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
  • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
  • F15B11/028—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force
  • F15B11/036—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the actuating force by means of servomotors having a plurality of working chambers
• • 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
  • F15B2211/30—Directional control
  • F15B2211/305—Directional control characterised by the type of valves
  • F15B2211/30505—Non-return valves, i.e. check 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
  • F15B2211/40—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
  • F15B2211/42—Flow control characterised by the type of actuation
  • F15B2211/421—Flow control characterised by the type of actuation mechanically
  • F15B2211/423—Flow control characterised by the type of actuation mechanically manually, e.g. by using a lever or pedal
• • 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
  • F15B2211/52—Pressure control characterised by the type of actuation
  • F15B2211/521—Pressure control characterised by the type of actuation mechanically
  • F15B2211/523—Pressure control characterised by the type of actuation mechanically manually, e.g. by using a lever or pedal
• • 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
  • F15B2211/52—Pressure control characterised by the type of actuation
  • F15B2211/528—Pressure control characterised by the type of actuation actuated by fluid pressure
• • 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
  • F15B2211/7055—Linear output members having more than two chambers
• • 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
  • F15B2211/76—Control of force or torque of the output member

Definitions

• Improvements to hand tools comprising a hydraulic cylinder for controlling the working members.
• the invention relates to tools in which pressure must be exerted on a working member, mounted movably in a head, by a hydraulic cylinder actuated by a suction and treading pump, at least until present, with manual control.
• such tools are pliers (for bending, cutting, punching, crimping, etc.), the hydraulic cylinder serving to control the movement of one jaw, said to be movable, relative to another, said to be fixed, both mounted in a head.
• the jaw head being interchangeable and fixed at the end of the jack through which the piston rod of said jack emerges, so as to allow the type and size of the jaws to be adapted. at work to be done.
• a given head can receive jaws of various shapes and sizes.
• the invention relates to a certain number of improvements to the tools of the aforementioned kind relating to the structure of the jack, the arrangement and the structure of the operating handle, the fixing of the head. working organ holder on the end of the jack.
• the invention provides, for the jack, a stage piston allowing a relatively large advancement amplitude per stroke, then decreasing in successive stages, each decrease corresponding, on the other hand, to an increase in the total thrust for the same force exerted on the lever of the pump.
• stage piston cylinders are known in themselves, they are differential cylinders (see for example FR-A-2242584), which make it possible to obtain a motive force varying with the stroke, when admitting a high pressure fluid.
• the force applied to the workpieces is a function of the effort provided by the operator and can only vary with this effort when the values of d and D defined above have been chosen. .
• the subject of the invention is a tool comprising at least one mobile working member, the relative displacement of which relative to at least one so-called fixed working member is linked to that of the piston of a single-acting hydraulic cylinder which is actuated by a suction and treading pump, remarkable in that said piston is a stage piston which fits into the cylinder body so as to delimit, in addition to the axial main chamber, at least one annular chamber, the annular chamber or chambers being successively placed in communication with the axial chamber during the advancement of the piston.
• the amplitude of advance per stroke of the pump as a function of the stroke of the piston of the jack, effectively varies in successive stages and, for this, to eliminate or at least to reduce as far as possible the interstitial leaks between the successive chambers, contrary to what happens in known differential stage piston cylinders where the softening of the variations is always admissible and sometimes sought (see FR-A-2242584 cited above).
• each step segment of the piston has at least one peripheral zone which remains in guide contact with an internal surface of the cylinder body, that in this zone at least one seal ensures the sealing between the upstream and downstream chambers and that the pressure supply to each annular chamber is ensured by a radial pipe which opens at one end into the discharge pipe of the pump and the other end is uncovered by the piston when the advancement of the latter reaches a predetermined value, while each chamber communicates with the fluid reservoir by a valve duct which discharges the chamber considered by manual control of the valve and, for the bedrooms annular, at the start, the filling of the chamber considered by depression_
