Tensioning apparatus

Abstract

A tensioning apparatus for an endless power transmission device is provided and utilizes the elastic properties of an elastomeric material to provide the tensioning action and such apparatus is supported adjacent the endless power transmission device to be tensioned and has components thereof operatively associated with the elastomeric material and with the device.

What is claimed is: 
     
       1. .[.A.]. .Iadd.In a .Iaddend.tensioning apparatus for an endless power transmission belt comprising, an elastomeric material, means supporting said elastomeric material adjacent an associated power transmission belt, and means operatively connected between said elastomeric material and said power transmission belt by engaging said elastomeric material and said power transmission belt and employing the elastic properties of said elastomeric material to exert a controlled tensioning force against said endless power transmission belt.Iadd., the improvement in which said means operatively connected between said elastomeric material and said belt comprises, shaft means disposed within and fixed against said elastomeric material, said shaft means comprising a shaft having at least one fin-like protrusion fixed thereto and extending radially therefrom, a lever having one end portion fixed to said shaft, and an idler roller engaging said power transmission belt and being carried on said lever, said elastomeric material being displaced from a normal relaxed condition thereof by said roller acting through said lever and shaft means so that the elastomeric material utilizes its elastic properties to transmit a force through said shaft means, lever, and roller to exert said controlled tensioning force against said belt.Iaddend.. 
     
     
       2. An apparatus as set forth in claim 1 in which said elastomeric material is a rubber compound. 
     
     
       3. An apparatus as set forth in claim 1 in which said elastomeric material is a synthetic plastic material. 
     
     
       4. An apparatus as set forth in claim 3 in which said synthetic plastic material is a urethane elastomer. 
     
     
       5. An apparatus as set forth in claim 1 in which said means supporting said elastomeric material comprises a housing containing said elastomeric material and means for supporting said housing. 
     
     
       6. An apparatus as set forth in claim .[.1 in which said means operatively connected between said elastomeric material and said belt comprises shaft means engaging said elastomeric material by being fixed thereagainst; a lever having one end portion detachably fixed to said shaft means, and belt-engaging means engaging said power transmission belt and being carried on said lever, said elastomeric material being displaced from a normal relaxed condition thereof by said belt-engaging means acting through said lever and shaft means so that the elastomeric material utilizes its elastic properties to transmit a force through said shaft means, lever and belt-engaging means to exert a controlled tensioning force against said belt.]. .Iadd.5 in which said housing has an inside surface and said elastomeric material is disposed with its exposed surface against said inside surface, and further comprising means fixing said elastomeric material within said housing.Iaddend.. 
     
     
       7. An apparatus as set forth in claim .[.6.]. .Iadd.1 .Iaddend.in which said shaft means .Iadd.further .Iaddend.comprises .[.a shaft having.]. at least .[.one.]. .Iadd.another .Iaddend.fin-like protrusion .[.extending therefrom, said shaft and its fin-like protrusion being fixed against said elastomeric material by being embedded therein.]. .Iadd.fixed to said shaft and extending radially therefrom in angularly spaced relation from said one protrusion, said shaft and its protrusions being embedded within and bonded against said elastomeric material which serves as a matrix therefor.Iaddend.. 
     
     
       8. An apparatus as set forth in claim .[.6.]. .Iadd.1 .Iaddend.in which said .[.belt-engaging means comprises a belt-engaging.]. roller .Iadd.is .Iaddend.rotably mounted at the outer end portion of said lever.Iadd., said elastomeric material is a self supported mass, and said means supporting said elastomeric material comprises a flange defined as an integral part of said mass and having at least one opening therein, said opening being adapted to receive a fastener therethrough to support said flange and mass of elastomeric material adjacent said belt.Iaddend.. 
     
     
       9. An apparatus as set forth in claim 5 in which said means supporting said elastomeric material further comprises a flange fixed to said housing and having a plurality of openings therein, said openings being adapted to receive fasteners therethrough for fastening said flange and housing into position. 
     
     
       10. An apparatus as set forth in claim .[.6.]. .Iadd.5 .Iaddend.in which said elastomeric material is displaced from a normal condition thereof .[.and placed in a condition of shear.]. .Iadd.to provide a shear loading therein .Iaddend.by said .].belt-engaging means.]. .Iadd.roller .Iaddend.acting through said lever and shaft means.Iadd., and said apparatus further comprises integral means for changing said loading an infinite number of loading values and indicating the amount of said tensioning force applied by said elastomeric material against said belt.Iaddend.. 
     
