US3412645A - Pneumatic motor of the reciprocable type - Google Patents
Pneumatic motor of the reciprocable type Download PDFInfo
- Publication number
- US3412645A US3412645A US527811A US52781166A US3412645A US 3412645 A US3412645 A US 3412645A US 527811 A US527811 A US 527811A US 52781166 A US52781166 A US 52781166A US 3412645 A US3412645 A US 3412645A
- Authority
- US
- United States
- Prior art keywords
- piston
- pressure
- cylinder
- chamber
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
- B25D9/06—Means for driving the impulse member
- B25D9/08—Means for driving the impulse member comprising a built-in air compressor, i.e. the tool being driven by air pressure
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
- B25D9/14—Control devices for the reciprocating piston
-
- D—TEXTILES; PAPER
- D03—WEAVING
- D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
- D03D49/00—Details or constructional features not specially adapted for looms of a particular type
- D03D49/24—Mechanisms for inserting shuttle in shed
- D03D49/26—Picking mechanisms, e.g. for propelling gripper shuttles or dummy shuttles
- D03D49/28—Driving mechanisms for the picker stick
- D03D49/34—Driving mechanisms for the picker stick operated by liquid or gas pressure
-
- D—TEXTILES; PAPER
- D03—WEAVING
- D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
- D03D49/00—Details or constructional features not specially adapted for looms of a particular type
- D03D49/24—Mechanisms for inserting shuttle in shed
- D03D49/42—Mechanisms for inserting shuttle in shed whereby the shuttle is propelled by liquid or gas pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B17/00—Reciprocating-piston machines or engines characterised by use of uniflow principle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
- F01B17/00—Reciprocating-piston machines or engines characterised by use of uniflow principle
- F01B17/02—Engines
-
- 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
- F15B15/22—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke
- F15B15/223—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke having a piston with a piston extension or piston recess which completely seals the main fluid outlet as the piston approaches its end position
Definitions
- a pneumatic motor has a main piston joined to a smaller coaxial secondary piston, both working in cylinders, the main piston draws the secondary piston out of its cylinder after moving a predetermined distance along its working stroke.
- Pressurized gas in a reservoir acts on one piston to start the working stroke which causes a reduction of pressure in the other cylinder until a seal between the pistons is broken after which gas pressure acts on both pistons. During the whole of a return stroke the cylinders are vented.
- the invention relates to a pneumatic motor of the reciprocable type which may be used, for example, as a pneumatic hammer or for throwing the shuttle of a loom.
- a pneumatic motor has a piston which is reciprocable in a coacting cylinder provided with a cylinder head, the head of the piston is provided with a coaxial cylindrical extension directed towards the cylinder head whereby the total effective area of the piston is the sum of the area of the circular portion defined by the end of the cylindrical extension remote from the piston head, and of the area of the annular portion defined by the junction of the cylindrical extension with the piston head, the cylinder head is formed with a bore for receiving the cylindrical extension, the annular portion of the piston in conjunction with its coacting cylinder and the cylinder head defines a chamber, another chamber communicates with the circular portion of the piston, 21 seal is arranged operatively between the cylindrical extension and the bore so that the two chambers will be isolated from each other during the limited axial movement of the piston in which the cylindrical extension coacts with the seal, one of said chambers is adapted to receive a supply of gas under pressure to act on the respective portion of the piston to urge the piston away from the cylinder head, means arranged to inhibit the ingress
- the bore in the cylinder head may communicate with the said one chamber, and the seal between the cylindrical extension and the bore is arranged to be broken by raising the pressure in the said one chamber to a value which will move the cylindrical extension of the piston, against the progressively increas- "ice ing force of the annular portion of the piston generated by the reduction of pressure in the said other chamber, out of sealing engagement with the bore.
- the chamber defined by the annular portion of the piston in conjunction with its coacting cylinder and the cylinder head may, according to another feature, form at least part of the said one chamber, and the seal 'between the cylindrical extension and the bore is arranged to be broken by raising the pressure in the said one chamber to a value which will move the cylindrical extension of the piston, against the progressively increasing force on the circular portion of the :piston generated by the reduction of pressure in the said other chamber, out of sealing engagement with the bore.
- the seal may be broken, according to a further feature, by opening -a valve to allow gas to enter the said other chamber whereby to reduce the force restraining the piston to a value such that pressure in said :one chamber is sufiicient to move the cylindrical extension of the piston out of sealing engagement with the bore.
