Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
  • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
  • B66F3/00—Devices, e.g. jacks, adapted for uninterrupted lifting of loads
  • B66F3/24—Devices, e.g. jacks, adapted for uninterrupted lifting of loads fluid-pressure operated
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
  • B66F3/00—Devices, e.g. jacks, adapted for uninterrupted lifting of loads
  • B66F3/24—Devices, e.g. jacks, adapted for uninterrupted lifting of loads fluid-pressure operated
  • B66F3/25—Constructional features
  • B66F3/35—Inflatable flexible elements, e.g. bellows
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
  • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
  • F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
  • F15B11/044—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out"
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
  • F15B15/08—Characterised by the construction of the motor unit
  • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
  • F15B15/1423—Component parts; Constructional details
  • F15B15/1476—Special return means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/405—Flow control characterised by the type of flow control means or valve
  • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
  • F15B2211/41509—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a directional control valve
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/42—Flow control characterised by the type of actuation
  • F15B2211/421—Flow control characterised by the type of actuation mechanically
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/46—Control of flow in the return line, i.e. meter-out control
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/50—Pressure control
  • F15B2211/505—Pressure control characterised by the type of pressure control means
  • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
  • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/50—Pressure control
  • F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
  • F15B2211/5153—Pressure control characterised by the connections of the pressure control means in the circuit being connected to an output member and a directional control valve
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
  • F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
  • F15B2211/7051—Linear output members
  • F15B2211/7052—Single-acting output members
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
  • F15B2211/75—Control of speed of the output member

