|Publication number||US3719112 A|
|Publication date||Mar 6, 1973|
|Filing date||Aug 24, 1970|
|Priority date||Aug 24, 1970|
|Publication number||US 3719112 A, US 3719112A, US-A-3719112, US3719112 A, US3719112A|
|Original Assignee||Lockheed Aircraft Corp|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (6), Classifications (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent 91 Kaelon March 6, 1973 1 DEVICE FOR TURNING AN ELEMENT Kenneth C. Kaelon, Calif.
 Inventor: Rosemaed,
 Assignee: Lockheed Aircraft Corporation,
22 Filed: Aug. 24, 1970 211 Appl. No.: 66,481
 US. Cl. ..81/57.39  Int. Cl. ..B25b 13/46  Field of Search ..81/54, 57.33, 57.34, 57.35,
FOREIGN PATENTS OR APPLICATIONS 1,030,280 5/1958 Germany ..81/54 Primary ExaminerJames L. Jones, Jr. Att0rneyFrank L. Zugelter and George C. Sullivan 5 7 ABSTRACT An assembled device for turning or torquing an element such as a nut, bolt or the like, comprising a pneumatic actuator operatively connected to a ratchet wrench, both being peculiarly tied to an anchoring or bar. A pneumatic source of pressure, such as air, is provided for operation of the actuator which includes a piston. A valve conveys fluid to the actuator and is operatively connected to a positioning mechanism provided for automatically actuating the valve to transmit the pneumatic pressure developed by the fluid flow to alternate sides of the piston in order to obtain reciprocation of the wrench about its element. This mechanism includes an assembled displaceable rod, operatively connected to the wrench, and a compressible spring for storing energy transferable to an arm which actuates the valve between its alternate positions. The mechanism stores sufficient energy dur ing either half-cycle of such reciprocation to snap the arm at each end of travel of the wrenchs angular rotation. The valve may be locked in either of its alternate positions by a detent means holding the arm in a corresponding one of its two positions. A cylinder means for directly measuring the force developed by the pneumatic actuator is mounted between the latter and the reaction bar to which it is connected, and a gauge is provided to record the force required to turn the element.
10 Claims, 5 Drawing Figures PATU-JTEEHAR e um SHEET 10F 3 INVENTOR. KENNETH C. KAELON BY l I *1- M Attorney k N mm 95 .7 Q at" E A\ .v
DEVICE FOR TURNING AN ELEMENT BACKGROUND OF THE INVENTION 1. Field of the Invention The field of art to which the invention is most likely to pertain is located in a class of devices generally relating to wrenches. Class 81, Tools, and Class 173, Tool Driving or Impacting, U.S. Patent Office Classifications, may be the applicable general areas of art in which the claimed subject matter of the type involved here may be classified.
2. Description of the Prior Art Examples of prior art devices in the arts to which this invention most likely pertains are U.S. Letters Pat. Nos. 1,808,959; 2,560,716; 2,786,379; 2,836,090.
3. Problems Encountered In the installation and removal of an airplane engine, prescribed downtime limit in removing it for maintenance operations and again installing the engine has been difficult to achieve. The situation in the past has required application of an ordinary torque wrench to the engines mounting bolts, one after the other, by several men in order to accomplish installation or removal. Limited access to and working room about the mounting bolts have added to the difficulty of such installation and removal. In addition, present-day maintenance of an airplane engine requires a limited time in which to change such engine in its mounting, as the cost of maintenance has risen sharply during recent years. The necessity of maximizing the time for utilization of the engine on the aircraft, in view of its price and maintenance costs, demands minimum downtime.
Furthermore, manual torquing to a high value does not provide a uniform degree of torque within required tolerance limitations for all mounting bolts for one engine. For example, a specific torque within the range of 600-800 lb-ft. is necessary for properly securing a jet engine in its mounting in one of todays giant aircraft, such as in the assignees L-lll aircraft. A torque wrench, although used in conjunction with a torque gauge, does not necessarily provide sufficient torque holding time at the required tolerable limit for all tightened bolts on such an engine, and as a result, the applied torque may vary from one bolt to the next. Also, use of an impact tool lacks tolerance control for a given torque value. The result is advanced or undue maintenance operation upon either the engine or its mounting structure, whereas were a uniform torque within tolerance controls achieved across all bolts, maximum proper securement without possible ill effect from otherwise improper torquing results.