- the valve may be pressure-operated and be set to open automatically when the pressure in the said one chamber has reached a predetermined desired value.
- the valve may be set to open automatically when the pressure in the other chamber, or the pressure difference between the said two chambers, has reached a predetermined desired value.
- the gas flow in to the said other chamber through the valve may be derived from the said one chamber or any other part of the gas pressure circuit for operating the pneumatic motor and, if the motor is operated by compressed air, the air flow into the said other chamber could be derived directly from the atmosphere.
- the piston may be arranged to deliver its working stroke through a coaxial piston rod which extends through a gas seal in a closure member for the end of the cylinder remote from the cylinder head, and the means for causing a. return stroke of the piston includes a port arranged in or adjacent the closure member so that a supply of gas under pressure may be applied at the end of a working stroke to the face of the piston axially remote from said circular and annular portions for returning the piston towards the cylinder head.
- the means for releasing gas from said other chamber after the seal has isolated the two chambers during the last part of the return stroke of the piston towards the cylinder head may be provided by a non-return valve arranged to allow gas to flow from the said other chamber to exhaust.
- a control valve may, according to another feature, be arranged in series with the nonreturn valve, the control valve is normally biased to its closed position and is arranged to be opened only when the pressure acting to return the piston towards the cylinder head has attained a predetermined high value.
- a fixed pressure may be arranged to act on the face of the piston axially remote from said circular and annular portions to increase the restraining force provided by the reduction of pressure in the said other chamber.
- a compression coil spring may be arranged to react between the piston and a closure member for the end of the cylinder remote from the cylinder head to increase the restraining force provided by the reduction of pressure in the said other chamber.
- FIGURE 1 shows a pneumatic motor in longitudinal section and also shows diagrammatically a manually-operated control circuit
- FIGURE 2 is a view similar to FIGURE 1 but illustrating another embodiment of the invention
- FIGURE 3 is a scrap section corresponding with the centre portion of FIGURE 1 but showing a modification
- FIGURE 4 is a scrap section corresponding with the bottom portion of FIGURE 2 but showing the same modification as FIGURE 3;
- FIGURE 5 illustrates a modification of the arrangement shown in FIGURE 3
- FIGURE 6 illustrates a modification of the arrangement shown in FIGURE 4.
- FIGURE 7 is a scrap section corresponding with the centre portion of FIGURE 1 but showing a further modification
- FIGURE 8 is a scrap section corresponding with the bottom portion of FIGURE 2 but showing the same modification as FIGURE 7.
- a piston 10 is provided with a pair of opposed peripheral sealing rings 11 for reciprocation in a cylinder 12 defined by a tube 13 having its ends spigotally engaged respectively by a cylinder head 14 and by a closure member 15.
- the opposite end of the cylinder head 14 to the cylinder 12 defines a chamber 16 in conjunction with an end member 17 and a tube 18 of which the ends are spigotally engaged respectively by the cylinder head 14 and by the end member 17.
- the closure member and the end member 17 are square in cross-section so they each present four corners overlapping the cylindrical body formed by the two tubes 13 and 18 and the cylinder head 14.
- the piston 10 is formed integral with a coaxial piston rod 25 which is supported for axial sliding by a bush 26 carried by a tubular plug 27 extending through a bore in the closure member 15.
- a flange 28 formed integral with the plug 27 prevents the latter from being forced through the bore in the closure member by air pressure in cylinder 12. Air is prevented from escaping between the plug 27 and the bore in the closure member 15 by an O-ring seal 29 and is prevented from escaping between the plug 27 and the piston rod 25 by an air seal 30.
- the end of the piston rod 25 is formed with a socket 31 to receive the stem of a hammer and with a set-screw 32 for locking the stem in position.
- An air passage 33 is formed in the closure member 12 and is connected by an air line 34 to a five port valve 35 so that the cylinder 12 can be connected optionally to an air supply port 36 as shown, or to an exhaust port 37 by moving the spool 38downwards in FIGURE 1.
- An air passage 39 is formed in the end member 17 and is connected by an air line 40 to the five port valve 35 so that the chamber 16 will be connected to an exhaust port 41 as shown whenever the cylinder 12 is connected to the air supply port 36, and the chamber 16 will be connected to the air supply port 36 whenever the cylinder 12 is connected to the exhaust port 37.
