US 3633445 A
A torque tool having a spring bar and plunger normally positioned in axial alignment with a cylindrical roller seated therebetween in opposing channels formed in the ends of the spring bar and plunger whereupon a predetermined torque being applied on said spring bar the roller is caused to roll up diagonally opposite vertical walls of the mating channels. This movement allows the bar limited relative movement with respect to the plunger, the bar colliding with the inner wall of the tubular housing surrounding the spring bar and plunger to produce an audible warning sound.
Description (OCR text may contain errors)
United States Patent llllllllllllllllllllllzwill!1/1/1111IIIIlllllllll/IIIIIIl/Il/111111Ill/n10,111 101 o 3,140,623 7/1964 Van Hoose 81/52.4 3,018,677 1/1962 Mutolo et al. 81/52.4 3,016,773 1/1962 Woods 8l/52.4
Primary Examiner.lames L. Jones, Jr. Attorney-Barlow and Barlow ABSTRACT: A torque tool having a spring bar and plunger normally positioned in axial alignment with a cylindrical roller seated therebetween in opposing channels formed in the ends of the spring bar and plunger whereupon a predetermined torque being applied on said spring bar the roller is caused to roll up diagonally opposite vertical walls of the mating channels. This movement allows the bar limited relative movement with respect to the plunger, the bar colliding with the inner wall of the tubular housing surrounding the spring bar and plunger to produce an audible warning sound.
PATENTEH JAM 1 m2 INVENTOR SULO A. AIJALA ATTORNEYS TORQUE RELEASE HANDTOOL BACKGROUND OF THE INVENTION This invention relates to improvements in .torque applying tools that produce an audible warning signal upon the application of a predetermined torque on the work.
The problems of torque-applying tools in the past have resulted from a wearing away of the surfaces of the recesses in the adjacent ends of the spring arm and plunger members and also a wearing away of portions of the essential surface configuration of the connecting member therebetween. This results in the torque-applying tool producing its audible signal at a torque force not in agreement with the setting on the housing ofthe tool.
Also the wearing away of the surfaces on the connecting member and the surfaces in the recesses at the ends of the plunger and spring arm vary the frictional resistances between the moving members during their sliding or rotating motion. These varying frictional resistances effect unavoidable inaccuracies with regard to the amount of torque required in causing the tool to produce its audible warning.
Additional problems have resulted where the connecting member rotates out of a recess in the plunger or spring arm and damages its surrounding surface by making Brinnel indentations.
SUMMARY OF THE INVENTION The torque-applying tool has a spring bar trough which the torque is transmitted to the work. The spring bar has a limited lateral movement with respect to the body of the tool and is resiliently coupled to the means through which the torque is applied on the spring bar. The resilient coupling includes a slidable spring-pressed plunger which is connected to the spring bar by means of cylindrical roller which normally seats in concave recesses formed in the ends of said plunger and spring bar. The recesses are adjacent each other and are in axial alignment with the roller held in position by spring bias on said plunger.
When a torque is applied on the spring bar sufficient to overcome the spring pressure on said plunger, the spring will yield and allow the spring bar to move laterally causing the cylindrical roller to roll up out of the bottom of each of the recesses to a tripped position. The distance of lateral movement of the spring bar is limited by its striking the inner wall of the tools tubular housing. The audible sound produced tells the user of the tool that the desired torque has been applied. In the tripped position the axes of the spring bar and plunger are out of alignment and the roller maintains line contact throughout its length with diagonally opposite top edges of the recesses on the respective plunger and spring arm. Upon the torque force being removed, the spring bar will return to normal and the roller returns to its seated position in the respective recesses.
One of the objects of the invention is to provide constant line contact along the diametrically opposite sides of the con necting member with two of the opposing top linear edges of the recesses of the spring bar and plunger respectively when the spring bar is in its tripped position.
Another object of the invention is to provide a tool of the above character wherein the free member connecting the plunger to the spring bar will always return to its initial seated position when the torque is released.
Another object of the invention is to provide a free connecting member of such a configuration so as to gain a more sensitive relationship between the torque applied to the tool handle and the force transmitted to the free connecting member which causes the connecting member to travel from its seated position.
