Abstract:
An adjustable jaw end power wrench, in which the adjustable jaw is operated by a worm gear, the worm gear is meshed with the rack of the movable jaw and the worm gear is driven by a reversible electric servomotor. Activation of the servomotor produces linear reciprocating motion of the adjustable jaw. Batteries in a wrench handle provide the power for the electric movement and a control switch controls the function of the wrench. The powered adjustable jaw wrench includes an anti-jamming coupling device provided for un-jamming the wrench when “binding” occurs between the adjustable jaw gear rack and the worm gear.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This Application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application No. 60/162,783 filed Nov. 1, 1999 by John A. Picone. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates broadly to power tools and, more particularly, to a powered adjustable wrench having a sliding side jaw. 
     2. Description of the Prior Art 
     A powered adjustable jaw wrench having a sliding side jaw and a stationery jaw is known in the prior art. As illustrated in FIG. 1, a fixed jaw  2  is integral with the wrench head  3  and a movable jaw  4  is adjustable relative to the fixed jaw. A worm gear  5  having a pulley  6  is rotated by a belt  7  and a motor pulley  8 . The adjustable jaw  4  is provided with an integral gear rack for engagement with the worm gear  5 . The worm gear  5  is positioned between the fixed jaw  2  and the pulley  6 . A double pole double throw (DPDT) switch  9  is used to control the opening and closing of the movable jaw  4 . With an upper handle housing removed, a bottom handle housing  10  houses an electric motor  12  connected to the motor pulley  8  by a shaft  13 . Wires  14  and  15  connect the electric motor  12  with the DPDT switch  9  and batteries  16  supply power for the switch and motor. A sub mini jack  18  is used for recharging the batteries  16 . The bottom handle housing  10  defines a battery recess  19  and a motor recess  20  containing the motor  12 . 
     However, wrenches of this type suffered certain drawbacks owing to a tendency of the adjustable jaw to jam when “binding” occurs between the adjustable jaw gear rack and the worm gear. One of the reasons of the “binding” to occur is the positioning of the pulley  6  relative to the fixed jaw  2 . When utilizing an adjustable wrench for either tightening or loosening, there are forces applied between the worm gear  5  and the moveable jaw  4 . The pressure that is applied from the moveable jaw rack, pushes the worm gear  5  away from the stationary jaw creating a binding condition between the worm gear  5  and the moveable jaw rack. Furthermore, when the moveable jaw  4  is fully extended, only part of worm gear leads are engaging the moveable jaw rack, because the moveable jaw rack can not fully extend due to position of the pulley  6  relative to the fixed jaw  2  and the worm gear  5 , as described above and illustrated in FIG.  1 . Thus, wrench-tends to bind in its fully open position due to lack of full engagement of the worm gear to the moveable jaw rack. 
     SUMMARY OF THE INVENTION 
     The present invention is an improvement over the powered adjustable jaw wrench of the prior art disclosed in U.S. Pat. No. 4,512,221 incorporated herein by reference. 
     It is therefore an object of the present invention to provide for a novel and improved powered adjustable jaw wrench including an anti-jamming coupling device provided for un-jamming the wrench when “binding” occurs between a gear rack of an adjustable jaw and a worm gear. 
     In accordance with the present invention, the powered adjustable jaw wrench includes a unitary single-piece body member having integral elongated handle portion and a head portion, a stationary jaw defined by the head portion, a movable jaw adjustable relative to the stationary jaw, actuated by a driven mechanism comprising a worm gear rotatably mounted in said head portion of said body member for advancing the movable jaw toward and away from the stationary jaw, and a first rotatable member drivingly coupled to the worm gear, a drive mechanism including a power source, and the anti-jamming coupling device provided for operably connecting the first rotatable member to the worm gear. The anti-jamming coupling device includes a drive member drivingly connected to the first rotatable member and a driven member drivingly connected to the worm gear. The drive member drivingly engages the driven member when the powered adjustable jaw wrench is activated by striking the driven member in order to upset the worm gear when jammed. 
