US3576151A - Piston lock for power cylinders - Google Patents

Piston lock for power cylinders Download PDF

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Publication number
US3576151A
US3576151A US806194A US3576151DA US3576151A US 3576151 A US3576151 A US 3576151A US 806194 A US806194 A US 806194A US 3576151D A US3576151D A US 3576151DA US 3576151 A US3576151 A US 3576151A
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Prior art keywords
piston
cylinder
locking
actuator
ring
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US806194A
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English (en)
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Jack J Sendoykas
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    • 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
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/26—Locking mechanisms
    • F15B15/261—Locking mechanisms using positive interengagement, e.g. balls and grooves, for locking in the end positions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q5/00—Driving or feeding mechanisms; Control arrangements therefor
    • B23Q5/54—Arrangements or details not restricted to group B23Q5/02 or group B23Q5/22 respectively, e.g. control handles
    • B23Q5/58—Safety devices

Definitions

  • the power cylinder of this invention be operated either by hydraulic pressure or by pneumatic pressure, and the need to hold the piston securely in either the fully advanced or fully retracted position exists in either mode of operation.
  • the need for a piston holding and locking means is particularly present in the case of a pneumatically operated cylinder.
  • Air-operated power cylinders and the auxiliary equipment which supplies air under pressure to the cylinder are much less expensive to install and maintain than their hydraulically operated counterparts.
  • pneumatically operable and hydraulically operable power cylinders are not necessarily interchangeable.
  • the present invention pennits either a pneumatically or an hydraulically operated cylinder to be used in the above situation to advance the slide and to lock and hold the piston mechanism in the fully advanced position during the feed stroke of the cutting tool and the piston holding and locking means holds the piston positively and solidly under these conditions to prevent any vibrating or chattering of the tool due to yielding or bouncing of the piston in the power cylinder as the tool moves forward on its feed stroke.
  • the piston holding and locking feature of this invention permits the use of either type of power actuator but more particularly, it permits the use of the less expensive air-operated power actuator in the above situation without the disadvantages described which necessarily obtain and normally attend this type of actuator.
  • any condition or circumstance that results in a loss or significant reduction of pressure in the power cylinderas for example, a leak or a loss of pressure in the line which supplies fluid to the power cylinder-causes a corresponding reduction in the holding force exerted by the cylinder against the workpiece; and this, of course, pennits the work to fly out of the machine with attendant danger to personnel and damage to the machine.
  • the positive piston holding and locking means of this invention pennits either an hydraulically operated power cylinder or a considerably less expensive airoperated power cylinder to be used to operate a work-holding clamp in a fixture of the type described above; and the piston locking and holding feature assures that full clamping pressure is maintained at all times regardless of minor variations in the size of different workpieces and regardless of whether a loss of pressure in the fluid supply line or other contingency occurs which otherwise would result also in a loss of pressure in the power cylinder and a loss of holding force against the work.
  • the piston of the power cylinder is provided with headed pins or studs which extend axially therefrom in at least one direction and the cylinder is provided at least at one end thereof with a power-operated part which is movable into and out of locking engagement with the pins. It is contemplated that the interlocking part be normally positioned to permit free travel of the piston in the cylinder and that it be movable to interfit with the pins when the piston approaches or reaches the: limit of its travel. If
  • actuation of the locking part can be controlled by suitable automatic means so that the piston is locked immediately after it reaches the limit of its travel and until the occurrence of some subsequent event causes the reverse actuation of the locking means to release the piston.
  • the locking means and the pistonlocking pins are uniquely constructed and mutually cooperable to exert a continuing positive force on the piston in the direction of its travel toward the locking means so that the piston is capable of exerting a considerably greater force on the part attached thereto and operated thereby than otherwise would be the case and of assuring a positive and continuing lock on the piston even though a loss of pressure should occur in the system which supplies fluid to the cylinder.