     
       11. .[.An.]. .Iadd.In an .Iaddend.endless power transmission belt drive system comprising; at least one driving sheave; at least one driven sheave; an endless power transmission belt operatively connected between said sheaves; and a tensioning apparatus for said belt comprising, an elastomeric material, means supporting said elastomeric material adjacent said belt, and means operatively connected between said elastomeric material and said belt by engaging said elastomeric material and said belt and employing the elastic properties of said elastomeric material to exert a controlled tensioning force against said belt, .Iadd.the improvement in which said means operatively connected between said elastomeric material and said belt comprises, shaft means disposed within and fixed against said elastomeric material, said shaft means comprising a shaft having at least one fin-like protrusion fixed thereto and extending radially therefrom, a lever having one end portion fixed to said shaft, and an idler roller engaging said power transmission belt and being carried on said lever, said elastomeric material being displaced from a normal relaxed condition thereof by said roller acting through said lever and shaft means so that the elastomeric material utilizes its elastic properties to transmit a force through said shaft means, lever, and roller to exert said controlled tensioning force against said belt.Iaddend.. 
     
     
       12. A system as set forth in claim 11 in which said elastomeric material is a rubber compound. 
     
     
       13. A system as set forth in claim 11 in which said elastomeric material is a synthetic plastic material. 
     
     
       14. A system as set forth in claim 13 in which said synthetic plastic material is a urethane elastomer. 
     
     
       15. A system as set forth in claim 11 in which said means supporting said elastomeric material comprises a housing containing a mass of said elastomeric material and means for supporting said housing. 
     
     
       16. A system as set forth in claim .[.11 in which said means operatively connected between said elastomeric material and said belt comprises shaft means engaging said elastomeric material by being fixed thereagainst, a lever having one end portion detachably fixed to said shaft means, and belt-engaging means engaging said power transmission belt and being carried on said lever, said elastomeric material being displaced from a normal relaxed condition thereof by said belt-engaging means acting through said lever and shaft means so that the elastomeric material utilizes its elastic properties to transmit a force through said shaft means, lever, and belt-engaging means to exert a controlled tensioning force against said belt.]. .Iadd.15 in which said housing has an inside surface and said elastomeric material is disposed with its exposed surface against said inside surface, and further comprising means fixing said elastomeric material within said housing.Iaddend.. 
     
     
       17. A system as set forth in claim .[.16.]. .Iadd.11 .Iaddend.in which said shaft means .Iadd.further .Iaddend.comprises .[.a shaft having.]. at least .[.one.]. .Iadd.another .Iaddend.fin-like protrusion .[.extending therefrom, said shaft and its fin-like protrusion being fixed against said elastomeric material by being embedded therein.]. .Iadd.fixed to said shaft and extending radially therefrom in angularly spaced relation from said one protrusion, said shaft and its protrusions being embedded within and bonded against said elastomeric material which serves as a matrix therefor.Iaddend.. 
     
     
       18. A system as set forth in claim .[.16.]. .Iadd.11 .Iaddend.in which said .[.belt-engaging means comprises a belt-engaging.]. roller .Iadd.is .Iaddend.rotatably mounted at the outer end portion of said lever.Iadd., said elastomeric material is a self supported mass, and said means supporting said elastomeric material comprises a flange defined as an integral part of said mass and having at least one opening therein, said opening being adapted to receive a fastener therethrough to support said flange and mass of elastomeric material adjacent said belt.Iaddend.. 
     
     
       19. A system as set forth in claim 15 in which said means supporting said elastomeric material further comprises a flange fixed to said housing and having a plurality of openings therein, said openings being adapted to receive fasteners therethrough for fastening said flange and housing into position. 
     
     
       20. A system as set forth in claim .[.16.]. .Iadd.11 .Iaddend.in which said elastomeric material is displaced from a normal condition thereof .[.and placed in a condition of shear.]. .Iadd.to provide a shear loading therein .Iaddend.by said .[.belt-engaging means.]. .Iadd.roller .Iaddend.acting through said lever and shaft means, said elastomeric material also serves .[.serving.]. as vibration-dampening means.Iadd., and said apparatus further comprises integral means for changing said loading an infinite number of loading values and indicating the amount of said tensioning force applied by said elastomeric material against said belt.Iaddend.. 
     
     
       21. .[.A.]. In a tensioning apparatus for an endless power transmission device comprising, an elastomeric material, means supporting said elastomeric material adjacent an associated power transmission device, and means operatively connected between said elastomeric material and said power transmission device by engaging said elastomeric material and said power transmission device and employing the elastic properties of said elastomeric material to exert a controlled tensioning force against said endless power transmission device.Iadd., the improvement in which said means operatively connected between said elastomeric material and said device comprises, shaft means disposed within and fixed against said elastomeric material, said shaft means comprising a shaft having at least one fin-like protrusion fixed thereto and extending radially therefrom, a lever having one end portion fixed to said shaft, and an idler roller engaging said power transmission device and being carried on said lever, said elastomeric material being displaced from a normal relaxed condition thereof by said roller acting through said lever and shaft means so that the elastomeric material utilizes its elastic properties to transmit a force through said shaft means, lever, and roller to exert said controlled tensioning force against said device.Iaddend.. 
     