     In accordance with the first embodiment of the present invention, the first rotatable member of the driven mechanism is a toothed sprocket drivingly coupled to the worm gear, and the drive mechanism comprises a reversible electric motor driving a second sprocket rotating the first sprocket through a toothed belt. A control switch assembly for controlling the electric motor is provided at the handle portion of the wrench body. The wrench body member defines a cavity housing the electric motor and electric batteries supplying an electric power to said electric motor. A handle cover is used to seal the cavity. 
     In accordance with the second embodiment of the present invention, the wrench body includes a unitary single-piece body member and a pair of opposite handle covers. 
     In accordance with the third embodiment of the present invention, the drive mechanism includes a chain drive mechanism. 
     In accordance with the forth embodiment of the present invention, the drive mechanism further includes a speed reduction gearing disposed between the electric motor and the second sprocket. 
     In accordance with the fifth embodiment of the present invention, the reversible electric motor is disposed in the head portion of the wrench body member. 
     In accordance with the sixth embodiment of the present invention, the wrench body further include a solar panel (i.e., a battery of solar cells) for recharging the electric batteries. 
     In accordance with the seventh embodiment of the present invention, the wrench further includes an illumination device mounted to the wrench body and adapted to provide direct illumination a work area in order to facilitate operation in a dark environment. 
     In accordance with the eighth embodiment of the present invention, the drive mechanism includes a fluid pressure motor as a power source. 
     In accordance with the ninth embodiment of the present invention, the powered adjustable jaw wrench includes a fluid-pressure turbine for driving the worm gear. The turbine is fluidly connected to a source of pressurized fluid through a fluid flow control valve for controlling direction of rotation of said fluid-pressure turbine. The source of pressurized fluid may be any appropriate external source of pressurized fluid, such as pneumatic pump or compressor. 
     The tenth embodiment of the present invention is similar to the ninth embodiment wherein the source of pressurized fluid is a pressurized gas cartridge disposed within the handle portion of the wrench body member. 
     In accordance with the eleventh embodiment of the present invention, the powered adjustable jaw wrench includes a pair of fluid-pressure turbines provided for driving the worm gear. The first turbine is adapted to rotate the worm gear in a clockwise direction, while the second turbine is adapted to rotate the worm gear in a counterclockwise direction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the invention will become apparent from a study of the following specification when viewed in light of the accompanying drawings, wherein: 
     FIG. 1 is a perspective view showing a powered adjustable jaw wrench of the prior art; 
     FIG. 2 is a perspective view of a powered adjustable jaw wrench in accordance with the first embodiment of the present invention; 
     FIG. 3 is a perspective view of a movable jaw; 
     FIG. 4 is an exploded perspective view of a wrench body of the powered adjustable jaw wrench in accordance with the first embodiment of the present invention; 
     FIG. 5 is an exploded perspective view of the wrench body of the powered adjustable wrench in accordance with the second embodiment of the present invention; 
     FIG. 6 is a side view of a driven mechanism including an anti-jamming coupling device in accordance with the present invention; 
     FIG. 7 is an exploded perspective view of a chain drive mechanism in accordance with the third embodiment of the present invention; 
     FIG. 8 is a schematic diagram of an electric circuitry for the powered adjustable jaw wrench in accordance with the first embodiment of the present invention; 
     FIG. 9A is a side view of a worm gear in accordance with the present invention; 
     FIG. 9B is a front view of a worm gear in accordance with the present invention; 
     FIG. 10A is a side view of a first sprocket in accordance with the present invention; 
     FIG. 10B is a front view of a first sprocket in accordance with the present invention; 
     FIG. 11 is a side view of the powered adjustable jaw wrench with removed handle cover in accordance with the fourth embodiment of the present invention; 
     FIG. 12 is a side view of the powered adjustable jaw wrench with removed handle cover in accordance with the fifth embodiment of the present invention; 
     FIG. 13 is a side view of the powered adjustable jaw wrench in accordance with the sixth embodiment of the present invention; 
     FIG. 14 is a cross-sectional view of a handle cover in accordance with the seventh embodiment of the present invention; 
     FIG. 15 is a side view of the powered adjustable jaw wrench with removed handle cover in accordance with the eighth embodiment of the present invention; 
     FIG. 16 is a side view of the powered adjustable jaw wrench with removed handle cover in accordance with the ninth embodiment of the present invention; 
     FIG. 17 is a side view of the powered adjustable jaw wrench with removed handle cover in accordance with the tenth embodiment of the present invention; 
     FIG. 18 is the driven mechanism of the powered adjustable jaw wrench in accordance with the eleventh embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The preferred embodiments of the present invention will now be described with the reference to accompanying drawings. 