Definitions

• the invention relates to a process and device for controlling a single-acting pneumatic piston. Specifically, though not exclusively, the invention is applicable to a bellows pneumatic piston used for lifting objects, in particular for raising one side of a motor vehicle.
• the main aim of the present invention is to provide a process for controlling a single-acting pneumatic piston which overcomes the above-described drawback.
• An advantage of the invention is that it provides a process which with a simple command fully and rapidly evacuates the pressurisable chamber of the pneumatic piston.
• a further advantage of the process is that it is simple and economical to realise.
• a further aim of the invention is to provide a control device for actuating the process of the invention which is relatively small, reliable, practical and safe.
• figure 1 shows a pneumatic jack provided with the control device of the invention
• figure 2 shows the control device of figure 1
• figure 3 is the pneumatic diagram of the control device of figure 2
• figure 4 is a front view of the valve body of the control device of figure 2
• figure 5 is a back view of the valve body
• figure 6 is a side view of the valve body
• figure 7 is a side view of the valve body, from the opposite side to the view in figure 6
• figure 8 shows section VIII- VIII of figure 6
• figure 9 is section IX-IX of figure 4
• figure 10 is section X-X of figure 8
• figure 11 is section XI-XI of figure 9
• figure 12 is section XII-XII of figure 9
• figure 13 is section XIII-XIII of figure 9.
• a pneumatic jack for raising objects comprising a single-acting pneumatic piston 2 comprising a bellows 3 made of a deformable material which delimits internally thereof a pressurisable chamber 4 which can be placed in connection with an external source of pressurised gas (for example, a compressed-air plant).
• An upper end of the bellows 3 is predisposed using known ways for raising an object, in particular for lifting a side of a motor vehicle in a workshop.
• the jack 1 is provided with a handle 5 bearing a control device 6 for the single- acting pneumatic piston, which is actuated, preferably manually, by an operator.
• the control device 6 operates between the pressurised gas source and the pressurisable chamber 4.
• the control device 6 comprises a normally closed two-way delivery valve 7 which on command places the external pressurised-gas source in communication with the pressurisable chamber 4 of the piston.
• a normally-closed two-way discharge valve 8 places the pressurisable chamber 4 in communication with a discharge 9.
• An auxiliary discharge conduit 10 has an intake zone 11 wliich on command can be connected to the pressurisable chamber 4.
• a venturi depression can be induced in the auxiliary discharge conduit 10.
• a normally-closed two-way total discharge valve 12 is predisposed on the auxiliary discharge conduit 10 between the gas source and the intake zone 11.
• the delivery valve 7, the discharge valve 8 and the total discharge valve 12 are associated to a valve group comprising a valve body 14 in a single block, as shown in the figure, or can be assembled on different blocks which can then be assembled together and interfaced.
• the valve block 14 comprises: an inlet mouth 15 for pressurised air which is connectable to a compressed-air plant; a first cavity 16 opening into a delivery mouth 17 for connecting to the pressurised chamber 4 of the piston; a second cavity 18 opening into a discharge mouth 19 on which a discharge silencer 27 operates; a first seating 20 for the delivery valve 7 and a second seating 21 for the discharge valve 8; and a third seating 22 for the total discharge valve 12.
• connection conduits are afforded inside the valve body 14: a first conduit 23 which i ter-connects the first seating 20, the first cavity 16, the second seating 21 and the second cavity 18; a second conduit 24 which inter-connects the inlet mouth 15, the first seating 20 and the first cavity 16; a third conduit 25 which interconnects the first seating 20 and the third seating 22; and a fourth conduit 26 which interconnects the third seating 22 and the second cavity 18.
• the third conduit 25 and the fourth conduit 26 are staggered with respect to the first conduit 23 an the second conduit 24.
• a transversal conduit 30 connects the third conduit 25 with the third seating 22.
• a transversal conduit 30 connects the fourth conduit 26 with the third seating 22.
• a transversal conduit 31 connects the fourth conduit 26 with the second cavity 18.
• the fourth conduit 26 is obliquely located.
• a transversal conduit 32 connects the third conduit 25 with the first seating 20.
• the second cavity 18 houses a venturi device, of known type and not illustrated., which is predisposed to induce a venturi effect in the intake zone 11.
• the delivery valve 7, discharge valve 8 and total discharge valve 12 are normal two-position two-way intercept valves, which are manually opened by means of a push-button, and which automatically close by means of a return spring when no thrust is present.
• the delivery valve 7 in the closed and open positions respectively opens and closes the first conduit 23 and the second conduit 24.
• the discharge valve 8 in the closed and open positions respectively closes and opens the first conduit 23.
• the total discharge valve 12 in the closed and open positions respectively closes and opens a connection between the third conduit 25 and the fourth conduit 26.
• the control device 6 activates a process for controlling the single- acting pneumatic piston 2, in which process the pressurisable chamber 4 of the piston is cyclically subjected to a delivery stage, during which the piston 2 raises an object, in which stage the chamber 4 receives a pressurised gas coming from a source thereof, and a discharge stage, in which the pressurised gas is evacuated from the chamber 4 and the object is lowered under the pressure of its own weight.
• the discharge stage in order to obtain full lowering of the object, gas is sucked from the chamber 4 by a venturi effect.
• This venturi effect is obtained by means of a gas flow generated by effect of an opening of the total discharge valve 12, thus placing the auxiliary discharge conduit 10 in communication with the source of pressurised gas.
• the pressurised gas generates a flow through the conduit 10 and, in particular, through the venturi device predisposed in the intake zone 11 in order to activate the suction.
• the intake zone 11 is placed in communication with the pressurisable chamber 4 through the discharge valve 8, which is left open for the purpose.
• the operator For using the jack, the operator first positions the jack below the object to be raised, then he activates the lifting operation by pressing the button of the delivery valve 7.
• the compressed air passes through the valve body 14 and is forced into the pressurisable chamber 4; in particular it passes through the inlet mouth 15, the delivery valve 7 housed in the first seating 20, the second conduit 24 and the delivery mouth 17.
• the delivery valve 7 returns into the closed position, stopping the piston 2 from rising while mamtaining the pressure in the chamber 4.
• the operator When the piston 2 is to be lowered, the operator first presses the control button of the discharge valve 8, the chamber 4 is placed in communication with the discharge 9; thus the piston 2 partially descends, facilitated by the downwards action of the weight of the raised object.
• the operator contemporaneously presses the discharge valve 8 and the total discharge valve 12; in this configuration the intake zone 11 is activated and communicates with the chamber 4, a suction action is begun of air from the chamber 4, causing the piston 2 to be completely lowered.
• the control button of the discharge valve 8 is released, the piston 2 stays in the completely lowered position and is ready for the next work cycle. Pressing only the total discharge valve 12 button does not in any way affect the position of the piston 2.
• a further embodiment of the invention could combine the functions of the discharge valve and the total discharge valves, by providing a single two-position four-way valve, with a return spring.
• the four ways are equivalent to the two valves 9 and 12 in the illustrated embodiment, associated two by two and arranged along the discharge conduit and the total discharge conduit.
• a first position is the closure position, a second position a position of opening of the discharge conduit and the auxiliary discharge conduit.
• the button activating the descent of the piston 2 at the same time also activates the venturi effect suction.
• a still further embodiment might include a four-way valve (as in the above- described further embodiment) but with three positions, i.e. a first position in which the discharge conduit and the auxiliary discharge conduit are closed, a second position in wliich only the discharge conduit is open and a third position in which both the discharge conduit and the auxiliary discharge conduit are open.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Structural Engineering (AREA)
• Multiple-Way Valves (AREA)
• Fluid-Pressure Circuits (AREA)
• Fluid-Driven Valves (AREA)
• Transplanting Machines (AREA)
• Hydraulic Clutches, Magnetic Clutches, Fluid Clutches, And Fluid Joints (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=11450768

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Family Cites Families (2)

• 2001
  • 2001-05-04 IT IT2001MO000082A patent/ITMO20010082A1/it unknown
• 2002
  • 2002-03-26 WO PCT/IT2002/000195 patent/WO2002090236A1/en active IP Right Grant
  • 2002-03-26 DE DE60211882T patent/DE60211882D1/de not_active Expired - Lifetime
  • 2002-03-26 AT AT02722683T patent/ATE327962T1/de not_active IP Right Cessation
  • 2002-03-26 EP EP02722683A patent/EP1383702B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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