Gear wrench

Abstract

A force multiplication wrench is provided in the form of a casing having a longitudinal input shaft at one end and a longitudinal output shaft at the other end. A transmission, such as a planetary gear unit, is disposed in the housing connecting the two shafts. Tandem planetary gear units may also be used for greater force multiplication. In the case of planetary gears, the inner wall of the housing is adapted as the ring gear.

What is claimed is: 
     
       1. A hand wrench comprising: longitudinally aligned input and output shafts.[.,.]..Iadd.; .Iaddend.   a housing rotatably supporting said shafts in tandem relation.[.,.]..Iadd.; .Iaddend.   means for holding the housing stationary relative to the shafts.[.,.]..Iadd.; .Iaddend.   planetary transmission means rotatably connecting said shafts to each other, said transmission means including .[.pinions and.]. .Iadd.a first planetary transmission stage comprising a first sun gear driven by said input shaft.Iaddend., internal teeth on said housing defining a ring gear and .Iadd.first group of .Iaddend.planet pinions .Iadd.driven by said first sun gear and .Iaddend.engaging said ring gear, .Iadd.and at least a second planetary gear stage comprising a second sun gear carried by and rotatable with said group of planet pinions of the preceding planetary transmission stage and a second group of planet pinions driven by said second sun gear and engaged with said ring gear, said second group of planet pinions comprising output drive means for said second planetary gear stage and said planetary transmission means and connected with said output shaft to drive the latter in rotation; .Iaddend.   .[.and.]. a knob for applying a manual force to the input shaft.Iadd.; .Iaddend.   the outer end of said output shaft having a non-circular .[.cross-section.]. .Iadd.cross section .Iaddend.for coupling the output shaft to a rotatable fastening member.[...]..Iadd.; .Iaddend.   .Iadd.means for locking the transmission so as to achieve a direct drive between said shafts..Iaddend. .[.2. A wrench as defined by claim 1, in which the planetary transmission comprises a sun pinion, the said planet   
     
     
        pinions engaging the sun pinion and the ring gear..]. .[.3.  A wrench as defined by claim 2, having a second group of planet pinions carried by the first group, said second group being in meshed relation with the teeth of 
     
     
        the ring gear and journaled to the output shaft..]. 4. A wrench as defined in claim .[.3.]. .Iadd.1.Iaddend., in which the second group of planet pinions are releasably engaged with teeth of the ring gear. .[.5. A wrench as defined in claim 1, and means for locking the transmission against 
     
     
        movement so as to achieve a direct drive between said shafts..]. 6. .[.A wrench as defined by claim 1, in which the transmission comprises.]. .Iadd.A hand wrench comprising longitudinally aligned input and output shafts, a housing rotatably supporting said shafts in tandum relation, means for holding the housing stationary relative to the shafts, planetary transmission means comprising .Iaddend.tandem planetary gear units .[.said transmission means.]. .Iadd.including pinions and internal teeth on said housing defining a ring gear, a knob for applying a manual force to the input shaft, the outer end of said output shaft having a non-circular cross section for coupling the output shaft to a rotatable fastening member, and means for locking the transmission so as to achieve a direct 
     
     
        drive between said shafts. .Iaddend. 7. A wrench as defined by claim 1 and a turning bar for engaging the input shaft for selectively rotating it. 
     
