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Publication numberUS3686983 A
Publication typeGrant
Publication dateAug 29, 1972
Filing dateJul 20, 1970
Priority dateJul 20, 1970
Publication numberUS 3686983 A, US 3686983A, US-A-3686983, US3686983 A, US3686983A
InventorsAndrew Flagge
Original AssigneeThor Power Tool Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Torque applying and tension controlling device
US 3686983 A
Abstract
A torque transmitting and controlling device is disclosed, wherein at least one fluid motor having a low stall torque is connected to one end of a shaft and is adapted to apply a predetermined low torque to one of a pair of threaded members connected to the other end of the shaft. At least one other fluid motor is connected to the shaft through an overrunning clutch so that the first motor is prevented from driving the second fluid motor during the low torque applying operation. When fluid under pressure is supplied thereto, the second fluid motor rotates the shaft an additional number of degrees to develop a desired tension in one or the other of the threaded members. A cam carried by one of the rotatable parts of the device actuates a valve in the fluid circuit of the device to shut off the flow of fluid to the second fluid motor after the shaft has rotated the additional number of degrees. At the completion of the torquing and tensioning operation, the device automatically applies a mark to structure adjacent the threaded members to indicate that the members have been tensioned. During or after disengagement of the device from the threaded members, an automatically or manually actuated valve in the fluid circuit of the device causes the first fluid motor or a separate fluid motor to rotate the shaft in a direction opposite from the direction of rotation thereof during the torquing operation until a pair of stops respectively carried by one of the parts of the overrunning clutch and the supporting frame of the device engage each other. The spacing between the two stops is adjustable to permit adjustment of the final tension obtained in one or the other of the threaded members.
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United States Patent Flagge [451 Aug. 29, 1972 [54] TORQUE APPLYING AND TENSION CONTROLLING DEVICE [72] Inventor:

[73] Assignee: Thor Power Tool Company, Aurora,

ill.

[22] Filed: July 20, 1970 [21] Appl. No.: 56,402

Andrew Flagge, Aurora, Ill.

Primary Examiner-James L. Jones, Jr. Attorney-Hibben, Noyes & Bicknell [57] ABSTRACT A torque transmitting and controlling device is dis closed, wherein at least one fluid motor having a low stall torque is connected to one end of a shaft and is adapted to apply a predetermined low torque to one of a pair of threaded members connected to the other end of the shaft. At least one other fluid motor is connected to the shaft through an overrunning clutch so that the first motor is prevented from driving the second fluid motor during the low torque applying operation. When fluid under pressure is supplied thereto, the second fluid motor rotates the shaft an additional number of degrees to develop a desired tension in one or the other of the threaded members. A cam carried by one of the rotatable parts of the device actuates a valve in the fluid circuit of the device to shut off the flow of fluid to the second fluid motor after the shaft has rotated the additional number of degrees. At the completion of the torquing and tensioning operation, the device automatically applies a mark to structure adjacent the threaded members to indicate that the members have been tensioned. During or after disengagement of the device from the threaded members, an automatically or manually actuated valve in the fluid circuit of the device causes the first fluid motor or a separate fluid motor to rotate the shaft in a direction opposite from the direction of rotation thereof during the torquing operation until a pair of stops respectively carried by one of the parts of the overrunning clutch and the supporting frame of the device engage each other. The spacing between the two stops is adjustable to pemiit adjustment of the final tension obtained in one or the other of the threaded members.

19 Claims, 18 Drawing Figures Patented Aug, 29, 1972 3,686,983

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Patented Aug. 29, 1972 115 Sheets-Sheet l0 Patented Aug. 29, 1972 3,686,983

15 Sheets-Sheet 11 15 Sheets-Sheet 12 Patented Aug. 29, 1972 Patented Aug. 29, 1972 1:5 Sheets-Sheet 13 TORQUE APPLYING AND TENSION CONTROLLING DEVICE This invention relates to a torque applying and tension controlling device and more particularly to a device for rapidly and accurately controlling the tension in one or the other of a pair of threaded members.

Various devices have been developed heretofore practicing the so-called tum-of-the-nut method of tensioning one or the other of a pair of threadedly engaged members in order to accurately control the tension developed in one of the members. Such method involves the application of a predetermined low torque to one or the other of the threaded members to eliminate any clearance between the members and to establish a reference torque setting, and thereafter rotating one or the other of the threaded members a predetermined additional number of degrees in a direction to increase the tension in one or the other of the threaded members to a desired value. A more detailed explanation of the turn-of-the-nut method of tightening threaded fasteners is contained in an article by 1.0. Almen entitled How Tight Should a Bolt Be?, which appeared in the Volume 1, Number 2 issue of Fasteners magazine (1944).