Furthermore, torque wrenches are notoriously known as knuckle busters, and even the most experienced and competent mechanic is subject to injury in application thereof at a given time and in a given instance. A form of feed-back which may take place is a tendency for a torque wrench to turn about its socket axis at the element; i.e., its socket will try to turn off of the element. For example, a turning moment in a vertical plane occurs on the device at the element being rotated in a horizontal plane. Slippage of the device completely off the element may quickly occur, with consequent injury to the mechanic and damage to element and surrounding structure easily following. Such likelihood of injury and damage increases with application of higher torque values.
SUMMARY OF THE INVENTION This invention generally relates to a device for turning or torquing and more particularly relates to an assembled device including a torque wrench and a pneumatic cylinder which are automatically reciprocated for tightening or loosening an element such as a nut, bolt, or the like.
An object of this invention is to provide a novel and efficient device for torquing.
Another object of the invention is to provide uniform and predetermined torque values accurately, with measurement thereof, whereby specified tolerance limits upon an element are achieved, highly desirable in the example of torquing a mounting bolt for an airplane en.- gine.
A further object of this invention is to provide reduction in costs, manpower and time in the installation and removal of an element such as an airplane engine mounting bolt.
Another object of the invention is to provide elimination of the problem of access and working room about an element by utilization of the device.
A further object of this invention is to provide rapid and automatic torquing or untorquing of an element for the purpose of reducing time to within prescribed limits in changing, coupling or uncoupling an element to a mounting structure.
A further object of the invention is to provide a sturdy and simplified construction for a device utilized in torquing an element.
Another object of the invention is to provide prevention of work slippage by including a reaction bar means as a feature of the invention, with corresponding greater degree of success of usage of the device on the element in a lesser time interval and without mishap.
Another object of the invention is to provide elimination of a reaction feed-back to an operator of the device during utilization thereof which in such instances, removes control of the device from the opera- 'tor, with resulting injury possible. A reaction bar fixed to and about which the wrench itself swings is used in connection with achieving this object.
These and other objects of the invention will become more apparent upon a full reading of the following description, the appended claims thereto, and the drawing accompanying this disclosure.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view generally of the preferred embodiment of the invention.
FIG. 2 is a side elevation of the embodiment shown in FIG. 1.
FIG. 3 is an enlarged view, partly in section, of a portion ofFIG. 2.
FIG. 4 is an elevation view, partly in section, at the socket end of the embodiment of FIG. 1.
FIG. 5 is an elevational view, partly in section, of an enlarged portion of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the FIGURES in which reference characters correspond to the following numerals, reference character 10 refers generally to my assembled torquing device. Device 10 comprises a pneumatic means 12 including a cylinder 14 and a piston 16 therein having a shaft 18 extending out its one end for pivotal connection to the handle of a wrench means 20, as at 22. Wrench means 20 is preferably a ratchet-type and readily known and available on the market. Means 12, 20 are mounted upon a reaction member 24 fashioned generally into an L-shaped element disposed below and generally aligned in a plane substantially parallel to the major axes of both means 12 and 20. Reaction member 24 generally comprises a rigid flat metal plate or bar fashioned in an L-shaped manner from stock material. Edge webs 2S and spaced stringers 26 are preferably welded thereto to add additional rigidity, and holes 27 are provided to lighten its weight. It extends rearwardly with the length of wrench means 20, to the proximity of the wrenchs handle where it then angularly turns to extend along the length of and under pneumatic means 12, to be then pivotally connected thereto at its one end. Its one end includes a flanged bushing 28 (FIG. 4) bearingly mounted as at 29 for adaptation of a number of differently sized sockets 30 slidably fitted to a stub 31 of wrench means 20 in a conventional and known way. A riser 32 (FIGS. 2, is welded at its other end for providing a horizontal projection to which a pivotal connection 33 on the rear end of pneumatic means 12 is attached.
