Tension monitor means

Abstract

An apparatus for measuring and monitoring the tension on a web or strand as it extends and/or moves over and around a roll including a support assembly for supporting at least one end of the roll, said support assembly including a bridge structure having spaced connected bridge portions aligned with the roll on opposite sides of the axis thereof, a mounting member attached to anchor one end of the bridge structure in fixed position, a diaphragm member attached to the opposite end of the bridge structure, a mounting structure for attaching the diaphragm member to the roll, at least two and preferably four strain sensitive gage members attached to one of said spaced connected bridge portions, and a bridge type electric circuit including circuit connections to said strain sensitivie gage members. The present apparatus may have a similar support assembly and associated components operatively connected to both opposite ends of the roll, each of the assemblies including a housing for around a bridge structure and a diaphragm member.

What is claimed is: 
     
       1. Apparatus for measuring the tension in a continuously moving web comprising in combination, two spaced frame members, a shaft extending between the frame members and having web engaging means rotatably mounted thereon, coupling members connecting opposite ends of the shaft to the respective frame members, each of the coupling members having .Iadd.substantially planar members arranged to be intersected at intermediate locations by and to be substantially normal to the axis of the shaft, and two spaced opposed .Iaddend.two spaced deflectable portions located respectively on opposite sides of the axis of the shaft, .Iadd.each of said deflectable portions including a member which is relatively deflectable in a preselected plane only and each having spaced end edges integrally connected with the respective spaced planar members whereby the deflectable portions and the planar members form an enclosed structure such that when pressure is applied to the shaft by the web in a direction to cause one of the planar members to move relative to the other the deflectable portions will deflect so as to maintain the planar members in essentially parallel relation, .Iaddend.means for holding the web in engagement with the rotatably mounted means for producing a web tension load component on the shaft with web tension load components deflecting the shaft and straining the deflectable portions .Iadd.while maintaining the spaced substantially planar members in an essentially parallel relation.Iaddend., and strain sensing transducing means located on at least one of the deflectable portions for conveying therefrom a signal derived from said straining and therefore representative of the tension in the web. 
     
     
       2. The apparatus of claim 1 wherein each of the coupling members includes .[.spaced opposed wall members connected integrally to opposite ends of the associated deflectable portions, and.]. means to limit movement of one of said .[.wall.]. .Iadd.planar .Iaddend.members relative to the other. 
     
     
       3. The apparatus of claim 2 wherein each of the coupling members includes a diaphragm member having a portion connected to one of said opposed .[.wall.]. .Iadd.planar .Iaddend.members and another portion connected to the shaft. 
     
     
       4. The apparatus of claim 1 wherein said strain sensing transducing means includes at least two strain responsive members attached at spaced locations to one of the deflectable portions, and circuit means connecting the strain responsive members into an electric circuit bridge. 
     
     
       5. The apparatus of claim 4 wherein four strain responsive members are attached to one surface of said deflectable portions, means connecting said strain responsive members into a Wheatstone bridge circuit, and other circuit means connected to said Wheatstone bridge circuit, said other circuit means including bridge means and means to indicate the tension on the shaft. 
     
     
       6. Apparatus to measure and monitor the tension on a strand comprising a frame member, a shaft extending from the frame member and having strand engaging means rotatably mounted thereon, a coupling assembly connecting one end of the shaft to the frame member, said coupling assembly .[.having.]. .Iadd.including spaced and opposed wall members located to be intersected at intermediate locations by and to be substantially normal to the axis of the shaft, one of said wall members being connected to the frame member and the other being operatively connected to the shaft, .Iaddend.at least two .Iadd.spaced and opposed .Iaddend.deflectable portions .Iadd.having opposite ends integrally connected respectively to and extending between the spaced wall members, the deflectable portions having cross sectional shapes which are substantially wider than they are thick so as to be more deflectable in the direction normal to their thickness, said deflectable portions being .Iaddend.located .[.respectively.]. .Iadd.extending between the spaced wall members with the wider dimensions facing each other .Iaddend.on opposite sides of the axis of the shaft .Iadd.so that when force is exerted on the shaft by the tension of a strand passing thereover substantially parallel deflection of the deflectable portions will occur and essentially parallel relative movement between the spaced wall members connected thereto.Iaddend., means for holding the strand in engagement with the strand engaging means for producing a strand tension load component on the shaft with strand tension load components deflecting the shaft and straining the deflectable portions, and strain sensing transducer means located on at least one of the deflectable portions for conveying therefrom a signal derived from said straining and therefore representative of the tension on the strand. .[.7. The apparatus of claim 6 wherein the coupling assembly includes spaced opposed wall members connected integrally to opposite ends of the 
     
     
        deflectable portions..]. 8. The apparatus of claim .[.7.]. .Iadd.6 .Iaddend.including a housing for around the coupling assembly, means connecting one of the opposed wall members to the housing, said housing being constructed to limit movement of the other of the spaced opposed 
     
     
        wall members relative to said one wall member. 9. The apparatus of claim .[.7.]. .Iadd.6 .Iaddend.wherein said coupling assembly includes a coupling member having a portion connected to said other opposed wall member and another portion connected to the shaft, said housing being constructed to also limit movement of the said coupling member under load. 
     
