US2759728A - Tensioning mechanisms - Google Patents

Description

Aug. 21, 1956 w. F. HUCK TENSIONING MECHANISMS Original Filed Aug. 25, 1947 iNVENTOR WaLuAM F Hucx,

ATTORNEY United States Patent TENSIONING MECHANISMS William F. Huck, Forest Hills, N. Y., assignor to Huck Em, New York, N. Y., a partnership Original application August 25, 1947, Serial No. 77 0,440,

now Patent No. 2,670,907, dated March 2, 1954. Digiadgegsa nd this application March 30, 1.953, Serial No.

5 Claims. (Cl. 271- 23) This invention relates to tensioning mechanisms, and more particularly relates to mechanisms for tensioning strips or webs of various'materials, as the said material is processed, or as the material proceeds fromone stage to another in a series of processes. The mechanism may be used to tension a plurality of superposed Webs or ribbons of paper or cloth while these web's or ribbons are being wound upon or unwound from a roll or during a printing, a collating or other process.

It is desirable in this type of apparatus that the tensioning mechanism be capable of maintaining a constant tension to a fine degree of accuracy despite the presence of many variables that may operate adversely to affect the tension. Tensioning mechanisms heretofore used, have been complicated, expensive to manufacture, and not always entirely satisfactory. Therefore, one object of the present invention is to provide new and improved tensioning mechanisms that will be simple to construct, easy to operate, and inexpensive to build, and which at the same time under all circumstances will produce satisfactory results.

Another object of the invention is to provide an improved tensioning mechanism having a surface that will at all times be in contact with at least a portion of the web that is being tensioned.

A further object of the invention is to provide an improved tensiom'ng mechanism that includes a drive pulley, a driven pulley, and a V-belt drivingly connecting the said two pulleys, one of which is a variable diameter pulley.

A still further object of the invention is to provide an improved tensioning mechanism having a surface that will at all times be in contact with at least a portion of the strand that is being tensioned and which includes a drive pulley, a driven pulley and a V-belt drivin'gly connecting the said two pulleys, one of which is a variable diameter pulley.

A further object of the invention is to provide a new and improved tensioning mechanism.

This application is a division of anap'plication filed by me on August 25, 1947, with Serial No. 770,440, now Patent No. 2,670,907.

For a more complete understanding of the invention and its mode of operation, reference should be made to the accompanying drawings which form a part of this specification. In these drawings,

Fig. 1 is a side elevational view of a preferred form of tensioning mechanism embodying this invention as applied to a plurality of web or ribbon forwarding rollers adapted for forwarding a single web or a plurality of collated webs or ribbons;

Fig. 2 is a plan view of the top portion of the mechanism shown in Fig. 1 as seen in the direction of the arrows 22 of Fig. l; and

Fig. 3 is a fragmentary sectional view taken on the line 3-3 of Fig. 1 and looking in the direction of the arrows.