Accurate control of the tension in one or the other of a pair of threaded members is important where the members comprise a fastener for holding other parts in assembled relation. For example, it is important that the tension forces in the fasteners that secure the connecting rods to the cranks of an internal combustion engine be substantially equal and within prescribed limits. If such forces are unequal or outside the prescribed limits, premature wear of the connecting rod bearings and/or failure of the fasteners may occur. While many of the devices heretofore advanced have proven generally satisfactory for this purpose, others have not for various reasons, such as inability to achieve uniform and accurate tensioning between successive operations, complexity of construction, and unreliability of operation.

Accordingly, it is the general object of the present invention to provide a novel and improved torque applying and tension controlling device for accurately controlling the tension developed in one or the other of a pair of threadedly engaged members.

Another object is to provide a novel torque applying and tension controlling device of the foregoing character, which is capable of rapidly and automatically developing a desired tension in one or the other of a pair of threaded members.

A further object is to provide a novel torque applying and tension controlling device of the foregoing character, which is particularly suited for use in mass production operations.

A more particular object is to provide a novel torque applying and tension controlling device for developing a predetermined tension in one or the other of a pair of threaded members wherein the stall torque of at least one fluid motor is utilized to apply a predetermined low torque to one of the threaded members such as will establish positive contact between the members and wherein at least one other fluid motor is utilized to rotate the threaded member a predetermined additional number of degrees in the same direction to establish a final tension in one or the other of the threaded members.

A specific object is to provide a novel and improved torque applying and tension controlling device which is capable of simultaneously and automatically tensioning a pair of threaded members, such as the nuts which secure the connecting rod bearing cap to the lower end of a connecting rod of an internal combustion engine.

Other objects and advantages of the invention will become apparent from the following detailed description and accompanying sheets of drawings, wherein:

FIG. 1 is a front elevational view of a torque applying and tension controlling device embodying the features of the present invention;

FIG. 2 is an enlarged side elevational view of the lower portion of the device shown in FIG. 1, taken substantially along the line 2-2 of FIG. 1, and showing the device as it would appear when in operation;

FIG. 3 is a transverse sectional view taken substantially along the line 3-3 of FIG. 1;

FIG. 4 is a top plan view taken substantially along the line 4-4 of FIG. 1;

FIG. 5 is a fragmentary, longitudinal sectional view,

with some parts in elevation, taken substantially along the line 5-5 of FIG. 3;

FIG. 6 is a fragmentary, longitudinal sectional view, with some parts in elevation, taken substantially along the line 6-6 of FIG. 3;

FIG. 7 is a transverse sectional view taken along the line 7-7 of FIG. 5;

FIG. 8 is a transverse sectional view taken substantially along the line 8-8 of FIG. 1, and showing the positions that certain parts of the device occupy during one portion of the operating cycle thereof;

FIG. 9 is a view similar to-FIG. 8 but showing certain parts of the device in the positions they occupy during another portion of the operating cycle of the device;

FIG. 10 is a schematic diagram of the fluid circuit utilized in the torque applying and controlling device illustrated in FIGS. 1-9, inclusive;

FIG. 11 is a front elevational view of another torque applying and controlling device embodying the features of the present invention;

FIG. 12 is a side elevational view of the lower portion of the device shown in FIG. 11, taken substantially along the line 12-12 of FIG. 11, and showing the device as it would appear when in operation;

FIG. 13 is a schematic diagram of the fluid circuit employed in the torque applying and controlling device illustrated in FIGS. 11 and 12;

FIG. 14 is a front elevational view of another torque applying and tension controlling device embodying the features of the present invention;

FIG. 15 is a somewhat enlarged side elevational view of the lower portion of the device shown in FIG. 14 taken substantially along the line 15-15 of FIG. 14 and showing the device as it would appear when in operation;

FIG. 16 is a transverse sectional view taken along the line 16-16 of FIG. 14;

FIG. 17 is a transverse sectional view taken along the line 17-17 of FIG 15; and

FIG. 18 is a schematic diagram of the fluid circuit utilized in the torque applying and tension controlling device illustrated in FIGS. 14-17.