It is to be seen in operation of device 10, that in torquing to a high value, such as occurs in torquing airplane engine mounting bolts, there is a turning moment developed on'bushing 28 and socket 30 about an element which tends to force device off the element. Webs 25 and stringers on ribs 26 assure whatever rigidity is required to overcome or withstand the effect of any such moment on wrench means 20. Member 24 is preferably of the configuration shown in the drawing. However, it should be understood that it may take any desirable contour for a given application.
Reaction member 24 may be attached in any suitable manner, say, such as by apertures 34, either directly or by intermediate structural fixtures, to other structure independent of the element, so that in the operation of device 10 on such element, the latter will rotate relative to member 24 which functions as an anchor means for pneumatic means 12 and wrench means 20.
A valve means 35 (FIG. 2,3) for controlling or transmitting flow of fluid to either side of piston 16 in cylinder 14 is mounted on a suitable tray frame 36 adjacently disposed to and supported on pneumatic means 12 by means of its end arms 37, 38. A source of fluid under pressure (not shown), such as bottled or shop air, is suitably connected to a hose 39 (FIG. 1) connected to a trigger means 40 conveniently mounted for the operator, preferably on an extension 41 of reaction member 24. Trigger means 40 actuates a conventional 2-way valve 42 for admission to valve means 35 via a hose 43 of the pneumatic fluid which generates such pressure. An air pressure regulator (not shown) may be connected to valve 42 for regulating the amount of fluid and pressure therefrom into device 10.
Valve means 35 (FIG. 3), although not shown in detail, is preferably a spool-type valve, an example of which is a Series 5040-50 spool valve manufactured and sold by Modernair, a subsidiary of The ARC Corporation, Bryan, Ohio. The Series 5040-50 is a 4-way valve, spring centered, with all ports blocked in neutral.
It conveniently includes for the purpose of this embodiment an arm 45, having its one end pivotally attachecl to an exposed bifurcated end portion of the valve spool shaft 46. Arm 45 is preferably intermediately pinned as at 47 in a bifurcation provided in a fulcrum element 48 provided on the valve housing, in order to make it function as a lever in this preferred embodiment. However,
it should be understood that other equivalent assembly,
between shaft 46 and the actuator means described hereinafter, may be utilized for actuating spool shaft 46 should it be desired. Furthermore, other valves, such as afriction valve, may be utilized to alternate flow of fluid to the opposite sides of piston 16, should this be preferred or desirable.
A roller 49 (FIG. 3) is rotatably mounted in. a bifurcation formed at the other end of arm 45, and engages a riding surface 50 fonned on a spring-biased member 52 slidable in ahousing 54 securely mounted to tray frame 36 above the level of valve means 35. Member 52 includes a key 56 slidable in a slot provided in a coverplate (not shown) for housing 54. A pair of suitably spaced bores 57 are provided in sliding member 52 for seating springs 58. Springs 58 engage the top of housing 54 to provide a downward bias for member 52, whose lower edge is contoured-shaped to provide two detent positions 59, 60. Roller 49 alternately seats in detents 59, 60, depending upon the position of arm 45. With roller 49 in detent position 59, as shown in FIG. 3, the corresponding position of spool shaft 46 of valve means provides for egress of fluid flow through a hose 62 (FIG. 1) from valve means 35 to the piston chamber at the rear end of cylinder 14. Pivoting of arm 45 causes roller 49 to ride into detent position 60, the alternate and corresponding position of spool shaft 46 providing for egress of fluid flow through hoses 62, 64, and thence to their respective side of piston 16 in cylinder 14. Exhaust ports 65, 66 are provided in valve means 35 for discharge of pressurized fluid generated along one side of piston 16 at the in stant arm 45 pivots to begin to establish pressure to the other side of piston 16.
