US3561330A - Fluid operable motor - Google Patents

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Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
  • B25B13/00—Spanners; Wrenches
  • B25B13/48—Spanners; Wrenches for special purposes
  • B25B13/50—Spanners; Wrenches for special purposes for operating on work of special profile, e.g. pipes
  • B25B13/52—Chain or strap wrenches
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
  • B25B5/00—Clamps
  • B25B5/06—Arrangements for positively actuating jaws
  • B25B5/061—Arrangements for positively actuating jaws with fluid drive
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
  • B25B5/00—Clamps
  • B25B5/06—Arrangements for positively actuating jaws
  • B25B5/061—Arrangements for positively actuating jaws with fluid drive
  • B25B5/065—Arrangements for positively actuating jaws with fluid drive involving the use of flexible pressure bags or diaphragms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
  • B25J15/00—Gripping heads and other end effectors
  • B25J15/0023—Gripper surfaces directly activated by a fluid
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
  • F15B15/08—Characterised by the construction of the motor unit
  • F15B15/10—Characterised by the construction of the motor unit the motor being of diaphragm type
  • F15B15/103—Characterised by the construction of the motor unit the motor being of diaphragm type using inflatable bodies that contract when fluid pressure is applied, e.g. pneumatic artificial muscles or McKibben-type actuators

