US3330110A

US3330110A - Fluid flow control system

Info

Publication number: US3330110A
Application number: US469716A
Authority: US
Inventors: Bryce I Sprayberry
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-07-06
Filing date: 1965-07-06
Publication date: 1967-07-11
Anticipated expiration: 1984-07-11

Description

y 11, 1957 B. 1. SPRAYBERRY 3,330,] 10

FLUID FLOW CONTROL SYSTEM Filed July 6, 1965 3 Sheets-Sheet 1 ZUAcK 1/2 a 114 113 A11 20 AV I 90 SUMP IN VENTOR Bryce I. Sprayberry B'Y 52f;

ATTORNEYS y 11, 1967 B. 1. SPRAYBERRY 3,330,110 v FLUID FLOW CONTROL SYSTEM 3 Sheets-Sheet,

Filed July 6, 1965 i 2 m6 Vb mm. q A. wm R Q \,P\ i Q W/ 5 e Mk 1 a w 3 15. a N 2 N Q9 93/ mm R vm mm .llilHii 4R i m6 mw x cm m N fl WW G afimx E W H @w mh w CT N2 mi Mv: v M T I R v m: A V Q3 W:

July 11, 1967 B. I. SPRAY-BERRY 3,330,110

FLUID FLOW CONTROL SYSTEM 3 Sheets-g 3 United States Patent 3,330,110 FLUID FLOW CONTROL SYSTEM Bryce I. Sprayberry, 441 Memorial Drive SE., Atlanta, Ga. 30312 Filed July 6, 1965, Ser. No. 469,716 17 Claims. (Cl. 60-52) This invention relates to a fluid flow control system for elevators and the like, and is more particularly directed to a valve mechanism which controls the flow of fluid between the pump and the jack of an elevator system.

In the past, the elevator industry has developed various methods of smoothly accelerating and decelerating elevator cars so that the passengers carried by these cars would not be needlessly and uncomfortably jerked and bumped by the cars at the beginning of and near the end of their movements between floors. The various apparatus developed to perform these functions is quite expensive, and the result has been that a smoothly operating elevator is quite costly. Over the years, however, the industry has endeavored to improve the smooth acceleration and deceleration characteristics in passenger elevator cars while increasing the speed of operation, all at a minimum of cost. However, until the development of this invention, the only successful way in reducing the cost of passenger elevators was to sacrifice the desirable acceleration and deceleration characteristics.

Thus, the present invention provides a method and apparatus for economically controlling the acceleration and deceleration characteristics of an elevator car by allowing the fluid pumped by the elevator pump to be initially bypassed back to the sump when the elevator motor is initially actuated, so that a gradual build-up of pressure can be obtained in the elevator jack which smoothly accelerates the elevator in the upward direction, and which opens slowly to begin bypassing fluid pumped from the elevator pump toward the jack to smoothly decelerate the elevator when approaching the desired floor level; and when traveling in the downward direction a valve is progressively opened to drain fluid from the jack that allows the elevator to smoothly accelerate in its downward direction, and when the elevator car approaches the desired floor level, the valve is progressively moved toward its closed position so the liquid being drained from the jack is restricted through a progressively narrowing aperture whereby the elevator car is decelerated gradually until it reaches a predetermined slow speed just prior to reaching its desired floor level, whereupon the valve is completely closed when the car reaches its desired level.

Accordingly, it is an object of this invention to provide an economical and eflicient fluid flow control system for an elevator so that the elevator car is rapidly smoothly accelerated and decelerated when traveling between floors of a building.

Another object of this invention is to provide a method and apparatus for accurately controlling the acceleration and deceleration characteristics of a hydraulic jack.

Another object of this invention is to provide a method and apparatus for accurately controlling the acceleration and deceleration of a reversible hydraulic jack.

Numerous other objects, features and advantages of the present invention will be apparent from consideration of the following specification, taken in conjunction with the accompanying drawing, in which:

FIG. 1 is a partial cross-sectional view of the valve mechanism of the fluid flow control system, with the components outside the valve structure being shown in schematic form.

FIG. 2 is a cross-sectional view of the up start-up and leveling valve mechanism.

3,330,110 Patented July 11, 1967 FIG. 3 is a cross-sectional view of the lowering down leveling valve mechanism.

Referring now more particularly to the drawing, an electric motor 10 of conventional design is connected to a hydraulic pump 12 by the connection 14. The pump 12 receives liquid from the sump 15 through the conduit 16 and pumps through the conduit 18 toward the valve mechanism 20, and ultimately toward the jack 22.

Main valve The valve mechanism 20 is composed of three parts, the main valve 24, the up start-up and leveling valve 26 and the lowering down-leveling valve 28. The main valve 24 is adapted to be attached to the pump 12 by the flanged portion 30, and comprises a central channel 32 having an entrance portion 33 and exit portion 34 which are divided by the check valve mechanism 35.

