This invention relates generally to multi-function hand tools and more particularly to a hand tool incorporating the functions of an adjustable wrench, pliers, and wire cutting dykes.
In various industrial arts, skilled laborers use a variety of tools that are each designed to perform a unique task. Many laborers carry a full compliment of tools to ensure that they have the necessary tools to complete the job. Unfortunately, a full set of tools is an expensive investment that requires a heavy tool box or other carrying case that may be both cumbersome and difficult to transport.
Prior attempts to combine similar tools into one multi-function tool have generally failed to provide a tool that is equally adept at performing the function of each particular tool. A number of designs merge the functions of an adjustable wrench with a pair of pliers, but the arrangement of the various moving parts limits the utility and ultimately reduces the strength of the tool. For example, U.S. Patent Application Publication 2004/0163505 discloses a combination plies and adjustable wrench that includes a first handle having a fixed jaw and a second handle having a sliding jaw. A pivot pin pivotally connects the first and second handles. An adjustable worm gear in the second handle allows the user to slide the sliding jaw towards or away from to the fixed jaw. However, the worm gear is positioned at the center of the pivotal connection between the first handle and the second handle, which creates two deficiencies in the tool. First, locating the worm gear inside the pivotal connection increases the distance between the pivot point and the two jaw faces, which reduces the amount of gripping leverage that a user can impart when using the tool as a pair of pliers. Second, locating the worm at the center of the pivot point requires that material must be removed from the pivot point to accommodate the worm gear. Because this area of the tool transmits all of the gripping and turning force that the user applies when using the tool, removing material in this area greatly reduces the mechanical strength of the tool. Moreover, the worm at the center of the pivot makes the connection between the two handles difficult to design and manufacture.
As a second example, U.S. Pat. No. 3,798,687 discloses a similar combination adjustable wrench and pliers tool, but the worm gear and shape of the sliding jaw are such that the pivot point for the two handles is located at a distance far enough from the engaging jaw faces to significantly reduce the amount of gripping leverage that may be imparted by the tool.
Finally, U.S. Pat. No. 5,150,488 discloses a similar combination adjustable wrench and pliers tool with the worm gear for driving the adjustable jaw located adjacent from the pivot point. However, the tool uses a locking detent mechanism that is positioned about the pivot point in such a way that requires the removal of a great deal of material from the handles, which increases the distance between the pivot point and the engaging jaw faces. This arrangement weakens the mechanical strength and durability of the tool and reduces the mechanical advantage that the user may impart by the tool.
Recognizing the limitations and shortcomings of the prior art, the present invention represents an improved combination pliers and adjustable wrench that offers solutions to problems presented by prior art designs.
The present invention recognizes and addresses disadvantages of prior art constructions and methods, and it is an object of the present invention to provide a multi-function hand tool incorporating at least the functions of an adjustable wrench, pliers, and wire cutting dykes. This and other objects may be achieved by a hand tool comprising a first member having a handle, a fixed jaw having a face defining a first end distal from the handle and a second end proximate to the handle, and a first pivot portion intermediate the fixed jaw and the handle. The first pivot portion defines a first pivot hole having a center positioned at a distance from the fixed jaw face second end within the range of about 7 to 15 millimeters. A second member has a slot transverse to an axis of the second member, a handle, a second pivot portion proximate to the slot and defining a second pivot hole, a recess defined through the second member proximate to the second member slot and disposed radially outward from the second member second pivot hole, and a worm gear rotatably received in the recess. A pivot pin pivotally connects the first and second members so that the first the second members pivot between a fully closed position and a fully open position. The pivot pin has a diameter within the range of about 4 to 10 millimeters and is received in both the first member first pivot hole and the second member second pivot hole. A sliding jaw has a face, and a gear rack, the sliding jaw face having a first end distal from the sliding jaw gear rack and a second end proximate the gear rack, where the sliding jaw gear rack is slidably received by the second member slot. The gear rack engages the worm gear such that rotation of the worm gear moves the sliding jaw within the second member slot. A detent is selectively movable to prevent the pivotal movement of the first member and the second member with respect to each other.