- the piston 10 is formed integral with a coaxial cylindrical extension 42 and with a shoulder 43 for abutting the cylinder head 14 as shown.
- a bore 44 passes right through the cylinder head 14 to communicate with the chamber 16, and the cylindrical extension 42 is accommodated with radial clearance within the bore 44 and sealingly coacts with an air seal 45 carried in an annular LE 46 formed in the wall of the bore 44.
- the total effective area of the piston 10 is thus divided into an annular portion 47 and a circular portion 48 which are separated by the seal 45 whenever the latter is engaged with any portion of the cylindrical extension 42.
- the annular portion 47 defines, in conjunction with the tube 13 and the cylinder head 14 and the cylindrical extension 42, a chamber 49 which is isolated from the chamber 16 by the seal 45.
- a passage 50 communicates between an air line 51 and the chamber 49, but air from the air line 51 is prevented from entering the chamber 49 by a spring-loaded ball 52 constituting a non-return valve.
- the spool 38 is moved downwards in FIGURE 1 so that the air in cylinder 12 is connected to exhaust duct 37, and the chamber 16 is connected to air supply duct 36 whereby the pressure in chamber 16 will rise as the pressure in the cylinder 12 drops towards atmospheric pressure which is also the prevailing pressure in chamber 49 as will be appreciated later.
- the pressure in chamber 16 exerts an upward force on the circular portion 48, as seen in FIGURE 1, and this upward force tends to move the piston 10 away from the cylinder head 14.
- chamber 16 which acts as an air reservoir
- air under pressure will suddenly leak past the seal 45 and act on the annular portion 47 in addition to the circular portion 48 whereby a large out of balance force will be applied suddenly to the piston 10 which will move rapidly from the cylinder head 14 to deliver a hammer blow.
- air is prevented from escaping through passage 50, non-return valve 52 and air line 51 by a control valve 53 of which the valve spool 54 is held by a compression coil spring 55 to block an exhaust port 56.
- the air in cylinder 12 tends to pass rapidly through passage 33 to exhaust but the compressibility of air and the normal frictional loss in the passage 33, the air line 34 and the five port valve 35 cause the air pressure in cylinder 12 to rise progressively as the piston 10 approaches the closure member 15 thus providing a cushioning effect.
- the spool 38 is returned to the position shown in FIGURE 1 so that the residual pressure in the interconnected chambers 16 and 49 will decay through exhaust port 41 as the piston 10 is returned towards the cylinder head 14 by the supply of air from air supply port 36 through air line 34 to cylinder 12.
- the cylindrical extension 42 Towards the end of the return movement of piston 10, the cylindrical extension 42 will engage the seal 45 thus isolating the chamber 49 from exhaust port 41 and causing the pressure in chamber 49 to rise. As the pressure in chamber 49 rises the pressure in cylinder 12 and the air line 34 will also rise, and the air pressure in air line 34 is also conveyed through an air line 57 to move the valve spool 54 downwards to the position shown in FIGURE 1, so that the air trapped in chamber 49 can escape through passage 50, non-return valve 52 and air line 51 to exhaust port 56.
- valve spool 54 will uncover the exhaust port 56 depending on the operating conditions of the motor but, when the piston 10 abuts the cylinder head 14 through the shoulder 43, the pressure in cylinder 12 will be a maximum thus ensuring that the valve spool 54 is connecting the air line 51 to the exhaust port 56 and thereby ensuring that the pressure in chamber 49 is substantially atmospheric, the actual pressure depending on the loading of the spring of the non-return valve 52.
- the shoulder 43 serves to prevent the piston from sealingthe passage 50.
- control valve 53 may, if desired, be omitted but it must be appreciated that th hammer blow will be of slightly lower power due to leakage through the non-return valve 52.
- FIGURE 2 is similar in some respects to the embodiment of FIGURE 1 and for this reason the same reference numerals have been used to indicate equival nt components, and only the structural and functional differences are now described.
- the pneumatic motor shown in FIGURE 2 is designed for lighter duties than that shown in FIGURE 1, and may be used for throwing the shuttle of a loom. For this reason the piston rod is made of a tube and passes directly through the air seal without being supported by a rectilinear hearing such as the bush 26 of FIGURE 1.