The check valve mechanism 35 comprises an annular valve seat 36, a valve guide 38 and a valve disc 39 attached to the guide 38 and arranged to seat on the valve seat 36. A valve stem 40 is connected to the valve disc 39 on the side opposite from the guide 38 and is slidably received within the guide member 41. With this arrangement, high pressure of the liquid in the entrance portion 33 and a low pressure in the exit portion 34 of the central channel will cause the check valve mechanism to open to the position shown in FIG. 1 so that the liquid in the entrance portion 33 will flow around the annular valve seat 36, the valve disc 39, and past the guide 41 toward the jack 22. When the pressure differential is reversed, the valve disc 39 will be guided by the guide 38 and the guide 41 so that the valve disc 39 will seat on the valve seat 36 to prevent the liquid from flowing from the jack 22 toward the pump 12. A return spring 42 is positioned between the guide 41 and the valve disc 39 so that the disc 39 is normally biased by the spring toward its seat 36 so that unless there is a pressure differential across the valve disc 39, it will remain in its seated position.

The main valve 24 has a discharge closure 45 with a channel 46 therethrough which is coincident with the central channel 32 of the main valve 24. The discharge closure 45 is attached to the main valve 24 at a flanged portion 48 and an O-ring seal 49 is inserted between the discharge closure and the main valve to prevent leakage therebetween. The discharge closure 45 has an abutment portion 50 that tends to maintain the guide 41 of the check valve mechanism 35 in its proper position. Also, the discharge closure 45 has an annular groove 51 therearound which functions to receive a clamping means for clamping a resilient conduit onto the closure so that' the liquid pumped by the pump 12 through the check valve mechanism can be conveyed to the jack 22.

Up start-up and leveling valve The main valve 24 has a conduit 55 in its entrance portion 33 that communicates on the upstream side of the check valve mechanism 35 with the up start-up and leveling valve 26. The up start-up and leveling valve 26 communicates with the conduit 55 of the main valve 24 through its conduit 56, and comprises generally a main chamber 58, a by-pass chamber 59, and an actuating chamber 60. The main chamber 58 and the by-pass chamber 59 are separated by an annular valve seat 61, and the by-pass chamber 59 and the actuating chamber 60 are separated by the annular control spool guide 62.

A control spool 64 is positioned in the up start-up and leveling valve 26 so that it communicates with all three chambers, main chamber 58, by-pass chamber 59, and actuating chamber 60. The control spool 64 has an annular flange 65 positioned in the actuating chamber 60 which is arranged to slide with relation to the wall of the chamber and formed so that an O-ring seal 66 is positioned within an annular groove 67 of the flange 65 to seal the actuating chamber 60 from the by-pass chamber 59. An opening spring 68 is positioned between an abutment 69 in the main chamber 58 and the control spool 64 so that the control spool 64 will be biased toward the right as shown in FIG. 1, in its open position.

The control spool 64 is cylindrically shaped and has a plurality of apertures 70 at its end remote from the annular flange 65, which apertures 70 are arranged to be sealed on their outer'sides by the annular valve seat 61 'when the control spool 64 is in the position shown in FIG.

1. When the control spool 64 is partially withdrawn from the annular valve seat 61 toward the right as shown in FIG. 1, it can be seen that the apertures 70 will communicate with the by-pass chamber 59. Since the conduit 55 of the main valve 24 communicates with the conduit 56 of the up start-up and leveling valve 26, which in turn communicates with the main chamber 58, it can be seen that the liquid in the entrance portion 33 of the main valve 24 will communicate through the apertures 70 of the control spool 64 through the interior portion 72 of the control spool and ultimately, the by-pass chamber'59.

The control spool 64 has a leveling mechanism located centrally thereof. The leveling mechanism 73 comprises a barrel 74 which is coaxial with the control spool 64, and which has a bottom ball check seat 76, a bottom ball check valve 77, a retaining spring 78, a top ball valve 79,'a compensating piston 80, a leveling needle 81,.a compensating spring 82, and an O-ring seal 83. The bottom ball check valve 77 is arranged to be withdrawn from the check seat 76 by the pressure of the liquid in the main chamber 58 so that a predetermined amount of liquid can enter the chamber behind the check valve 77 to force the compensating piston 80 to the right, as shown in FIG. 2, and force the leveling needle 81 to protrude outwardly, toward the right as shown in FIG. 2, of the barrel 74. It can be seen that if the leveling needle 81 is forced against the top ball valve 79 that the liquid trapped bebind the bottom ball check valve 77 will be allowed to escape past the top ball valve 79 into the compensating spring chamber 84 and out of the valve 74 through the conduit 85. This, of course, will allow the compensating piston 80 to retain its original position and the leveling needle 81 will be withdrawn into the barrel 74 of the leveling mechanism 73.

An end cap 90 is connected to one end of the up start- 7 up and leveling valve 26 by its flanged portion 91 and cap screws 92 so that it forms an end wall of the actuating chamber 60. The end cap 90 has an aperture 94 located centrally thereof which is aligned with the leveling needle 81 of the control spool 64. The aperture 94 of the end cap 90 is counter-bored at 95 and an adjustable screw 96 is threaded into the aperture 94. The adjustable screw 96 is hollow and has a plurality of apertures 97 arranged radially therearound at the approximate midpoint of its'length, and an annular groove 98 in the adjustable screw 96'communicat'es with each of the apertures 97; An O-rin'g'seal arrangement 99 is positioned on each side of the annular groove 98. An adjustable nut 93 is positioned in the counter-bored portion 95 of the end cap 90 and adjustably threaded onto the adjustable screw 96; V

'A leveling speed screw 100 is threaded into the hollow portion of the adjustable screw 96. The leveling speed screw 100 has a bore 101 at its interior portion, an exterior annular groove therearound along a portion of the length of the screw occupied by the bore 101, and a plurality of ports are bored through the leveling speed screw 100 between the bore 101 and the annular groove 103, whereby the bore 101 communicates with the annular groove 103.