In a second embodiment, a hand tool comprises a first member having a handle, a fixed jaw having a face defining a first end distal from the handle and a second end proximate to the handle, and a first pivot portion intermediate the fixed jaw and the handle and defining a first pivot hole. A second member has a slot transverse to an axis of the second member, a handle, a second pivot portion proximate to the slot defining a second pivot hole, a recess defined through the second member proximate to the second member slot and disposed radially outward from the second member pivot point, and a worm gear rotatably received in the recess. A pivot pin is received in both of the first and second pivot holes and pivotally connects the first member first pivot portion and the second member second pivot portion so that the first and second members pivot between a fully closed position and a fully open position. The pivot pin has a diameter within the range of about 4 to 10 millimeters. A sliding jaw has a gear rack slidably received by the second member slot so as to engage the worm gear so that rotation of the worm gear causes the sliding jaw to move within the slot, and a jaw face having a first end distal from the sliding jaw gear rack and a second end proximate to the gear rack. A detent is moveable to prevent the pivotal movement of the first member and the second member with respect to each other.
In a third embodiment, a hand tool comprises a first member having a handle, a fixed jaw having a face defining a first end distal from the handle and a second end proximate to the handle, and a first pivot portion intermediate the fixed jaw and the handle defining a first pivot hole, the first pivot hole having a center positioned at a distance from the fixed jaw face second end within the range of about 7 to 15 millimeters. A second member has a slot transverse to an axis of the second member, a handle, a second pivot portion proximate to the slot defining a second pivot hole, a recess defined through the second member proximate to the second member slot and disposed radially outward from the second member pivot point, and a worm gear rotatably received in the recess. A pivot pin received in both the first and second pivot holes and pivotally connecting the first member first pivot portion and the second member second pivot portion so that the first and second members pivot about the first and second pivot points between a fully closed position and a fully open position. A sliding jaw having a gear rack slidably received by the second member slot so as to engage the worm gear so that rotation of the worm gear causes the sliding jaw to move within the slot. A jaw face has a first end distal from the sliding jaw gear rack and a second end proximate to the gear rack. A detent selectively prevents the pivotal movement of the first member and the second member with respect to each other.
A full and enabling disclosure of the present invention, including the best mode thereof directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.
Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
First member jaw 18 has a jaw face 40 having a first end 43 located distal from first member pivot portion 24, and a second end 45 proximate to the first member pivot portion. In one preferred embodiment, jaw face 40 may have a grasping region 42 located proximate to first member first end 16 that is suitable for grasping work pieces as described below. Jaw face 40 may also have a wire cutting edge 44 located proximate to first member pivot portion 24 (
Second member pivot portion 28 has a lobe 50 having an end face 52 that partially defines second member first end 26. Lobe 50 extends from second member pivot portion 28 radially outward from second pivot hole 38. Referring to
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Sliding jaw face 68 may have a grasping region 82 located proximate to sliding jaw first end 64 that cooperate with first member jaw grasping region 42 for grasping rusty nails, electrical wires, or other similar materials that have rough surfaces. Additionally, jaw face 68 may have a wire cutting edge 84 located proximate to sliding jaw second end 66 opposite first jaw cutting edge 44. Preferably, jaw face 68 also has a bolt turning region 86 that includes three flat surfaces 87, 88, and 89 positioned opposite first jaw bolt turning region 46 for engaging the flat surfaces of a hexagonal bolt head, nut, or the flat surfaces on many common pipe fittings and other similar hardware. It should be understood that jaw face 68 may have other regions suited for other functions such as shearing or cutting sheet metal, and that the grasping, wire cutting and bolt turning regions described above may be arranged in different arrangements relative to each other, but it should be understood that corresponding regions on first member jaw 18 and sliding jaw 62 must be arranged symmetrically so as to perform their intended functions properly.