Briefly described, the present invention contem-- plates a novel torque applying and tension controlling device for applying a predetermined low torque to one or the other of a pair of threadedly engaged members and then rotating one or the other of the threadedly engaged members an additional number of degrees to obtain a desired tension in one of the members. While the specific embodiments of the device, to be hereinafter described in detail, are adapted to simultaneously apply torque to a pair of nuts so as to tension studs on which the nuts are threaded, such embodiments may also be used to apply torque to and simultaneously tension a pair of cap screws, if such mode of operation is desired. The torque applying and tension controlling device comprises a support in the form of arielongated frame having driving means extending from one end thereof. Such driving means comprises a pair of longitudinally extending, transversely spaced spindles which are rotatably mounted in the lower portion of the frame. The lower ends of the spindles may be provided with a socket or other device for transmitting torque to an associated threaded member.-

First drive means in the form of at least one and preferably a pair of fluid motors are mounted on the frame and connected to the spindles to effect rotation thereof in a direction to apply a predetermined low torque to the threaded members with which the spindles are engaged and thereby establish positive contact between the members. Such low torque is obtained by adjusting or designing the first pair of fluid motors so that they will stall at the predetermined low torque.

Second drive means in the form of at least one other and preferably a pair of second fluid motors are also mounted on the frame closely adjacent to and in sideby-side relation with the first pair of fluid motors and are connected to the spindles through overrunning clutches. The second pair of fluid motors are turned on after the first pair of fluid motors have stalled and serve to rotate the spindles a predetermined additional number of degrees to thus obtain a final tension in one or the other of the threaded members. The overrunning clutches are arranged so that during the application of the low torque to the threaded members the second pair of fluid motors are not driven by the first pair of fluid motors.

Shut-off of the second pair of fluid motors after the desired tension is obtained in the threaded members is achieved by rotation limiting means in the form of a valve mounted on the frame of the device and operable to effect a shut-off of the flow of fluid under pressure to the second pair of fluid motors. Such rotation limiting valve, in the present instance, is actuated by a plunger which rides on a cam secured to one of the clutch members of one of the overrunning clutches. 7

On completion of the tensioning operation, the torque applying and tension controlling device of one of the embodiments includes means for automatically restarting the first pair of fluid motors upon disengage ment of the device from the previously tensioned threaded members so that the device is recycled and ready to be engaged with and tension another pair of threaded members. In this embodiment, an actuating member in the form of an elongated push rod is shiftably mounted in the frame of the device for engaging structure between or adjacent to the threaded members. The push rod is connected to a flow reversing valve in the fluid circuit of the device and such valve effects a reversal of the direction of flow of fluid to the first pair of fluid motors, which are reversible in this embodiment, to thus effect rotation of the spindles in a reverse direction. The cam carried by one of the clutch members of one of the overrunning clutches thus also runs in a reverse direction until stopped by stop means.

Such stop means comprises a first stop member mounted on the frame of the device and another stop member mounted on the clutch member which carries the cam. Thus, in this embodiment, the device is automatically reset for another torquing and tensioning operation upon removal or disengagement of the sockets on the lower ends of the spindles from the threaded members with which the device was previously engaged.

In a second embodiment, reversal of the first set of bodiment, after the first pair of fluid motors has applied a predetermined low torque to the threaded members and the second pair of fluid motors has rotated the threaded members through a predetermined number of degrees to obtain a final tension therein, restarting of the first pair of fluid motors and rotation thereof in a reverse direction after the device has been removed from the threaded members is achieved by manually operating the aforementioned reversing valve. In this embodiment, the first pair of fluid motors are also reversible but operation thereof in a reverse directionv to recycle the device requires actuation of a manually operated valve.

' In a third embodiment, recycling of the device also requires actuation of a manually operated valve carried on the frame of the device. Howev'enunlike the previous embodiments, the first pair of fluid motors of this embodiment are not reversible. Instead, on additional or auxiliary fluid motor is connected to the gearing of the driving means and the first pair of fluid motors. Thus, when the auxiliary fluid motor is operated, the spindles and consequently the cam carried by one of the clutch members of one of the overrunning clutches rotate in a reverse direction until the stop members engage each other.

In each of the embodiments, marking means in the form of an air pen is provided for automatically applying paint or other marking material to structure between or adjacent to the threaded members to indicate completion of a torquing and tensioning operation.

The torque applying and tension controlling device of the present invention also includes a fluid circuit for' supplying fluid under pressure to and controlling the operation of the first and second pairs of fluid motors. Such circuit comprises supply conduit means adapted to be connected to a source of fluid under pressure, preferably compressed air, for supplying fluid under pressure to the first and second pairs of fluid motors. The supply conduit means includes a first supply branch conduit connected to the first pair of fluid motors and a second supply branch conduit connected to the second pair of fluid motors. First and second fluid pressure actuated valve means are also respectively provided in the first and second supply branch conduits for controlling the flow of fluid under pressure to the fluid motors.