- the piston 10 is formed integral with the cylindrical extension 42 but is made generally hollow as shown and is provided with an inwardly-directed annular flange 58.
- the end of the piston rod 25 adjacent the piston 10 is formed with an outwardly-directed annular flange 59 which is urged towards the flange 58 by a nut 60 which is a close sliding fit over the piston rod 25 and engages female threads 61 of the piston 10.
- a skirted member 62 has an outwardlydirected annular flange 63 trapped between the flanges 58 and 59 by the action of the nut 60, and has its skirt closely engaging the interior wall of the tubular piston rod 25.
- a pair of air seals 64 are arranged one between the flanges 58 and 63 and the other between the flanges 59 and 63.
- the main structural difference is that the end member 17 of FIGURE 1 has been omitted and the tube 18 has been arranged coaxially around the tube 13, thus shortening the length of the motor whilst increasing its overall diameter slightly.
- the tube 13 is spigotally engaged as before with the cylinder head 14 and the closure member 15 but only one O-ring seal 24 is used and this is arranged betw en the tube 13 and the closure member 15 to prevent leakage between cylinder 12 and chamber 16.
- Tube 18 is spigotally en aged with the cylinder head 14 and the closure member 15 and an O-ring seal 24 is arranged at each spigotal engagement to prevent the escape of air under pressure from within the motor.
- the chamber 16 is of annular configuration and the passage 39 to air line is defined by an internally-threaded boss 65 welded to the tube 18.
- the bore 44 is formed in the cylinder head 14 but is in the form of a blind bore which communieates onlv with air line 51 through passage and nonreturn valve 52.
- the total effective area of the piston 10 is divided as before into an annular portion 47 and a circular portion 48 which are se arated by the seal 45 whenever the seal is engaged with any portion of the cylindrical extension 42.
- the annular portion 47 defines, in conjunction with the tube 13 and the cylinder head 14 and the cylindrical extension 42, a chamber 49 which is permanently connected to chamber 16 through a series of ports 66 formed through the wall of tube 13. Whilst the seal 45 is engaged with the cylindrical extension 42, the chamber 49 is isolated by the seal 45 from a chamber 67 defined by the cylindrical extension 42 and the blind bore 44.
- Cylinder 12 is connected as before through passage 33 to air lines 34 and 57 which lead respectively to the five port valve 35 and to the control valve 53 both of which are operated exactly as before.
- Air lines 40 and 51 are connected exactly as before respectively to the five port valve 35 and to the control valve 53.
- the spool 38 is moved downwards to connect cylinder 12 to exhaust duct 37 and to connect chamber 16 to air supply duct 36.
- the pressure in chambers 16 and 49 rises as the pressure in cylinder 12 drops to atmospheric pressure which is also the prevailing pressure in chamber 67.
- the pressure in chamber 49 exerts an upward force on the annular portion 47 which tends to move the piston 10 away from the cylinder head 14.
- movement of the piston 10 away from the cylinder head 14 also tends to reduce the pressure of the air in the chamber 67 below atmospheric pressure so that a downward force is exerted on the piston 10 dependent on the pressure ditference of the air in cylinder 12 and chamber 67.
- a depression 68 is provided in the cylindrical extension 42 of the piston 10 to prevent the passage 50 from being sealed.
- the seal 45 could be broken before the pressure in chamber 16 of FIGURE 1 or the chamber 49 of FIGURE 2 has reached the required pressure. As shown in FIGURE 3, this can be achieved for a pneumatic motor of the kind taught by FIGURE 1 by forming a passage 70 in the cylinder head 14 between the chambers 16 and 49, and a non-return valve 71 having a preloaded seating spring 72. When the pressure difference between the chambers 16 and 49 reaches a predetermined value, the non-return valve 71 will open so that air from the chamber 16 will enter the chamber 49 to increase the absolute pressure and thus reduce the restraining force on the piston 10 until the seal 45 is broken.
- FIGURE 4 this can be achieved for a pneumatic motor of the kind taught by FIGURE 2 in substantially the same manner, the passage 70 leading from the chamber 16 to the non-return valve 71, and a passage 73 connecting the non-return valve 71 to the passage 50 which is permanently connected with the depression 68.
- the arrangements shown in FIGURES 3 and 4 do suffer a slight disadvantage in that a proportion of the compressed air in their chambers 16 will be lost through their respective passages 70.
