US3036787A - Apparatus for controlling tension in moving webs of material - Google Patents

Description

y 1962 R. Q. TRlQUET 3,036,787

APPARATUS FOR CONTROLLING TENSION IN MOVING WEBS OF MATERIAL Filed Sept. 15, 1958 y S F INVENTOR.

1/5521! Q. Tr/Quef 3,036,787 APPARATUS FOR CONTROLLING TENSKON 1N MOVING WEBS F MATERIAL Russell Q. Triquet, 848 Reed St., Kalamazoo, Mich. Filed Sept. 15, 1958, Ser. No. 7 60,966 Claims. (Cl. 242-754) v This invention relates to improvements in apparatus for controlling tension in moving webs of material. The principal objects of this invention are:

First, to provide a relatively inexpensive apparatus for accurately controlling the tension in moving webs of matenijal by maintaining a substantially constant drag on the we Second, to provide an unroll stand for supporting a roll of material such as paper, the stand being provided with automatically variable means for creating a uniform brake horsepower resisting rotation of the roll of material as a web of the material is pulled off of the roll.

Third, to provide an unroll stand adapted to rotatably support a roll of material and having a hydraulic pump connected to be driven at variable speeds by unrolling motion of the roll and having pressure and volume regulating mechanism associated with the pump to automatically maintain constant pressure volume ratio in the output of the pump so that the pump applies a constant tension opposing unrolling motion of the roll.

Other objects and advantages of the invention will be apparent from a consideration of the following descrip tion and claims. The drawing illustrates a highly practical form of the invention applied to an unroll stand for processing rolls of paper and other web-like material.

FIG. 1 is a perspective view of the unroll stand.

FIG. 2 is a side elevational view of a roll of paper mounted in unrolling delivering relation to a forward roll and having the tension regulating elements of the invention illustrated conventionally in operative relation to the roll of material.

The present invention was developed primarily for use in paper mills where large rolls of paper are frequently unwound for delivery to rewinding, slitting or other processing operations. However, the apparatus of the invention is equally applicable to the handling of other weblike materials wherever it is desired to maintain a constant tension in the web of material delivered from a supply roll.

In FIG. 1 there is illustrated a base 1 having a first pedestal 2 with a stub shaft 3 rotatably mounted thereon.

5 Laterally adjustably mounted on the base '1 is a second L pedestal 4 mounting a second stub shaft 5. The shafts 3 and 5 are of the expanding core type arranged to be inserted in the core of a roll of paper and expanded therein to drivingly engage the roll. The shaft 5 is connected by belts or chains 6 and pulleys 7 and 8 to a hydraulic pump and to the regulating mechanism mounted within the pedestal 4.

As is shown more clearly in FIG. 2 the shaft 5 along with the shaft 3 rotatably support a roll 9 of paper or other web-like material to deliver the web 10 to a pair of coacting feed rolls 1 -1 11 rnou nted on a stand 12. The feed rolls 11 are drivenas by the chain 13 and motor 14 to continuously pull oif the Web 10 from the roll. A chain 15 is also driven by the motor '14 and extends to rej winding or processing apparatus not illustrated which receives the web 10 from the rolls 11.

Within the pedestal 4 the driven pulley 7 is connected to the rotor 16 of a positive displacement variable capacity pump. The pump includes a cylinder block '17 having a cylindrical pump chamber 18 formed therein. The rotor 16 has radially extending blades 19 which rotate within the chamber with the rotor 16 and positively displace oil 3,636,787 Patented May 29, 196 2 ice or other liquid from an inlet 20 to an outlet or discharge 21. The rotor 16 is mounted for rotation about a fixed axis but the pump block '17 is movable transversely of the axis of rotation to vary the effective volume of the pump chamber and therefore the volumetric output of the pump. The pump body 17 is moveably supported within the walls 22 of a chamber 23 so that the pump chamber 18 can be moved into and out of concentric relation with the rotor 16. The chamber 23 constitutes a regulating pressure chamber open to one face of the pump block. An adjustable screw 24 threaded into the upper wall 22 yieldably and adjustab'ly urges a spring 25 against the pump block in opposition to any pressure existing in the chamber 23 and toward maximum volume output.