• the arrangement in steps of the piston of the jack may interest the external lateral surface of said piston cooperating with combined shoulders of the internal lateral surface of the body of the jack. It can also be provided on the internal surface of an axial digging of the piston capping a core traversed longitudinally by the delivery pipe of the pump and having conjugated shoulders.
• the adoption for the cylinder of a stage piston makes it possible, as has been said, to significantly reduce the force to be exerted on the pump without thereby decreasing either the final pressure exerted by the cylinder, or the speed of advancement of the piston at start-up. It is then possible to provide for actuation of the pump by a cam driven by a light electric motor, of sufficiently low power to be powered by rechargeable batteries or built-in rechargeable batteries.
• the invention also relates to a structure and a specific position of the handle.
• the latter has two arms subjected to the action of an elastic means tending to separate them from each other in the manner of those of a shears, l r a being rigidly fixed to the cylinder body and having a U-shaped cross-section into which the movable branch fits, at least partially, so as to increase the travel of the latter as much as possible, without increasing the maximum spacing of the ends of the two branches, while the bisector of the angle formed by said branches in position • maximum spacing is substantially perpendicular to the longitudinal axis of the jack.
• a safety valve limiting the pressure at the end of the stroke, the sudden return of which produces a click constituting an audible signal and which, being able to be controlled manually, simultaneously plays the role of relief valve of the axial main chamber. It is therefore advantageous to provide a single lever for controlling the discharge valves of the different chambers.
• FIG. 1 is a side view of a tool according to the invention, here a crimping tool
• - Figure 2 is a longitudinal section on a larger scale of a two-stage cylinder fitted to the tool of Figure 1,
• FIG. 3 is a simplified section of a cylinder with three forward speeds according to another embodiment, in which the engagement of the piston in the body is respectively male and female.
• a tool according to the invention comprises a hydraulic cylinder having a body 1 in which slides, in the direction of the arrow F., a piston 2 under the action of the thrust of a fluid coming from a reservoir 3, while the return of the piston, when the hydraulic thrust ceases, is ensured by the action of a helical spring 4 working under compression.
• the fluid is extracted from the reservoir 3 and sent to the piston, in a discharge line 5 by a suction and treading pump, the piston 7 of which is actuated by means of an oscillating arm 8 operated manually.
• the passage and the retention of the fluid during the suction, then the delivery are ensured by two non-return valves 9a and 9b opposite.
• the arm 8 is maneuverable with one hand and for this purpose it is associated to a fixed arm 6 (FIG. 1) from which it departs under the action of an elastic means (not shown) for controlling the suction and which it approaches by manual action to ensure delivery under pressure, the two arms, fixed and oscillating, being grasped in the operator's hand in the manner of the two handles of a pruning shears.
• the piston 2 has at its internal end, an axial hollow 10 delimiting a tail or skirt 11 connected, on the opposite side, to the head of the piston by a shoulder 12 forming one of the bearing surfaces of the spring 4.
• the interior of the cylinder 1 is machined so as to have a conjugate housing of the particular shape of the piston with a chamber central 13 bounded by the bottom of the widening 10 and an annular chamber 14 delimited by the end face of the shank 11 of piston.
• the central chamber 13 is supplied by the delivery pipe 5 which opens directly into said chamber.
• the annular chamber 14 first filled by vacuum as will be said below, is then supplied by a radial pipe 16 starting from the discharge pipe 5 and whose orifice in the chamber 14 remains closed during the first part of the piston stroke.
• a number of O-rings and rings seal the moving parts and isolate the chambers 13 and 14 from each other until the orifice of the pipe 16 is not discovered.
• a discharge valve 17 retained on its seat by a calibrated spring 18 is interposed on a pipe 15 putting the discharge pipe 5 into communication with the reservoir 3.
• the valve 17 is lifted from its seat to free the passage of the fluid, either automatically when the hydraulic pressure exceeds the setting of the spring 18, then playing the role of safety to avoid deterioration of the cylinder, either under the action of a lever 20 operated manually (arrow F_) to obtain the retraction of the piston during work from the end of work.
• a pusher 19 allows the erasure of a ball valve 21 interposed between the two parts 22 and 22. of a pipe connecting the ab chamber 14 and the reservoir 3.
• the pusher 19 is controlled manually, at the same time as the valve 17 by the lever 20.