  • FIG. I is a side view showing parts in section and parts in elevation of a power cylinder embodying the invention and illustrating the piston in the fully retracted position and the locking and holding mechanism released from the piston;
  • FIG. 2 is a transverse sectional view taken on the line 2-2 of FIG. 1;
  • FIG. 3 is a view similar to FIG. 1 but showing the piston in the fully advanced position and the locking and holding mechanism engaged with the piston;
  • FIG. 4 is a transverse sectional view taken on the line 4-4 of FIG. 3;
  • FIG. 5 is a fragmentary, longitudinal sectional view taken on the line 5-5 of FIG. 3;
  • FIGS. 6, 7 and 8 are fragmentary sectional views showing progressive positions of the piston locking and holding member and illustrating how the latter functions to hold the piston locked and under full pressure in different axial positions in the cylinder;
  • FIG. 9 is a side elevational view showing a power cylinder embodying this invention incorporated as part of a workholding clamp and illustrating the clamp in a work-holding position;
  • FIG. 10 is a view similar to FIG. 9 but showing the clamp in a work-releasing position.
  • FIG. 11 is a side view showing parts in section and parts in elevation of a power cylinder embodying the invention and illustrating the same as part of a machine tool for advancing and retracting a slide which carries a tool head.
  • the power cylinder 18 of this invention comprises a tubular body 20 one end of which is closed by a header 22 and the other end of which is closed by a header 24 and an intermediate mounting ring 26.
  • the header 22 is generally square and relatively thick and is formed with a peripheral, axially inwardly extending annular flange 28 which surrounds and snugly fits the end portion 30 of the body 20.
  • An O-ring 32 disposed within an inner annular recess 34 in the flange 30 seals the joint between the body and the header 22.
  • the ring 26 surrounds and snugly fits the other end portion 36 of the housing 28 and it has a radially inwardly extending flange 38 at the outer end thereof that overlays and butts against the end face of the housing. At the opposite or inner end of the ring 26 is a radially outwardly extending flange 40 that seats the header 24 and positions the latter axially on the body 20.
  • An O-ring 42 disposed within an inner annular recess 44 provided in the ring 26 seals the joint between the ring and the housing 20.
  • the header 24 preferably is of the same or substantially the same shape as the header 22 and it also is essentially thick.
  • An axially extending annular flange 46 on the header 24 surrounds and snugly fits the ring 26 and butts endwise against the flange 40 as hereinabove described.
  • An O-ring 50 disposed in an inner annular recess 52 in the header flange 46 hugs the periphery of the ring 26 and seals the joint between the header flange and the ring.
  • Tie bars 54 (FIG. 9) connect the headers 22 and 24 exteriorly of the housing 20 to hold the parts hereinabove described securely together and to provide and assure a fluidtight cylinder unit 56.
  • a piston 58 having a piston rod 60 which extends through a central opening 62 in the header 24, and the projecting end of the piston rod is formed with a threaded extension 64 which adapts the rod for attachment to a part to be actuated by the piston.
  • An O-ring 66 mounted in an annular recess 68 provided in the header 24 around the opening 62 bears on the piston rod 60 to seal the joint between the rod and the header, and a second seal 70 mounted in an annular recess 72 provided in the outer face of the header 24 around the opening 62 also bears on the rod 60 to prevent dirt and other foreign matter from being drawn into the cylinder 56 by reciprocation of the piston rod 60.
  • the piston 58 is equipped with the usual ring 74, here shown in the fonn of an O-ring, which is mounted in a recess 76 provided in the periphery of the piston for sealing the joint between the piston and the cylinder wall 20 so that fluid introduced into the cylinder 56 at one side or the other of the piston causes the latter to advance or retract in the cylinder.
  • the piston rod 60 may be connected to the piston 58 in any suitable or conventional manner but, in the particular form of the invention here shown by way of illustration, the piston is provided with a central opening 78 having a counterbore 80 in the rod or inner side of the piston and a counterbore 82 at the opposite or outer side of the piston.
  • the end of the rod 60 has a portion 84 of reduced diameter which extends into and snugly fits the counterbore 80 and a portion 86 of the still smaller diameter which extends into and snugly fits the central opening 78.
  • a threaded stud portion 88 on and extending from the rod portion 86 carries a nut 90 which fits within and is entirely received by the outer counterbore 82. As shown in FIG.
  • the rod portion 84 seats on the bottom of the counterbore 80 and when the nut 90 is tightened on the threaded stud 88, the portion of the piston 58 between the two counterbores 80 and 82 is clamped solidly between the rod portion 84 and the nut 90 to hold the piston rod 60 attached securely to the piston.
  • a collar 92 of a relatively soft metal such as brass or the like is provided around the rod portion 84 and confined between the inner face of the piston 58 and a radial shoulder 94 provided at the juncture of the rod portion 84 and the main body of the piston rod 60.