     
           A wrench as defined by claim 6, in which one of the planetary units is removable said removable planetary transmission being capable of being combined with a shorter housing to form a more compact hand wrench. .[.9. A wrench as defined by claim 6, and means for locking one of the planetary units relative to the other..]. .Iadd. 10. A hand wrench comprising: longitudinally aligned input and output shafts;   a housing rotatably supporting said shafts in tandem relation;   means for holding the housing stationary relative to the shafts;   planetary transmission means rotatably connecting said shafts to each other, said transmission means comprising a plurality of tandem planetary gear stages each including a sun gear as an input, a group of planet pinions as an output and a ring gear formed internally of said housing, said planet pinions mutually engaging said ring gear and a corresponding sun gear;   said input shaft driving the first said sun gear;   said output shaft being driven by the last said group of planet pinions; a knob for applying a manual force to the input shaft;   the outer end of said output shaft having a non-circular cross section for coupling the output shaft to a rotatable fastening member; and   means for locking the transmission so as to achieve a direct drive between said shafts. .Iaddend. .Iadd. 11. A hand wrench as defined in claim 1, wherein said means for holding said housing stationary comprises a support disposed substantially, radially outwardly from the output shaft for preventing the rotation of said housing. .Iaddend..Iadd. 12. A hand wrench as defined in claim 1, wherein said means for locking the transmission so as to achieve a direct drive between said shafts comprises a reciprocatable input shaft that locks the first sun gear and first group of planet pinions and the second sun gear and second group of planet pinions relative to each other so as to provide a direct drive between said input and output shafts. .Iaddend..Iadd. 13. A hand wrench as defined in claim 6, wherein said means for holding said housing stationary comprises a support disposed substantially, radially outwardly from the output shaft for preventing the rotation of said housing. .Iaddend..Iadd. 14. A hand wrench as defined in claim 6, wherein said means for locking the transmission so as to achieve a direct drive between said shafts comprises a reciprocatable input shaft that locks the first planetary gear unit and the second planetary gear unit relative to each other so as to provide a direct drive between said input and output shafts. .Iaddend..Iadd. 15. A hand wrench as defined in claim 10, wherein said means for holding said housing stationary comprises a support disposed substantially, radially outwardly from the output shaft for preventing the rotation of said housing. .Iaddend..Iadd. 16. A hand wrench as defined in claim 10, wherein said means for locking the transmission so as to achieve a direct drive between said shafts comprises a reciprocatable input shaft that locks a first planetary gear stage and subsequent planetary gear stages relative to each other so as to provide a direct drive between said input and output shafts. .Iaddend. .Iadd. 17. A hand wrench comprising:   longitudinally aligned input and output shafts;   a housing rotatably supporting said shafts in tandem relation;   planetary transmission means rotatably connecting said shafts to each other, said transmission means including a first planetary transmission stage comprising a first sun gear driven by said input shaft, internal teeth on said housing defining a ring gear and first group of planet pinions driven by said first sun gear and engaging said ring gear, and at least a second planetary gear stage comprising a second sun gear carried by and rotatable with said group of planet pinions of the preceding planetary transmission stage and a second group of planet pinions driven by said second sun gear and engaged with said ring gear, said second group of planet pinions comprising output drive means for said second planetary gear stage and said planetary transmission means and connected with said output shaft to drive the latter in rotation;   a support for engaging and holding the housing stationary relative to the shafts, said support being disposed substantially, radially outwardly from said output shaft for preventing the rotation of said housing and said internal teeth which define said ring gear;   a knob for applying a manual force to the input shaft; and   the outer end of said shaft having a non-circular cross section for coupling the output shaft to a rotatable fastening member. .Iaddend. .Iadd. 18. A hand wrench defined in claim 17, including means for locking the transmission so as to achieve a direct drive between said shafts. .Iaddend..Iadd. 19. A hand wrench defined in claim 18, wherein said means for locking the transmission so as to achieve a direct drive between said shafts comprises a reciprocatable input shaft that locks the first sun gear and first group of planet pinions and the second sun gear and second group of planet pinions relative to each other so as to provide a direct drive between said input and output shafts. .Iaddend. .Iadd.20. A hand wrench comprising longitudinally aligned input and output shafts, a housing rotatably supporting said shafts in tandem relation, planetary transmission means comprising tandem planetary gear units including pinions and internal teeth on said housing defining a ring gear, a support for engaging and holding the housing stationary relative to the shafts, said support being disposed substantially, radially outwardly from said output shaft for preventing the rotation of said housing and said internal teeth which define said ring gear, a knob for applying a manual force to the input shaft, and the outer end of said output shaft having a non-circular cross section for coupling the output shaft to a rotatable fastening member. .Iaddend. .Iadd.21. A hand wrench comprising:   longitudinally aligned input and output shafts;   a housing rotatably supporting said shafts in tandem relation;   planetary transmission means rotatably connecting said shafts to each other, said transmission means comprising a plurality of tandem planetary gear stages each including a sun gear as an input, a group of planet pinions as an output and a ring gear formed internally of said housing, said planet pinions mutually engaging said ring gear and a corresponding sun gear;   said input shaft driving the first said sun gear;   said output shaft being driven by the last said group of planet pinions;   a support for engaging and holding the housing stationary relative to the shafts, said support being disposed substantially, radially outwardly from said output shaft for preventing the rotation of said housing and said ring gear formed internally of said housing;   a knob for applying a manual force to the input shaft; and   the outer end of said output shaft having a non-circular cross section for coupling the output shaft to a rotatable fastening member. .Iadd.22. A hand wrench as defined in claim 20, including means for locking the transmission so as to achieve a direct drive between said shafts. .Iaddend..Iadd. 23. A hand wrench as defined in claim 22, wherein said means for locking the transmission so as to achieve a direct drive between said shafts comprises a reciprocatable input shaft that locks the first planetary gear unit and the second planetary gear unit relative to each other so as to provide a direct drive between said input and output shafts. .Iaddend..Iadd. 24. A hand wrench as defined in claim 21, including means for locking the transmission so as to achieve a direct drive between said shafts. .Iaddend. .Iadd. 25. A hand wrench as defined in claim 24, wherein said means for locking the transmission so as to achieve a direct drive between said shafts comprises a reciprocatable input shaft that locks a first planetary gear stage and subsequent planetary gear stages relative to each other so as to provide a direct drive between said input and output shafts. .Iaddend.