Means are provided to automatically position the valve means 35 to transmit fluid flow alternately to either side of the piston 18 upon the arm 45 pivoting when the wrench means 20 reaches either one of its extreme limits in its cyclic reciprocation. The arm 45 is operatively connected to an actuator means 67. In this preferred embodiment, the arm 45 includes an opening 68 through which a draw rod 69 of actuator means 67 is disposed. Actuator means 67 comprises draw rod 69 mounted in a hollow cylindrical case 70 having an intermediate vertically disposed passageway 71 through which arm 45 is disposed and pinned at 72 thereto. A slot (shown in phantom in FIG. 3) is provided in case 70 for vertical displacement of pin 72 as arm 45 pivots and when case 70 displaces, as it will be seen that case 70 displaces only in a horizontal linear direction compared to the arcuate movement for arm 45. Case 70 includes a pair of opposing bores 72, 74 each having a spring 76, 78, respectively, retained therein by means of a slidable retainer 80 and a snap ring 82 preventing egress of each retainer.
Rod 69 for drawing case 70 and arm 45 to-and-fro projects each of its ends outwardly of case 70 so as to provide for mounting of an end contact element 84, 86 thereon. Each such end element 84, 86 is adapted to contact or engage its associated slidable retainer 80, so as to correspondingly compress springs 76, 78, respectively, in case 70, upon a corresponding lineal displacement of rod 69 in the same direction as the particular end element 84 or 86 compressing its spring 76 or 78. For ease of assembly, contact element 84 is pinned to rod 69, the latter then inserted through case 70, and thereafter contact element 86 threaded and suitably secured to rod 69. Actuator rod 69 is preferably guided in its lineal displacement by means of a tube 88 suitably mounted by means of spaced brackets 90 mounted to tray frame 36.
Rod 69 is securely held or locked to a suitable element 94, which may be a clevis, by suitable means such as a pair of nuts 95.'The element 94 is suitably secured, such as by welding, to the piston shaft 18. Such securement is in juxtaposition to the pivot connection 22 of shaft 18 to the handle of ratchet wrench 20. The relative position of rod 69 is preferably adjustable to element 94 in order to vary the degree of angular rotation of wrench 20 in its cyclic reciprocation, as will become apparent hereinafter.
Thus, actuator means 67 constitutes an assembly or structure for generating and storing energy during reciprocation of wrench means 20 Sufficient energy is stored at either limit of the reciprocation of the wrench means 20 so that it instantly reacts in its cooperation with arm 45 to actuate valve means 35. It should be understood that various modifications may be made in the design of means 67 and arm 45 and which will perform the same functions as those illustrated in this preferred embodiment.
Tray frame 36 at its ends is securely mounted by means of a pair of threaded nuts 99 (FIG. 1) securing its one arm 37 to a tubular projection 100 (FIG. 2) and by its other arm 38 being mounted on a projection 102, both preferably projections integrally formed on the opposite ends of cylinder 14 (FIGS. 2, 5). A pin 104 is secured to arm 37, and extends through a riser 106 welded to tie bar plate member 24. Pin 104 together with threaded nuts 99 on projection 100 assist in maintaining the relative substantially stationary relationship for and between tray 36, pneumatic means 12 and reaction means 24. Piston shaft 18 extends through and out of projection 100 and through a flange bushing 110 seated loosely in an aperture (not shown) of riser 106, to pivotally connect at 22 with ratchet means 20. The flange of bushing 110 is disposed between riser 106 and element 94. Utilization of loosely fitting bushing 110 provides for an efficient operation of device 10, as an arc of movement is demanded for pivot connection 22 in the angular rotation of the handle of wrench means 20. As it may be observed from FIG. 1, the handle of wrench means 20 rotates to its phantom-lined position (exaggerated), piston shaft 18, to a slight degree, changes its axis locus as it advances to rotate such handle. However, the provision of loosely fitting bushing 110 in riser 106 assures that piston 16 does not bind in its chamber motion as its shaft 18 advances and retracts. Of course, cylinder 18 is free to swing about its rear pivot 33 for the slight lateral displacement required during reciprocation of wrench means 20.