  • Fluid under pressure is introduced into the cylinder 56 behind the piston 58 through a passage 96 in the header 22, and fluid under pressure is introduced into the cylinder in front of the piston through a passage 98 in the header 24.
  • the power cylinder 18 of this invention be operated either hydraulically or pneumatically, and it is contemplated also that either liquid or air under pressure be supplied to the passages 96 and 98 from any suitable conventional source of fluid pressure (not shown).
  • the outer ends of the passages 96 and 98 preferably are threaded to receive fluid supply pipes (not shown) in the usual manner.
  • the fluid supply means include a conventional valve means (not shown) which is operable to direct fluid under pressure either to the passage 96 or to the passage 98 while simultaneously venting the passage not so connected to a sump or the like (not shown).
  • a conventional valve means (not shown) which is operable to direct fluid under pressure either to the passage 96 or to the passage 98 while simultaneously venting the passage not so connected to a sump or the like (not shown).
  • a primary feature of this invention is the provision of means for holding and mechanically locking the piston 58 at one or both ends of its travel in the cylinder 56.
  • the holding means comprises headed pins on the piston and a locking ring on one of the headers which is operable to engage or release the pins when the piston is at the end of its travel.
  • a holding and locking means of the type described is shown for holding the piston 58 in the fully advanced position only.
  • a locking ring and operating means therefor is mounted in and associated with the header 24 and the piston 58 is provided with forwardly extending pins which interlock with the ring to hold the piston fully advanced
  • a locking ring canbe mounted similarly in the header 22 and that the piston can be provided with pins which extend rearwardly rather than for wardly for engagement with the ring to hold the piston in the fully retracted position.
  • locking rings and operating means therefor can be provided in both of the headers 22 and 24 and the piston can be provided with two sets of pins which extend both forwardly and rearwardly.
  • one set of pins engages and cooperates with a locking ring in the header 22 to maintain the piston fully retracted and the other set of pins engages and cooperates with a locking ring in the header 24 to maintain the piston fully advanced. Since the holding and locking means is identical in both instances and since the lock ring and the pins coact in the same manner to hold the piston 58 at the end of its travel, a detailed description of but one of these arrangements will suffice.
  • the holding and lockingmechanism is here shown in the header 24, and it comprises a locking ring 100 which is mounted in a central recess 102 provided in the inner face of the header 24.
  • the locking ring 100 fits the recess 102 peripherally relatively snugly but with sufficient clearance to permit free rotational movement or oscillation thereof; and the peripheral portion of the ring 100 is confined between the bottom of the recess 102 and the inner flange 38 of the mounting ring 26, so as to prevent significant axial movement of the ring.
  • Rotational movement is imparted to the locking ring 100 by a piston or plunger 104 which is mounted in a bore or cylinder 106 provided in the header 24 outwardly of the ring 100. As shown in FIG.
  • the bore which forms the cylinder 106 extends transversely entirely through the header 24; and the ends thereof are closed by plates 108 and 110 which are fastened to the header by screws 112 and 114, respectively.
  • Fluid from any suitable source is admitted to one end or the other of the cylinder 106 through pipes 116 and 118 having connecting nipples 120 and 122 screwed into holes 124 and 126 in the plates 108 and 110, respectively.
  • the plunger 104 is here shown in the form of a relatively elongate rodlike or cylindrical member and the opposite ends thereof are sealed against the cylinder 106 by suitable rings such as the O-rings 128.
  • a generally square or rectangular slide 130 mounted on a pivot 132 carried by and extending forwardly from the locking ring 100 is snugly but slidably received in a transverse slot 134 in the plunger 104.
  • the plunger 104 has limited reeiprocable travel in the cylinder 106 and as it travels it acts through the slide 130 pivot 132 to rotatably actuate the locking ring 100.
  • movement of the pivot 132 transversely of the piston is accommodated by movement of the slide in the slot 134.
  • the limited travel of the plunger 104 results in a correspondingly limited rotational movement of the locking ring 100 so that full movement of the plunger 104 back and forth in the cylinder 106 produces an oscillatory movement of the locking ring 100.
  • the piston 58 is provided with a plurality (here shown as 3) of equispaced, axially forwardly extending headed pins 136, 138 and 140 which are adapted to be received in correspondingly spaced and positioned arcuate keyhole slots 142, 144, 146 respectively.