The fluid circuit also includes control conduit means connected to the supply conduit means for controlling the operation of the first and second fluid pressure actuated valve means. Thus, the control conduit means includes a first control branch conduit connected to the first fluid actuated valve means and a second control branch conduit connected to the second fluid pressure actuated valve means. In addition, at least one and preferably a pair of throttle valves are provided in the control conduit means for starting and stopping the device.

The arrangement is such that when an operator shifts the throttle valves to a position to start the device, fluid under pressure is communicated to the first fluid pressure actuated valve means and the latter shifts in one direction to permit fluid under pressure to be supplied to first pair of fluid motors through the first supply branch conduit. A predetermined low torque is thus applied to the threaded members. Sequencing means in the form of a restriction in the second control branch conduit connected to the second fluid pressure actuated valve means prevents actuation of the second fluid pressure actuated valve means and operation of the second pair of fluid motors until a predetermined time interval has elapsed sufficient to allow the first pair of fluid motors to apply the low torque to the threaded members.

After the second fluid pressure actuated valve means has shifted to a position permitting fluid under pressure to be supplied through the second supply branch conduit to the second pair of fluid motors and the latter are rotating, a rotation limiting and position responsive valve in a third control branch conduit of the circuit causes the second fluid pressure actuated valve means to shift to another position preventing fluid under pressure from being supplied to the second pair of fluid motors. Consequently, the second pair of fluid motors are shut off after the threaded members with which the device is engaged have rotated the predetermined additional number of degrees. At the same time, the marking means is actuated and the structure adjacent to the threaded members is marked to indicate completion of the tensioning operation.

In the one embodiment, disengagement of the device from the threaded members after completion of a tensioning operation permits the flow reversing valve in a fourth control branch conduit of the circuit to be opened by extension of the push rod. The first fluid pressure responsive valve is then shifted to another position reversing the flow of fluid under pressure in the first supply branch conduit to reverse the direction of rotation of the first pair of fluid motors and thus recycle the device.

In the second embodiment, the flow reversing valve is manually operated when the device is disengaged from the work after a tensioning operation, rather than being automatically operated by a push rod.

In the third embodiment, the additional or auxiliary fluid motor is provided in a third supply branch conduit of the circuit and the manually operated flow reversing valve is mounted in a fourth control branch conduit and is connected so as to cause a third fluid pressure actuated valve means to permit fluid under pressure to be supplied to the additional or auxiliary fluid motor to recycle the device at the completion of a tensioning operation.

THE EMBODIMENT SHOWN IN FIGS. 1-10 In FIG. 1 a torque applying and tension controlling device embodying the features of the present invention is illustrated. The device shown in FIG. 1 comprises a support or frame 21 upon which the other components of the device are mounted. As shownin FIG. 1, the frame 21 includes a yoke having vertically extending legs 22 and a connecting portion 23 connecting the upper ends of the legs 22. A socket 25 is shown mounted on the upper side of the connecting-portion 23 for receiving the lower end of a support arm (not shown) which facilitates movement of the'device.

The upper ends of a pair of extensions 24 are pivotally connected, as by screws 26, to the lower ends of the legs 22 of the yoke to permit pivotal movement of the extensions 24 about the screws 26. Set screws 27 may be threaded into the lower ends of the legs 22 for engaging the extensions 24 and maintaining a desired angular relationship between the extensions 24 and the legs 22.

A generally circular plate 30 (FIGS. 1, 2 and 3) is secured, as by screws 31, to the lower ends of the extensions 24 and serves as a mounting for first and second drive means of the device. Such first drive means, in the present instance, comprises a pair of closely adjacent, transversely spaced fluid motors 32 and 33 (FIG. 2) secured to the upper surface of the plate 30 by screws 34 which extend through a mounting plate 35 at the lower end of each motor and which are threaded into the plate 30. The fluid motors 32 and 33 are preferably of the type manufactured and sold by the Thor Power Tool Company of Aurora, Illinois, and identified by their number 3301 M-275, model No. 1101 1A.

Second drive means in the form of another pair of closely adjacent, transversely spaced motors '36 and 37 (FIGS. 1 and 2) are also mounted on the upper surface of the plate 30, in side-by-side relation with the motors 32 and 33, as by screws 38 which extend through a mounting flange 39 at the lower end of each motor and which are threaded into the plate 30. The fluid motors 36 and 37 are likewise preferably of the type manufactured and sold by the Thor Power Tool Company of Aurora, Illinois and-identified by their number 6M- 300R, model No. S-098l9-AA. The function and sequence of operation of the fluid motors 32,33 and 36,37 will be described more fully hereafter and in connection with the operation of the device shown in FIG. 1.

