US3618870A

US3618870A - Tension control apparatus

Info

Publication number: US3618870A
Application number: US831791*A
Authority: US
Inventors: Frank Samuel Martin
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1969-02-17
Filing date: 1969-02-17
Publication date: 1971-11-09
Anticipated expiration: 1988-11-09

Abstract

A tension control and brake assembly for maintaining tension on strip material includes a coil support having a braking surface, and a tension control arm pivotally mounted at the coil support and having its arm extending in the direction of the strip leaving the coil. A guide member is positioned on the arm at a point remote from the pivotal mounting of the arm for engaging the strip. A brake structure is disposed to brake the rotation of the coil support. A link connects the tension control arm and the brake and is arranged to actuate the brake on movement of the tension control arm in the direction of rotation of the coil. A first spring urges the tension control arm in the direction of rotation of the coil, and a second spring urges the brake into engagement with the coil support.

Description

United States Patent [72] inventor Frank Samuel Martin Wenham, Mass. 211 App1.No. 831,791 [22] Filed Feb. 17, 1969 Division of Ser. No. 586,713, 061. 14, 1966. Pat. No. 3.465935 [45] Patented Nov. 9, 1971 [73] Assignee The Gillette Company Boston, Mass.

[54] TENSION CONTROL APPARATUS 2 Claims, 4 Drawing Figs.

[52] US. Cl 242/7543, 242/ 1 56.2 [51] 1nt.Ci. B6511 25/24, B65h 59/38 [50] Field 01 Search 242/7543, 156.2, 75.42, 75.45, 75.3, 156, [56] References Cited UNITED STATES PATENTS 1,829,337 10/1931 Brueshaber 242/75.43

2,946,536 7/1960 Froelich 242/156 X 1,952,196 3/1934 Coil 242/7543 2,869,684 1/1959 Tarbuck 242/7543 2,948,488 8/1960 Schoebel et a1 242/7543 3,222,008 12/1965 Purzycki 242/75.43

Primary Examiner-George F. Mautz Assistant Examiner-Gregory A. Walters Attorney-Willis M. Ertman ABSTRACT: A tension control and brake assembly for maintaining tension on strip material includes a coil support having a braking surface, and a tension control arm pivotaliy mounted at the coil support and having its arm extending in the direction of the strip leaving the coil. A guide member is positioned on the arm at a point remote from the pivotal razor edge must also be designed 1 TENSION CONTROL APPARATUS This application is a division of my copending patent application Ser. No. 586,713, filed Oct. 14, 1966, now U.S. Pat. No. 3,465,935.

This invention relates to apparatus and components thereof for handling strip material and more particularly to apparatus for manipulating a continuous ribbon of thin. steel having a razor edge thereon for use in strip razors f the type disclosed in U.S. Pat. N0. 3,262,198.

A number of criteria must be met by any apparatus for manipulating a continuous ribbon of sharpened razor steel. Obviously, any apparatus for manipulating material having a to avoid any damage to the delicate edge and to minimize any safety hazard to operating personnel. Because continuous strip material is supplied in coils, it is necessary to provide tension to the coil and braking means to stop the coil on reduction of machine speed so that the strip will not have a tendency to uncoil as a result of loss of tension. 0n the other band, it is desirable to avoid the complication of a system which requires the large and changing mass of a coil of strip material to be rapidly and frequently accelerated and decelerated, a problem which arises from the inherent intermittent nature of a segmenting operation.

It is therefore a principal object of this invention to provide apparatus which will simply, accurately, and with minimal danger and risk of damage to the delicate razor edge thereof, segment a continuous ribbon of razor steel. Another object of this invention is to provide appropriate tension and brake means at the supply of coiled ribbon material. Still another object of this invention is to provide an arrangement of components thereof in which the coil from which the strip material is drawn may be rotated at a more or less uniform rate despite the intermittent nature of the segmenting operation.

It has been discovered that the objects of this invention may be achieved with tension control and brake means at the supplystation for continuously applying a tensioned force to the strip material as it passes from the coil thereof. That. apparatus includes a coil support having a braking surface, and a tension control arm pivotally mounted at thecoil support and having its arm extending in the direction of the strip leaving the coil. A guide member is positioned on the arm at a point remote from the pivotal mounting of the arm for engaging the strip. A brake structure is disposed to brake the rotation of the coil support. A link connects the tension control arm and the brake and is arranged to actuate the brake on movement of the tension control arm in the direction of rotation of the coil. A first spring urges the tension control arm in the direction of rotation of the coil, and a second spring urges the brake into engagement with the coil support, both springs and the direction of rotation of the coil support acting to apply a braking force which is opposed by the tension of the strip material passing over the guide member.

Other objects, features, and advantages of this invention will be appreciated by those skilled in the art from the following detailed description thereof together with the accompanying drawings in which:

FIG. 1 is a diagrammatic according to the invention;

Fig. 2 is an enlarged side elevation of the supply station of the apparatus taken along the lines 2-2 of FIG. 1;

FIG. 3 is a view taken along the lines 3-3 of FIG. 2;

FIG. 4 is a view similar to FIG. 3 showing a different operating position of the tension control and brake assembly at the supply station.