     Referring now to FIG. 2, an improved powered adjustable jaw wrench according to the first embodiment of the present invention illustrated generally at  21  and comprises a wrench body  22  including a wrench body member  23  provided with a stationery jaw  28 , and a handle cover  29  removably fastened to the wrench body member  23 , and a movable jaw  30  adjustable relative to the stationery jaw  28 . The movable jaw  30  is formed integral with a toothed rack  32 , as shown in FIG.  3 . The wrench body member  23  includes a handle portion  24  and a head portion  26 . The stationery jaw  28  is integral to the head portion  26 . Preferably, the handle portion  24  and the head portion  26  of the wrench body member  23 , illustrated further in detail in FIG. 4, form a unitary single-piece part. It will be appreciated by those skilled in the art that the wrench body member  23  may be made of any appropriate material such as metal (steel, aluminum, etc.) or plastic material. The metal wrench body member  23  may be manufactured, preferably, of stainless steel by forging. However, any other appropriate methods for manufacturing the wrench body member  23  made of metal, such as die-casting or punching from a metal plate, are within the scope of the present invention. The plastic wrench body member is manufactured, preferably, by injection molding. However, any other appropriate methods for manufacturing the wrench body member  23  made of plastic material well known in the prior art, are within the scope of the present invention. 
     In the modified version according to the second embodiment of the present invention, illustrated in FIG. 5, the wrench body  22  includes a unitary single-piece wrench body member  23  and a pair of opposite handle covers  29 ′ and  29 ″ removably fastened to the wrench body member  23 ′, preferably by bolts or screws. 
     The powered adjustable jaw wrench  21  according to the present invention further includes a driven mechanism comprising a worm gear  34  and a first rotatable member both rotatably mounted in the head portion  26  of the wrench body member  23  coaxially with respect to each other. The worm gear  34  is operably connected to the toothed rack  32  of the movable jaw  30  so that the rotatable movement of the worm gear  34  is transformed into the linear movement of the movable jaw  30 . In the first embodiment of the present invention, as illustrated in FIGS. 2 and 6, the first rotatable member is in the form of a first toothed sprocket  38  mounted on a stationary shaft  42  coaxially relative to the worm gear  34 . The stationary shaft  42  is mounted in the head portion  26  of the wrench body member  23 . 
     The powered adjustable jaw wrench  21  according to the present invention further includes a drive mechanism having a power source and a second rotatable member. In accordance with the first embodiment of the present invention, illustrated in FIG. 2, the drive mechanism comprises a reversible electric motor  44  mounted in the handle portion  24  and drivingly connected to a second toothed sprocket  46 . The reversible electric motor  44  is employed for rotating the worm gear  34  through the second toothed sprocket  46 , an endless toothed belt  48  and the first toothed sprocket  38 . 
     In contrast with the prior art powered adjustable wrench, the powered adjustable jaw wrench  21  according to the present invention includes the first toothed sprocket  38  mounted in the head portion  26  between the stationery jaw  28  and the worm gear  34  coaxially thereto. Such an arrangement significantly reduces the possibility of “binding” between the adjustable jaw gear rack and the worm gear, and, thus, the tendency of the powered adjustable jaw wrench  21  to jam. 
     In the modified version according to the third embodiment of the present invention, illustrated in FIG. 7, the drive mechanism includes an endless chain  48 ′ interconnecting first and second sprockets  38 ′ and  46 ′ respectively. 
     It will be appreciated by those skilled in the art that any other type of an endless torque-transmitting element known in the prior art is within the scope of the present invention. 
     As illustrated in FIG. 2, the electric motor  44  is electrically connected to a control switch assembly  56  including a switch actuator  57 , controlling the motor  44  and at least one electric battery  58  supplying electric power to the motor  44  and the control switch assembly  56 . Preferably, two batteries  58  are provided. The batteries  58  may be rechargeable. In this case, a sub mini jack  60  is used for recharging the batteries  58 . The electric motor  44 , the control switch assembly  56  and the electric battery  58  are disposed in compartments  50 ,  52  and  54  respectively, formed in the handle portion  24  of the wrench body member  23 , as illustrated in FIG.  4 . The handle cover  29  is adapted to seal the compartments  50 ,  52  and  54 . 