Referring to the drawings, this invention is shown in a preferred form in Figs. 1, 2and 3 as applied to a tensioning mechanism having a plurality of web or ribbon forwarding rollers indicated generally by the numerals 78 and 79. These rollers are supported in a manner presently to be described. In order to accomplish this a pair of side frames 81 and 81' carry a cross shaft 82 which rockably supports, by means of bearing lugs 84 and 84 a pair of spaced tension responsive arms or lever 83 and 33. Except for being opposite hand, the two levers 83-83 are identical and therefore they will be described together. Lever 83 (83') has an upwardly extending double lug 85 (85') which is apertured to receive a pin 87 (87) which rockably supports a balanced lever 86 (86). As seen in Fig. 1, the right or distal end 88 (88') of the lever 83 (83) has a vertical hole 89 (89') through which passes a vertically disposed rod 90 (90'). The lower end 91 (91') of the rod 90 (90) is fulcrumed on a stud 92 (92') supported by the frame 81 (81). A washer 93 (93') carried on the rod 90 (90) supports the lower end of a coiled spring 94 (94'), the upper end of which supportsthe distal end 88 (88) of the lever 83 (83) urging it upwardly. A second coiled spring 95 (95'), carried on the upper surface of the end 88 (88') is coiled around the rod 90 (90) and due to a hand wheel 96 (96), which is threaded onto the upper end 97 (97) of the rod '90 '(90), urges the end 88 (88') of the arm 83 (83") downwardly. Both ends of the balanced lever 86 (86) are apertured, and the two levers 86 and 86 cooperate to support cross shafts 99 and 100. Each end of the shafts 99 and 100 is provided with a retaining screw 123 (123) and washer 122 (122). Shaft 100 supports the roller 79, which is made up of two freely rotatable half- rollers 101 and 102, whereas, shaft 99 supports the roller 78, which is made up of two freely rotatable half rollers 103 and 104. Each of the roller halves 101, 102, 103, and 104 are provided with a raised annular flange'105, these flanges being so constructed and arranged that the outer margins of a single web or a plurality of collated webs or ribbons passing between the rollers are frictionally engaged by the flange. The flanges 105 form moving surfaces which are always in rolling contact with webs or ribbons B, hereinafter referred 'to. It will be noted that the shafts 99 and 100 form connections between the flanges or moving surfaces 105 and the V-belt pulleys 106 hereinafter mentioned. The shaft 100, and thereby the roller halves 101 and 102, are adjustably carriedin the balanced levers 86 by being held in slotted holes 120 by adjusting screws 121, which act against the shaft 100, whereby, the pressure by which the rollers 79 can be forced against the roller 78 is adjustable. The movement of the arm 83 (83') may be controlled by any well known damping means, as for example, a damping cylinder 190 (190') having a piston 191 (191) carried by a rod 192 (192); the rod 192 (192) being attached to its arm 83 (83) by a pivot pin 194 (194') and thepart 190 (190') being attached to the frame81 (81) by means of a pivot pin 193 (193). Each half roller 101, 102, 103, and 104 is provided with its own driven, V-beltpulley 1'06 and is thereby driven independently by its own V-belt 107. Each of the four V-belts 107 is driven from a separate variable diameter V-belt drive pulley designated 'by the numeral 114, two of the drive pulleys being mounted on a shaft a and two on a shaft 11012. The shafts 110a and 11% are driven by a chain of gears comprising gears 111, 112, and 113. Each of the pulleys 1 14 (Fig. 3) is a two-part variablediameter V-belt pulley each having two identical, though opposite hand, flanged pulley-halves 116, each slidably mounted on its respective shaft 110a or 11% as the case may be. Each pulley-half 116 is biased longitudinally on the shaft on which it is mounted by a helical spring 117.,

which reacts against a collar that .is secured to the shaft 110a or 11% as the case may be. From this it will be noted that each pulley 114 is made up of six separate parts; viz. two flanged pulley-halves 116, two springs 117, and two collars 115. It should also be noted that the mechanism, hcreinshown, has four sets of these pulleys 114. The pulleys 114 drive respectively the roller- halves 101, 102, 103 and 104. The V-belts 107 are individually adjusted to a predetermined position on the various variable-diameter pulleys and the forwarding of the ribbon or ribbons is accelerated or retarded in such a manner as to maintain the predetermined desired tension in the ribbons. This is accomplished as follows: The helical springs 117, which surround the shafts, urge and contact the collars 115 as well as the flange on the pulley-half 116 urge the pulley-halves 116-116 toward one another, and thereby press against the V-belt 107. This causes the V-belt to assume a running position as far from the center of the pulley 114 as the length of the belt 107 will allow. In the event that the tension in the belt 107 is increased sufliciently the springs 117 will yield and allow separation of the pulley-halves 116 thus allowing the V-belt 107 to assume a running position closer to the center of the shaft on which the pulley is mounted.

By reference to Fig. 1, it will be realized that a balance exists between a plurality of forces, that attempt to move the lever 83 about its fulcrum 82. Material B, which as indicated by the arrows 108, is being pulled downwardly, tends to move or pivot the lever 83 counterclockwise. The belts 107 pull downwardly and tend to move the lever 83 clockwise. The springs 94 and 95 may be adjusted so as to supply a force that will tend to move the arm 83 either clockwise or counterclockwise, as desired. In constructing the mechanism it is desirable to mount the shafts 99 and 100 in the balanced levers 86 and 86 with sutficient clearance or looseness so that the half- rollers 102 and 103 near the front frame 81 may assume a slightly diflerent position than the rollers 101 and 104 near the rear frame 81. Furthermore, the right hand roller 79 will balance the left hand roller 78 and vice versa.