Another generally circular plate 40 is connected to the underside of the plate 30 and maintained in vertically spaced relation therefrom by four, vertically ar ranged, symmetrically spaced rods 42 (FIGS. 1 and 2). The rods 42 are preferably hexagonal in cross section between the plates 30 and 40 and have threaded, smaller diameter cylindrical upper and lower ends which extend through openings in the plates 30 and 40 and which define shoulders on the rods 42 that engage the lower surface of the plate 30 and the upper surface of the plate 40, respectively. A nut 43 may be threaded onto the lower end of each rod 42 to secure the plate 40 thereto. The upper ends of the rods 42 extend through openings in the plate 30 and are threaded in axial bores in the lower ends of four other rods 44 (FIGS. 1, 2 and 3) which extend upwardly from the upper surface of the plate 30. The rods 44 are also hexagonal in cross section and have their upper ends 46 threaded into another circular plate 50 spaced above the plate 30. The plate 50 serves as a mounting for the upper ends of the motors 32,22 and 36,37, and also as a manifold for directing fluid under pressure into and receiving fluid discharging from the motors, as will be more fully described hereafter.

The device illustrated in FIG. 1 also includes driving means for applying torque to and increasing the tension to a desired value in one or the other of two pairs of threadedly engaged members. Such driving means, in the present instance, comprises a pairof spindles S2 and 53 FIGS. 1, 2 and which are rotatably mounted in bearings 56 and 57 in the plates 30 and 40, respectively. The lower end of each spindle 52 and 53 may be provided with a spring loaded adaptor 58 to which a socket 59 or other torque transmitting device may be secured. In FIG. 2, the sockets 59 are shown engaged with a pair of hexagonal nuts 62 such as are used to secure a bearing cap 63 to the lower end 64 of a connecting rod of an internal combustion engine and around a crank portion 65 of the engine crank shaft.

The upper end of the spindles 52 and 53 are splined .to the output shafts of the motors 32 and 33, respectively, so that the motors 32.and 33 impart rotation to the sockets 59 directly through the spindles 52 and 53 when the motors 32 and 33 are in operation. The output shaft of the motor 32, is indicated at 66 in FIG. 5.

As heretofore mentioned, the torque applying and tension controlling device illustrated in FIG. 1 includes overrunning clutch means for transmitting torque from the second pair of fluid motors 36 and 37 after the first .pair of fluid motors 32 and 33 have applied a predetermined low torque to the threaded members with which the device is engaged and after the first pair of fluid motors have stalled and are shut off. Such overrunning clutch means comprises'a pair of overrunning clutches 70 and 71 (FIGS. 1, 2 and 5), respectively mounted on the spindles 52 and 53. The overrunning clutch 70, in the present instance, comprises a first or inner, annular clutch member 72 mounted on the spindle 52 and fixed against rotation relative thereto as by a key 73. A second or outer clutch member 74 includes a hub portion 76 mounted on and relatively rotatable with respect to the spindle 52 and a larger diameter, annular portion 77 which depends from the hub portion 76 and is spaced radially outwardly from the clutch member 72. A plurality of intermediate clutch elements 78 are positioned between the clutch member 72 and the annular portion 77 of the clutch member 74, and are retained in such relation by an annular plate 82 which engages the lower ends of the clutch elements 78. A snap ring 83 holds the plate 82 in the clutch member 74. The lower end of the inner or first clutch member 72 bears against a plate 84 which is secured to the annular plate 40 by a plurality of screws, only one of which is shown in FIG. 5 and is indicated at 86. The plate 84 also serves to retain the lower bearing assembly 57 for the spindle 5 2 in the plate 40.

An annular gear 92 is mounted on the hub portion 76 of the second clutch member 74 and is fixed against rotation relative thereto as by a key 93 positioned in axially extending key ways respectively formed in the outer surface of the hub portion 76 and the inner surface of the opening in gear 92. A snap ring 94 retains the gear 92 on the hub portion 76 and confines the key 93 in the key ways.

As best seen in FIG. 7, the gear 92 has external teeth 96 which mesh with external teeth 97 on another gear 98 that is mounted on and fixed against rotation with respect to the output shaft, indicated at 102, of the fluid motor 36. In order to prevent relative rotation between the shaft 102 and gear 98, the shaft 102 is externally splined as at 103 and the inner surface of the gear 98 is axially grooved to receive the splines 103 of the shaft 102. The lower end of the shaft 102 is supportedin a bearing 104 in the plate 40.