- Alternative arrangements which prevent this loss of pressure are shown in FIGURES 5 to 8.
- FIGURE 5 the arrangement taught by FIGURE 3 is modified by changing the path of the passage 70 so that it leads from the non-return valve 71 to atmosphere. Apart from preventing a loss of compressed air from the chamber 16, this arrangement has the advantage that the opening of the non-return valve 71 depends only on one variable, that is the pressure in the chamber 49 assuming that atmospheric pressure is substantially constant.
- the arrangement shown in FIGURE 6 is similar in principle to that shown in FIGURE 5, but illustrates the application of the modification to a pneumatic motor of the kind taught by FIGURE 2.
- the path of the passage 70 is again changed so that it leads from the non-return valve 71 to atmosphere whereby the opening of the nonreturn valve 71 will depend only on the pressure in the depression 68, and no compressed air will be lost from the chamber 16.
- FIGURE 7 which shows the application of this alternative arrangement to a pneumatic motor of the kind taught by FIGURE 1
- the passage 70 in the cylinder head 14 is connected to a passage 74 that leads to atmosphere but is blocked by a piston 75 slidable in a bore 76 of which the blind end is connected to atmosphere by a vent 80.
- the piston 75 is formed with a diametral valve passage 77 but is urged axially by a preloaded compression coil spring 78 against a retaining spring clip 79 so that the body of the piston 75 blocks the passage 74.
- FIGURE 8 The arrangement shown in FIGURE 8 is similar in principle to that shown in FIGURE 7, but illustrates the application of the alternative arrangement to a pneumatic motor of the kind taught by FIGURE 2 and ditiers principally in that the passage 70 leads to the head of the piston 75 which operates in the opposite direction, and the compression coil spring 78 reacts against the spring clip 79.
- the piston 75 When the pressure in chamber 16 has reached a predetermined value, the piston 75 will have been moved downwards against the action of the compression coil spring 78 so that the valve passage 77 will allow air from the atmosphere to flow directly through the passages 74 and 73 to the passage 50 and the depression 68 to increase the absolute pressure acting on the cylindrical extension 42 and thus reduce the restraining force on the piston 10 until the seal 45 is broken.
- the restraining force on the piston 10 of either FIGURE 1 or FIGURE 2 could be increased by arranging a compression coil spring between the closure member and the piston 10, or by retaining a proportion of fluid pressure in cylinder 12.
- FIGURE 1 or FIGURE 2 could be arranged to reciprocate automatically by using pressure signals from suitable parts of the apparatus to operate the five port valve 35.
- these signals could be high and low pressure signals from the passage 50 or 51.
- a pneumatic motor including a main piston, structure defining a coacting cylinder for the main piston, a secondary piston of smaller diameter than the main piston, structure defining a coacting cylinder for the secondary piston, said secondary piston coaxially secured to the main piston, said main piston adapted to perform a working stroke and a return stroke relatively to its coacting cylinder, said main piston arranged to withdraw the secondary piston from its coacting cylinder after the main piston has moved through an initial distance in the direction of its working stroke relatively to its coacting cylinder, structure defining a reservoir for gas under pressure, said reservoir adjacent and continuously connected to one of said coacting cylinders for the gas pressure to act on the corresponding one piston in the direction of said working stroke, means arranged to inhibit the flow of any gas into the other of said coacting cylinders including sealing means arranged to eliect a seal between the secondary piston and its coacting cylinder whilst the secondary piston is within its coacting cylinder thereby isolating the two coacting cylinders where
- a pneumatic motor according to claim 1, in which the reservoir is operatively connected to the coacting cylinder for the secondary piston, and structure defines a gas inlet port to the reservoir whereby the gas pressure acting on the secondary piston may be increased to a predetermined value at which the secondary piston will disengage the sealing means against the progressively increasing force on the main piston generated by the reduction of pressure in the coacting chamber for the main piston.
- a pneumatic motor according to claim 1, in which the reservoir is operatively connected to the coacting cylinder for the main piston, and structure defines a gas inlet port to the reservoir whereby the gas pressure acting on the main piston may be increased to a predetermined value at which the secondary piston will disengage the sealing means against the progressively increasing force on the secondary piston generated by the reduction of pressure in the coacting chamber for the secondary piston.
