Abstract:
A signaling torque driver that includes a casing assembly with a grip portion, a click arm with a fastener-engaging portion that projects from said casing assembly at one end and operably coupled to a torque-limiting means housed within said casing assembly at the other, torque-adjusting means within said casing assembly and coupled to said torque-limiting means for adjusting the torque-limiting means to a desired torque value, audible signaling means operably coupled with said torque-limiting means and/or visual signaling means operably coupled with said torque-limiting means such that an audible and visual indicator is activated to signal that the desired torque has been reached.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of the filing date under 35 USC 119(e) of the filing date of U.S. Provisional Application Ser. No. 60/955,200, filed Aug. 10, 2007 and pursuant to 37 CFR 1.7, this application is considered timely as Aug. 10, 2008 fell on Sunday. 
    
    
     BACKGROUND 
     This application relates generally to driving tools such as screwdrivers, nut drivers, bolt drivers, wrenches and the like wherein the amount of torque that the tool can apply to a given fastener is limited to a settable value and the user is given a signal or indication that the desired torque level has been obtained. More specifically, this application relates to torque signaling mechanisms, both visual and audible, usable in said tools that identifies when the desired torque is reached, thereby preventing the user from overtorquing a given fastening device. 
     This application relates to drivers that are able to give a user an improved signal that a desired torque level has been reached and is designed for uses where torque tolerances are critical. The need for a torque driver that can drive a given fastener at a desired torque value is useful in a variety of fields including sporting goods, electronics and computer assembly, and any other use where specific tolerances are required. However, it would be desirable if there were a tool that would allow a user an improved indication that the desired torque level has been obtained such that each time a fastener was torqued, the user was confident that the desired torque was properly obtained. It would also be desirable for such a tool to be low-cost and suitable for mass production without sacrificing precision. 
     SUMMARY 
     This application discloses a signaling torque driver that is economical to produce, of simple construction and capable of mass production, but also capable of providing a clear indication to a user that the desired torque level has been obtained. 
     In particular, this application discloses a signaling torque driver that includes a casing assembly with a grip portion, a click arm with a fastener-engaging portion that projects from said casing assembly at one end and operably coupled to a torque-limiting means housed within said casing assembly at the other, torque-adjusting means within said casing assembly and coupled to said torque-limiting means for adjusting the torque-limiting means to a desired torque value, audible signaling means operably coupled with said torque-limiting means such that an audible indicator is activated to signal that the desired torque has been reached. 
     This application also discloses a signaling torque driver that includes a casing assembly with a grip portion, a click arm with a fastener-engaging portion that projects from said casing assembly at one end and operably coupled to a torque-limiting means housed within said casing assembly at the other, torque-adjusting means within said casing assembly and coupled to said torque-limiting means for adjusting the torque-limiting means to a desired torque value, visual signaling means operably coupled with said torque-limiting means such that a visual indicator is activated to signal that the desired torque has been reached. 
     In a further embodiment, this application discloses a signaling torque driver that includes a casing assembly with a grip portion, a click arm with a fastener-engaging portion that projects from said casing assembly at one end and operably coupled to a torque-limiting means housed within said casing assembly at the other, torque-adjusting means within said casing assembly and coupled to said torque-limiting means for adjusting the torque-limiting means to a desired torque value, audible signaling means operably coupled with said torque-limiting means, visual signaling means operably coupled with said torque-limiting means such that an audible and visual indicator is activated to signal that the desired torque has been reached. 
     In a further embodiment, this application discloses a method for signaling when a desired torque setting has been obtained by providing a signaling torque mechanism coupled to a click arm and housed within a casing assembly and coupled to a torque-limiting mechanism, setting a torque-adjusting mechanism coupled to said torque-limiting mechanism, and applying a force to the fastener engaged driver thereby activating the signaling torque mechanism. 
     Further, this application discloses a signaling torque driver that includes a casing assembly with a grip portion, a click arm with a fastener-engaging portion that projects from said casing assembly at one end and operably coupled to a torque-limiting means housed within said casing assembly at the other, torque-adjusting means within said assembly and coupled to said torque-limiting means for adjusting the torque-limiting means to a desired torque value, signaling torque means operably coupled with said click arm such that an indicator is activated to signal that the desired torque has been reached and wherein the fastener-engaging portion is further characterized by having orientation means such that driver is always in the correct orientation which allows the user to tighten the fastener while taking advantage of the desired torque-limiting and signaling torque means. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings, when considered in connection with the following description, are presented for the purpose of facilitating an understanding of the subject matter sought to be protected. 