     
        0. The apparatus of claim 6 wherein said strain sensing transducer means includes at least two strain responsive members attached at spaced locations to one of the deflectable portions, and circuit means connecting 
     
     
        the strain responsive members into an electric circuit. 11. The apparatus of claim 10 wherein four strain responsive members are attached to one surface of said one deflectable portion, means connecting said strain responsive members into a Wheatstone bridge circuit, and other circuit means connected to said Wheatstone bridge circuit, said other circuit means including bridge means and means to indicate the tension on the 
     
     
        shaft. 12. Means to measure tension forces on a member moving over and around a roll comprising a roll rotatable about an axis,   means supporting the roll from at least one end thereof including means responsive to forces on said roll in a direction to deflect said roll, said force responsive means including   a fixed support structure and a support member having a first end portion anchored to the fixed support structure and a second end portion, said support member including a pair of spaced deflectable portions extending between and integrally connecting the first and second end portions, said deflectable portions being located on opposite sides of a line extending through the axis of roll,   a diaphragm member interposed between the second end portion of the support member and the one roll end, said diaphragm having a hub portion connected to the second end portion and a rim portion outwardly therefrom,   means connecting the rim portion to the said one roll end,   means on said fixed support structure engageable by the second end portion of said support member and by the rim portion of the diaphragm when the roll is under predetermined tension force to limit the amount of possible deflection of said support member, and   sensor means attached to at least one of said pair of deflectable portions   
     
     
        at a location to indicate the deflection thereof. 13. The means defined in claim 12 including similar means supporting the roll at both opposite ends 
     
     
        thereof. 14. The means defined in claim 12 wherein the fixed support structure includes an annular wall portion anchored at one end, the first and second end portions of the support member being round and being positioned inside the annular wall portion of the fixed support structure and said spaced deflectable portions being relatively flat and in spaced 
     
     
        parallel planes. 15. The means defined in claim 14 wherein the sensor means include a pair of strain gages respectively attached to one of the 
     
     
        deflectable portions adjacent opposite ends thereof. 16. The means defined in claim 14 wherein the sensor means include two pairs of strain gages, one pair of strain gages being attached adjacent each opposite end of one 
     
     
        of said deflectable portions on the same surface thereof. 17. The means defined in claim 16 including means connecting the strain gages into a 
     
     
        bridge circuit. 18. The means defined in claim 14 wherein said annular wall portion limits movement of the first end portion relative to the 
     
     
        second end portion. 19. The means defined in claim 12 wherein the 
     
     
        diaphragm includes a flexible portion. 20. Means to measure tension forces on a strand member moving over and around a rotatable member comprising a member rotatable about an axis, means for supporting said rotatable member including means responsive to forces on said rotatable member in a direction angularly related to the axis thereof, said force responsive means including   a fixed support structure and a support member having a first end portion anchored to the fixed support structure .Iadd.at a location such that the axis of the rotatable member intersects said first end portion at an intermediate location thereon .Iaddend.and a second end portion axially spaced from the rotatable member .Iadd.and in position to also be intersected at an intermediate location thereon by the axis of the rotatable member.Iaddend., said support member having a pair of spaced deflectable portions extending between and integrally connecting the first and second end portions, .Iadd.each of .Iaddend.said deflectable portions .[.being.]. .Iadd.including a planar member that is deflectable primarily in a preselected plane only, said planar members being arranged in spaced and opposed relationship .Iaddend.located on opposite sides of the axis of the rotatable member.[.,.]. .Iadd.in the space between the first and second end portions, tension forces on the strand member applied to the rotatable member produce essentially parallel deflection of the deflectable portions and essentially parallel movement between the first and second end portions,   other means fixedly connected to said second end portion of the support member for connecting the support member to the rotatable member, said other means having a portion operatively connected to said rotatable member,   means on the fixed support structure in position to be engageable by said other means connected to the second end portion when the rotatable member is under predetermined tension force to limit the amount of possible movement of said rotatable member and of the deflectable portions, and   sensor means attached to at least one of said pair of deflectable portions at a location to respond to the deflection thereof.