The end of cap 90 has an annular groove 106 therearound which communicates with the'casing of the up start-up and leveling valve 26. O-ring seal arrangements 107 are positioned on each side of the annular groove 106 ing valve 26. A conduit 108 is positioned so that it communicates the annular chamber 106 with the aperture 94 in the end cap in the vicinity of the annular groove 98 of the adjustable screw 96. With this arrangement, it can be seen that a fluid passage is createdbetween the actuating chamber 60 of the up start-up and leveling valve 26, through the open end of the adjustable screw, through the bore 101 of the leveling speed screw 100, through the ports 104, to the grooved portion 103 of the leveling speed screw 100, through the apertures 97 of the adjustable screw 96, through the annular groove 98 and through the conduit 108 to the annular chamber 106.

Since the aperture 94 of the end cap 90 is coaxial with the leveling mechanism 73 of the control spool 64 of the upstart up and leveling valve 26, it can be seen that when the control spool 64 is positioned toward the right of FIG. 1 of the drawing, the leveling needle 81 will enter the hollow end of the adjustable screw and the bore 101 of the leveling speed screw to block or partially block, the aforementioned fluid passageway created by the construction of the leveling speed screw, adjustable screw, and end cap. Also, the projection 88 of the control spool 64 will come to rest on the adjustable nut 93, thereby limiting the movement of the control spool in this direction. a

An up start-up manifold 110 is connected to the cas-' screws function to determine the eflective opening of these conduits and adjustably restrict the flow of liquid therethrough. A solenoid actuated up leveling pilot valve 122 is located in the conduit 115, and a solenoid actuated unloader pilot relief valve 123 is positioned in the conduit 117. The conduits 115, 117 and 118 each communicate with the low pressure conduit 125, which in turn communicates with the by-pass chamber 59 of the up start-up and leveling valve 26. The conduit 116 communicates with the pump pressure conduit 126, which in turn is connected to the main chamber 58.

Lowering-down leveling valve The lowering down-leveling valve 28 comprises three chambers; low pressure chamber 130, main chamber 131 and actuating chamber 132. A conduit 134 communicates the main chamber 131 with the conduit 135 of the main valve. The conduit 135 of the main valve 24 is located 'down stream of the check valve mechanism 35 so that the pressure of the liquid entering the main chamber 134 is substantially the same as that in the exit portion 34 i an annular flange 144 at its other end. The annular flange 144 has an O-ring seal arrangement therein which is adapted to seal the main chamber 131 of therlowering' down-leveling valve 28' from; the actuating chamber 132. An end cap 145 closes the lowering down-leveling.

valve 28 at the end, remote fromthe low pressure chamber 130, and is connected thereto by the flange portion 146 and the cap screws 147; A closing spring 150 is positioned between the end cap 145 and the valve spool 142 so as to bias the valve mechanism toward its seated position to prevent the communication of the liquid between the low pressure chamber 130 of the lowering down leveling valve 28 and the exit portion 34 of the main valve 24.

The valve spool 142 of the valve mechanism 139 has a central bore 151 which is co-axial with said valve spool 142. The central bore 151 is counterbored at 152 and a needle guide 153 is threaded therein. A leveling needle 155 is positioned within the central bore 151 and the internal portion of a needle guide 153 and the outward movement thereof is limited by the flanged portion 158 of the needle abutting the flanged portion 156 of the needle guide 153. A spring 159 is positioned in the central bore 151 and adapted to bear against the flanged portion 158 of the leveling needle 155 to urge the same outwardly of the central bore 151.

The end cap 145 is centrally bored at 168 in the same manner as the end cap 90 of the up start-up and leveling valve 26, and an adjustable screw 161 and a leveling speed screw 162, each essentially of the same configuration as the adjustable screw 96 and the leveling speed screw 100, respectively, of the up start-up and leveling valve 26 are positioned with the aperture 160 of the end cap 145. The leveling speed screw 162 is bored at 163, grooved at 165 and apertured at 166, all in the same manner as in the leveling speed screw 108 of the up start-up and leveling valve 26. The adjustable screw 161 is grooved at 168, apertured at 169, and sealed at 170 all in the same fashion as the adjustable stop screw 96 of the up start-up and leveling valve 26. Furthermore, the end cap 145 has an annular groove 171, sealing means 172 and a conduit 173, all in the same fashion as the end cap 91) of the up start-up and leveling valve 26. Accordingly, a fluid passageway is created between the actuating chamber 132 of the lowering down-leveling valve 28 and the annular chamber 171 defined by the casing of the lowering-down leveling valve 28 and the annular groove 171 of the end cap 145 through the passageway formed through the end of the adjustable screw 161, and bore 163 of the leveling speed screw 162 ports 166 and annular groove 165 of the leveling speed screw 162, apertures 169 and annular groove 168 of the adjustable screw 161 and the conduit 173 of the end cap 145.