An inlet port 26 in one of the walls 22 connects with an elongated cavity 27 opening to the inlet passage 26 and a discharge port 28 in the opposite wall opens to a cavity 29 communicating with the discharge passage 21.

The discharge port 28 is connected by a pipe or conduit 30 with the inlet 31 to a valve 32. The valve 32 has an adjustable needle valve element 33 threaded into the valve body with its inner end coacting with a valve seat 34 to form a fixed but adjustably variable orifice in the valve body. The outlet 35 from the valve empties into a reservoir 36. The inlet port 26 is connected by the conduit 37 to the reservoir or sump 36 for circulation of oil or other liquid through the system.

The valve 33 and seat 34 form an adjustable restriction or orifice in the discharge line 30, 31 and from the pump so that a given volumetric output of the pump will create a predetermined pressure in the conduit 30. A pressure sensing or sampling conduit 38 opens through a selectively opened or closed valve 39 to the conduit 39 ahead of the restricting valve 32 and communicates through the port 40 with the pressure chamber 23. A branch pressure sensing conduit 41 opens first through a valve 42 to pressure reducing volume increasing differential piston 43. The low pressure high volume side of the diiierential piston is connected through the conduit 44 and a valve 45 to the primary pressure sensing conduit 38 and the port 40'. The pressure sensing conduits 38 and 41 are used alternatively depending upon the pressure of the biasing spring 25 and the presence or absence of need for amplifying the volume of regulating liquid directed to the chamber 23.

With the valve 39 closed and valves 42 and 45 open the alternate sensing conduit 41 will be subjected to the pressure in the discharge conduit 30 by the restricting valve 32 and the smaller face of the differential piston 43 will be moved upwardly delivering a multiplied volume of liquid to the chamber 23. With the valve 39 open and the valve 42 and 45 closed the pressure build up in the conduit 30 is transmitted directly to the chamber 23.

In either adjusted positions of the valves 39, 42 and 45 the chamber 23 will be subjected to a pressure which remains constant so long as the rotation of the pump rotor 16 remains constant. As the size of the roll of material 9 decreases by the uniform withdrawal of the web 10 therefrom the rotational speed of the rotor 16 increases tending to increase the volumetric output of the pump through the conduit 30. Due to the presence of the restri'cting valve 32 in the conduit 30' the increased volume cannot pass tothe conduit 35 without increased pressure and the sensing conduit 38 is subjected to an increas in pressure. The increased pressure acting in the chamber 23 moves the pump block 17 upwardly so that the effective displacement volume of the pump is decreased. The system thus seeks and maintains. a constant pressure volume output so that the power necessary to drive the rotor 16 remains substantially constant. Due to its connection with the roll 9 the pump rotor 16 forms the principal drag or brake opposing rotation of the roll 9. A constant drag on the roll 9 creates a constant tension in the Web 10 being delivered and this greatly facilitates rewinding or processing of the web as the rewinding or processing can be adjusted or operated on a web of uniform tension.

What is claimed as new is:

1. In combination with a paper processing apparatus having a pair of coacting driven feed rolls arranged to feed a Web of paper to the apparatus, paper tensioning means comprising a rotatable shaft supported to support a roll of paper with a web of paper from the roll extending to said feed rolls, a positive displacement pump adjustable to deliver different volumes at a fixed speed and having its driven part connected to be driven by said shaft, an adjustable part in said pump movable to vary the volume output of the pump, a spring biasing said part toward maximum output posit-ion, means for adjusting the pressure of said spring, means forming a fluid chamher in said pump opening to a surface of said part in opposed relation to said spring, an intake for said pump connected directly and solely to a sump, an oulet conduit from said pump arranged to discharge entirely into said sump, means forming an adjustable fixed restriction in said conduit, a first regulating conduit opening between said chamber and said outlet conduit ahead of said restriction forming means, an alternate regulating conduit con-t nected in parallel with said first regulating conduit and having a difierential piston therein with the larger face of the piston opposed to said chamber, and Valves in said regulating conduits adapted to selectively and alternatively open one of the regulating conduits, said pump, said conduits and said sump being connected in a fluid circuit independent of pressure sources other than said pump.