Definitions

• ABSTRACT A fluid operable motor element made of a tube interest; LeOIlald L- KlaSllOW, WOICeStel', of elastic deformable material (e.g. rubber) closed at one end.
• MaSS- i by mesne assignmemapaltimelesi The tube is restrained against deformation transverse to its Comnuaton 0f application Sel ⁇ -N0 longitudinal axis, and against longitudinal deformation in a 622,183, Mal'- l0, 1967, 0W aballdOlledlimited region of its side walls. The remainder ofthe sidewalls is free to execute elastic deformation in the longitudinal direction.
• This invention relates in general to a new form of motor element having the property that it flexes and can exert a force in response to ari applied fluid force, and to combinations of such motor elements to provide grasping tools and manipulative and prosthetic devices.
• manipulative and other devices Many classes of tools ⁇ grasping devices and manipulative and other devices are known which make use of motor or force-exerting elements which pivot or execute a quasiflexural motion to accomplish their purposes. Some devices such as pliers, some wrenches and clamps (both hand operated and powered) use levers; chain wrenches are another type of device which may be said to encircle the workpiece.
• Manipulative devices range from small part clamping and assembling devices to remote handling components and systems for radioactive and corrosive materials, and materials at high temperatures. Prosthetic devices, some including manipulative components, virtually seek to duplicate the flexural mode of operation of fingers and other jointed members of the body.
• a further object of the invention is to provide combinations of such motor elements with other elements, including but not limited to other similar motor elements, for the purpose of making tools such as pliers and wrenches, clamping devices, grasping devices, both hand and power operated, manipulative devices, prosthetic devices, self-actuating hooks, and wrapping devices, as examples.
• a more specific object of the invention is to provide an artificial human hand which closely duplicates a human hand in both function and appearance, and which is simple in coristruction yet capable of executing complex movements.
• Another specific object of the invention is to provide pliers, wrenches, clamping and manipulative devices and the like which can conform themselves to the contourof an article being handled.
• a fluid-operable motor element comprising a hollow member of substantially tubular form having sidewalls surrounding a chamber extending on an axis located between said sidewalls, restraining means connected to a portion of said sidewalls for substantially preventing a change in dimension of said portion parallel to said axis, at least a portion of the remainder of said sidewalls in the same transverse region of said member as saidrestraining means being capable of and free to execute elastic deformation parallel to said axis.
• the restraining means may, for example, be an elongated flexible but longitudinally substantially inextensible member associated with the wall of the hollow member and extending in the axial direction.
• the motor element executes a flexural motion about the restraining means due to elastic deformation parallel to the tube axis of the sidewalls of the hollow member remote from the restraining means.
• the motor element returns to its relaxed posture. Only the strength of the materials used, and the pressure applied to the operating fluid, limit the force that can be applied by the motor element, or the work that cari be done by it.
• FIG. 1 (A--D) shows a method of making a motor element according to the invention
• FIG. 2 (A,B) shows another method of making the motor element
• FIG. 3 (A,B) shows another method of making the motor element
• FIG. 4 (A-C) illustrates a mode of operation of motor elements according to the invention
• FIG. 5 illustrates another embodiment of the invention
• FIG. 6 illustrates still another embodiment of the invention
• FIG. 7 and 7A illustrate a prosthetic device according to the invention
• FIGS. 8 and 8A illustrate a manipulative device according to the invention
• FIG. 8B illustrates a modification of the device of FIG. 8
• FIG. 9 illustrates another manipulative device according to the invention.
• FIG. 10 shows another embodiment of the motor element according to the invention.
• FIG. l 1 shows an alternative structure according to the concept of FIG. l0;
• FIG. 12 shows a modification applicable in general to motor elements of the invention
• FIG. 13 illustrates a modification of the device of FIG. 8 according to FIG. 12.
• FIG. 14 illustrates a pressure gauge incorporating a motor element according to the invention as the sole movable element thereof.
• FIG. l illustrates a method of making a motor element 15 according to the invention.
• a longitudinal restraint member l1 such as a piece of nylon or cotton cord, is attached to the tube along its outer side, running in the axial direction.
• the restraint member has the property that it is flexible but, compared to the tube l0, substantially nonextensible; it is attached by a rubber cement, or other suitable adhesive to the tube l0.
• a split mandrel 12, 13 is fitted into the tube l0 and the parts pushed together to fit it snugly in the tube.
• a cord 14 such as nylon or cotton cord, is helically wrapped tightly around the tube and longitudinal restraint member l1, as shown schematically in FIG. 1C, until the tube 10 is substantially entirely wrapped helically.
• This helical winding 14 may then also be bonded to the tube l0, like the restraint member 11.
• the mandrel l2, 13 is removed by pulling its parts away from each other. This is facilitated by lubricating the mandrel parts 12 and 13 with talcum powder, for example, before they are put in the tube (FIG. 1B).