While a fluid passageway is created in this manner, it should be noted that movement of the valve mechanism 139 of the lowering-down leveling valve 28 to the right as shown in FIG. 1, will cause the leveling needle 155 to enter the bore 163 or" the leveling speed screw 162 and block or partially block the liquid passageway so created. Furthermore, movement of the valve mechanism 139 to the right will cause the portion of the valve spool 142 immediately surrounding the needle guide 153 to abut on adjustable stop nut 164, similar to that of the up start-up and leveling valve 26, thus, limiting the movement of the valve mechanism 139 in this direction.

As with the up start-up and leveling valve 26, a lowering down-leveling valve manifold 18% is connected to the lowering down-leveling valve 28, and the

conduits

181, 182, 183, 184, and 193 lead from various portions of the lowering down-leveling valve 28 to the

conduits

185, 186, 187, 188 and 195 of the lowering down-leveling valve manifold 180, respectively. Adjustment screws 189 and 190 are located so as to adjustably restrict the conduits 185 and 187, respectively. A solenoid actuated down leveling pilot valve 191 communicates with the conduit 185, and a solenoid actuated lowering pilot valve 192 communicates with the conduit 187, down stream of the juncture of conduit 195 with conduit 187. The pilot valve 192 is large enough to handle the fluid flowing from both the conduit 195 and conduit 187. The conduits 185 and 187 also communicate down stream of their respective pilot valves with the low pressure conduit 194, which in turn communicates with the low pressure chamber 130 through the

conduits

188 and 184. The

conduit 186 also communicates with the conduit 194, which in turn communicates with the low pressure chamber 130. The adjustment screw 196 which is normally closed, adjustably restricts the flow through the conduit 186, in order to provide a means of manually opening the valve.

Operation When the motor 10 is not running, and the pump 12 is not creating a fluid pressure in the line 18, the return spring 42 of the check valve mechanism 35 in the main valve 24 and the line pressure from the elevator jack will cause the valve mechanism 35 to be closed, the opening spring 68 of the up start-up and leveling valve 26 will cause the control spool 64 to be moved to the right as viewed in FIG. 1 so that the ports 70 will be in their unblocked position and the up start-up and leveling valve 26 will be in its open position, and the closing spring 150 of the lowering down-leveling valve 28 and the line pressure from the elevator jack Will cause the valve mechanism 139 to be in its closed position. Thus, when the motor 10 is initially actuated and the pump 12 begins to pump liquid through the conduit 18 into the central channel 32 of the main valve 24, the liquid will initially be channeled through the opened up start-up and leveling valve 26 to its by-pass chamber 59, back through the return conduit 200 to the sump 15.

Up start-up and leveling valve operation When the motor begins to reach its normal operating speed the pressure created in the conduit 18 will raise the pressure in the conduit 126 so that the liquid will communicate through

conduits

126, 116, and 112 to flow into the actuating chamber 60 of up start-up and leveling valve 26. As the liquid pressure builds up in the actuating chamber 60 it forces the control spool 64 against the bias of this opening spring 68 toward the left as shown in FIG. 1 toward its closed position, thus gradually choking off the flow of liquid from the main valve 24 through the up start-up and leveling valve 26, as the control spool 64 closes the main check valve 39 opens under the pressure of the pump so that the liquid begins to flow to the jack 22 to operate the elevator.

As the control spool 64 approaches its fully closed position the apertures 70 are progressively closed by the annular valve seal 61, and in order to prevent an abrupt choking off of the flow of fluid through the up start-up and leveling valve 26, the circular apertures 70 are formed with small key ways 71 which eifectively extend the opening of the apertures 70 beyond the limits of their circular configuration so that when the entire circular aperture 70 is covered the key ways 71 will remain in temporary communication with the by-pass chamber 59 so that an abrupt closing is not effected on the system. The control spool 64 subsequently progresses further into its fully closed position and the key ways 71 of the apertures 70 are ultimately withdrawn from communication with the by-pass chamber 59.

As the control spool 64 of the up start-up and leveling valve 26 moves toward its closed position, the pressure created in the main chamber 58 acts against the bottom ball check valve 77 to cause it to move away from its seat 76, and a small portion of the liquid in the main chamber 58 enters the chamber of the barrel 74 behind the bottom ball check valve 77. This increased pressure in the chamber of the barrel 74 causes the compensating piston to move toward the right, as seen in FIGS. 1 and 2, so that the top ball valve 79, compensating piston 80 and leveling needle 81 are also moved to the right, and the leveling needle is caused to protrude further from the barrel 74 of the control spool 64. After the control spool 64 is moved to its fully closed position by the liquid in the actuating chamber 60, and the pressure in the main chamber 58 is equalized with presure behind the compensating piston 80 and the bottom ball check valve 77 will move to its closed position by the retaining spring 78. Thus, the leveling needle 81 will remain in its projected position until the liquid behind the compensating piston 80 is removed.

' As the elevator'car approaches the floor desired by its operator, the solenoid actuated up leveling pilot valve 122 located in the up start-up manifold 110 is actuated to open the conduit 115 and allow the liquid in the actuating chamber 60 to flow through the adjustable stop nut 93, leveling speed screw 100, end cap 90 and conduit 111, through the conduit 115 to the low pressure conduit 125, through the conduit 200, back to the sump 15. The adjustment screws 120 and 121 are adjusted so that the flow of liquid to the actuating chamber 60 through the conduit 116 is slower than the flow of the liquid being removed from the actuating chamber 60 through the conduit 115. Thus, the liquid will escape from the actuating chamber 60 at a faster rate than it enters, causing the control spool 64 to move toward its open position.