- a pneumatic motor including a piston rod coaxially fast with the pistons, a closure member sealingly engaged with the end of the coacting cylinder for the main piston that is remote from the secondary piston, a gas sealing means supported by the closure member and sealingly engaged with the piston rod, and the closure member defining a gas inlet port to the coacting cylinder for the main piston whereby the application of gas under pressure through the gas inlet port at the end of a working stroke of the pistons will cause the pistons to perform their return stroke.
- a pneumatic motor according to claim 1, in which the means for releasing gas from the said other coacting cylinder after the sealing means has isolated the two cylinders during the last portion of the return stroke includes a non-return valve and structure defining an exhaust port, and the non-return valve is arranged to allow gas to flow from the said other coacting cylinder through the exhaust port.
- a pneumatic motor including a control valve arranged in series with the non-return valve and operable between a closed position and an open position, means biasing the control valve to its closed position, a piston rod coaxially fast with the pistons, a closure member sealingly engaged with the end of the coacting cylinder for the main piston that is remote from the secondary piston, a gas sealing means supported by the closure member and sealingly engaged with the piston rod, the closure member defining a gas inlet port to the coacting cylinder for the main piston whereby application of gas under pressure through the gas inlet port at the end of the working stroke of the pistons will cause the pistons to perform their return stroke, and pressure-responsive means connected to the gas applied through the gas inlet port and arranged to operate the control valve to its open position when the pressure of the gas applied through the gas inlet port exceeds a predetermined value.
- a pneumatic motor including a main piston, structure defining a coacting cylinder for the main piston, a secondary piston of smaller diameter than the main piston, structure defining a coacting cylinder for the secondary piston, said secondary piston coaxially secured to the main piston, said main piston adapted to perform a working stroke and a return stroke relatively to its coacting cylinder, said main piston arranged to withdraw the secondary piston from its coacting cylinder after the main piston has moved through an initial distance in the direction of its working stroke relatively to its coacting cylinder, structure defining a reservoir for gas under pressure, said reservoir adjacent and continuously connected to one of said coacting cylinders for the gas pressure to act on the corresponding one piston in the direction of said working stroke, means arranged to inhibit the flow of any gas into the other of said coacting cylinders including sealing means arranged to effect a seal between the secondary piston and its coacting cylinder whilst the secondary piston is within its coacting cylinder thereby isolating the two coacting cylinders whereby movement of the
- valve means is pressure-operable, structure defines a gas passage connecting the valve means to the reservoir for the valve means to be operated by the pressure of the gas in the reservoir, and the valve means is arranged to open when the pressure in the reservoir attains a predetermined desired value.
- a pneumatic motor in which structure defines a gas duct from the reservoir to the said other coacting cylinder, and the valve means is arranged to control the flow of gas through the gas duct.
- a pneumatic motor in the case where the motor is to be operated by compressed air, in which structure defines a gas duct from the atmosphere to the said other coacting cylinder, and the valve means is arranged to control the flow of gas through the gas duct.
- valve means is pressure-operable, structure defines a first gas passage connecting the valve means to the reservoir and a second gas passage connecting the valve means to the said other coacting cylinder for the valve means to be operated by the pressure difference between the reservoir and the said other coacting cylinder, and the valve means is arranged to open when the pressure dilference between the reservoir and the said other coacting cylinder attains a predetermined desired value.
- a pneumatic motor according to claim 11, in which the valve means is arranged to control the flow of gas between the first and second gas passages.
- a pneumatic motor according to claim 11 and in the case where the motor is to be operated by compressed air, in which structure defines a gas duct from the atmosphere to the valve means, and the valve means is arranged to control the flow of gas from the gas duct to the said other coactin g cylinder.
- a pneumatic motor in which structure defines a gas duct from the reservoir to the said other coacting cylinder, and the valve means is arranged to control the flow of gas through the gas duct.
- valve means is pressure-operable, structure defines a gas passage leading from the valve means to the said other coacting cylinder for the valve means to be operated by the pressure of the gas in the said other coacting cylinder, and the valve means is arranged to open when the pressure in the said other coacting cylinder has dropped to a predetermined desired value.
- a pneumatic motor in the case where the motor is to be operated by compressed air, in which structure defines a gas duct from the atmosphere to the valve means, and the valve means is arranged to control the flow of gas from the gas duct to the said other coacting cylinder.