Also an object of the invention is to provide a tool of the above character which allows for corrections to be made between the free connecting member and its seated recess to maintain the necessary tolerances.
A further object of the invention is to provide a free connecting member restricted in its movement such that it doesn't produce surface indentations upon the surface surrounding the recess.
Another object of the invention is to provide a torque tool whose free connecting member is of such a configuration as to prevent, upon repeated usage. the wearing away of the bottom surfaces of the recesses and also wearing away of the essential contact surfaces of the free connecting member which have formerly produced inaccuracies as to the amount of actual torque being applied.
Also an object of the invention is to provide a free connecting member of such a configuration that there is reduced frictional resistance between the free member and the wall surfaces of the recesses as they move relative to each other which results in a more precise measurement of the release torque.
DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the torque tool;
FIG. 2 is a longitudinal sectional view taken along a horizontal plane through the center of the tool as viewed from beneath the tool;
FIG. 3 is a fragmental elevational view of the adjacent ends of the spring bar and the plunger with a roller member in its resting position;
FIG. 4 is a fragmental elevational view of the roller member in its tripped position;
FIG. 5 is a fragmental elevational view partly in section of an alternative embodiment having an adjusting screw in both the plunger and the spring bar to vary the depth of the channel; and
FIG. 6 is a fragmental elevational view of an alternative embodiment having shims to reduce the depth of the channel.
DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIGS. 1 and 2, the number 10 designates the torque applying tool. The elongated tubular housing 12 has a flattened and horizontally slotted end portion providing spaced parallel walls 14 on the top and bottom of the housin g. The other end of the tubular housing is externally screw threaded as at 16. The spring bar 18 has a circular head 20 which is of a thickness substantially the distance between the top and bottom walls 14 and is positioned therebetween. The circular head of the bar 18 is pivotally secured in position by a pivot pin 19 which passes through circular holes in the top and bottom walls 14 with the mid portion 24 of the pin being of rectangular cross section which extends through a similarly shaped opening in the circular head 20. A C-clamp 26 secures the top of the pivot pin 19 to prevent the pin from dropping out through the bottom wall 14. Thus the head 20 and the pivot pin are secured to each other to be turned in unison; while at either side of this rectangular section the pin is cylindrical and rotatably mounted in the walls 14. The pivot pin would have a work engaging projection of rectangular cross section at its lowermost length.
An antifriction bearing 30, which in the present embodiment is in the form of a sleeve 32, is inserted in the other end of the housing. A plurality of circular rows of openings extend through the walls of the sleeve and ball bearings 34 are positioned in the said openings. The ball bearings are of a diameter slightly larger than the wall thickness of the sleeve and will engage the walls of the bore 36 of the housing 12 and also project slightly within the bore 38 of the sleeve 32. A plunger 40 extends through the bore 38 and slidably engages said ball bearings and is provided with flange 42 to limit the sleeve travel toward the spring. At one end of the plunger a cap 44 having a flange 46 is slidingly engaged over the tip of the cap with ball bearing 48 therebetween.
The spring bar with its shank 22 normally extend in axial alignment with the plunger 40, their two ends being in juxtaposition. The adjacent ends of the shank and plunger have opposing channels 50 and 52 respectively with a free connecting member 54 therebetween. The shape of the channels is rectangular and they extend across the entire diameter of their respective members. Connecting member 54 is the shape of a cylindrical roll and is positioned such that its top and bottom surfaces rest against the bottom surfaces in the opposing rectangular channels and the connecting member is maintained in this position by means of a spring bias placed on the plunger as will now be described.
The tubular housing has a handle 60 screw threaded upon its open end. Protruding from the closed inner end of the bandle is a stem 62 over which one end of compression spring 64 slips. The other end of the spring slides over the end of cap 44 and abuts flange 46. Turning the handle relative to the tubular housing will increase or decrease the tension of the spring on the plunger 40 depending upon the direction of rotation of said handle.