After the control spool begins movement towards its open position, the leveling needle 81 will enter the open end of the leveling speed screw 100 to partially block the fluid passage therethrough. Thus, the rate of the liquid flowing out of the actuating chamber 60 will be progressively diminished as the leveling needle 81 enters the leveling screw 100 until the liquid flowing out of the chamber 60is flowing at the same rate as the liquid flowing into the chamber. With this arrangement it can be seen that the control spool 64 will be moved toward its'f'ully opened position only to the extent permitted by the leveling needle 81 as it enters the leveling speed screw 100.

Since both the by-pass adjusting screw 96 and the leveling speed screw 100 are adjustable, they can be inserted into the end cap 90 and adjusted to any preselected position so that the leveling needle 81 will enter and block the fluid communicating therethrough at a preselected position, whereby the extent of a movement of the control spool is selectively adjustable.

After the control spool 64 is moved to its partially opened position, as described above, the elevator car will continue to slowly move to the level preselected by its operator until the preselected level is reached, and the solenoid actuated unloader pilot relief valve 123 and the off switch (not shown) of the motor 10 are actuated simultaneously so that the pump 12 duit 117 leading from the actuating chamber 60 of the up start-up and leveling valve 26 is opened to drain the fluid remaining in the actuating chamber back to the sump 15, at the same time the main valve assembly 35 is moving to its closed position so that it is just cracked and closes when the pressure flow stops. Thus, the control spool 64 will be urged toits full opened position by the opening spring 68 and the liquid pressure remaining in the central channel 32 of the main valve 24 will be bypassed back to the sump 15 through the up start-up and leveling valve 26, and the leveling needle 81 will be forced against the bore 10-1 of the leveling speed screw 100 so that it will cause the top ball valve '79 to be removed from the compensating piston 80 and allow the liquid trapped in the chamber of the valve 74 to flow through the compensating spring chamber 84 and through the conduit 85 to a low pressure area, whereupon the leveling needle 81 will be repositioned to its withdrawn position inside the valve 74 by the compensating spring 8-2.

' Lowering down leveling valve operation When the elevator car is to be moved in a downward direction, the liquid that was formerly forced to the jack 22 to move the elevator car in an upward direction stops and the conr duits 134 and 135. In order to allow the liquid to'flow from the jack 22 through the lowering down-leveling valve 28 back tothe sump 15 the solenoid actuated lowering pilot valve 192 in the lowering down-leveling valve manifold 180 which has a capacity large enough to exhaust fluid through both conduits 187 and 195 are opened so that the liquid pressure in the actuating chamber 132 behind the valve mechanism 139 is reduced and the pressure in the main chamber 131, which is the same as the pressure in the main chamber .131, which is the same as the pressure on the jack 22, will cause the valve mechanism 139 to move to its'opened position, towards the right as viewed in FIG. 1. Since the seat 138 of the valve mechanism 139 defines an aperture leading to the lowpressure chamber that is smaller in area than the area of the actuating chamber 132, the liquid pressure in the main chamber has a larger surface in the flanged portion 144 of the valve spool 142 to act on than in the valve disc 139. Thus, the liquid pressure inthe main chamber exerts a force toward the right on the valve spool 142, as viewed in FIG. 1. The reduction of the pres-sure in the actuating chamber 132 causes a total pressure differential across the valve mechanism (the pres sure against the flanged portion 144 of the valve spool minus the pressure of the liquid in the actuating chamber .132 minus the force of the closing spring plus the pressure of the liquid in the low pressure chamber 130) to move the valve mechanism to its opened position, thereby allowing the liquid to flow from the jack 22 to the low pressure chamber 130, back to the sump 15 through the conduit 20-4, thereby lowering the elevator car.

As the valve mechanism 139 is positioned in its fully opened position the portion of the valve spool 142 immediately surrounding the needle guide 153 will abut the adjustable stop nut 164 and the leveling needle'lSS will abut the edge of the bore 163 of the leveling speed screw 162. The leveling speed screw 162 is adjustedto a position where it will come into contact with the leveling needle 155 before the valve spool 142 abuts the adjustable stop screw 161 and the spring'159 will allow the leveling needle to be retracted inside the needle guide 153 and central bore 151. Any liquid trapped in the central bore 151 behind the flanged portion 158 of the leveling needle 155 will be allowed to escape through the conduit 205 leading from the central bore 151 to the actuating chamber 132. V