A gauge 120 (FIG. 1) is provided for recording a desired dynamic torque applied to an element through wrench means 20 and may be calibrated in terms of lb.- ft., or in terms of pressure generated by pneumatic means 12 and correlated to a torque standard. The gauge 120 may be included in a mechanism or means 122 for measuring the torque generated by the operation of device 10, and as illustrated in FIG. 5. Mechanism 122 comprises a hydraulic chamber 124 formed in a casing 125 and a slidable piston head 126 therein firmly connected to pivot connection 33 through its stern 128. A base 130 is preferably made integral with the casing 124 and is a base 130 threaded to the rear end projection 102 of the casing or cylinder 14 partially forming the pneumatic means 12. As pressure develops in the chamber to either of piston 16 of pneumatic means 12, and ratchet means 20 is turned about its element, a reaction therefrom causes cylinder 14, and thus base 130 to compress upon hydraulic chamber 124, as pivot connection 33 on the reaction bar is fixed, thereby transmitting the value during the operation of the device 10 of the developed hydraulic pressure to the gauge 120 connected to such chamber 124 via a hose 132.
It may be noted here that the mechanism or load cell 122 is oriented in line with the axis of the piston 16, so that the actual value of the force generated by the piston 16 under pressure is accurately measurable by the reaction in the mechanism 122. The use of the gauge 120 provides the operator an immediate indication of such force, but in the more useful terms of torque (lb.-ft.). A closer tolerance in torque values can thus be held in the operation of device 10, with a finer sensitivity in reading the actual torque values. The calibration of the load cell 122 is based on the length of the handle of the wrench means 20 (its pivot distance, i.e.).
The operation of device 10 should be readily apparent from the above description. However, to briefly summarize, socket 30 is engaged to its element and tie bar means 24 is securely fixed to structure independent to that on which the element is mounted. Trigger means 40 is actuated. Air under pressure flows to and through valve means 35, and through one of the two hoses 62, 64 to one of the two ends of cylinder 14. Piston 16 is forced under pressure to linearly displace therein, thereby causing its shaft 18 to rotate the bandle of wrench means 20 about the element. As shaft 18 advances or retracts, as the case may be, actuator rod 69 correspondingly linearly displaces to an extreme left or right as it is operatively connected to shaft 18 through the clevis 94. A corresponding one of control element 84, 86 consequently compresses its associated spring 76, 78 by means of its cooperating retainer ring 80, until such spring generates sufficient kinetic energy to snap case in the direction corresponding to linear movement of rod 69. This in turn pivots arm 45 which is operatively connected to the valve means 35. As the roller 49 rides on surface 50 of spring-biased sliding member 52 and into its alternate detent or locked position 59, 60, valve shaft 46, attached to arm 45, has
shifted the supply of fluid from one of the hoses 62, 64 to the other so that pressure now generated in cylinder 14 causes piston 16 to linearly displace in the opposite direction. This, wrench means 20 and socket 30 are rotated in a likewise opposite direction. This cycle is automatically continued as long as trigger means 40 is maintained in actuated position.
It matters not as to where the handle of wrench means 20 is resting upon triggering valve 42; i.e., at either of its ends of reciprocating travel or intermediate such ends, or in which direction its ratchet mechanism will take effect, assuming a pressure charge exists in either end of cylinder 14. Device operates. The conventional mechanism in the head of wrench means 20 determines in which rotational direction its ratchet effect will be directed; i.e., in either tightening or loosening an element. This direction, of course, is readily determinable even before beginning the operation of device 10.
The generated torque about an element is readily measured with each half-cycle of reciprocation of wrench means 20 by a visual inspection of gauge 120, during, say, tightening of a nut and which records the force of the pneumatic means 12 measured by the load cell 122.
During operation of device 10, the reaction means 24 is securely held to a fixed structural mount independent of the mount on which the element is to turn. This, of course, becomes apparent in actual application, as otherwise, the entire device 10 would rotate about the element upon application of pressure in pneumatic means 12. Such an independent structural mounting is readily ascertainable and prepared by a skilled mechanic in the pertinent art, upon knowledge of physical structures surrounding the element to which device 10 is applied.