If the tension in the ribbons B changes, the balance of forces acting on the lever 83 will be disturbed. For example, if the tension in the ribbons B above the bite of the rollers 7879 is increased, the arm 83 moves counterclockwise. This tensions the belts 107 and causes them to run on a smaller pitch line on the pulleys 114 and this in turn slows down the speed of the pulleys 105 and the rollers 78 and 79 driven thereby. This causes less of the ribbons to be pulled through and thus restores the balance. If, on the other hand, the tension in the ribbons B above the rollers 7879 is decreased, the arm 83 is moved clockwise. This causes the belts 107 to run on a larger pitch line on pulleys 114, to speed up the pulleys 105 and rollers 78 and 79. This pulls more ribbon through the rollers and again restores the balance.

It should also be noted that the four half rollers 101, 102, 103, and 104 are capable of independent action. This follows from the fact that each half roller has its own variable diameter V-belt drive. If the mechanism is being used to forward a collated ribbon of several layers, the tension in either outside sheet can be corrected independently of the other sheets. For example, if the right sheet of the collated ribbon B requires more tension, the right hand roller 79 will independently tend to increase its speed in order to restore gradually the tension of the right hand sheet by causing a slight slippage between it and the left hand ribbon. It will also be noted that the total forces between the right hand and left hand sheets will be maintained, by causing a slight increased tension in the left sheet, while the tension in the right sheet may be slightly decreased. Furthermore, since the front halfrollers 102 and 103 are independently driven with respect to the rear half rollers 101 and 104, the front or rear edges of the ribbon can be independently tensioned. This arrangement of four independently driven half-rollers, tends to maintain an even tension on all four points where the ribbon is contacted by the four raised portions 105. Thus the mechanism of this invention is capable of correcting for all sorts of difierent forwarding conditions caused by many variables as for example variables in humidity etc.

From the above it will be noted that I have provided a mechanism capable of forwarding and regulating the tension in a single ribbon or a collated ribbon of several layers, that includes among other elements (1) a rotating roller which is always in contact with the moving ribbon, (2) a driven pulley, which in the illustrated embodiment takes the form of a V-belt pulley, (3) a driving pulley, which is shown as a variable diameter V-belt pulley, (4) a V-belt drivingly connecting the two pulleys, (5) a connection between the driven pulley and the rotating roller, (6) a pivoted tension responsive lever or arm, which is responsive to the tension in the moving ribbon, and (7) a connection between the tension responsive arm and the V-belt. This structure provides an automatic means for tensioning moving ribbons in which movable or floating drive rollers act upon the ribbons in such a way that the length of the ribbon, between a fixed point located before the movable drive rollers and a second fixed point located beyond the movable drive rollers, will not change.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A mechanism for regulating the tension of a moving ribbon, comprising, a frame, a pair of rockably-supported tension-responsive levers and each of said levers having a distal end provided with a hole; a rod passing through each of said holes, one end of each of said rods being fulcrumed on one of said frames; a hand wheel threaded on the other end of each of said rods; a pair of coiled springs surrounding each of said rods and in the case of both rods, one of the springs being located between the tension-responsive lever and the frame and the other of said springs being located between said lever and the handwheel; a balanced lever rockably supported at its center from each of said tension-responsive levers; a pair of parallel cross shafts supported by said balanced levers; a pair of raised annular flanges carried by each of said cross shafts; a driven V-belt pulley provided on each of the annular flanges; a variable-diameter V- belt driving pulley located adjacent each of said driven pulleys; a V-bclt connecting each of said driven pulleys with its respective driving pulley; and means for driving said driving pulleys.

2. A mechanism for regulating the tension of a moving ribbon, comprising, a frame; a pair of rockablysupported tension-responsive levers and each of said levers having a distal end; a rod adjacent to each of said distal ends, the lower end of each of said rods being fulcrumed on said frame; an adjustable member on the upper end of each of said rods; a pair of coiled springs associated with each of said rods and in the case of both rods, one of the springs being located between the tension-responsive lever and the side frame and the other of said springs being located between said lever and the handwheel; a balanced lever rockably supported from each of said tension-responsive levers; a pair of parallel cross shafts supported by said balanced levers; a pair of raised annular flanges carried by each of said cross shafts; a driven V-belt pulley provided on each of the annular flanges; a variable-diameter V-belt driving pulley located adjacent each of said driven pulleys; a V-belt connecting each of said driven pulleys with its respective driving pulley; and means for driving said driving pulleys.