' As the elevator car travels in a downward direction and approaches the level desired by its operator the solenoid actuated lowering pilot valve 192 is deactuated 7 so that it closes the conduit 187 and the solenoid actuated down-leveling pilot valve 191 is actuated so that it opens 'the conduit 185. The actuation of the valves 191 and 192 in this manner is simultaneous. The pressure of the fluid from the jack 22 is continuously communicated through the main valve 24, main chamber 131 of the lowering down-leveling valve 28, its. conduit 193, conduits 195 projected into the leveling speed screw 162 under the" bias of the spring 159 until the flanged portion 158 of the leveling needle comes in contact with the flanged portion 156 of the needle guide 153, whereupon the leveling needle begins to withdraw from the bore 163 of the leveling speed screw 162. 'As the leveling needle withdraws from the leveling speed screw 162 a fluid passageway is opened between the actuating chamber 132, through the leveling speed screw 162, by-pas' s adjusting screw 161, conduit 173 of the end cap 145, annular chamber 171, and the

conduits

181, 185, 194, 188, and 184 to the low pressure chamber .130. This allows the liquid flowing into the actuating chamber 132 to begin to be exhausted from the actuating chamber, and continued movement of the valve mechanism 139 toward its closed position will further withdraw the leveling needle 155 from the adjustable stop screw 161 and the leveling speed screw 162 until the flow of liquid into the actuating chamber 132 is equal to the flow of liquid being exhausted from the actuating chamber 132, whereupon the valve mechanism 139 stops its movement toward its closed position. Thus, the flow of liquid from the jack through the main valve 24, past the valve mechanism 139, is gradually choked 011 so that the jack is progressively decelerated.

When the elevator car reaches the level desired by its operator, the solenoid actuated down leveling pilot valve 191 is deactuated so that the valve 121 is closed to stop the flow of liquid from the actuating chamber 132 through the adjustable stop screw 161 and the leveling speed screw 162, whereupon the liquid flowing through the conduit 195 from the main chamber 131 to the actuating chamber 132 causes the valve mechanism 139 to move to the left as viewed in FIG. 1, until it is completely seated on the valve seat 138, thereby stopping the flow of liquid through the lowering down-leveling valve 28, and further operation of the jack 22 and elevator car.

It can be seen that the configuration of the guide 141 of the valve mechanism 139 is such that the valve will function to initially open with a small opening and then gradually build into a large opening for large volume liquid flow and close with a gradual closing function, so that when either opening or closing the valve will not cause the flow of liquid therethrough to surge.

The adjustment screw 198 is adjusted so that the flow of liquid through the conduit 183 is not too rapid to cause the valve mechanism 139 to suddenly move to the right to start the elevator down with a jerk. Lowering pilot valve 192 has enough capacity to handle both the pressure flow through both conduits 195 and 187. The rate of flow through conduit 187 is adjusted by means of adjustment screw 190.

When lowering pilot valve 192 is closed, the flow continues in by adjusting screw 190 through conduit 183 but down-leveling pilot valve 191 is actuated so that even though the leveling needle 155 is projected into the fiuid passageway through the leveling speed screw 162 some oil starts to flow out through

conduit

163, 166, 165, 169, 168, 173, 171, 181, by adjusting screw 189, 185, through down-leveling

pilot valve

191, 199, 188, 134 to to the low pressure chamber 130.

It will be obvious to those skilled in the art that many variations may be made in the embodiments chosen for the purpose of illustrating the present invention without departing from the scope thereof as defined by the appended claims.

I claim:

1. Apparatus for controlling the movement of an elevator car, comprising:

(A) a motor,

(B) a pump having an inlet and an outlet connected to said motor,

(C) a valve mechanism associated with said pump,

said valve mechanism comprising:

(1) a main valve comprising:

(a) a casing having an inlet connected to the outlet of said pump, (b) a check valve mechanism, (c) a first by-pass outlet upstream of said check valve mechanism, (d) a second by-pass outlet downstream of said check valve mechanism,

(e) a discharge outlet downstream of said check valve mechanism,

(2) an up start-up and leveling valve mechanism,

comprising:

(a) a casing having an inlet connected to said first by-pass outlet and an outlet,

(b) a valve positionable between said inlet and said outlet to control the flow of fluid therebetween,

(c) spring means biasing said valve toward its open position,

(d) an actuating chamber,

(e) means continuously communicating said pump outlet with said actuating chamber so that fluid flows from said pump to said actuating chamber at a predetermined rate to close said valve,

(f) first means for selectively communicating said actuating chamber with said pump inlet so that fluid flows from said actuating chamber toward said pump at a rate greater than said predetermined rate to open said valve,

(g) second means for selectively communicating said actuating chamber with said pump inlet so that fluid flows from said actuating chamber toward said pump at a rate greater than said predetermined rate to open said valve,

(h) restricting means carried by said valve for restricting the flow of fluid through said second means so that when said valve is in a predetermined partially open position the flow of fluid through said second means is equal to the flow of fluid through said continuously communicating means,

(3) a lowering down-leveling valve mechanism,

comprising:

(a) a casing having an inlet connected to said second by-pass outlet and an outlet,

(c) spring means biasing said valve toward its closed position,

(d) an actuating chamber,

(e) means continuously communicating said main valve discharge outlet with said actuating chamber so that fluid flows from said main valve discharge outlet to said actuating chamber at a predetermined rate to close said valve,

( f) first means for selectively communicating said actuating chamber with said pump inlet so that fluid flows from said actuating chamber toward said pump at a rate greater than said predetermined rate to open said valve,

(h) restricting means carried by said valve for restricting the flow of fluid through said second means so that when said valve is in a predetermined, partially open position the flow of fluid through said second means is equal to the flow of fluid through said continuously communicating means,

(D) a jack communicating with said discharge outlet of said main valve, and

(E) an elevator car operatively connected to said jack.