     In accordance with the second embodiment of the present invention, illustrated in FIG. 5, the wrench body member  23 ′ is provided with through openings  50 ′,  52 ′ and  54 ′ housing the electric motor  44 , the control switch assembly  56  and the electric battery  58 , respectively. 
     It will be appreciated that any appropriate type of electrical switches known in the prior art may be utilized in the present invention, such as a double pole double throw (DPDT) switch. Preferably, the control switch assembly  56  includes a pair of single pole double throw (SPDT) switches  56 ′ and  56 ″ and the switch actuator  57 , as shown in FIG.  8 . 
     The powered adjustable jaw wrench  21  according to the present invention further comprises an anti-jamming coupling device  35  designed for un-jamming the wrench when “binding” occurs between the adjustable jaw gear rack and the worm gear. The anti-jamming coupling device  35 , as illustrated in detail in FIGS. 6,  9 A,  9 B,  10 A and  10 B, includes a drive member in the form of a drive key  40  axially protruding from the first sprocket  38  and a driven member in the form of a driven key  36  axially protruding from the worm gear  34 , wherein the drive key  40  is adapted to positively engage the driven key  36  for drivingly connecting the first sprocket  38  to the worm gear  34 . Prior to actuation of the electric motor  44 , the drive key  40  is circumferentially spaced from the driven key  36 . When the control switch assembly  56  actuates the electric motor  44 , the drive key  40  rotates toward the driven key  36  and engages it. The engagement of the driven key  36  by the drive key  40  is accompanied by the striking (or hammering) action that upsets the jammed wrench  21  when “binding” occurs between the gear rack  32  of the movable jaw  30  and the worm gear  34 . 
     Preferably, the first sprocket  38  forms a unitary single-piece part with the drive key  40 . Similarly, the worm gear  34  forms a unitary single-piece part with the driven key  36 . 
     The anti-jamming coupling device is also illustrated in connection with the third embodiment of the present invention. As shown in FIG. 7, the first sprocket  38 ′ is provided with an integral drive key  40 ′ axially protruding therefrom and the worm gear  34  is provided with the integral drive key  36  axially protruding therefrom. 
     In the forth embodiment of the present invention, illustrated in FIG. 11, the power wrench  21 ′ includes a gear reduction mechanism  62  including a pinion gear  64  fixed to a shaft  45  of the electric motor  44 , and a gear  66  fixed to a shaft  68  rotatably supporting the second rotatable member in the form of a second pulley  46 ″. The second pulley  46 ″ is adapted to transfer torque to the first rotatable member in the form of a first pulley  38 ″ via an endless belt  48 ″. The above described anti-jamming coupling device  35  is provided between the first pulley  38 ″ and the worm gear  34 , including the drive key (not shown) axially extending from the first pulley  38 ″ adapted to positively engage the driven key (not shown) axially extending from the worm gear  34 . 
     In the fifth embodiment of the present invention, illustrated in FIG. 12, powered adjustable jaw pipe-wrench  21 ″ comprising a unitary single-piece wrench body member  23 ″ provided with a stationery jaw  28 ″, and a movable jaw  30 ″ adjustable relative to the stationery jaw  28 ″. The wrench body member  23 ″ includes a handle portion  24 ″ and a head portion  26 ″. The stationery jaw  28 ″ is integral to the head portion  26 ″. A drive mechanism comprises the reversible electric motor  44  mounted in the head portion  26 ″ and drivingly connected to a second toothed sprocket  46  through a speed reduction gearing  62 ″. The reversible electric motor  44  is employed for rotating the worm gear  34  through the second toothed sprocket  46 , the endless toothed belt  48  and the first toothed sprocket  38 . The above described anti-jamming coupling device  35  is provided between the first sprocket  38  and the worm gear  34 , including the drive key (not shown) axially extending from the first sprocket  38  adapted to positively engage the driven key (not shown) axially extending from the worm gear  34 . 