The teeth 97 of the gear 98 are also meshed with external teeth 105 on another annular gear 106 secured, as by a key 107, to the hub portion indicated at 108, of the outer clutch member of the overrunning clutch 71 (FIGS. 6, 8 and 9). The hub 1080f the overrunning clutch 71 is mountedon the spindle 53 and is rotatable relative thereto in the manner of the clutch member 74 of the overrunning clutch 70. The overrunning clutch 71 also includes an annular, inner clutch member (not shown) secured to the spindle or shaft 53 as by a key (also not shown), and a plurality of intermediate clutch elements, identical to the clutch elements 78 of the overrunning clutch 70, are positioned between the inner and outer clutch members of the overrunning clutch 71. The overrunning clutch 71 is otherwise identical in construction and operation with the overrunning clutch 70.

The teeth 105 of the gear 106 mesh with external teeth 112 on another gear 113 mounted on the output shaft, indicated at 114, of the fluid motor 36; The gear 113 is fixed against rotation relative to the shaft 114 in the same manner as the gear 98 and shaft 102, that is, the shaft 114 is provided with external splines 115 which are received in axial grooves in the inner periphery of the gear 113. The lower end of the shaft 114 is rotatably joumaled in a bearing 116 in the plate 40, in the same manner as the shaft 102.

Thus, when the motors 32 and 33 are in operation and the spindles 52 and 53 are being driven in a direction to apply torque to the threaded members with which the device is engaged, the overrunning clutches 70 and 71 prevent the motors 32 and 33 from transmitting torque to the motors 36 and 37. In other words, the overrunning clutches 70 and 71 freewheel when the motors 32 and 33 are operating in a direction to apply a predetermined low torque to the threaded members with which the device of FIG. 1 is engaged.

The amount of torque applied by the motors 32 and 33 during the low torque applying operation is controlled by torque limiting means. Such torque limiting means, in the present instance, comprises at least one pair of control valves which are respectively positioned in the fluid passages of the motors 32 and 33 and which restrict the cross sectional areas of the passages. The control valves thus limit to a predetermined value the torque developed by each motor and transmitted to the threaded members with which the device is engaged.

Thus, the motors 32 and 33 stall when the predetermined low torque is reached. In the present instance, the torque control valves of the motors 32 and 33 are positioned in the supply portions of the fluid passages in the motors and are adjustable by manipulation of extensions, indicated at 122 and 123 in FIG. 4, respectively, which project above the plate 50. Another pair of extensions 124 and 125 are also shown in FIG. 4 and these may be used to adjust another pair of valves located in the return portions of the fluid passages in the motors 32 and 33, if the latter were to be operated in a reverse or left-hand direction during a low torque applying operation of the device. The motors 36 and 37 also include torque control valves having extensions 126 and 127 (FIGS. 1 and 4), respectively, which likewise project above the plate 50 and which permit adjustment of the maximum torque developed by these motors by restricting fluid flow through the fluid passages of the motors.

As heretofore mentioned, after a predetermined low torque has been applied to the threaded members by the motors 32 and 33 and the latter have been shut off, the fluid motors 36 and 37 are brought into operation to rotate the spindles 52 and 53, and consequently the threaded members, a predetermined additional number of degrees to obtain a final tension in the members with which the device is engaged, or in an associated pair of threaded members. Thus, when fluid under pressure is supplied to the motors 36 and 37, as will be described hereafter in connection with the operation of the device, the shafts 102 and 114 thereof are driven in a counterclockwise direction as viewed in FIG. 7. Consequently, the gears 92 and 106 and likewise the outer clutch members associated with the hubs 76 and 108, rotate in a clockwise direction. Rotation of the outer clutch members of the overrunning clutches 70 and 71 in a clockwise direction causes the clutch elements to interconnect the inner and outer clutch members. Consequently, the spindles 52 and 53 rotate in a clockwise direction and likewise the threaded members with which the device is engaged. The tension in the threaded members is therefore increased.

In order to limit the amount of rotation of the spindles 52 and 53 by the fluid motors 36 and 37 to a predetermined number of degrees, rotation limiting means is provided. Such rotation limiting means, in the present instance, comprises a valve 130 (FIGS. 1, 2, 8 and 9) in the fluid circuit of the device operable when opened to effect a shut-off of the flow of driving fluid under pressure to the motors. The valve 130 includes a valve body 131 that is mounted on the upper surface of the plate 40 FIG. 1) and includes a reciprocable plunger 132 which extends outwardly from the valve body 131 and into engagement with a cam surface 133 formed in the outer periphery of an annular cam member 134. The cam member 134 is secured around the outer surface of the annular portion 77 of the outer clutch member 74 of the overrunning clutch 70 and, in the present instance, comprises a pair of semi-circular rings 136 and 137 secured together as by screws 138. The screws 138 extend tangentially of the cam member and across the end faces of the rings with the heads of the screws engaging recessed shoulders in the ring 137.

