Abstract:
A handgrip for a torque tool, such as a screwdriver, provides enhanced tool torque capabilities and improved driving capabilities. The handgrip has a top or free-end segment available for low-torque twirling action using the fingertips, and a bottom or working-end segment that together with the top segment is grasped in one&#39;s hand for high torque application. The handgrip has the configuration approaching that of a three-sided bell that provides finger holds, bearing surfaces, and outlying lobes which alone or in combination improve torque capabilities and/or driving capabilities for the effort applied.

Description:
BACKGROUND OF THE INVENTION 
     Tools such as screwdrivers and nut drivers are implemented by hand rotation about an axis. This rotation axis is normally the longitudinal axis of the tool. The tool normally has a handle (or handgrip) end and a working (or tool) end. The working member often includes a shaft or shank bridging the handle and a tool element, the handle being connected or joined to such shaft or shank. The handle is rotated or torqued to transfer the applied torquing forces to the shank and tool element. Improved torque capabilities or efficiencies is desirable to increase the torquing forces transferred to shank and tool element for a given handle rotation effort or exertion. 
     It is also desirable to readily spin a screwdriver and the like about the rotation axis when only a low degree of torque is required for a task. Improved downward pressure (or driving) capabilities is also desirable. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is a handgrip for a torque tool, such as a screwdriver, that provides enhanced tool torque capabilities and improved driving capabilities. The handgrip has a top or free-end segment available for low-torque twirling action using the fingertips, and a bottom or working-end segment that together with the top segment is grasped in one&#39;s hand for high torque application. The handgrip has a configuration approaching that of a three-sided bell that provides finger holds, bearing surfaces, and outlying lobes which alone or in combination improve torque capabilities and/or driving capabilities for the effort applied. The invention is also a torque tool that includes such a handgrip and has enhanced tool torque capabilities and improved driving capabilities. The present invention is also method of using such a torque tool whereby enhanced tool torque capabilities and improved driving capabilities are realized. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 is a perspective view of a screwdriver and a handgrip of the invention; 
     FIG. 2 is a partially cutaway side view of the screwdriver of FIG. 1; 
     FIG. 2 a  is a cross-sectional view of the screwdriver of FIG. 1, taken along plane A of FIG. 2; 
     FIG. 2 b  is a cross-sectional view of the screwdriver of FIG. 1, taken along plane B of FIG. 2; 
     FIG. 2 c  is a cross-sectional view of the screwdriver of FIG. 1, taken along plane C of FIG. 2; 
     FIG. 3 is a top view of the screwdriver of FIG. 1; 
     FIG. 4 is a perspective view of the bottom of the hand grip of the screwdriver of FIG. 1; 
     FIG. 5 is a perspective view of the screwdriver of FIG. 1 being gripped by the fingertips of a hand; 
     FIG. 6 is a perspective view of the screwdriver of FIG. 1 being gripped by a hand; 
     FIG. 7 is a perspective view of a soil aerator with a handgrip of the invention; and 
     FIG. 8 is a flow-diagram of the method of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     There is seen in FIG.  1  through FIG. 4 a hand tool, namely a screwdriver  10  comprised of a handgrip  12  and a working member  14 . The working member  14  is comprised of a shank element or shank  16  and a tool element  18 . The tool of the present invention can be any torque implement, utensil or tool. The most commonly known torque tool is probably, as exemplified, a screwdriver. Among other torque tools are, without limitation, nut drivers, augers, other tools that are rotated to produce or deepen holes, such as some awls and soil aerators, tools that are rotated to sweep or cut via a wing or shaft protuberances, such as some weeders and cultivators, and tools that are rotated to turn or revolve and downwardly drive a coil spiral, such as some soil cultivators and most cork screws. Torque tools are implemented by rotation about an axis. This rotation axis is normally, but not necessarily, the longitudinal axis of the tool. The tool normally has a handle end and a working end. The working end is comprised of a working member, which at times is comprised of a shaft or shank element and a tool element. The handle or handgrip is commonly attached to the working member at the shaft or shank, opposite the working element, or via another type of interconnection element. The handgrip is rotated or torqued to transfer the applied torquing forces to the working member. 