  • a plurality here shown as 3
  • the large diameter portion 148 of each keyhole slot 142, 144, 146 extends entirely through the locking ring 100 and the relatively narrow portion 150 of each keyhole slot has a countersink 152 in the outer face of the locking ring 100 which extends from and is of substantially the same width as the large diameter portion 148.
  • the plunger 104 When the plunger 104 is at one end of its movement in the cylinder 106, it positions the locking ring 100 with the large diameter portions 148 of the keyhole slots 142, 144, 146 in position to receive the headed pins 136, 138, 140 respectively.
  • the headed pins 136, 138, 140 are received in the large diameter portions 148 with the enlarged head portions of the pins aligned laterally with the countersinks 152.
  • the locking ring 100 is rotated or oscillated to move the relatively narrow portions of the keyhole slots 142, 144, 146 along the shank portions of the headed pins 136, 138, 140.
  • the enlarged head portions of the pins 136, 138, 140 are accommodated in the countersinks 152; and, as the head portions of the pins move into the countersinks 152, they extend laterally of the narrow portions of the keyhole slots to lock the piston 58 to the ring 100 and to provide positive interlocking of the pins with the ring which prevents retraction of the piston 58 in the cylinder 56.
  • the piston 58 is held positively in the advanced position until the plunger 104 is returned to its initial position to rotatably actuate or oscillate the locking ring 100 in a reverse direction to bring the large diameter portions 148 of the keyhole slots 142, 144, 146 into registration with the heads of the pins 136, 138, 140.
  • the bottom surfaces 154 of the countersinks 152 are beveled or inclined from the large diameter ends 148 of the keyhole slots 142, 144, 146 toward the outer side 156 of the locking ring 100.
  • the countersinks 152 become increasingly shallower in a direction away from the large diameter portions of the keyhole slots 142, 144, 146.
  • the undersides 158 of the head portions of the pins 136, 138, 140 are tapered or beveled, as shown in the drawings, so that the head portions are of reduced thickness toward the peripheries thereof.
  • the taper angles of both the countersinks 152 and the under surfaces of the pin head portions is relatively flat; but it is particularly desirable that the bottom surfaces 154 of the countersinks 152 provide a locking angle which will prevent fluid pressure in the cylinder 56 ahead of the piston 58 from acting through the pins 136, 138, 140 to rotate the locking ring 100 independently of the plunger 104.
  • An angle of approximately 7 between the beveled surfaces 154 and a plane at right angles to the axis of the ring 100 is suitable for this purpose.
  • the primary reason for beveling the undersurfaces of the head portions of the pins 136, 138, 140 is to increase the area of contact between the head portions and the beveled seating surfaces 154.
  • the head portions of the pins seat on the keyhole countersinks 152 some place along the length of the latter which then acts as a thread or helix so that continued pressure on the plunger 104 tending to rotate the locking ring farther simply wedges the bottom surfaces 154 of the countersinks more tightly against the head portions of the pins and this wedging action tends to hold the piston 58 in the cylinder 56 all the more securely.
  • one of the pins 136, 138, 140 (here shown as the pin 140) is made relatively longer than the others to aid in orienting or positioning the parts properly at assembly.
  • the head portions of the pins 136 and 138 are entirely accommodate in the countersinks 152 of the keyhole slots 142 and 144 with which they are associated in all rotative positions of the locking ring 100, as shown in FIGS. 6, 7 and 8, whereas the head portion of the pin 140 is relatively considerably longer and extends beyond the countersink 152 of the keyhole slot 146 and into a hole or socket in the header 24 which preferably is provided with a bushing 162 or hardened steel or the like.
  • the socket 160 is here shown to be a part of the fluid passage 98 and the head of the pin 140 is formed with peripheral flats 164 which provide free flow of fluid from the passage 98 to the keyhole slot 146 and thence to the cylinder 56 ahead of the piston 58.
  • the socket 160 receives the projecting end portion of the pin 140 and thus rotatably positions the piston 58 in the cylinder 56 at assembly and assures a proper rotative position of the piston and of the locking ring 100 with respect to the plunger 104 so that the latter is automatically positioned at assembly properly to turn the locking ring so as to engage and release the piston through the pins 136, 138, 140 as the plunger 104 moves back and forth in the cylinder 1.06.