The cam surface 133 is preferably formed by a circumferentially extending groove or reduced diameter portion around the upper end of the cam member 134 which extends over an angle of about 180. The ends of the groove merge with the full diameter of the ring within a few degrees from each end of the cam surface 133. Thus, when the plunger 132 of the valve 130 is engaged with the cam surface 133, the valve 130 is closed and the fluid circuit is set up so that fluid underpressure is supplied to the motors 36 and 37. While fluid under pressure is being supplied to the motors 36 and 37 to cause rotation thereof and the spindles 52 and 53 for the final tensioning operation, the plunger 132 rides on the cam surface 133 as shown in FIG. 8 as the cam member 134 rotates with the clutch member 74.

After the spindles 52 and 53 have rotated the aforementioned additional number of degrees, in the present instance about 180 plus or minus 10, the outer end of the plunger 132 of the valve 130 rides up onto the full diameter portion of the cam member 134, as shown in FIG. 9. Consequently, the plunger 132 is shifted inwardly into the valve body 131 causing the valve 130 to open. When this occurs, fluid under pressure is prevented from being supplied to the motors 36 and 37 and rotation of the motors as well as spindles 52 and 53 is terminated.

Opening of the valve 130 to shut off the motors 36 and 37 also actuates marking means for applying indicia to structure adjacent to the threaded members to provide a visual indication of the fact that the members have been tensioned. Such marking means preferably comprises an air pen 140 (FIG. 1) secured to the plate device of FIG. 1.

After the motors 36 and 37 have ceased to rotate due to opening of the valve 130, and after a spot of paint has been applied to structure between the threaded members by the air pen 140, the operator moves the device away from the threaded members until the sockets 59 are disengaged from the threaded members. Thereafter, a pair of operating levers 144 and (FIG. 3) pivotally mounted adjacent the inner ends of the handles 142 and 143, respectively, are released. Release of the levers 144 and 145 opens an associated pair of throttle valves in the fluid circuit of the device and sets up the circuit for a recycling operation.

As the device is lifted away from the work, the lower end, indicated at 146, of an elongated spring-pressed push rod 147 (FIG. 2) remains in contact with structure between or adjacent to the threaded members so that the push rod 147 moves outwardly or downwardly relative to the device. In FIG. 2, the lower end 146 of the push rod 147 is shown engagedwith the bearing cap 63 at the lower end of the connecting rod 64. Such movement permits a valve 150 in the fluid circuit of the device, which is mounted on the upper surface of the plate 50 (FIG. 1) and which is normally closed when the sockets 59 of the device are engaged with the threaded members or nuts 62, to move to an open position. When the sockets 59 are disengaged from the threaded members or nuts 62 at the completion of a tensioning operation, the flow of fluid under pressure supplied to the fluid motors 32 and 33 is reversed. Consequently, the motors 32 and 33 rotate in a reverse or left-hand direction.

Rotation of the motors 32 and 33 in a reverse direction effects a similar rotation of the spindles 52 and 53 and also of the inner clutch members connected thereto. Reverse rotation of the'inner clutch members of the overrunning clutches 70 and 71 cause the clutch elements to interconnect the inner and outer clutch members. Thus, the cam members 134 is caused to rotate with the outer clutch member 74 in a counterclockwise direction from the position thereof shown in FIG. 9 toward the position thereof shown in FIG. 8.

Rotation of the cam member 134 in a counterclockwise direction from the position thereof shown in FIG. 9 continues until such movement is arrested by stop means. Such stop means preferably comprises a generally triangularly-shaped stop member 152 mounted on the upper surface of the plate 40, and a generally arcuately-shaped stop member 153 mounted on the under surface of the cam member 134 and positioned to engage the stop member 152 as the cam member 134 rotates. In order to permit adjustment of the rotated position of the cam member 134 when the stop member 153 engages the stop member 152, as shown in FIG. 8, the stop member 153 may be provided withza series of circumferentially spaced, axial bores therethrough for receiving a pair of screws 154 and 155 which are inserted into a selected pair of the axial bores in the stop member 153 and threaded into holes in the cam member 137. Thus, since each cycle of operation of the device of FIG. 1 is initiated when the stop members 152 and 153 are engaged and since the position of the stop member 153 is adjustable, the amount of additional rotation imparted to the spindles 52 and 53 by the motors 36 and 37 during the final tensioning operation of the threaded members with which the device is engaged can be accurately controlled. In other words adjustment of the position of the stop member 153 permits accurate control of the point at which the valve 130 is opened and consequently the number of degrees through which the spindles 52 and 53 will rotate before the valve is opened and the motors 36 and 37 are shut off.