2. An apparatus of the type for controlling fluid flow to an elevator jack having a motor, a pump, a sump, a

jack and a main valve mechanism between said pump and said jack whereby fluid is pumped from said sump through said valve to said jack, the combination therewith of an up start-up and leveling valve comprising:

(A) a casing having a main chamber, an actuating chamber and a by-pass chamber,

7 (B) an inlet to said main chamber communicating with the upstream side'of said main valve mechanism,

(C) an outlet from said by-pass chamber communicating with said sump,

(D) a control spool positionable between said inlet and said outlet to close and open fluid communication 'therebetween,

(1) said control spool extending into said actuating chamber, 7 r

(E) a spring means biasing said control spool into said actuating chamber to open said valve,

(F) means for communicating the output of said pump with'said actuating chamber,

(G) first selectively actuatable means for communicating said actuating chamber with said sump,

(H) second selectively actuatablemeans for communicating said actuatingchamber with said sump,

(1) means associated with said control spool for limiting the rate of communication of said second selectively actuatable means.

3. An apparatus of the type for controlling the flow of a fluid having a check valve mechanism with an inlet and an outlet upstream of a check valve and at least one outlet downstream of said check valve, the combination therewith of a valve mechanism having an inlet communicating with said up stream outlet and an outlet, a control spool for opening and closing communication between the inlet and outlet of said valve mechanism, means for biasing said control spool toward its open position, said control spool defining an actuating area, a source of fluid pressure for communicating with said actuating area to move said control spool toward its closed position, means for communicating said actuating area with a source of low pressure, a leveling needle carried by said control spool and adapted to be actuated by said source of fluid pressure so as to project outwardly of said control spool to limit said means for communicating, and means for deactuating said leveling needle.

4. The invention as set forth in claim 3 and further comprising means for selectively adjusting the distance between said leveling needle and said means for communicating when said-control spool is in its closed position.

5. The invention as set forth in claim 3 and further comprising adjustably positionable means for limiting the movement of said valve spool toward its open position.

6. An apparatus of the type for controlling the flow of a fluid comprising a source of fluid pressure, fluid conduit, a check valve in said fluid conduit to maintain unidirectional flow of fluid therethrough, and a by-pass valve upstream of said check valve for by-passing fluid away 1.2. annular flangeto bias said control spool toward its open position, said remote end of said spool defining an actuating chamber, a first fluid conduit communicating with said actuating chamber, a second fluid conduit communieating with said actuating chamber, a leveling needle car ried centrally of and projecting from said spool, means for introducting and maintaining fluid within said control spool to further project said leveling needle from said control spool whereby said leveling needle limits the flow of fluid through said second fluid conduit, and means for partially retracting said leveling needle within said control spool.

8. Valve mechanism of the type for controlling the flow of a fluid from an elevator jack to an area of'low pressure, said mechanism comprising a valve spool positionable in a fluid flow conduit to block the flow of fluid therethrough, spring means biasing said valve spool toward its closed position, said valve spool having a first pressure surface of a given area arranged so that fluid pressure thereon forces said valve spool toward its open position, said valve spool having a second pressure sur:

face of an area larger than said given area and arranged so that fluid pressure thereon forces said valve spool toward its closed position, first communicating means for constantly communicating fluid pressure from said elevator jack to said first pressure surface, second communicating means for selectively communicating fluid pressure from said elevator jack to said second pressure surface,

third communicating means for selectively communicating said second pressure surfacewith said area of low pressure, restricting means carried by said valve spool for V limiting the fluid flow through said third communicating means.

9. The invention set forth in claim 8 and further comprising resilient means enabling said restricting means to be forced inside said valve spool.

10. The invention set forth in claim 8 and further comprising means for selectively adjusting the distance between said restricting means and said third communicating means when said valve is closed.

11. The invention as set forth in claim 8 and further comprising adjustably positionable means for limiting the movement of said valve spool toward its open position.

12. Apparatus for controlling the flow of a fluid comprising a valve housing, a check valve in said valve housing, duct means defining an inlet opening and an outlet;

7 ber for communication with a'source of low fluid presfrom said check valve, the improvement in said combina- 7 tion of said by-pass valve having a spring means for constantly biasing said by-pass valve in an open position, an

' actuating area defined by said by-pass valve, means for communicating a source of fluid pressure to said actuating area to close said valve, means for communicating a low pressure source with said actuating area to allow said valve to open, a restricting means carried by said by-pass valve, means for projecting and maintaining said restrictsure, a flow blocking member carried by said valve spool and projecting from said control spool toward said second duct means, said valve spool being movable to communicate said inlet opening with said outlet opening and to project said flow blocking member at least partially into said' second duct means.

13. Apparatus for controlling the flow of fluid toward and away from a high pressure zone comprising a main valve housing including an inlet for connec tion to the outlet of a fluid pump, a check valve in said housing, a first outlet upstream of said check valve, a second outlet downstream of said check valve, and a third outlet downstreamof said check valve for communication with the zone of high pres-- communication with the inlet of the fluid pump, and

a pressure chamber including a first aperture communicating with the inlet of said first bypass valve and an outlet aperture for communication with the inlet of the pump, a control spool disposed in said first bypass valve and responsive to fluid pressure in its pressure chamber to selectively separate and communicate the inlet and the outlet of said first bypass valve, and blockage means carried by said control spool to at least partially block said outlet aperture of said pressure chamber when the inlet and outlet of said first bypass valve communicate with each other,

a second bypass valve including an inlet opening connected to the second outlet of said main valve housing, an outlet opening for communication with the inlet of the pump, and a pressure chamber including first and second outlet apertures for communication with the inlet of the pump, a control spool disposed in said second bypass valve and responsive to fluid pressure in its pressure chamber to selectively separate and communicate the inlet opening and the outlet opening of said second bypass valve, and blockage means carried by said control spool of said second bypass valve to at least partially block one of said outlet apertures of said pressure chamber of said second bypass valve when the inlet and outlet openings of said second bypass valve communicate with each other.