     The screwdriver  10  as shown is a simple slot screwdriver having a slot screwdriver tool element or tip  18 . The screwdriver  10  exemplified obviously could also have been a phillips tip (for driving phillips head screws), or a socket driver tip or the like, each having a shank plus a characteristic tool element. 
     The tip  18  and the shank  16  as shown in FIG. 1 are formed in conventional fashion as a single, unitary piece of metal or other strong material, such as reinforced composites. The tip  18  is located at the far end, or distal end, of the shank  16 . The shank  16  is attached to the handgrip  12  at the shank&#39;s  16  opposite or proximal end in conventional fashion, such as being received, and keyed to or otherwise suitably secured in, an axial bore (not shown). The shank  16  and the internal interconnection between shank  16  and handgrip  12  (not shown) must be sufficiently strong and rigid to resist substantial torque without distortion or separation. Such a strong and rigid shank  16  and interconnection between shank  16  and handgrip  12  are conventional and well known in the hand tool field. The tip  18  (tool element) and the shank  16  in this embodiment comprise together the working member  14  of the screwdriver  10 . 
     The handgrip  12  is shaped in the form of a deformed snub-nosed cone. Its base  22  presents an end-view or bottom-view tri-lobed profile. From the base  22  the handgrip  12  tapers up to a stubby, rounded apex  24 . The apex  24  is the handgrip&#39;s free end or proximal end. The base  22  is the handgrip&#39;s working end or distal end that receives the working member  14  of this tool. 
     The handgrip  12  has three lateral or side surfaces or faces or handgrip sides  26  meeting at rounded longitudinal edges or corners  27 . Each side face  26  has a bell-shaped or webbed-footed triangular planar side-view profile. The webbed-footed portion of such profile is formed by a pair of lobes or protuberances  34  described below. Above the webbed-footed portion such profile runs upward in substantially a straight line to the rounded apex  24 . 
     In the upper portion of the handgrip  12  (upper, top, lower, bottom and like references being taken as if the screwdriver  10  was oriented with the working member  14  pointed downward solely for convenience and clarity purposes), each of the handgrip&#39;s side surfaces  26  is substantially flat, except about its rounded longitudinal edges  27 . That is, the handgrip&#39;s three faces  26  are substantially flat from the handgrip&#39;s apex  24  down to about the handgrip&#39;s longitudinal mid-point. Below the handgrip&#39;s longitudinal mid-point, these three faces  26  are concave. The bottom or base  22  surface is also concave. 
     The handgrip  12  thus is comprised of three moderately-triangulate, and partially-concave faces  26 , (a first face  36 , a second face  38  and a third face  40 ), and a concave tri-lobed base  22 . Each of the faces  26  meets the other faces  26  and the base  22  at the rounded comers  27 . The three faces  26  converge at the rounded apex  24  or vertex. Each of the lobes  34  is disposed at a juncture of two faces  26  and the base  22 . In more detail, the first lobe  44  is at the point where the first face  36 , the second face  38  and the base  22  converge. The second lobe  46  is at the point where the second face  38 , the third face  40  and the base  22  converge. The third lobe  48  is at the point where the third face  40 , the first face  36  and the base  22  converge. 
     The handgrip&#39;s top segment  50  has a substantially triangular cross-sectional profile or shape (seen best in FIG. 2 a ), the size of such triangulate profile growing progressively larger from the top apex  24  downward to about the handgrip&#39;s mid-section. The handgrip&#39;s bottom segment  52  has a substantially palmate (tri-lobate) cross-sectional profile or shape (seen best in FIG. 2 b ) from about the handgrip&#39;s longitudinal mid-section down to about the bottom edges of the faces  26  at their longitudinal center lines (shown in phantom by line E in FIG.  2 ). The size of such tri-lobate palmate cross-section profile grows progressively larger from about the handgrip&#39;s longitudinal mid-section downward until the handgrip&#39;s axial center ends at the center or bottom of the concave base  22 , leaving the three spaced apart lobes  34 . Therefore, below the cross-sectional plane in which the center or bottom of the concave base  22  lies (shown in phantom as line C of FIG. 2) (which in the embodiment shown would pass through at each of the bottom edges of the faces  26  at their longitudinal center lines), the cross-sectional profile of the handgrip  12  is a lobed whorl (seen best in FIG. 2 c ). 