  • the relatively long pin 140 serves to take any rotational tendency out of the piston due to the wedging action of the locking ring 100 thus eliminating deflection in a long piston rod.
  • FIGS. 9 and 10 show a typical environmental situation in which a power cylinder 18 equipped with the piston-locking feature of this invention has particular utility.
  • FIGS. of the drawings show the power cylinder 18 of this invention operatively associated with a form of work clamp having a U-shaped body 166.
  • the clamp body 166 is fixed to a suitable supporting surface 168 such as the bed of a machine tool, for example, and a clamping bar 170 is mounted on a pivot 172 extending between and carried by the upstanding sides of the body 166.
  • the clamping bar 170 has a T-shaped head portion which is arranged generally vertically between the sides of the body 166 and the lower arm of the head portion is joumaled on the pivot 172.
  • the power cylinder of this invention also is mounted between the upstanding sides of the body 16 behind the clamping am 170 with the front header 24 attached to the upstanding sides of the body by pivots or trunnions 174.
  • the piston rod 160 extends in the direction of the clamping arm 170 and a clevis 176 on. the threaded end 64 of the rod is pivoted at 178 to the upstanding arm portion of the clamping arm head portion.
  • a workclamping member 180 adjustably fastened to the forward end of the work-clamping arm 170 by a threaded shank 182 and held in a selected adjusted position by lock nuts 184 and 186 is adapted to clamp a workpiece 188 against the surface 168.
  • the power cylinder is free to rock on the trunnions 174; and,
  • the piston-locking feature of this invention offers a solution to both of these problems. It holds and locks the piston 58 in the fully advanced position; and, as the locking ring 100 engages the piston-carried pins 136, 138, 140, it exerts a wedging force in a direction to advance the piston in the cylinder 56 and thus augments the force exerted by the fluid pressure in the cylinder behind the piston.
  • the compounded forces exerted both by the piston-locking ring 100 and the fluid pressure in the cylinder 56 is utilized in clamping the workpiece 188.
  • the piston-locking ring 100 holds the work clamping member 180 against the work 188 with full clamping force even though a loss of pressure should occur in the fluid line which supplies the power cylinder 18. This full clamping pressure will be maintained notwithstanding the loss of fluid pressure in the supply line until the piston-locking ring 100 is disengaged and the piston is retracted in the power cylinder.
  • the need for toggle arms or other form of pressure applying and holding means on the clamping fixture is eliminated.
  • the surfaces 154 wedge relatively quickly against the headed pins 136, 138, 140, as shown in FIG. 6.
  • the wedge surfaces 154 wedge against the headed pins 136, 138, about midway, as shown in FIG. 7.
  • the wedge surfaces 154 do not wedge against the headed pins 136, I38, 140 until the locking ring 100 has made a complete or substantially complete oscillatory movement, as shown in FIG. 8.
  • the wedge surfaces 154 have a length of at least 1 inch although this dimension, of course, can be varied depending on the existencies of the particular situation.
  • a typical workclamping fixture having relatively dimensional parts as shown and having relatively long wedge surfaces 154 inclined at angles of approximately 7"
  • an adjustment of approximately oneeighth inch is provided at the clamping end of the arm 170.
  • the same wedging force will be exerted by the surfaces 154 against the headed pins 136, 138, 140 in all positions of the locking ring 100 in which the wedge surface exerts a wedging action against the heads of the pins.
  • fluid at 50 pounds line pressure in the cylinder 106 exerts sufficient force against the plunger 104 so that, acting through the wedge surface 154, an additional force of approximately 400 pounds is exerted on the piston 58 tending to advance the latter.
  • FIG. 11 shows by way of example another typical environmental situation in which a power cylinder 18 is equipped with the piston lock feature of this invention can be used to advantage.
  • This view shows a typical tool head of a machine tool wherein a slide 190 is mounted for reciprocation on a base 192 and in the present instance is actuated by the power cylinder 18.
  • Mounted on the slide 190 is a tool head 196 having a rotatable and reciprocable spindle 198 which carries a drill 200.
  • the spindle 198 is rotatably driven by a motor 202 through the endless belt 204, and a power cylinder 206 is operatively connected to the spindle 198 to advance and retract the same relative to a workpiece 208.
  • suitable means nonnally is provided to detachably clamp the workpiece 208 on the base 192 or other suitable support so that it is held solidly when the spindle 198 is advanced to move the tool 200 into the work as shown in the drawing.