Pursuant to the requirements of the patent statutes, the principle of this invention has been explained and exemplified in a manner so that it can be readily practiced by those skilled in the art to which it pertains, or with which it is most nearly connected, such exemplification including what is presently considered to represent the best embodiment of the invention. However, it should be clearly understood that the above description and illustrations are not intended to unduly limit the scope of practiced appended claims, but that therefrom the invention may be practice otherwise than as specifically described and exemplified herein, by those skilled in the art, and having the benefit of this disclosure.
Therefore, what 1 claim as patentably novel is:
l. A device for torquing an element comprising in combination,
means fitable to the element,
pneumatic means including a piston having a shaft operatively connected to and for reciprocating said means fitable to the element,
valve means for alternately conveying fluid and thereby transmitting pressure to one of the two sides of said piston,
an arm for actuating said valve means,
means for actuating said arm upon release of generated and stored energy in said actuating means, whereby fluid in said valve means is conveyed to the alternate side of said piston, and
detent positioning means co-operatively related to said arm,
release of such energy in said actuating means pivotan actuator rod in said case and projecting from its ends,
spring means mounted and retained in each half of said case about actuator rod,
a contact element mounted along each end of said actuator rod for compressing its corresponding spring means upon reciprocation of said means fitable to the element, and
means securing said rod to said shaft whereby said rod displaces with such reciprocation.
4. The device of claim 1 in which said detent positioning means comprises a biased slidable member having alternate detent positions connected by a contoured riding surface, and
a roller mounted on said arm for riding on said surface into either of said detent positions,
said roller being locked in one of said detent positions until the release of energy generated and stored in said actuating means causes said arm to actuate said valve means,
thereby re-positioning said roller in the other of said detent positions and said valve means in its alternate position.
5. A device for turning an element such as a nut, bolt or the like comprising in combination,
wrench means including a handle adapted for the element to be turned,
a pneumatic means including a piston having its shaft extending through its one end operatively connected to the handle of said wrench means for rotating said wrench means about such element,
a reaction member having one of its two ends operatively connected to said wrench means, said pneumatic means being operatively connected at its other end to said reaction member, said member being adapted for securement to a fixture independent of such element,
valve means for transmitting fluid flow to either side of said piston,
means for automatically positioning said valve ineans to transmit such fluid flow alternately to either side of said piston,
said positioning means comprising,
an actuator means, and I an arm being operatively connected to said valve means for alternately positioning said valve means and being operatively connected to said actuator means,
said actuator means comprising,
a rod having its one end operatively secured to said shaft in juxtaposition to said one end of said wrench means,
spring means mounted and retained on said rod for generating and storing sufficient energy to cause said operatively connected arm to react upon an extreme displacement of said rod by said shaft, and
means for compressing said spring means thereby generating such energy,
whereby said arm so reacts as to reposition said valve means.
6. The device of claim including a case about said rod and having a passageway intermediate its length separating into respective halves said case,
said arm extending through said passageway, being pinned to said case,
said spring means comprising a pair of coiled springs mounted on said rod each being retained in one of said respective halves,
opposing contact elements secured on said rod each capable of compressing a respective one of said pair of coiled springs upon displacement of said rod in the direction of lineal movement of such contact element. I
7. The device of claim 6 in which said arm is pivotable about said valve means.
8. The device of claim 7 in which said arm is a lever fulcrumed to said valve means.
9. The device of claim 6 including detent positioning means for locking said valve means in one of its two alternate positions.
10. The device of claim 9 in which said detent positioning means comprises a biased slidable member having two detent positions connected by a contoured surface and a roller mounted on said arm for riding on said contoured surface to either of said detent-positions as said arm is caused to re-act uponactuation of said actuator means.
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|International Classification||B25B21/00, B25B23/145|
|Cooperative Classification||B25B21/005, B25B23/145|
|European Classification||B25B23/145, B25B21/00D2|