     The faces  26  and base  22  are the outer or external surfaces of the handgrip  12 . The handgrip&#39;s apex  24  can be formed or molded as a continuation and convergence of the faces  26  or, as shown, can be an end cap  54 . 
     Referring now to FIG. 5 also, the top or proximal end of the handgrip  12  provides a flared knob or knob section that can be easily gripped or held by the user&#39;s fingertips  56 , and the screwdriver  10  twirled or spun by fingertip motion. In this fashion the screwdriver  10  can be twirled for low torque tasks substantially as if it were equipped with a conventional tubular (circular cross-sectional profile) handle. There are no obstructions or impediments hampering fingertip twirling of the screwdriver  10 . Moreover, a handgrip or handle having an upper portion with a circular cross-sectional profile is not excluded from the broad embodiments of present invention. In the preferred embodiment shown, there is an enhancement of the torque and driving capabilities even when fingertip action is the only effort applied. Any fingertips  56  placed on about the center of any of the faces  26  will at least somewhat bear against the ridge separating the center portions of adjacent faces  26 , making the applied twirling effort more efficient than it would be on a handle having an effective circular cross-sectional profile. In addition, the outwardly sloping surfaces of the top of the handle will increase the downward driving force of the screwdriver  10 , making the downward pressure more efficient than it would be on a handle having an effective circular cross-sectional profile. Even during low-torque, twirling uses of a screwdriver, some downward pressure is applied at least to hold the tip against the screw being driven. In the preferred embodiment shown, the handgrip&#39;s top segment  50  has outwardly sloping surfaces at every point along its circumference. 
     Referring now to FIG. 6 also, there is a greater enhancement of the torque and driving capabilities when a full hand action is the effort applied for high torque application. When the handgrip  12  is grasped in a hand  58 , the handgrip&#39;s top segment  50  fits smoothly into the palm  60  and the stubby apex  24  bears against the bottom  62  of the palm  60 . The first face  36  provides a comfortable bearing surface for the side of the hand  58  below the thumb  64  and comfortable groove or depression or seat for the thumb  64  within its concave surface area. The ridge or corner  66  at the convergence of the first face  36  and a second face  38  fits snugly between the thumb  64  and first finger  68 . The top  70  of the first finger  68  is held against the base  22  between the shank  16  and the second lobe  46 . The first finger  68  thus bears against the base  22 , firming the hand&#39;s grip on the handgrip  12 . The middle finger  72  and the remaining fingers  73 ,  74  clamp over the ridge  76  between the second face  38  and the third face  40 , that ridge  76  fitting snugly into the fold of those fingers  72 ,  73 ,  74  at their lower joints. The top of the middle finger  72  is seated with the concave groove or depression or seat of the third face  40  at the handgrip&#39;s bottom segment  52 . The tops of the remaining fingers comfortably fit around and bear against the handgrip&#39;s top segment  50  about the ridge  78  between the third face  40  and the first face  38 . When the rotational motion is initiated, the thumb  64  will slide at least somewhat towards the first lobe  44 , and torque will be increased as one of the pressure-points of rotational force approaches the tip of a lobe  34 . There are no obstacles or impediments during the normal shifting of the hand position after a screwdriver  10  has turned through an typical arc (an arc of about 30° to about 50° is believed conventional). In fact, the typical user would use the first lobe  44  as a type of springboard for the hand-shift movement, pushing off the first lobe  44  with the thumb  64  as the hand shifts in the direction opposite the screwdriver  10  rotation direction. After the first hand shift, the thumb  64  bears against the third face  40 , the top of the first finger  68  is seated between the shank  16  and the first lobe  44 , and so forth. 
     When using the screwdriver  10  with a full hand grasp, the hand  58  and fingers  64 ,  68 ,  72 ,  73 ,  74  not only contact the outwardly sloping surfaces of the handgrip&#39;s top segment  50  at many points, from about 40% to about 70% of the inner hand and finger surfaces bear against from about 80% to about 90% of the handgrip&#39;s side surfaces. This immense bearing contact will considerably increase the downward driving force of the screwdriver  10 , making the downward pressure more efficient than it would be on a handle having an effective circular cross-sectional profile. 