As can be seen from FIG. 3, in the normal resting position the free connecting member 54 will rest flat against the substantially parallel bottom walls of the channels and resiliently hold the spring bar and plunger connected together to move in unison upon turning of the handle in one or the other direction. It will also be seen that when resistance of the work to be turned (which may be the tightening of a nut) is greater than the frictional contact of the free member with the bottom walls of the channels, the resistance of the shank 22 will cause a relative lateral movement between the housing and the shank. During this relative lateral movement the free connecting member will ride up two of the diagonally opposite walls of the opposing channels to the tripped position shown in FIG. 4 and this movement causes the plunger to travel outwardly against the bias of spring 64. Upon yielding of the resilient coupling a relative lateral movement takes place between the housing and the shank to provide an audible signal upon the shank striking the inner wall 36 of the housing. After the torque force applied to the handle is released, the spring pressure on the free member 54 acting thereon through the plunger 40 will roll the free member in the other direction to return the shank 22 to its normal rest position.
The tool is adjustable as to what torque will cause the shank to strike the inner wall of the tubular housing. It is calibrated in torque units indicated by a scale 70 on the housing and datum lines 72 on the handle which may be moved into register therewith to indicate the torque applied to the work. Turning the handle to advance the same along the housing 12 will increase the pressure of the spring 64. Turning the handle to withdraw the same from the body will decrease the pressure of the spring 64. A locking ring 76 of ordinary design is provided for locking the handle at any desired torque setting.
The problem of assembling torque tools are often aggravated by finding that the tolerances of interconnecting pieces have not been maintained. This can be especially troublesome when the connecting member is oversized. FIG. discloses an alternative embodiment showing a shank 23 having an adjustable screw formed in its bore that may be raised or lowered to vary the depth of the channel to provide a proper fit for the connecting member 54. A like adjusting screw 43 is mounted in the bore of the plunger 41. Another method of solving this problem is to use shims 21 to reduce the depth of the channel as seen in FIG. 6.
1. A torque tool which produces an audible warning signal comprising an elongated housing having a tubular bore open at one end, a work engaging member pivotally mounted in the other end of the tubular housing, a bar rigidly connected to said work engaging member and extending therefrom through the bore of the tubular elongated housing, a plunger slidably mounted within the open end of the housing, the ends of said plunger and said bar adjacent each other each having a laterally extending rectangular channel therein, said channels opening toward each other, a cylindrical roller positioned between the ends of said plunger and said bar resting with opposite longitudinal surfaces along the bottom surfaces of the respective channels, whereupon a predetermined torque being applied on said bar the roller 15 caused to roll up diagonally opposite vertical walls of the mating channels which movement allows the bar limited relative lateral movement with respect to said plunger, the bar colliding with the inner wall of the tubular housing to produce an audible signal, and when the torque is released the roll returns to its resting position.
2. A torque tool as recited in claim 1 wherein a shim is positioned in the channel at the end of the spring bar beneath the roll.
3. A torque tool as recited in claim 1 wherein the bottom of the recess is at the end of the spring bar and provided with an adjusting screw to raise or lower the bottom surface of the channel.
4. A torque tool which produces an audible warning signal comprising an elongated housing having a tubular bore open at one end, a work engaging member pivotally mounted in the other end of the tubular housing, a bar rigidly connected to said work engaging member and extending therefrom through the bore of the tubular elongated housing, a plunger slidably mounted within the open end of the housing, the ends of said plunger and said bar adjacent each other being connected by a laterally shiftable coupling, a tubular handle having a closed end adjustably secured to said housing, a cup having a bottom wall embracing and guiding the end of the plunger which is distant from said bar, a ball bearing between the said cup bottom wall and the adjacent end of said plunger, a flange fixed to said cup and of a diameter to engage the end of said housing and a spring acting between said flange and the closed 'end of said handle and urging said flange into engagement with the end of said housing, whereupon a predetermined torque being applied on said bar the coupling is caused to allow the bar limited relative lateral movement with respect to said plunger, the bar colliding with the inner wall of the tubular housing to produce an audible signal, and when the torque is released the coupling returns to its resting position.
5. A torque tool as in claim 4 wherein a stern on the closure end of said handle extends into and guides the end of said spring.