     
       22. In .Iadd.a .Iaddend.combination.[.:.]. .Iadd.comprising .Iaddend.an endless power transmission device and a tensioning apparatus for said endless power transmission device, said apparatus comprising, an elastomeric material, means supporting said elastomeric material adjacent said device, and means operatively connected between said elastomeric material and device by engaging said elastomeric material and said device and employing the elastic properties of said elastomeric material to exert a controlled tensioning force against said device.Iadd., the improvement in which said means operatively connected between said elastomeric material and said device comprises, shaft means disposed within and fixed against said elastomeric material, said shaft means comprising a shaft having at least one fin-like protrusion fixed thereto and extending radially therefrom, a lever having one end portion fixed to said shaft, and an idler roller engaging said power transmission device and being carried on said lever, said elastomeric material being displaced from a normal relaxed condition thereof by said roller acting through said lever and shaft means so that the elastomeric material utilizes its elastic properties and to transmit a force through said shaft means, lever, and roller to exert said controlled tensioning force against said device.Iaddend.. 
     
     
       23. A combination as set forth in claim 22 in which said device comprises a sprocket chain. 
     
     
       24. A combination as set forth in claim 22 in which said device comprises a timing belt. 
     
     
       25. A combination as set forth in claim 22 in which .[.said means operatively connected between said elastomeric material and said device comprises a shaft engaging said elastomeric material by being embedded therein,.]. said elastomeric material .[.being.]. .Iadd.is .Iaddend.in the form of a self supported .[.cylindrical.]. mass .[.serving as a matrix for said shaft,.]. .Iadd.and .Iaddend.said means supporting said elastomeric material comprises a flange defined as an integral part of said .[.cylindrical.]. mass and having at least one opening therein, said opening being adapted to receive a fastener therethrough to support said flange and elastomeric material adjacent said device.[., a lever having one end portion detachably fixed to said shaft, and device-engaging means engaging said device and being carried on said lever, said elastomeric material being displaced from a normal relaxed condition thereof by said device-engaging means acting through said lever and shaft so that the elastomeric material utilizes its elastic properties to transmit a force through said shaft, lever, and device-engaging means to exert a controlled tensioning force against said device.].. 
     
     
       26. A combination as set forth in claim .[.25.]. .Iadd.22 .Iaddend.in which said shaft has external splines thereon, and said one end portion of said lever has an internally splined opening therein which receives said external splines of said shaft therethrough. 
     
     
       27. A combination as set forth in claim .[.25.]. .Iadd.22 .Iaddend.in which said shaft has an internally splined opening therein which is adapted to receive a cooperating splined .[.member.]. .Iadd.portion .Iaddend.comprising said one end portion of said lever. 
     
     
       28. A combination as set forth in claim 22 in which said elastomeric material is a rubber compound. 
     
     
       29. A combination as set forth in claim 22 in which said elastomeric material is a synthetic plastic material. 
     
     
       30. A combination as set forth in claim 29 in which said synthetic plastic material is a urethane elastomer. .Iadd. 31. An apparatus as set forth in claim 1 in which said elastomeric material is defined as a mass having opposed ends, said fin-like protrusion has opposed end edges, and said protrusion is embedded within and bonded against said elastomeric material which serves as a matrix therefor with the end edges of said protrusion being disposed axially inwardly of the opposed ends of said elastomeric material, said protrusion assuring that said shaft means and mass of elastomeric material are prevented from relative movement therebetween including both relative rotary as well as relative axial movement. .Iaddend..Iadd. 32. An apparatus as set forth in claim 1 in which said elastomeric material is defined as a substantially tubular mass which has a particular wall thickness and is disposed outwardly of said shaft, and said fin-like protrusion has a radial dimension which extends through the major part of said wall thickness. .Iaddend. .Iadd. 33. In a tensioning apparatus for an endless power transmission device comprising, an elastomeric material, means supporting said elastomeric material adjacent an associated power transmission device, and means operatively connected between said elastomeric material and said power transmission device by engaging said elastomeric material and said power transmission device and employing the elastic properties of said elastomeric material to exert a controlled tensioning force against said endless power transmission device, the improvement in which said elastomeric material is a self supported mass and said means supporting said elastomeric material comprises integral flange means adapted to be used in fastening said mass of elastomeric material adjacent said device. .Iaddend.