         FIG. 1  is a top plan view of a signaling torque driver; 
         FIG. 2  is a side e view of the driver  FIG. 1 ; 
         FIG. 3  is a sectional view of the driver taken generally along the line  3 - 3  in  FIG. 2 ; 
         FIG. 4  is a sectional view of the driver taken generally along the line  4 - 4  in  FIG. 1 ; 
         FIG. 5  is a front view of the fastener-engaging portion of the driver in  FIG. 1 ; 
         FIG. 6  is a cut-away perspective view of the driver in  FIG. 1 ; 
         FIG. 7  is an exploded view of the driver in  FIG. 1 ; 
         FIG. 8  is a perspective view of a second embodiment of a fastener-engaging portion; 
         FIG. 9  is an isolated sectional view similar to the view in  FIG. 3  shown under a force to activate the signaling mechanism; 
         FIG. 10  is a cut-away perspective view of a second embodiment of the signaling torque driver; and, 
         FIG. 11  is an isolated sectional view of the driver in  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-5 , shown therein and generally designated by the reference character  10  is the preferred embodiment of the signaling torque driver  10  constructed in accordance with the following description. The driver  10  includes a casing assembly  20 , a fastener-engaging portion  30 , a torque-limiting mechanism  40 , an adjusting mechanism  50 , an audible signaling mechanism  60 , and/or a visual signaling mechanism  70 . 
     As may be seen more clearly in  FIGS. 5 and 8 , the fastener-engaging portion  30  is adapted to engage a fastener (not shown), and includes a shaped inner surface  31  adapted to mateably receive a fastener. The inner surface  31  may include driver orientation means such as channels  32  that in one embodiment only span a portion of the inner surface  31  such that the driver can only engage a fastener in one direction and ensures that driver is in the correct orientation when the operator attaches it to a given fastener. See  FIG. 5 . In a second embodiment  33 , the upper surface  34  of the fastener-engaging portion  30  may include driver orientation means such as an orientation limiting rim  35  that ensures that driver is in the correct orientation when the operator attaches it to a given fastener. The correct driver orientation allows the user to tighten the fastener while taking advantage of the desired torque-limiting and signaling means. The fastener-engaging portion  30  is integral with a click arm  41  and extends into and sits within the casing assembly  20 . The casing assembly  20 , which includes top and lower portions  21  and  22  and a grip portion  23  and forms the handle portion of the driver, remains stationary as the fastener-engaging portion  30  is maintained between and is able to pivot within the channels  24  of the top and lower portions  21  and  22 . The distal end of the click arm  41  is operably associated with the torque-limiting mechanism  40  as discussed in more detail below. 
     As may be seen more clearly in  FIGS. 3 ,  4  and  6 , the torque-limiting mechanism  40  disposed within the casing assembly  20  includes a click arm  41  with its cam surface  42 , a spring  43 , a cam follower  44  with its pin  45  and roller  46 , a shim  47 , a locking nut  48 , and an adjustment plug  51 . The spring  43  is disposed between a recessed portion  44 A of the cam follower  44  and the shim  47 . The cam follower  44  includes a roller  46  mounted rotateably to said follower  44  body by means of a rotateable pin  45 , and together with the spring  43 , shim  47 , locking nut  48 , and adjustment plug  51  serves to create a force when the spring  43  is compressed on the cam follower  44  which engages the roller  46  into the distal end of the click arm  41 , more specifically, the detent radius  49  of the click arm  41 . The distal end of the click arm  41  also includes an angled edge  401  that receives the roller  46  when the force applied to the driver overcomes the force of the spring  43  upon the cam follower  44 . Preferably, the click arm  41  includes a metal core  90  for strength and integrity and a moldable plastic like covering  91  about its surface and within the fastener-engaging portion  30  to help prevent damage to the fastener the driver  10  is engaged upon. The force is applied to the spring  43  by the adjustment plug  51  given it is threaded surface  53  and is received through a threaded bore  48 A in the locking nut  48 . As the plug  51  is rotated in a given direction, a force is applied to the shim  47  and the adjacent spring  43  is compressed (discussed more fully below). The locking nut  48  is held in position by utilizing inner surfaces  25  of the top and lower portions  21  and  22  of the casing assembly  20 , such that the locking nut is mateably received and unable to rotate given the abutment to the inner surfaces  25 . Alternatively, as shown in  FIGS. 10 and 11 , an inner casing assembly  80  may be utilized to house and maintain the integrity of the torque-limiting mechanism  40 . As shown, the inner casing assembly  80  is substantially rectangular shaped and includes upper and lower portions  81  and  82  and is used to house a portion of the cam follower  44 , the spring  43 , the shim  47 , the locking nut  48 , and portion of the adjustment plug  51 . The inner casing assembly  80  includes inner surfaces  83  that abut the surface of the locking nut  48  and hold it in place so that the desired torque can be set and maintained. 