After the stop members 152 and 153 are engaged and rotation of the motors 32 and 33 as well as the spindles 52 and 53 hasceased, the flow of fluid under pressure to the motors 36 and 37 is shut off after a predetermined delay. When this occurs, the cycle of operation of the device is completed.

If the operator of the device should at any time release one or the other or both of the operating levers 144 and 145 during a torquing and tensioning operation, the device must be recycled and the operation begun again. To do this, the sockets 59 must be disengagedfrom the threaded members and the device must be shifted a sufficient distance away from the work area to cause the push rod 147 to open the valve 150 and effect a reversal of the direction of flow of fluid under pressure to the motors 32 and 33. These motors will then run in a reverse direction until the stop member 153 engages the stop member 152 and the device is recycled.

DESCRIPTION OF THE FLUID CIRCUIT OF FIG. 10

In F IG. 10 the fluid circuit of the torque applying and controlling device of FIG. 1 is a diagramatically illustrated. Like reference numerals have been used to identify the parts of the device shown in the diagram and illustrated and described in the preceding figures.

The circuit includes an inlet portion having an inlet end 161 that is adapted to be connected to a source of fluid under pressure, preferably compressed air. However, it will be understood that fluids other than compressed air could be used in the circuit shown in FIG. 10.

A filter 162, pressure regulator 163, and a lubricator 164 are represented by circles in the inlet portion 160 of the circuit and identified by legend. Downstream from the lubricator 164, the inlet portion 160 of the circuit divides into a supply conduit means, indicated generally at 165, and a control conduit means, indicated generally at 166. v

' The supply conduit means 165 includes a first supply branch conduit 167 connected to a first fluid pressure actuated valve means in the form of a four-way valve 168. Downstream from the four-way valve 168, the.

supply branch conduit 167 divides into reversible supply and discharge branch conduits 172 and 173, which are connected to the fluid motors 32 and 33 through passages in the manifold plate 50.'Thus, the I direction of rotation of the motors 32 and 33 is deterflows through the branch conduit 172, and in a coun terclockwise direction when compressed air flows through the branch conduit 173. 4

Another or second supply branch conduit 174 is connected to other passages in the manifold plate 50 for supplying compressed air to the passages in the motors 36 and 37 to effect operation thereof. A second fluid pressure actuated valve means in the form of a threeway valve 175 is provided in the supply branch conduit 174 for controlling the flow of air under pressure to the manifold plate 50 and the motors 36 and 37. The threeway valve 175 is normally biased to a position preventing flow through the conduit 174 bya spring 176.

When in the latter position, the valve 175 vents the fluid passages in the motors 36 and 37 to the atmosphere.

The control conduit means 166 of the circuit illustrated in FIG. 10 includes a first portion 177 connected to a shiftable throttle valve 178 to which the left handle 142 of the device is secured. The throttle valve 178 includes a plunger 182 (FIG. 3) positioned to be shifted by movement of the operating lever 144 of the device. A spring 184 normally maintains the valve 178 in a closed position preventing flow through the valve and into a second portion, indicated at 185, of the control conduit means 166, downstream from the throttle valve 178.

The second portion 185 of the control conduit means 166 is connected to another throttle valve 186 (FIGS. 1, 2 and 3) having a plunger I87 positioned to be shifted by the operating lever 145 to open the throttle

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3821991 *May 11, 1972Jul 2, 1974Rockwell International CorpFastener tool
US4219921 *Apr 19, 1979Sep 2, 1980Rockwell International CorporationTension control of fasteners
US4226015 *Apr 19, 1979Oct 7, 1980Rockwell International CorporationTension control of fasteners
US4403663 *Apr 13, 1981Sep 13, 1983Wolff Manufacturing CompanyPower-operated torque wrench
US4442738 *Mar 29, 1982Apr 17, 1984Standard Pneumatic Motor Co., A Division Of Hamilton CompanyAutomatic push-to-start screwdriver
US4522269 *Nov 18, 1982Jun 11, 1985Atlas Copco AktiebolagFor tightening threaded joints
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Classifications
U.S. Classification81/429, 173/178, 81/468, 81/470
International ClassificationB25B23/145, B25B21/00
Cooperative ClassificationB23P19/069, B25B21/002, B25B23/145
European ClassificationB23P19/06E, B25B23/145, B25B21/00C