• the resulting motor element l5 is capable of longitudinal elongation except where restrained by the longitudinal restraint member l1.
• the helically-wrapped cord 14 provides restraint against radial expansion of the tube 10, while permitting its longitudinal expansion. It is therefore obvious that the motor element of the invention is distinguished from the Bourdon tube and similar devices in both form and function.
• a Bourdon tube is flattened in cross section in the relaxed state, and tends to distend or deform transverse to its longitudinal axis when under pressure, thereby producing a straightening effect. There is no differential elastic deformation of its walls parallel to its longitudinal axis. In the present invention, moreover, radial distortion is restrained, and does not enter into the motor function.
• a motor element 15 may also be made as shown in FIG. 2, where FIG. 2A shows a rectangular sheet 20 of india or gum rubber, to one side of which the longitudinal restraint member 1l has been attached as by rubber cement. Crossing the rubber sheet, on the same side, and passing over the longitudinal restraint member, are a plurality of pieces of cord 14: closely placed and fastened as by rubber cement or other suitable adhesive to the rubber sheet 20. One edge 23 of the sheet. parallel to the transverse cord pieces 14'. is shown crosshatched, so that it can be found in FIG. 2B. After being so prepared, the sheet is wrapped into a tube, as shown in FIG.
• FIG. 3 shows another method of producing a motor element l5, which uses part of the process of FIG. 2 and part of the process of FIG. l.
• a sheet 30 of suitable rubber is fitted with the longitudinal restraint member 11, as shown in FIG. 3A, and then rolled into a tube as shown in FIG. 3B, with the longitudinal restraint member in the desired place, which may be embedded in the wall of the tube, and extending in the axial direction.
• These steps provide the part shown in FIG. 1A, which is then processed as described above in connection with FIGS. 1B-D, inclusive. It will be understood that further layers or plies of rubber and/or restraint elements may be added, if desired, to motor elements produced by the foregoing methods.
• Control mechanism shown in reduced scale compared to the motor element l5, comprises a reservoir 43 for a liquid, a pump P for providing a source of fluid under pressure, represented by a box 44 to which the pump is connected via a one-way valve, a stopcock 45 in a riser 46 from the source 44, and a two-way (three-port) valve 47 connected between the stopcock and the input pipe 42.
• a pipe 48 connects from the two-way valve to the reservoir input 49, to carry exhaust fluid back to the reservoir.
• a suitable fluid for operating the motor element 15 is water, oil, or other liquid.
• a compressed gas may also be used, but FIG4 4 is drawn to illustrate operation with a liquid under pressure in excess of ambient.
• the fluid under excess pressure is not permitted to enter the motor element I5. and it remains relaxed, and undistorted, as shown.
• the stopcock 45 is turned to pass fluid under excess pressure from the source 44 through the three-port valve 47 into the motor element l5
• the motor element flexes about the longitudinal restraint member ll, as shown in FIG. 4B.
• the outer surface of it furthest removed from the longitudinal restraint member ll stretches, or elongates, a distance A l, and assumes the length I+ A I.
• the longitudinal restraint member l1 describes the arc of a circle, so that l Ra where R is the radius of the circle; and ot is the angle of the arc.
• the motor element In the deflected state under excess pressure the motor element is restrained from radial expansion by the circumferentially-wrapped cords 14, 14'.
• the tubular structure can change its longitudinal dimension, parallel to its axis, everywhere except where restrained by the longitudinal restraint member 11.
• the stopcock 45 is closed, and the three-port valve 47 is turned to pass fluid from the interior of the motor element 15 to the exhaust conduit 48. Exhaust fluid may be discarded, or returned to the reservoir 43, as desired.
• the motor element l5 can flex in the direction opposite to that shown in FIG. 4B if the fluid in it is brought to a pressure below the ambient (e.g.: atmospheric) pressure.
• a pressure below the ambient pressure e.g.: atmospheric
• the motor element 15 can be made to flex in the direction shown in FIG. 4B, or in the opposite direction, as desired.
• the motor element 15 is illustrated, for convenience, simply as a tubular structure having a longitudinal restraint member 11 on it, the radial restraint member(s) 14 or 14' being omitted but understood to be present.
• a motor element may be illustrated simply as a tubular structure without showing a stopper for one end or a fluid input for the other, since it is easily understood that such parts will be present in practice.
• This convention serves to illustrate the basic structure of a motor element, and will be followed in illustrating other embodiments of the invention.
• a motor element 55 in tubular form having a restraint member 51 attached to the outer surface of its wall, which extends from one end to the other of the tubular member but in a direction having components both longitudinal and circumferential.
• this motor element When caused to flex, this motor element will tend to take the form of a helix, illustrated in FIG. 9, and if it is long enough will assume the shape of a prehensile tail.
• FIG. 6 illustrates the basic structure of another motor element 65, made of a tubular member 60 having short sections of longitudinal-restraint members 6l, 62, etc. on its outer wall, displaced circumferentially one from another.