As will be seen from F 1G. 1 of the drawings, the segmenting apparatus 10 includes a plurality of components linearly arranged (the bends in the strip 14 path shown in FIG. 1 being used only to diagrammatically indicate continuity thereof) between a supply station 30 and the segmenting station 120. Pullout rollers 49 positioned in the strip path after supply station 30 draw the strip 14 from the coil 13 thereof at supply station 30. Pullout rollers 49 draw the strip 14 from the coil 13 at the average speed of the strip through the remainder of applan view of segmenting apparatus paratus 10. As shown in FIG. 2 the strip 14, of razor steel, has a razor edge 15 which is fed in an upright position through apparatus w to avoid damage thereto.

A tension control and brake assembly 33 is provided between pullout rollers 49 and supply station 30 for exerting a tensional force on strip 14 at the coil 13 thereof at station 30 in the direction of rotation thereof and for braking the coil in response to a tension decrease below a predetermined level.

After pullout rollers 49 the strip 14 path forms a slack loop containing a greater amount of strip material therein than a segment length thereof, which loop is maintained by a flow of air from jet 50. Photoelectric cell detectors 52 are provided at the position of the loop to sense any increase in the loop beyond the position therebetween to signal pullout rollers 49 to slow down or stop. Microswitch 53 detects and signals any loss of the loop. From rollers 49 movement of strip 14 through apparatus 10 is incremental, the slack' loop, however, permitting the strip 14 to be drawn from coil 13 at a relatively constant speed.

From the loop the strip 14 proceeds between guide rollers 54 and thence to a vacuum tension control block 56 which exerts a retarding force on the strip 14 as it passes therefrom. The vacuum tension control block 56 simply comprises a block adjacent the side of the strip path having perforations at that side through which a vacuum is applied to the side of the strip 14. The frictional engagement of the strip 14 and the block'56 thereby engendered creates a tension in the strip 14 from that point forward in the apparatus.

From the vacuum tension control block 56, the strip 14 passes through a series of inspection stations 20 which are adapted to detect any defects in the strip 14 and to store the information in a mechanical memory cell (not show) to signal actuation of a rejects mechanism at a later stage when the strip 14 reaches the rejects mechanism. Details of structure and function of these inspection stations may be had with reference to U.S. Pat. No. 3,431,624.

From the inspection stations the strip path extends through tab placement apparatus 58 which is positioned three strip segment lengths from the segmenting means 122, later to be described, for operation in the stopped position of the incremental movement of strip 14 therethrough. At the tab placement apparatus 58 tabs comprising generally U-shaped members with a perforation on one side thereof are fed from feed bowls 60 and placed on strip 14 side by side. The tabs are fastened at placement apparatus 58 to the strip 14 by punches which move through the perforations and deform the strip material and portion of tabs therebehind. Also at apparatus 58 is another vacuum tension control block 57, similar to block 56, to assist in tensioning the strip 14 and to prevent wavering of the strip 14 as tabs are placed thereon.

From the tab placement apparatus the strip path moves through fine adjustment and tab detector apparatus 62 which adjusts the position of the strip 14 prior to the placement of the next set of tabs by placement apparatus 58 to assure accuracy of placement thereof, and which detects the presence or absence of tabs and in the absence of one or more tabs signals an apparatus stop circuit.

From the fine adjustment and tab detector mechanism 62 the strip 14 moves to bidirectional control apparatus 98 which prevents any slack from moving backwardly through the strip 14 thereby to maintain tension therebehind and which also functions to exert a retarding tensioning influence on the strip 14 as it passes therefrom to the segmenting station next in the line of the strip path.

Finally, the apparatus 10 is provided with a segmenting station 120 at which means are provided for pulling the strip through the apparatus, for segmenting the strip at the position between tabs for depositing the strip in trays 174 on a conveyor 176 therebelow, and for rejecting a defective strip segment.

In greater detail, supply station 30 includes a rotatable table 32 mounted on apparatus frame 11 as shown in FIGS. 3 and 4 on which a coil 13 of strip razor steel 14 is mounted with its sharpened edge 15 up, as in FIG. 2. As is perhaps best shown in FIG. 4 the tension control and brake assembly 33 at station 30 includes a tension arm 34 pivotally mounted coaxially of table 32 about shah 35. Arm 34 extends generally in the direction of the path of strip 14, as it leaves the coil 13, and has on the end thereof a pair of freely rotatable guide rollers 36 through which the strip 14 passes as it is drawn by pullout rollers 49. A spring 38 is interconnected between an extension 37 of arm 34, to the other side of pivot 35 from guide rollers 36, and a stationary post 39 mounted in frame 1 1 thereby biasing arm 34 in the direction of rotation of table 32 and creating a tensioning force on a strip 14 between coil l3 and pullout rollers 49.