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A through-slot 118 is formed in first member pivot portion 24 at a position proximate to first handle 22. Through slot 118 is closed on all sides and has a counter-bored portion 119 (
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It should be understood from the figures that the area of first member 12 where through slot 118 is formed is thicker than the area of second member 14 where slot 130 is formed. Thus, a larger length of detent post 104 is received in through slot 118 than in slot 130. This configuration is advantageous when the tool is used as an adjustable wrench. In particular, as torque is applied on a workpiece between the jaws, a twisting force is exerted on detent post 104 by first and second members 12 and 14. The twisting force causes detent post 104 to canter in slots 118 and 130. However, because a larger portion of the length of detent post 104 is received in slot 118 as compared to slot 130, there are two points of contact between the walls of slot 118 and detent post 104 and only one point of contact between detent post 104 and slot 130. As a result, the twisting force is received by the walls of slot 118, which are stronger than the walls of slot 130. If, on the other hand, a larger length of detent post 104 is received in slot 130, then two contact points would result between detent post 104 and the walls of slot 130 and only one point of contact would exist between detent post 104 and the walls of slot 118. In this configuration, because one side of slot 130 is open, the twisting force applied to the walls of slot 130 would pry the opposing walls apart from each other causing the locking mechanism to fail. Thus, in preferred embodiments, a larger length of detent post 104 should be received in slot 118 as compared to slot 130.
In operation, hand tool 10 may perform the operations of pair of pliers and an adjustable wrench among other things. Referring to
As previously discussed, pivot pin 34 is located at a position that minimizes the distance between both the first member jaw face second end 45 and second member first end 26 and the pivot pin center 35 (
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In the present invention, the location of center 35 helps maximize the amount of gripping or cutting leverage, also known as mechanical advantage, that the tool may exert on a work piece without compromising the mechanical integrity of first and second members 12 and 14. For example, in one preferred embodiment, the distance between pivot pin center 35 and the first end 16 and sliding jaw first ends 64 is approximately 57.5 millimeters, while the distance between pivot center 35 and first and second member second ends 20 and 30 is approximately 165 millimeters. In this arrangement, if the distance between pivot pin center 35 and first member jaw face second end 45 is 11.6 millimeters, the tool will offer a mechanical advantage in the range of 2.83 to 14.05. The mechanical advantage value of 2.83 represents the mechanical advantage at the first jaw and sliding jaw first ends 16 and 64, and the mechanical advantage value of 14.05 represents the mechanical advantage at first jaw face second end 45. The above described configuration provides a combination pliers/adjustable wrench that meets or exceeds the ASME standards for a nine inch linesmen tool and a six inch adjustable wrench. In particular, the above design will cut a 0.091 inch diameter wire at cutting edges 44 and 84 with less than 1020 in/lbs of cutting force and can apply a minimum rotational torque of 1450 in/lbs between surfaces 48 and 88 to a workpiece.
It should also be understood that the mechanical advantage of the tool can be increased by increasing the distance between pivot pin center 35 and first and second member second ends 20 and 30. Moreover, the overall scale of the tool can be changed by scaling the dimensions of the tool. For example, for a six inch adjustable pliers, a scale factor of 0.666 (6 in/9 in) results in the distance between pivot pin center 35 and jaw first ends 16 and 64 of approximately 38.3 millimeters, while the distance between pivot center 35 and first and second member second ends 20 and 30 is approximately 110 millimeters. In this arrangement, if the distance between pivot pin center 35 and first member jaw face second end 45 is 7.73 millimeters, the tool will offer a mechanical advantage in the range of 2.87 to 14.23. The mechanical advantage value of 2.87 represents the mechanical advantage at jaw first ends 16 and 64, and the mechanical advantage value of 14.23 represents the mechanical advantage at first jaw face second end 45. The above described configuration provides a combination pliers/adjustable wrench that meets or exceeds the ASME standards for a six inch linesmen tool and a four inch adjustable wrench. That is, the above design will cut a 0.08 inch diameter wire at cutting edges 44 and 84 with less than 600 in/lbs of force and can apply a minimum rotational torque of 600 in/lbs at surfaces 48 and 88 to a workpiece.
Referring to
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It should be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit of the invention. It is intended that the present invention cover such modifications and variations as come within the scope and spirit of the appended claims and their equivalents.