     The hand grasping illustration and description provided above is for a right-hand grasp followed by a clockwise turn (as viewed from the perspective of the user). Clockwise is the normal rotation direction for driving in a screw, and is the most comfortable rotation direction for a right-handed person. When a screwdriver is used in the right hand, but with a counter-clockwise rotation, or when used with the left hand for a clockwise rotation, the benefits of the present invention would be similarly obtained. 
     The handgrip  12  as shown has a lobe-tip to lobe-tip span of about three inches. The handgrip  12  is about  4 . 2  or  4 . 3  inches high when measured from the plane defined by the three lobe  34  bottoms (shown as line D in FIG. 2) to the top of the apex  24 , and about four inches high when measured from the plane defined by the bottom center edges of the three faces  26  (shown as line C in FIG. 2) to the top of the apex  24 . Its profile would fit within an equilateral triangle having about a three inch base and sides about six inches long (shown as lines F and G and interconnecting section of line D in FIG. 2) with the bottoms of its lobe  34  on the base line and the sides of the handgrip&#39;s top segment  50  on the side lines. This size of handgrip approaches the largest size practical for the typical human hand. Smaller sizes would be proportionally smaller. The present invention in broad embodiment is not limited to specific dimensions. In preferred embodiment, the handgrip of the present invention: (a) has a lobe-tip to lobe-tip span of from about two to about four inches; (b) is from about three to about five inches high when measured either from the plane defined by the lobe bottoms, or from the plane defined by the bottom center edges of its three faces, to the top of its apex, and (c) its profile would fit within an equilateral triangle having about a two to four inch base and sides about five to seven inches long. In more preferred embodiment, the handgrip of the present invention: (a) has a lobe-tip to lobe-tip span of from about 2.5 or 2.7 to about 3.3 or 3.5 inches; (b) is from about 3.8 or 4.0 to about 4.5 or 4.7 inches high when measured from the plane defined by the lobe bottoms to the top of its apex, (c) is from about 3.6 or 3.8 to about 4.2 or 4.5 inches high when measured from the plane defined by the bottom center edges of its three faces to the top of its apex, and (d) its profile would fit within an equilateral triangle having from about a 2.5 or 2.7 to about a 3.2 or 3.5 inch base and sides from about 5.5 or 5.7 to about 6.2 or 6.5 inches long. 
     Referring now to FIG. 7, there is shown a different torque tool, namely a soil aerator  80  having a working member, namely a sharp-pointed long, rigid spiral coil  82 , and handgrip  84 . The spiral coil  82  penetrates deeper and deeper into the soil with the rotation of the aerator using the handgrip  84 . The features and operation of the handgrip  84  are substantially as described above for the screwdriver  10 , and will not be repeated here. In this embodiment, the spiral coil  82  is a combined tool element and working element. 
     Referring now to FIG. 8 there is shown a flow diagram, designated generally by reference number  100 , of the method of using a hand-held torque instrument of the present invention. The torque instrument being used (not shown) is within the present invention. The torque tool has a working member and a handgrip. The handgrip has a proximal end, a distal end and a rotational axis. The proximal end of the handgrip provides a flared knob member. The distal end of the handgrip has a plurality of longitudinally-extending thumb holds separated by bearing means extending outwardly from the rotational axis beyond the thumb holds. As shown in FIG. 8, the method has two separate lines of steps. On the left side are low-torque-use steps. On the right side are high-torque-use steps. The generic step  110  common to both low-torque and high-torque use of the tool (and normally presumed) is to obtain the torque tool as defined. For low-torque use (“Itu”), step one  112  is to hold the handgrip at the flared knob member by a plurality of fingertips. Step two  114  is to twirl the torque instrument about its rotational axis with a twirling action of the fingertips. For high-torque use (“htu”), step one  116  is to hold the handgrip with one hand, the thumb of the hand disposed within one of the thumb holds. Step two  118  is to rotate the torque instrument about its rotational axis with a turning action of the hand, the thumb bearing against adjacent upstream bearing means. Step three  120  is to move the thumb over the downstream bearing means to the downstream thumb hold. Step four  122  is to return to step two  118  to repeat the action from step two  118  downward. 