3. A mechanism for regulating the tension of a moving ribbon, comprising, a frame; a cross shaft supported by said frame; a pair of spaced tension responsive levers rockably supported by said cross shaft and each of said levers having a distal end provided with a vertical hole; an upstanding lug formed integral with each of said tension responsive levers; a vertical rod passing through each of said vertical holes, the lower end of each of said vertical rods being fulcrumed on one of said frames; a hand wheel threaded on the upper end of each of said rods; a pair of resilient members associated with each of said rods and in the case of both rods, one of the resilient members biasing said tension responsive lever upward and the other of said resilient members biasing said lever downwards; a pin carried by each of said upstanding lugs on said tension responding lever; a balanced lever rockably supported at its center from each of said tension responsive levers; two pairs of half-rollers carried by said tension responsive levers; a raised annular flange formed on each of said half-rollers; a driven V- belt pulley provided on each of the half-rollers; a variable diameter V-belt driving pulley located adjacent each of said driven pulleys; a V-belt connecting each of said driven pulleys with its respective driving pulleys; and means for driving said driving pulleys in synchronism.

4. A mechanism for regulating the tension of a moving ribbon, comprising, a pair of spaced side frames; a cross shaft supported by said frames; a pair of spaced tension responsive levers rockably supported by said cross shaft and each of said levers having a distal end provided with a vertical hole; an upstanding lug formed integral with each of said tension responsive levers; a vertical rod passing through each of said vertical holes, the lower end of each of said rods being fulcnumed on one of said frames; a hand wheel threaded on the upper end of each of said rods; a pair of coiled springs surrounding each of said rods and in the case of each rod, one of the springs being located between the tension responsive lever and the side frame and the other of said springs being located between said lever and the handwheel; a pin carried by each of said upstanding lugs on said tension responsive lever; a balanced lever rockably supported at its center from each of said pins and each of said balanced levers having both ends apertured by horizontal holes; a pair of parallel cross shafts supported by the apertured opposite ends of the said balanced levers; a pair of half-rollers carried by each of said cross shafts; a raised annular flange formed on each of said half-rollers; a driven V-belt pulley provided on each of the half-rollers; a variable diameter V-belt driving pulley located adjacent each of said driven pulleys; a V-belt connecting each of said driven pulleys with its respective driving pulley; and means for driving said pulleys in synchronism. v

5. A mechanism for regulating the tension of material in the form of a plurality of collated webs, comprising two pairs of rollers, the rollers of each pair having relatively narrow web engaging surfaces and the rollers of the respective pairs being disposed to frictionally engage between them opposite surfaces of the web collation and at opposite lateral edge regions thereof, the rollers forming each pair being journalled in a respective rockable lever, an independently pivoted tension-responsive arm for each pair of rollers, pivoted about an axis parallel to the roller axes, said rockable levers being pivoted on the respective arms about axes parallel to the roller axes and intermediate therebetween, oppositely-acting springs connected to each tension-responsive arm to bias the same to a position :of pivotal equilibrium with reference to its pivotal mount, an independent V drive pulley connected to each of said rollers, a V- power pulley for each drive pulley disposed away from the drive pulley in the general direction of web travel, and a V belt connecting each drive pulley with its corresponding power pulley, one pulley of each set being of the spring-biassed variable pitch diameter type, whereby the effective driving speeds of said rollers are independently controlled in accordance with web speed at both surfaces of both edges of the web collation.

References Cited in the file of this patent UNITED STATES PATENTS 1,975,122 Potdevin Oct. 2, 1934 2,029,854 Cannity Feb. 4, 1936 2,082,456 Leidtke et al. June 1, 1937 2,096,231 Ensign et al. Oct. 19, 1937 2,166,551 Perry July 18, 1939 2,199,270 Roselius et al. Apr. 30, 1940 2,341,636 Luehrs Feb. 15, 1944 2,349,659 Huck May 23, 1944 2,427,943 Butterworth et al. Sept. 23, 1947 2,579,741 Houston Dec. 25, 1951 2,650,090 Davidson et al. Aug. 25, 1953

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