of pressure to the actuator in the shortest possible period of time, but it is 35 lish communication between said lchambers, means including a member responsive to the pointed out that when it is desired to so operate pressure in the outlet Chamber for applying a the Control valve mechanism å as to establish force to said valve to move it to another position small increments or decrements of pressure in to prevent communication between said Cham-` the actuator 5, operation of the magnet to hold the intake valve in open position might seriously 40 bers, and means including a magnet effective on movement of said valve to said one position interfere with the Sensitive operation of the Valve, for maintaining the valve in said position until and the mechanism is therefore preferably con the force exerted by the second named means structed as above described, in such a manner exceeds that exerted by the ?rst named means that the magnet becomes effective only when the operator's Control pedal is operated to move the 45 by a predetermined value. 4. The combination in a ?uid pressure control intake valve to fully open position, In the event valve mechanism having a valve movable to open the operator has already' adjusted the valve to and closed positions for controlling the ?oW of provide a desired pressure in the actuator, and fluid therethrough, of force applying means for then desires to further depress the control pedal in order to obtain a slight increase of pressure in 50 moving the valve to open position, force apply ing means for moving the valve to Closed posi the actuator, it is to be understood that the Cor tion, and means including a magnet operable responding pressure increase which will occur in when the valve is in open position for maintain the outlet Chamber E3 and in Íthe diaphragm ing the latter in said position until the force Chamber lll Will occur with su?ioient rapidity to prevent the additional force exerted by the grad 55 exerted by said second named means exceeds that exerted by the ?rst named means by a prede uating spring from forcing the valve actuating termined amount. . element 23 and the armature ll? downward suni under the action of the excess force accumulated 5. The combination in a ?uid pressure control ' ciently to be attracted by the poles of the magnet, valve mechanism having a casing provided With the result being that under this condition of op eration the valve mechanism Will have a mode 60 inlet and outlet chambers, a port between said chambers, and a valve movable for opening and of operation comparable with that of the ordi closing said port, of a spring adjustable for ex nary and Well known self-lapping graduating erting a force to move said valve to open posi type control valve. tion, means including a member responsive to' While the invention has been described and illustrated herein with Considerable particularity, 65 the pressure in the outlet Chamber for opposing the force exerted by said spring and moving the it is to be understood that the same is not limited valve to closed position, and means including a to the form shown, but may receive a variety of magnet for holding said valve in open position, mechanical expressions as will readily appear to the holding force exerted by said magnet being those skilled in the art. Reference will, there fore, be had to the appended claims for a de?ni 70 substantially equal to the force required to Com press the spring during movement of said valve tion of the limits of the invention. from open to closed position in response to the What is Claimed is: force exerted by said pressure responsive mem 1. In a ?uid pressure control valve of the-self ber. lapping type having an inlet Chamber, an outlet 6. The Combination in a self-lapping control Chamber, and a valve for controlling the connec 'Z _ valve mechanism having a pair of valves for con trollingthe flow of ?uid pressure therethrough, 8 until the pressure in the outlet chamber exceeds a, predetermined value, said means permitting unrestricted movement of said element to effect lapping of said valves when said pressure exceeds means for normally maintaining one of said valves in open position and the other valve in closed position, and a valve Operating element said predetermined value. for moving said one valve to closed position and 8. In a control valve mechanism having a cas said other valve to open position, of means for ing provided with an inlet chamber, an outlet applying a force to said element for moving said Chamber, a port connecting said chambers, and valves to one of said positions, means responsive a valve for normally closing said port, means in to the pressure in said valve mechanism for ap 10 cluding a graduating spring for moving said valve plying a force to said element for moving the in one direction to fully open position, means in valves to said otherV position, and means includ ing a magnet for holding said element and main taining the valves in one of said positions when difference in the forces applied to said element cluding a member responsive to the pressure in the outlet chamber for opposing the operation of the moving means and moving the valve in the opposite direction to closed position, and means including a part supported by the pressure re by said force applying means is less than a pre sponsive member and a part supported by the determined value. '7. In a self-lapping valve of the type having casing, and arranged to contact with each other only when the valve is moved to substantially an outlet chamber adapted to be connected with an actuated device, inlet and outlet valves for 20 fully open position, said parts being so con controlling the flow of ?uid pressure to and from structed and arranged as to hold the valve in fully open position until the force exerted by the said Chamber, lmeans including a, pressure-re sponsive- element adapted to be subjected to the pressure responsive member to_ close the valve exceeds the force exerted by the moving means pressure of the fluid in the outlet chamber for controlling the opening, lapping and exhaust 25 to open the valve by a predetermined value. movements of said valves, and means including a magnet for preventing lapping of said valves WILFRED A. EATON.