     The audible signaling mechanism  60  for signaling that the desired torque has been achieved on a given fastener is shown in  FIGS. 6 and 9 . The audible signaling mechanism  60  includes the cam follower  44  with a lateral surface  61  and a clicker cam  62  with an angled edge  63  integrated upon said surface  61 , and a clicker  64 . The clicker  64  includes a planer surface  65  and integrated therein a substantially circular convex surface  66  and a flanged portion  67  located at a first end  68 . The convex surface  66  extends in an outward lateral direction relative to the spring  43 . The second end  69  of the clicker  64  is held in position by utilizing the inner surfaces  25  of the top and lower portions  21  and  22  of the casing assembly  20 , however, the first end  68  is left relatively unobstructed so that the first end  68  can be deflected a given distance. The audible signaling mechanism  60  then proceeds, briefly, as follows: As the click arm  41  is displaced due to a radial force on the grip portion  23  that exceeds the spring force on the cam assembly  40 A (click arm  41  and cam follower  44 ), the first end  68  of the clicker  64  is deflected causing the convex surface  66  to depress and emanate a “click” sound. The clicker  64  is preferably made of thin metal materials so to provide enough flexibility for deflection and the “click” sound. When the force applied by the operator is lessened to a level below the spring force on the cam assembly  40 A the clicker  64  returns back to its initial position. The audible signaling mechanism  60  is discussed more fully below. 
     In use, the adjustment of the driver  10  is accomplished by utilizing the adjusting mechanism  50 , which includes the adjustment plug  51 , which is characterized by having a socket  52  at its distal end that is mateably shaped to receive an adjustment tool (not shown) and further characterized by an annular externally threaded surface  53  that is mateably received by the internally threaded bore  48 A of the locking nut  48 . As the adjustment plug  51  is rotated to cause axial movement, this in turn creates an axial force on the torque-limiting mechanism; namely, the shims  47 , and compression of the spring  43  against the cam assembly  40 A. The spring  43  can be compressed to correspond to a desired torque limit. The torque limit of the driver  10  can be adjustable by a user or fixed at a specific setting once assembled. When a radial load is applied to the grip portion  23  in a direction perpendicular to the axis of the driver  10  and on a parallel plane consistent with the click arm  41  the torque moment force rises on the fastener engaged by the fastener-engaging portion  30  to the desired torque setting which causes the roller  46  to lift from the detent radius  49  and as more force is applied by the operator, onto the angled edge  401  ( FIG. 9 ). As the torque applied by the user exceeds the force of the spring  43 , and the roller  46  is lifted from the detent radius  49 , the roller  46  begins to ride upon the angled edge  401  of the cam surface  42 , which in turn causes cam follower  44  to be forced toward the distal end of the driver  10  as the spring  43  is compressed. As the cam follower  44  is forced to the distal end of the driver  10 , the flanged portion  67  of the clicker  64  is forced upon the angled edge  63  of the clicker cam  62 . This in turn causes the clicker  64  to deflect and the convex surface  66  to depress and emanate a “click” sound; thereby providing an audible indication that the applied load on the grip portion  23  has reached the desired torque setting of the driver  10 . The angled edge  401  allows the click arm  41  to be forced by the roller  46  back to the start location in the detent radius  49  by the force of the spring  42  as the force against the grip portion  23  is reduced, thereby causing the cam follower  44  to return to its start location and the clicker  64  to return to its non-deflected state. 
     The visual signaling mechanism  70  for signaling that the desired torque has been achieved on a given fastener is shown in  FIGS. 1 and 6 . The visual signaling mechanism  70  utilizes a pair of indicators  71  located on opposite sides of the click arm  41 . The indicators  71  may be colored so that they contrast with the color of click arm  41 . The visual signaling mechanism  70  also includes a pair of windows  72  fixably attached within bores  80  on the upper and lower portions  21  and  22  of the casing assembly  20 . In the resting state, the indicators  71  are hidden from view under the upper and lower portions  21  and  22  of the casing assembly  20 . In operation (as described more fully above), when a radial load is applied to the grip portion  23  in a direction perpendicular to the axis of the driver  10  and on a parallel plane consistent with the click arm  41  the torque moment force rises on the fastener engaged by the fastener-engaging portion  30  to the desired torque setting which causes the roller  46  to lift from the detent radius  49  and as more force is applied by the operator, onto the angled edge  401  ( FIG. 9 ). This causes the click arm  41  to deflect a given distance and the indicators  71  to now come in position under the windows  72  and thereby viewable to the operator; thereby indicating that the desired torque setting has been obtained. 
     While the present disclosure has been described in connection with what is considered the most practical and preferred embodiment, it is understood that that this disclosure is not limited to the disclosed embodiments, but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. To that end, various torque-limiting mechanisms are known in the prior art that are adaptable to the disclosed signaling means.