• a motor element made this way will ⁇ when caused to flex, execute a compound. motion, one transverse region 62.5 flexing about its restraint member 62, while the adjacent transverse region 61.5 flexes in a different direction about its restraint member 6l.
• Motor elements of the invention can be made in any desired shape in the relaxed condition, and can be made to assume another desired shape in the energized condition.
• the embodiments illustrated generally show motor elements which are straight when relaxed and flexed into a curved shape when energized, it will be understood that a motor element can be curved in the relaxed state and straight'in the energized state, or can be curved in the relaxed state and further curved in the energized state. ln any case, it is characteristic of motor elements of the invention to flex with an attendant change of shape when energized. t
• FIG. 7 shows such a combination to provide an artificial human hand, which can be used as a prosthetic device.
• a manifold 70 has an input port 7l for operating fluid, and five output ports 72 for a thumb and 73, 74, 75 and 76 for index, middle, ring and little fingers, respectively.
• Attached to the thumb port 72 is a thumb motor element 152 which has its remote end or tip 152.1 closed and in the general shape of a finger tip. This motor element is bent in the relaxed state at a joint region 152.2 corresponding to the large joint in a human thumb.
• a second portion 151.4 between the joint region and the tip has a second restraint member 112.4, and is slightly curved in a convex shape to resemble the ball portion of a human thumb.
• the thumb motor element 152 can be rotated about the thumb port 72 so that when it is energized its motion will closely approximate that of a human thumb.
• An index finger motor element 153 is connected to the index finger port 73. As seen in FIG. 7A, this motor element can be made with a thicker wall near the root on the palm side of the hand than at the tip or back side, so that when energized its flexure about the restraint member 1 13 will be nonuniform in a desired pattern.
• the tip 153.1 is closed and rounded to resemble a finger tip.
• the remaining fingers 154, 155 and 156 have similarly disposed and oriented restraint members 114, 115 and 116, respectively, so that when energized all the fingers will flex together, as in a human hand.
• FIG. 7 The entire structure of FIG. 7 can be enclosed in a suitable sheath 77, indicated partially enclosing the structure by a dashed line in FIG. 7, to make it look like a human hand. It will be understood that in' practice means to affix the artificial hand to an ann, and means to bring fluid to the manifold input 71, and to discharge fluid therefrom, will be provided.
• a suitable fluid under pressure is introduced into the manifold 70 at the input port 71 the ngers 113-116, inclusive, flex toward the palm and the thumb 152 flexes toward the flexed fingers, as in a human hand.
• the forefinger 113 is shown partly flexed at 113', in FIG. 7A. When the fluid pressure is released, the ngers and thumb relax, and resume the shape shown in FIG. 7.
• An artificial human hand has been constructed according to FIG. 7, and has shown itself capable of grasping objects such as cans, bottles and ping-pong balls, and has actually shaken hands with a person with an effect remarkably similar to a true human hand.
• FIGS. 8 and 8A illustrate a manipulative tool which can be used as a grasping device, or a wrench.
• a manifold member 80 has an input port 8l and four output ports, of which only three pons 82, 83 and 84 are shown, connected together by an interior plenum chamber 85.
• Operating fluid (not shown) under ⁇ Asuitable pressure is brought to the input port 81 over a conduit 90 through a normally closed control valve 91, pipe section 86 and tee 88.
• a normally closed pressure-relief valve 92 is fitted to the tee 88.
• Each valve 91 or 92- is of a type which can be momentarily opened by pressing a button 91.5 or 92.5,
• control valve button 91.5 when the control valve button 91.5 is depressed, fluid under pressure may be admitted to the plenum chamber 85, and when the pressure-relief valve button 92.5 is depressed fluid under pressure may be released from the plenum chamber.
• a motor element 158 with restraint member 118 is fitted to each output port.
• FIG. 8A there are two output ports on each sloped side 85, 87 of the manifold.
• the FIG. shows one pair of adjoining motor elements fitted to the output ports 83, 84 on one sloped side 85, connected together by a web 89.
• the motor elements when fluid under pressure is admitted to the plenum chamber 85 ⁇ the motor elements flex toward each other from the sloped sides 85 and 87. If an object, such as a can or bottle (shown in dotted line) is being grasped, the use of pairs of motor elements joined to each other as by a web 89 assures a firm grasping of the object. l have found that if a single motor element 158 is used on each side of the grasping device, there is a risk of scissorslike motion, as when one attempts to grasp a device between only two fingers, which may result in dropping the article being grasped.
• the ends of the motor elements 158 are closed with fingerlike projections 141, which are useful in picking up small objects. Either or both of the projections 141 and the confronting surfaces of the motor elements along the restraint regions may be made rough, to enhance the ability of the device to hold objects, and to function as a wrench.
• the tool of FIG. 8 can be modified as shown in FIG. 8B, to substitute a platform member 80.5 on one side of the manifold member 80.1, which in other respects is the same as the manifold member 80.