2. In combination with a paper processing apparatus having a driven feed roll arranged to feed a web of paper to the apparatus, paper tensioning means comprising a rotatable shaft supported to support a roll of paper with a web of paper from the roll extending to said feed roll, a positive displacement pump adjustable to deliver different volumes at a fixed speed and having its driven part connected to be driven by said shaft, an adjustable part in said pump movable to vary the volume output of the pump, a spring biasing said part toward maximum output position, means forming a fluid chamber in said pump opening to a surface of said part in opposed relation to said spring, an intake for said pump connected directly and solely to a sump, an outlet conduit from said pump arranged to discharge entirely into said sump, means forming a fixed restriction in said conduit, a first regulating conduit opening between said chamber and said outlet conduit ahead of said restriction forming means, an alternate regulating conduit connected in parallel with said first regulating conduit and having a differential piston therein with the larger face of the piston opposed to said chamber, and valves in said regulating conduits adapted to selectively and alternatively open one of the regulating conduits, said pump, said conduits and said sump being connected in a fluid circuit independent of pressure sources other than said pump.

3. In combination with a paper processing apparatus having a pair of coacting driven feed rolls arranged to feed a web of paper to the apparatus, paper tensioning means comprising a rotatable shaft supported to support a roll of paper with a web of paper from the roll extending to said feed rolls, a positive displacement pump adjustable to deliver different volumes at a fixed speed and having its driven part connected to be driven by said shaft, an adjustable part in said pump movable to vary the volume output of the pump, a spring biasing said part toward maximum output position, means for adjusting the pressure of said spring, means forming a fluid chamher in said pump opening to a surface of said part in opposed relation to said spring, an intake for said pump, an outlet conduit from said pump, means forming an adjustable fixed restriction in said conduit, a first regulating conduit opening between said chamber and said outlet conduit ahead of said restriction forming means, an alternate regulating conduit connected in parallel with said first regulating conduit and having a differential piston therein with the larger face of the piston opposed to said chamber, and valves in said regulating conduits adapted to selectively and alternatively open one of the regulating conduits, said pump and said conduits being connected in a fluid circuit independent of pressure sources other than said pump.

4. In combination with a paper processing apparatus having a pair of coacting driven feed rolls arranged to feed a web of paper to the apparatus, paper tensioning means com-prising a rotatable shaft supported to support a roll of paper with a web of paper fromthe roll extending to said feed rolls, a positive displacement pump adjustable to deliver different volumes at a fixed speed and having its driven part connected to be driven by said shaft, an adjustable part in said pump movable to vary the volume output of the pump, a spring biasing said part toward maximum output position, means forming a fluid chamber in said pump opening to a surface of said part in opposed relation to said spring, an intake for said pump, an outlet conduit from said pump, means forming a fixed flow regulating orifice in said conduit, a first regulating conduit opening between said chamber and said outlet conduit ahead of said orifice, an alternate regulating conduit connected in parallel with said first regulating conduit and having a diflferential piston therein with the larger pendent of pressure sources other than said pump.

5. In combination with a web processing apparatus having a driven feed roll arranged to feed a web of mate-t rial to the apparatus, web tensioning means comprising a rotatable shaft supported to support a roll of the material with a web of material from the roll extending to said feed roll, a positive displacement pump adjustable to deliver different volumes at a fixed speed and having its driven part connected to be driven by said shaft, an adjustable part in said pump movable to vary the volume output of the pump, a spring biasing said part toward maximum output position, fluid pressure actuated means in said pump acting on said part in opposed relation to said spring, an intake for said pump, an outlet conduit from said pump, means forming a fixed flow restriction in said conduit and a regulating conduit opening between said pressure actuated means and said outlet conduit ahead of said restriction and having a ditferential piston therein with the larger face of the piston opposed to said chamber, said pump and said conduits being connected in a fluid circuit independent of pressure sources other than said pump.

References Cited in the file of this patent UNITED STATES PATENTS 2,164,600 Tyler July 4, 1939 2,427,248 Backus Sept. 9, 1947 2,600,632 French June 17, 1952 2,636,693 Littell et a1. Apr. 28, 1953 2,740,256 OMalley Apr. 3, 1956 2,813,601 De Bourgues Nov. 19, 1957 FOREIGN PATENTS 841,265 Germany June 3, 1952 hm. MM,

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