- a pneumatic motor including a piston rod coaxially fast with the pistons, a closure member sealingly engaged with the end of the coacting cylinder for the main piston that is remote from the secondary piston, a gas sealing means supported by the closure member and sealingly engaged with the piston rod, and the closure member defining a gas inlet port to the coacting cylinder for the main piston whereby the application of gas under pressure through the gas inlet port at the end of a working stroke of the pistons Will cause the pistons to perform their return stroke.
- a pneumatic motor in which the means for releasing gas from the said other coacting cylinder after the sealing means has isolated the two cylinders during the last portion of the return stroke includes a non-return valve and structure defining an exhaust port, and the non-return valve is arranged to allow gas to flow from the said other coacting cylinder through the exhaust port.
- a pneumatic motor including a control valve arranged in series with the nonreturn valve and operable between a closed position and an open position, means biasing the control valve to its closed position, a piston rod coaxially fast with the pistons, a closure member sealingly engaged with the end of the coacting cylinder for the main piston that is remote from the secondary piston, a gas sealing means supported by the closure member and sealingly engaged with the piston rod, the closure member defining a gas inlet port to the coating cylinder for the main piston whereby application of gas under pressure through the gas inlet port at the end of the working stroke of the pistons will cause the pistons to perform their return stroke, and pressureresponsive means connected to the gas applied through the gas inlet port and arranged to operate the control valve to its open position when the pressure of the gas applied through the gas inlet port exceeds a predetermined value.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Textile Engineering (AREA)
- Actuator (AREA)
- Percussive Tools And Related Accessories (AREA)
- Portable Nailing Machines And Staplers (AREA)
- Fluid-Pressure Circuits (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB7422/65A GB1091431A (en) | 1965-02-20 | 1965-02-20 | Improvements in or relating to a pneumatic motor of the reciprocable type |
Publications (1)
Publication Number | Publication Date |
---|---|
US3412645A true US3412645A (en) | 1968-11-26 |
Family
ID=9832824
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US527811A Expired - Lifetime US3412645A (en) | 1965-02-20 | 1966-02-16 | Pneumatic motor of the reciprocable type |
Country Status (8)
Country | Link |
---|---|
US (1) | US3412645A (es) |
BE (1) | BE676593A (es) |
DE (1) | DE1299171B (es) |
DK (1) | DK126440B (es) |
ES (1) | ES323293A1 (es) |
GB (1) | GB1091431A (es) |
NL (1) | NL6602069A (es) |
SE (1) | SE322739B (es) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3499369A (en) * | 1967-03-06 | 1970-03-10 | Michel Joseph | Pneumatic punch press |
US3561323A (en) * | 1968-02-29 | 1971-02-09 | Commissariat Energie Atomique | Device for moving a movable shaft back and forth |
US3800670A (en) * | 1969-10-21 | 1974-04-02 | Caterpillar Tractor Co | High pressure implement hydraulic circuit |
US3933080A (en) * | 1971-09-14 | 1976-01-20 | Martonair Limited | Pneumatic actuators |
US4034958A (en) * | 1974-06-14 | 1977-07-12 | Messier Hispano | Independent device for opening and closing rotary valves by remote control |
US6038956A (en) * | 1998-04-02 | 2000-03-21 | Lane; Norman | Dynamic pressure regulator cushion |
ES2310460A1 (es) * | 2006-11-21 | 2009-01-01 | Festo Pneumatic, S.A.U. | Cilindro actuador lineal neumatico de simple efecto. |
CN109356904A (zh) * | 2018-12-03 | 2019-02-19 | 江苏丰东热技术有限公司 | 一种自动往复气缸以及自动往复气缸*** |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4641793A (en) * | 1985-04-16 | 1987-02-10 | Rieter Machine Works Limited | Thread winding machine and method of performing automatic changeover of winding of a thread |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1129964A (en) * | 1911-06-27 | 1915-03-02 | Harrison W Rogers | Reciprocating motor. |