14. Fluid flow control apparatus comprising a pump,

a motor, main valve means including an inlet connected to the outlet of said pump and an outlet connected to said motor, a bypass valve including a housing defining a first chamber communicating with the inlet of said main valve and the outlet of said pump, a bypass chamber communicating with the inlet of said pump, and a pressure chamber, a valve control spool disposed in said housing and spring biased toward a position wherein said first and bypass chambers in open communication with each other, open conduit means communicating said first chamber with said pressure chamber, said housing defining aperture means opening outwardly from said pres sure chamber, said valve control spool including needle means movably carried therewith and extending outwardly therefrom into said pressure chamber toward said aperture means, whereby said needle means extends at least partially into said aperture means when said valve control spool is positioned to allow communication between said first chamber and said bypass chamber.

15. Apparatus for controlling fluid flow to an elevator jack comprising a fluid supply, a source of fluid pressure, and a control mechanism controlling the flow of fluid between said source of fluid pressure and said jack, said control mechanism comprising a valve including a valve spool for opening and closing communication between said source of fluid pressure and said fluid supply, said valve spool including a pressure surface, first duct means for communicating said source of fluid pressure wit-h said pressure surface of said valve spool to urge said valve spool toward its closed position, second duct means for communicating said pressure surface of said valve spool with said fluid supply to allow said valve spool to move toward its closed position, means carried by and movable with said valve spool for limiting the flow of fluid through said second duct means.

16. Apparatus for controlling fluid flow to an elevator jack comprising a fluid supply, a source of fluid pressure communication with the fluid supply, and a control mechanism controlling the flow of fluid between said source of fluid pressure and said jack, said control mechanism comprising a valve including a valve spool for opening and closing communication between said jack and said fluid supply, said valve spool including a pressure surface, first duct means for communicating said jack with said pressure surface of said valve spool to urge said valve spool toward its closed position, second duct means for communicating said pressure surface of said valve spool with said fluid supply to allow said valve spool to move toward its closed position, means carried by and movable with said valve spool for limiting the flow of fluid through said second duct means.

17. Apparatus of the type for controlling fluid flow to an elevator jack having a motor driven pump, a sump communicating with the inlet of said pump, a main valve mechanism communicating with the outlet of said pump, and a jack communicating with said main valve mech anism, the combination therewith 'of a bypass valve comprising an inlet communicating with the outlet of said pump and an outlet communicating with said sump, a valve element, a pressure chamber disposed adjacent said valve element, first duct means for communicating a source of high pressure fluid with said pressure chamber upon initial operation of said pump to move said valve element to a position blocking communication between the inlet and the outlet of said valve, second duct means for communicating said pressure chamber to a source of low pressure fluid, means carried by said valve element for at least partially blocking said second duct means.

References Cited UNITED STATES PATENTS 2,280,291 4/1942 Jaseph -52 X 2,319,125 5/1943 Grote 6052 X 2,944,401 7/1960 Beck 6052 2,953,902 9/1960 Arbogast et al. 6052 2,984,982 5/1961 Jaseph 6052 FOREIGN PATENTS 239,475 12/ 1924 Great Britain.

EDGAR W. GEOGHEGAN, Primary Examiner.

Claims

3. AN APPARATUS OF THE TYPE FOR CONTROLLING THE FLOW OF A FLUID HAVING A CHECK VALVE MECHANISM WITH AN INLET AND AN OUTLET UPSTREAM OF A CHECK VALVE AND AT LEAST ONE OUTLET DOWNSTREAM OF SAID CHECK VALVE, THE COMBINATION THEREWITH OF A VALVE MECHANISM HAVING AN INLET COMMUNICATING WITH SAID UP STREAM OUTLET AND AN OUTLET, A CONTROL SPOOL FOR OPENING AND CLOSING COMMUNICATION BETWEEN THE INLET AND OUTLET OF SAID VALVE MECHANISM, MEANS FOR BIASING SAID CONTROL SPOOL TOWARD ITS OPEN POSITION, SAID CONTROL SPOOL DEFINING AN ACTUATING AREA, A SOURCE OF FLUID PRESSURE FOR COMMUNICATING WITH SAID ACTUATING AREA TO MOVE SAID CONTROL SPOOL TOWARD ITS CLOSED POSITION, MEANS FOR COMMUNICATING SAID ACTUATING AREA WITH A SOURCE OF LOW PRESSURE, A LEVELING NEEDLE CARRIED BY SAID CONTROL SPOOL AND ADAPTED TO BE ACTUATED BY SAID SOURCE OF FLUID PRESSURE SO AS TO PROJECT OUTWARDLY OF SAID CONTROL