• Figure 2 is conventional.
• the longitudinal axis of the valve 17 and of the pipe 15 is not in the same diametral plane as the axis of the pusher 19, the middle part 22 Q (indicated in the figure in broken lines) of the pipe 22 , 22 not cutting the housing of the valve 17.
• valve 17 and the pusher 19 are angularly offset in a transverse plane relative to the axis of the jack, the lever 20 extending itself transversely relative to this axis and having an end 20 folded down 90 degrees (Figure 1) to be operated by the thumb of the operator.
• Each stroke of the pump brings into the chamber 13 a volume of fluid determined by the diameter and the stroke of the piston 7 of the pump, for example T70 mm.
• a volume of fluid determined by the diameter and the stroke of the piston 7 of the pump, for example T70 mm.
• the chamber 13 is active and if the bottom of the digging 10 is, for example, 283
• each stroke of the pump will advance the piston by 0.6 mm.
• the volume of liquid supplied at each stroke of the pump is distributed between the chambers 13 and 14, that is to say over a larger total surface, for example 2 1/2 times the first and the advancement per stroke will only be 0.24 mm, but at the same time the same manual effort will exert a pressure 2 1/2 times stronger. It is thus possible to reach forces of the order of 25,000 N and this with a relatively low number of strokes, for example twenty, as long as the total advancement remains low (between 5 and 7 mm approximately) which is the case for crimping pliers or others.
• the internal pressure continues to increase until the valve 17 is raised against the spring 18, before suddenly falling back onto its seat, making a clicking noise which constitutes an audible signal indicating that it is necessary to recall the piston by actuating the lever 20.
• the end of the cylinder 1 corresponding to the outlet of the piston 2 can be provided with an external thread 23 intended to receive by screwing a fixing ring 25 for a head 28 of interchangeable tool.
• This arrangement makes it possible first of all to have a single jack for tools of the same type but of different sizes and also for tools of different types, for example crimping, punching, cutting, bending pliers, etc.
• by screwing or unscrewing the ring 25 it is possible to adjust the initial position of the mobile working member 26 and consequently the initial spacing of the working members 26 and
• the reservoir 3 is semi-rigid, that is to say retractable and expandable so as to follow the variations in volume of the liquid remaining in reserve without risk of entry of air. For this it is simply engaged elastically on a ring-shaped appendage 24 of the cylinder 1 on which it is held by an elastic ring cooperating with a circular groove. It is clear that there can be several annular chambers such as 14 each corresponding, at the time of their communication with the discharge line 5, to an increase in the total pressure exerted by the mobile tool and to a decrease in forward speed.
• the tiered arrangement of the piston of the jack can also be achieved by fitting the piston into the body with shoulders from the external lateral surface of the piston and combined shoulders from the internal lateral surface of the body of the jack.
• Such an embodiment with two annular chambers (three forward speeds) is shown very schematically in Figure 3.
• each annular chamber communicates with the housing of the valve 21 by a pipe 22. of filling by depression and discharge.
• the delivery pipe 5 is extended by an uncorked bore 5 axially formed in the piston 102 to supply the pipes 116 and 116.
• the handles 6 and 8 respectively fixed and movable, have an insulating coating provided with fingerprints and guards 6, 8.
• the plane B perpendicular to the longitudinal axis of the jack and passing through the axis of articulation of the movable handle 8, is close to the bisector plane of handles 6 and 8 in position of maximum separation.
• the fixed handle 6 has a section in U and the movable handle 8 is embedded at least partially in this U.
• the stepped position of the piston makes it possible to reduce in large proportions the engine force to be exerted on the piston 7 of the pump. It is then possible to actuate this piston by a cam or a connecting rod driven by a light electric motor of sufficiently low power to be powered by accumulators or rechargeable batteries incorporated, for example, in the then fixed handle of the tool.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Actuator (AREA)
• Fluid-Pressure Circuits (AREA)
• Shearing Machines (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9303389

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (23)

Family Cites Families (18)

• 1984
  • 1984-04-20 FR FR8406346A patent/FR2563291A1/fr active Pending
• 1985
  • 1985-04-19 EP EP85902052A patent/EP0179112B1/de not_active Expired
  • 1985-04-19 US US07/119,247 patent/US4823588A/en not_active Expired - Lifetime
  • 1985-04-19 JP JP60501847A patent/JPS61502246A/ja active Pending
  • 1985-04-19 DE DE8585902052T patent/DE3569219D1/de not_active Expired
  • 1985-04-19 WO PCT/FR1985/000091 patent/WO1985004831A1/fr active IP Right Grant

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events