     The present invention in other words is a torque tool comprising a handgrip having a working-end tri-lobed base tapering up to a free-end stubby apex and a working member attached to the handgrip at the handgrip&#39;s working-end. The handgrip preferably has three lateral faces meeting each other at longitudinal corners and converging at the apex. The handgrip preferably has an upper section and a lower section, wherein in the upper section the handgrip&#39;s faces have substantially flat mid-sections, and wherein in the lower section the handgrip&#39;s faces have substantially concave mid-sections. The base preferably has a substantially concave midsection. Each of the faces preferably meets the other faces and meets the base at rounded comers, and each of the lobes preferably is disposed at a juncture of two faces and the base. The handgrip&#39;s three faces preferably are substantially flat from the apex down to about the handgrip&#39;s longitudinal mid-point. Below the handgrip&#39;s longitudinal mid-point, these the faces preferably are substantially concave. 
     The present invention also is the handle for the torque instrument. The handle in other words can be described as having a first face, a second face and a third face, converging at an apex, each of the faces preferably being moderately-triangulate, and partially-concave. The handle preferably has a base having a first lobe, a second lobe, and a third lobe. The first lobe is disposed at the convergence juncture of the first face, the second face and the base. The second lobe is disposed at the convergence juncture of the second face, the third face and the base. The third lobe is disposed at the convergence juncture of the third face, the first face and the base. The handle preferably is comprised of a top segment and a bottom segment. The top segment has a substantially triangular cross-sectional profile, the size of the triangulate profile progressively increasing from the apex downward. The bottom section has a substantially tri-lobate palmate cross-sectional profile, the size of such tri-lobate palmate cross-section profile progressively increasing downward to the base. The handle&#39;s cross-sectional profile at the base is a lobed whorl. 
     The present invention is also a method of using a hand-held torque instrument, wherein the torque instrument has a working member and a handgrip, the handgrip having a proximal end, a distal end and a rotational axis, the proximal end of the handgrip providing a flared knob member, and a distal end of the handgrip having a plurality of longitudinally-extending thumb holds separated by bearing means extending outwardly from the rotational axis beyond the thumb holds. The method comprises the steps of: 
     (A) for low-torque use, holding the handgrip at the flared knob member by a plurality of fingertips and twirling the torque instrument about its rotational axis with a twirling action of the fingertips, and 
     (B) for high-torque use, 
     (a) holding the handgrip with one hand, the thumb of the hand disposed within one of the thumb holds, 
     (b) rotating the torque instrument about its rotational axis with a turning action of the hand, the thumb bearing against adjacent upstream bearing means, 
     (c) then moving the thumb over the downstream bearing means to the downstream thumb hold, and 
     (d) returning to step (b) to repeat the action sequence. 
     When the bearing means of the handgrip are each comprised of a ridge and a lobe, and when the handgrip further includes a base surface disposed between the lobes, the method preferably includes positioning the first finger of the hand at least partially on the base surface between the working member and one of the lobes when the thumb is in one of the thumb holds. When the handgrip has three lobes, namely a first lobe, a second lobe, and a third lobe equidistant from the handgrip&#39;s rotational axis and equidistant from each other, and when the base surface is concave, the method preferably further includes holding the flared knob member between the palm of the hand and the fourth and fifth fingers of the hand, and pressing the handgrip into the palm with the first finger. The method also preferably includes pressing the torque tool downward by the force of the palm and the fourth and fifth fingers on the flared knob member. 
     It is well within the skill of a person in the technical field, upon becoming conversant with, or otherwise having knowledge of, the present invention, to select suitable combinations of handgrip components, tool working members, tool elements, method lines and/or steps and the like in view of the type of handgrip and/or tool being designed and/or constructed and/or used. 
     The above described embodiments are exemplitive, and the terminology is employed for illustration purposes and not limitation purposes. The present invention is not limited to the combinations and subcombinations illustrated herein.