  • the slide 190 has a forwardly extending part 210 that carries a guide bushing 212 which is positioned closely adjacent to the work 208 during the drilling operation and which steadies and guides the drill in its feed stroke.
  • the slide 190 normally is retracted to permit the workpiece 208 to be mounted in the machine.
  • the slide 190 is advanced by the power cylinder 18 of this invention until it engages a fixed stop 214 to position the guide bushing 212 is proximity to the workpiece 208. This positioning of the bushing 212 reduces the amount of overhanging of the drill as it moves from the guide bushing into the work.
  • the motor 202 is energized as soon as the slide 190 engages the fixed stop 214; and the power cylinder 206 operates to advance the spindle 198 and to feed the tool 200 in to the work 208.
  • said locking mechanism comprises a powered actuator movable into and out of position behind said shoulder, at least one of said shoulder and said actuator having a beveled surface and said actuator being operative through said beveled surface to lock said piston in the held position and to exert said axial pressure against said piston.
  • said powered actuator comprises a rotatably movable ring mounted in the mentioned end of the cylinder and a fluid motor including a plunger operatively connected to said ring to oscillate the same, said ring having a plurality of keyhole slots disposed to receive said headed pins in one oscillatory position of said ring and to engage behind the headed portions of said pins in another oscillatory position of said ring, at least one of said pins and said keyhole slots having beveled surfaces operable by oscillating movement of said ring to exert axial pressure on said piston through said pins.
  • a locking mechanism for holding said piston under mechanical pressure in at least one of said limit positions against a load upon release of pressure on said fluid medium
  • said locking mechanism comprising a locking element operably associated with said piston and movable therewith. and a locking member independent of said piston and said locking element movable between nonlocking and locking positions, said locking member in nonlocking position being disengaged and released from said piston and said locking element so as to permit the piston to reciprocate in said cylinder and said locking member in locking position being in locking engagement with said locking element to hold said piston under mechanical pressure, said locking element and said locking member being movable relative to each other without interference during movement of said piston to said one limit position, and means operably associated with sad locking member for moving the latter into said locking relationship and engagement with said locking element when the latter and said piston are in said one limit position, whereby said locking member exerts a resistance to reciprocating movement of said piston from said one limit position at least equal to the load on said piston upon release of pressure on said fluid medium, said means being operable to release said locking member from said locking element
  • actuator means operably associated with said retaining means for moving the latter into said wedging relation ship, whereby said retaining means exerts a force on said locking means which creates a resistance to return reciprocatory movement of the piston at least equal to any load on the piston, said actuator means being operable to release said retaining :means from said locking means to permit return travel of the piston.
  • a powered actuator swingable relative to said locking element into a wedging locking position with said locking element, at least one of said locking element and said actuator having a beveled surface, said locking element and said actuator being movable relative to each other without interference during reciprocatory movement of said piston to said limit position, said actuator being movable into said wedging relationship with said locking element and operable through said beveled surface to lock said piston in the limit position, said actuator adapted to exert an axial force on said locking element which resists return movement of said piston from said limit position, said force being at least equal to any load that may occur on the piston upon release of pressure on said fluid medium, said actuator being releasable from said locking element to permit said return movement of said piston.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