Brake arm 40 having a brake surface 41 adapted to engage the circumferential surface of table 32 is pivotally mounted by pivot pin 42 on a post 43, mounted in frame ii, for movement against and away from table 32. A spring 44 interconnected between brake arm 40 and another post 45 mounted in frame ll normally biases the brake arm 40 toward table 32. A link 46 pivotally connected to extension 37 by pivot pin 47 interconnects tension arm 34 and brake arm 40. The link 46 is connected to arm 40 by shaft 48 fixedly mounted on brake arm 40 and slidably positioned within a slot 51 in the end of link 46 thereadjacent, slot 51 extending generally in the direction of movement of link 46.

in operation, if tension in the strip 14 as it leaves coil 13 is reduced the spring 38 exerts a force on arm 34 to move that arm in the direction of rotation of the coil thereby to exert a tension between the coil 13 and pullout rollers 49. As arm 34 thus rotates, spring 44 urges brake arm 40 into engagement with table 32 to apply a braking force thereto. Elongated slot 51 allows arm 34 to continue to rotate, under the influence of spring 38, and take up slack between coil 13 and pullout rollers 49. As tension is increased in the strip 14, the procedure is reversed and the other end of slot 51 engages shaft 48 overriding the biasing force of spring 44 to move the brake arm 40 away from table 32, to permit free rotation thereof.

Springs

38 and 44 are selected for strength, and the moment arms thereof positioned, so that the force exerted by the spring 44 is substantially less than that of spring 38 as otherwise it obviously would be impossible to release the brake.

Other embodiments of this invention will occur to those skilled in the art which are within the scope of the following claims.

What is claimed is:

l. A tension control and brake assembly for maintaining tension on strip material between a rotating supply coil thereof and pullout means drawing said strip off said coil and for braking said supply coil in response to a reduction of tension below a predetermined level, comprising:

a coil support having a braking surface;

a tension control arm pivotally mounted at the axis of rotation of said coil support and having its arm portion extending in the direction of said strip leaving said coil;

at least one guide member on said arm at a portion remote from the pivotal mounting thereof adapted for engaging the side of said strip corresponding to the other side thereof on said coil; first biasing means connected to said arm on the opposite side of said axis from said guide member and urging said arm in the direction of rotation of said coil;

brake means for braking said coil;

second biasing means connected to said brake means urging said brake means into engagement with said braking surface of said coil support; and

means interconnecting said arm and said brake means for actuating said brake means into engagement with said braking surface of said coil support on movement of said arm in said direction.

2. A tension control and brake assembly for maintaining tension on strip material between a rotating supply coil thereof and pullout means drawing said strip off said coil and for braking said supply coil in response to a reduction of tension below a predetennined level, comprising:

a coil support having a braking surface;

a tension control ann pivotally mounted at said coil support and having its arm portion extending in the direction of said strip leaving said coil;

at least one guide member on said arm at a portion remote from the pivotal mounting thereof adapted for engaging the side of said strip corresponding to the outer side thereof on said coil;

first biasing means connected to said arm urging said arm in the direction of rotation of said coil;

brake means for braking said coil;

a link interconnecting said arm and said brake means for actuating said brake means into engagement with said braking surface of said coil support on movement of said arm in said direction, said link extending between said arm and said brake means, and being pivotally connected to one of them and slidably connected to the other of them, one of said other of them and said link including a slot extending generally along the path of movement of said link and a shaft slidably in said slot extending to and fixedly connected to said other of them,

Claims

1. A tension control and brake assembly for maintaining tension on strip material between a rotating supply coil thereof and pullout means drawing said strip off said coil and for braking said supply coil in response to a reduction of tension below a predetermined level, comprising: a coil support having a braking surface; a tension control arm pivotally mounted at the axis of rotation of said coil support and having its arm portion extending in the direction of said strip leaving said coil; at least one guide member on said arm at a portion remote from the pivotal mounting thereof adapted for engaging the side of said strip corresponding to the other side thereof on said coil; first biasing means connected to said arm on the opposite side of said axis from said guide member and urging said arm in the direction of rotation of said coil; brake means for braking said coil; second biasing means connected to said brake means urging said brake means into engagement with said braking surface of said coil support; and means interconnecting said arm and said brake means for actuating said brake means into engagement with said braking surface of said coil support on movement of said arm in said direction.

2. A tension control and brake assembly for maintaining tension on strip material between a rotating supply coil thereof and pullout means drawing said strip off said coil and for braking said supply coil in response to a reduction of tension below a predetermined level, comprising: a coil support having a braking surface; a tension control arm pivotally mounted at said coil support and having its arm portion extending in the direction of said strip leaving said coil; at least one guide member on said arm at a portion remote from the pivotal mounting thereof adapted for engaging the side of said strip corresponding to the outer side thereof on said coil; first biasing means connected to said arm urging said arm in the direction of rotation of said coil; brake means for braking said coil; second biasing means connected to said brake means urging said brake means into engagement with said braking surface of said coil support; and a link interconnecting said arm and said brake means for actuating said brake means into engagement with said braking surface of said coil support on movement of said arm in said direction, said link extending between said arm and said brake means, and being pivotally connected to one of them and slidably connected to the other of them, one of said other of them and said link including a slot extending generally along the path of movement of said link and a shaft slidably in said slot extending to and fixedly connected to said other of them.