• FIG. 9 shows a greatly elongated motor element 160 having restraint 161 along its side, an input conduit 162 at one end and a closure 163 at the other end.
• the constraint may be configured according to FIG. 5.
• a motor element in this configuration will wrap itself around an object in helical fashion when fluid under pressure is supplied to it. It may be used as a grasping device for objects of various shapes. If attached at the end of a lifting device, such as a chain fall or a cable, it can function as a self-attaching hook.
• a bellows 170 which can be made of metal, closed at one end 171 and having an input conduit 172 at the other, is constrained at one side by a flexible but substantially longitudinally inextensible member 173.
• a tubular member 175 having convoluted walls may be used, withconstraint 176 along one side of the walls; in this case the walls may be made of a material which is longitudinally extensible, like the circumferentially restrained motor element l5, the convoluted form of the walls contributing additional longitudinal freedom.
• FIG. l2 A motor element which resists the tendency to assume a helical configuration when flexed due to applied fluid under pressure is shown in FIG. l2.
• a tubular member 180 similar in all respects to the circumferentially restrained tubular member of the motor element 15 (FIGS. 1-3) is supplied with a longitudinal restraint member 181 in the form of two side elements 182 and 183 joined by cross-elements 184.
• This restraint member is preferably made in the manner of a bicycle chain, so that it resists twisting, and a motor element using it will then tend to flex in a plane.
• Such motor elements may be used singly on either side 85, 87 o f the manipulative tool shown in FIG. 8, as is illustrated in FIG. 13.
• the restraint member 18 if in the form of' a bicycle chain, can be a single restraint member extending between both motor elements, and can be joined at an intermediate region to the top wall 188 of the manifold 80.
• This arrangement provides a highly improved chain wrench.
• FIG. 14 shows a pressure gauge 190 incorporating a motor element 191 according to the invention.
• the gauge has a housing 192 provided with a cover (not shown) having an arcuate window 193 shown in dashed outline.
• the motor element is mounted at the pressure input end 191.5 in a tube 194 passing through the housing 192 and bent inside the housing so that when the motor element 191 is in the relaxed state its closed end 191.7 lies under the left hand end (in FIG. 14) of the window 193.
• An indicator mark 195 is on the motor element near the closed end 191.7 and disposed to be visible through the window 193.
• the longitudinal restraint member 196 of the motor element 191 is so oriented that when fluid under pressure in excess of ambient atmospheric pressure is admitted to the motor element (via the tube 194) the motor element flexes to the right (in FIG. 14) and the indicator mark 195 moves along the window 193. Indicia (not shown) can be located along the window so that deflection of the indicator mark 195 can indicate the pressure applied at the tube 194.
• This arrangement is a sensitive pressure gauge, which can be made to measure small pressure changes over a full scale deflection of the indicator mark 195. Unlike Bourdon gauges, which flex only very slightly, the gauge of FIG. 14 does not require additional mechanical elements to move a pointer over a scale.
• the motor element 191 is the sole movable member. 1t will be understood that the gauge 190 can be designed to measure absolute pressures as well as relative pressures, since as is explained above, the motor element 191 can flex in response to applied pressure below ambient in addition to applied pressure in excess of ambient.
• An elongated tubular body comprising a structure which is limited against circumferential extension substantially uniformly throughout its length, a longitudinal section of said structure being limited against extension in the longitudinal direction, the remainder of said structure being rcversibly cxtensible in said longitudinal direction, whereby inflation of said structure with a fluid will cause said structure to flex.
• An elongated tubular body comprising a flexible structure, means for limiting said structure against circumferential extension substantially uniformly throughout its length, means for limiting a longitudinal section of said structure against extension in the longitudinal direction, the remainder of said structure being reversibly extensible in the longitudinal direction, whereby inflation of said structure with a fluid will cause said structure to flex.
• a tubular body according to claim 2 in which said means for limiting against circumferential extension comprises elongated substantially nonextensible material oriented transversely to said longitudinal direction in restraining relation with the walls of said body.
• a tubular body according to claim 2 in which said means for limiting said longitudinal section against extension comprises flexible but substantially nonextensible material oriented in said longitudinal direction in restraining relation with said longitudinal section.
• a tubular body according to claim l a wall of which varies in thickness along said longitudinal direction, whereby inflation of said structure with a fluid will cause said structure to flex nonuniformly along said direction.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Engineering & Computer Science (AREA)
• Robotics (AREA)
• Actuator (AREA)

Abstract

Description

Claims (7)

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Cited By (21)

Citations (1)

• 1969
  • 1969-11-24 US US872456A patent/US3561330A/en not_active Expired - Lifetime

Patent Citations (1)

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