  • Jigs For Machine Tools (AREA)
US806194A 1969-03-11 1969-03-11 Piston lock for power cylinders Expired - Lifetime US3576151A (en)

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US80619469A 1969-03-11 1969-03-11

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Cited By (15)

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US4484510A (en) * 1982-09-01 1984-11-27 Hirzel Paul M Fluid motor having lockable helically displaceable output shaft
US5020418A (en) * 1989-08-02 1991-06-04 Sendoykas Jack J Piston lock for power cylinders
US5081910A (en) * 1990-04-10 1992-01-21 Ascenzo Jr Frank D Locking linear actuator
US5163351A (en) * 1991-07-30 1992-11-17 John Dominka Hydraulic lock cylinder
US5216942A (en) * 1992-03-06 1993-06-08 Sendoykas Jack J Piston lock for power cylinders
US5460358A (en) * 1993-11-29 1995-10-24 Sendoykas; Jack J. Power clamp
EP0747602A2 (de) * 1992-01-23 1996-12-11 Smc Corporation Kolbenstangenlose Zylindereinheit mit Bremse
US6004092A (en) * 1998-02-06 1999-12-21 The Heil Co. Swinging arm loading refuse collection vehicle arm restraint
FR2781016A1 (fr) * 1998-07-08 2000-01-14 Aro Verin a precourse d'approche et course de travail, pour la manoeuvre d'un outil
US6071096A (en) * 1997-04-25 2000-06-06 Grasl; Andreas Pneumatic cylinder, in particular for actuating fume extraction valves in fume and heat extraction plants
US20040007127A1 (en) * 2002-07-15 2004-01-15 Colby Douglas D. Cylinder lock
US7918149B1 (en) * 2008-02-27 2011-04-05 Millo Bertini Machine slide tool assembly and a drive mechanism therefor
CN102011764A (zh) * 2010-06-05 2011-04-13 常州液压成套设备厂有限公司 液压油缸锁定装置
US20150097054A1 (en) * 2012-05-10 2015-04-09 Graco Minnesota Inc. Electro-hydraulic actuated spray guns
US11988232B2 (en) * 2017-09-19 2024-05-21 L3Harris Release & Integrated Solutions, Ltd. Actuator rotational alignment device

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Cited By (21)

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Publication number Priority date Publication date Assignee Title
US4484510A (en) * 1982-09-01 1984-11-27 Hirzel Paul M Fluid motor having lockable helically displaceable output shaft
US5020418A (en) * 1989-08-02 1991-06-04 Sendoykas Jack J Piston lock for power cylinders
US5081910A (en) * 1990-04-10 1992-01-21 Ascenzo Jr Frank D Locking linear actuator
US5163351A (en) * 1991-07-30 1992-11-17 John Dominka Hydraulic lock cylinder
EP0747602A2 (de) * 1992-01-23 1996-12-11 Smc Corporation Kolbenstangenlose Zylindereinheit mit Bremse
EP0747602A3 (de) * 1992-01-23 1998-02-25 Smc Corporation Kolbenstangenlose Zylindereinheit mit Bremse
US5216942A (en) * 1992-03-06 1993-06-08 Sendoykas Jack J Piston lock for power cylinders
US5460358A (en) * 1993-11-29 1995-10-24 Sendoykas; Jack J. Power clamp
US6071096A (en) * 1997-04-25 2000-06-06 Grasl; Andreas Pneumatic cylinder, in particular for actuating fume extraction valves in fume and heat extraction plants
US6004092A (en) * 1998-02-06 1999-12-21 The Heil Co. Swinging arm loading refuse collection vehicle arm restraint
WO2000003145A1 (fr) * 1998-07-08 2000-01-20 Aro Verin a precourse d'approche et course de travail, pour la manoeuvre d'un outil
FR2781016A1 (fr) * 1998-07-08 2000-01-14 Aro Verin a precourse d'approche et course de travail, pour la manoeuvre d'un outil
US6474215B1 (en) 1998-07-08 2002-11-05 Aro Actuator with approach pre-stroke and working stroke for operating a tool
US20040007127A1 (en) * 2002-07-15 2004-01-15 Colby Douglas D. Cylinder lock
US6832539B2 (en) * 2002-07-15 2004-12-21 Delaware Capital Formation, Inc. Cylinder lock
US7918149B1 (en) * 2008-02-27 2011-04-05 Millo Bertini Machine slide tool assembly and a drive mechanism therefor
CN102011764A (zh) * 2010-06-05 2011-04-13 常州液压成套设备厂有限公司 液压油缸锁定装置
US20150097054A1 (en) * 2012-05-10 2015-04-09 Graco Minnesota Inc. Electro-hydraulic actuated spray guns
US9764343B2 (en) * 2012-05-10 2017-09-19 Graco Minnesota Inc. Electro-hydraulic actuated spray guns
US10882063B2 (en) 2012-05-10 2021-01-05 Graco Minnesota Inc. Electro-hydraulic actuated spray guns
US11988232B2 (en) * 2017-09-19 2024-05-21 L3Harris Release & Integrated Solutions, Ltd. Actuator rotational alignment device

Also Published As

Publication number Publication date
DE2116580B2 (de) 1973-03-22
BE765811A (fr) 1971-08-30
DE7113157U (de) 1972-01-27
DE2116580C3 (de) 1973-10-11
DE2116580A1 (de) 1972-10-19

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