US3146678A (en) * | 1962-03-12 | 1964-09-01 | Henry Von Den Benken | Fluid actuated motor with fluid flow control |
US3260167A (en) * | 1964-10-26 | 1966-07-12 | Case Co J I | Hydraulic cylinder with fast-acting means |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2979938A (en) * | 1956-10-19 | 1961-04-18 | Gen Dynamics Corp | Actuator |
GB862348A (en) * | 1958-12-19 | 1961-03-08 | Keelavite Co Ltd | Fluid-operated reciprocating devices |
-
1965
- 1965-02-20 GB GB7422/65A patent/GB1091431A/en not_active Expired
-
1966
- 1966-02-16 US US527811A patent/US3412645A/en not_active Expired - Lifetime
- 1966-02-16 BE BE676593D patent/BE676593A/xx unknown
- 1966-02-17 NL NL6602069A patent/NL6602069A/xx unknown
- 1966-02-18 SE SE2103/66A patent/SE322739B/xx unknown
- 1966-02-18 DE DEM68454A patent/DE1299171B/de active Pending
- 1966-02-19 ES ES0323293A patent/ES323293A1/es not_active Expired
- 1966-02-19 DK DK88266AA patent/DK126440B/da unknown
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1129964A (en) * | 1911-06-27 | 1915-03-02 | Harrison W Rogers | Reciprocating motor. |
US3146678A (en) * | 1962-03-12 | 1964-09-01 | Henry Von Den Benken | Fluid actuated motor with fluid flow control |
US3260167A (en) * | 1964-10-26 | 1966-07-12 | Case Co J I | Hydraulic cylinder with fast-acting means |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3499369A (en) * | 1967-03-06 | 1970-03-10 | Michel Joseph | Pneumatic punch press |
US3561323A (en) * | 1968-02-29 | 1971-02-09 | Commissariat Energie Atomique | Device for moving a movable shaft back and forth |
US3800670A (en) * | 1969-10-21 | 1974-04-02 | Caterpillar Tractor Co | High pressure implement hydraulic circuit |
US3933080A (en) * | 1971-09-14 | 1976-01-20 | Martonair Limited | Pneumatic actuators |
US4034958A (en) * | 1974-06-14 | 1977-07-12 | Messier Hispano | Independent device for opening and closing rotary valves by remote control |
US6038956A (en) * | 1998-04-02 | 2000-03-21 | Lane; Norman | Dynamic pressure regulator cushion |
ES2310460A1 (es) * | 2006-11-21 | 2009-01-01 | Festo Pneumatic, S.A.U. | Cilindro actuador lineal neumatico de simple efecto. |
CN109356904A (zh) * | 2018-12-03 | 2019-02-19 | 江苏丰东热技术有限公司 | 一种自动往复气缸以及自动往复气缸*** |
Also Published As
Publication number | Publication date |
---|---|
BE676593A (es) | 1966-07-18 |
SE322739B (es) | 1970-04-13 |
GB1091431A (en) | 1967-11-15 |
NL6602069A (es) | 1966-08-22 |
ES323293A1 (es) | 1967-01-16 |
DE1299171B (de) | 1969-07-10 |
DK126440B (da) | 1973-07-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0449945B1 (en) | Shock-absorbing fluid-actuated fastener installation tool | |
US3320861A (en) | Locking fluid cylinder | |
US3908767A (en) | Percussion tool | |
US3426649A (en) | Multistage hydraulic mine prop | |
US3412645A (en) | Pneumatic motor of the reciprocable type | |
US3511048A (en) | Hydropneumatic clamping cylinder | |
US3869963A (en) | Hydraulic actuator having a self-aspirating actuator rod seal | |
US3024592A (en) | Pin actuating device | |
US3687008A (en) | Pressure fluid controlled reciprocating mechanism | |
US3948051A (en) | Fluid pressure amplifier | |
US3633365A (en) | Hydraulic jack | |
US2747370A (en) | Fluid pressure device | |
US5092745A (en) | Automatic pressure-driven compressor | |
US4472111A (en) | Apparatus for generating high pressure fluid | |
US3148707A (en) | Automatic hydraulic buffer | |
US5050482A (en) | Apparatus for driving piston by fluid pressure | |
US5992584A (en) | Dashpot for power cylinder | |
US11293463B2 (en) | Externally verifiable thermal compensation of cowl opening actuator | |
US4964292A (en) | Shock-absorbing fluid-actuated pressure system | |
GB2092717A (en) | Hydraulic control valve assembly | |
US3815481A (en) | Power cylinder with piston return by own vacuum force | |
US3726187A (en) | Servo-actuator mechanism | |
US5927178A (en) | Press driven tool actuator module | |
US3072104A (en) | Cylinder with piston cushioning feature | |
EP0347921A3 (en) | A fluid spring |