     In the sixth embodiment of the present invention, illustrated in FIG. 13, the power wrench  21  is provided with a battery of solar cells, i.e. solar panel  70 , employed to recharge electric batteries  58 . The solar panel  70  is mounted to the handle portion of the wrench body  22 , preferably to the handle cover  29 . 
     As shown in FIG. 13, the power wrench  21  may be provided with a through-hole  27  disposed at a distal end of the handle portion  24  of the wrench body  22  for tethering and/or hanging the power wrench  21 . 
     In the seventh embodiment of the present invention, illustrated in FIG. 14, the power wrench  21  is provided with an illumination device mounted to the wrench body  22  and adapted to provide direct illumination of a work area in order to facilitate operation in a dark environment. The illumination device comprises a lamp bulb  72  disposed in a raised lamp housing  74  formed in the handle cover  29 . A switch  76  is utilized to operate the lamp bulb  72 . Electric wires  78  connect the lamp bulb  72  with the switch  76  and electric batteries  80 . Alternatively, the electric batteries  58  supplying electric power to the motor  44 , may be used to supply power to the lamp bulb  72 . 
     The eighth embodiment of the present invention, illustrated in FIG. 15, discloses a powered adjustable jaw wrench  121  similar to the power wrench  21 ′ in accordance with the forth embodiment of the present invention illustrated in FIG. 10, wherein instead of the electric motor  44  a fluid-pressure motor  144 , such as pneumatic or hydraulic motor, is employed. The fluid-pressure motor  144  is fluidly connected to an external source of pressurized fluid (not shown) via inlet tubing  158  and return tubing  159 . A fluid flow control valve  156  including a valve actuator  157 , is provided to control direction of rotation of the motor  144 . 
     Alternatively, a pressurized gas cartridge, such as CO 2  cartridge, (not shown), or a rechargeable pressurized gas storage tank (not shown), mounted in the handle portion  24 , may be utilized. Gas under pressure may be charged into the storage tank through the gas fitting by external sources of the compressed gas, such as a hand pump, compressor, charging tanks or cartridges. 
     In the ninth embodiment of the present invention, illustrated in FIG. 16, a power wrench  221  includes a fluid-pressure turbine  238  as the first rotatable member. The fluid-pressure turbine  238  is rotatably mounted to a shaft  242 . An anti-jamming coupling device  235  is provided between the turbine  238  and the worm gear  34 , including a drive key  240  integral with the turbine  238  and the driven key  36  integral with the worm gear  34 . The drive key  240  positively engages the driven key  36  when the turbine  238  is activated. 
     The fluid-pressure turbine  238  is fluidly connected to an external source of pressurized fluid (not shown), such as pressurized gas (e.g. air or carbon dioxide), via fluid tubing  242 ,  243 ,  244  and  246 . A fluid flow control valve assembly  256  including a valve actuator  257 , is provided to control direction of rotation of the turbine  238 . 
     Alternatively, in accordance with the tenth embodiment of the present invention, as illustrated in FIG. 17, a pressurized fluid cartridge, such as CO 2  cartridge,  258  mounted in the handle portion  224 , is utilized as a source of pressurized fluid. As shown in FIG. 17, the power wrench  221  may be provided with a through-hole  227  disposed at a distal end of the handle portion  224  of the wrench body  222  for tethering and/or hanging the power wrench  21 . 
     In the eleventh embodiment of the present invention, illustrated in FIG. 18, the fluid-pressure turbine  238  consists of two interconnected turbines: a first turbine  238 ′ adapted for rotating the worm gear  34  in one direction, and a second turbine  238 ″ adapted for rotating the worm gear  34  in opposite direction. 
     Therefore, the powered adjustable jaw wrench in accordance with the present invention includes a novel arrangement of the w anti-jamming coupling device provided for un-jamming the wrench when “binding” occurs between the adjustable jaw gear rack and the worm gear. 
     The foregoing description of the preferred embodiments of the present invention has been presented for the purpose of illustration in accordance with the provisions of the Patent Statutes. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments disclosed hereinabove were chosen in order to best illustrate the principles of the present invention and its practical application to thereby enable those of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated, as long as the principles described herein are followed. Thus, changes can be made in the above-described invention without departing from the intent and scope thereof. It is also intended that the scope of the present invention be defined by the claims appended thereto.