CA1074692A - Fabric cutter - Google Patents

Abstract

A circular cutter for use in cutting rubberized fabric, includes a circular body with a circular outer peripheral cutting edge, the circular outer peripheral edge has a center on the circular body; a mounting bore in the body is provided for mounting the cutter on a shaft for rotating the cutter; the body has a pair of oppositely disposed side surfaces; the center of the mounting bore is eccentric relative to the center of the body; the cutting edge is planar with one of the side surfaces of the body; and the cutting edge tapers to merge with the other one of the side surfaces.

Description

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This invention relates to a cutter elastomeric or rubberized fabric material and is especially useful in pneumatic tire manufacture, and more particularly concerns a circular cutter for cutting ply stock material which is er~loyed in the construction and manufacture of pneumatic tires.

This application is a division of Canadian Patent Application Serial No. 284,855, filed August 15, 1977.
In the manufacture of pneumatic tires, one of the principal members used to build the tire carcass is a thin sheet of uncured rubber-like material known as a fabric, building ply or ply stock. In the manufacture of such ply stock, parallel cord~ of fabric, wire cord or high strength cord such as Kevlar cord axe passed through a pair of rolls in cooperation with calendering rolls which work and calendar unvulcanized rubber onto the parallel ccrds as they pass through the pinch - rolls to form a continuous sheet of material with the parallel strands of cord embedded therein and running in a direction that is parallel to the longitudinal center-line of the material.
Thereafter, such sheet material is bias cut into sections of fabric which are then spliced together to make a building ply or ply stock with cords therein located at a desired bias angle relative to the longitudinal centerline of the ply stock, Such stock or ply stock may also be at a ninety degree angle to the longitudinal centerline of the ply stock formed, however, for purpose of this description and example, the invention will be described wherein the cords are at some small acute angle relative to the longitudinal centerline of the ply stock. Layers of ply stock are applied to a tire building drum in such a manner that cord mer~ers of ovex-lapping plies crisscross with respect to the cord member~

above or below. The tire beads are then set against the - 1 - ~

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ends o~ the ply stock and the plies are turned thereover.
Additional plies, chafer strips sidewall strips~ breakers, overhead belts and a tread ply may be applied in varying orders, and stitched thereto. Such carcass is substan-tially a flat band, wherein the angle is measured be-tween the cords and the circumferential line around the crown of the tire. In the case of conventional bias ply pneumatic tires, this may be approximately sixty degrees.
However, this apparatus can cut fabric material with strands of Kevlar cord therein which make a small acute angle with the circumferential centerline of the tire.
After the removal of such green tire, the tire is given a torodial shape during vulcanization or on a second machine prior to vulcanization, wherein the angle after vulcanization will change depending on many factors in-cluding drum set. The above description has generally referred to tires manufactured from fabric, however, the present invention is also directed to building plies which use non-extensible cord materials such as nylon, Kevlar cord and wire. In the processing of ply stock containing Kevlar cord, processing has been difficult because of tremendous strength of the material, which cutting is particularly compounded by the very low bias angle cutting on such stock wherein the cutters tend to fray the ends of the Kevlar cord. which action interferes with the splice to be effected. This apparatus can also cut stock which has zero bias angle In bias cutting rubberized fabric the con-ventional way of cutting i8 to use a pair of fingers that `` ~CI7~

lift the fabric away from the conveyor belt on which it travels, so that a rapidly rotating cutter disk is above the fingers but is cooperative therewith to cut the fabric. The application of this conventional apparatus to cut rubberized Kevlar cord fabric including fabric for radial tires is difficult and unsatisfactory. The rotating cutter of the present invention is mounted off-center giving the rotating cutter a shearing action on ~he rubberized fabric material as the cutter iA moved transversely across the material in co-operation with a linearly movable anvil that is supportedin its movement to assure a firm cutting action during the shearing cut. Upon the completion of a cut across the fabric material, it is desirable to move the cutter and anvil out of the way so that as the cutter and anvil are returned to their starting position the fabric material can be advanced or indexed to the next position in preparation for the succeed-ing cut. -According to the invention there is provided a circular cutter for use in a cutting apparatus, the cutter having a circular body with a circular outer peripheral cutting edge, the circular outer peripheral edge having a center on the body, a mounting bore in the body for mounting the cutter on a shaft for rotating the cutter, the body having a pair of oppositely disposed side surface~, the centre of the mounting bore being eccentric relative to the center of the body, the cutting edge being planar with one of the side surfaces of the body, and the cutting edge tapering to merge with the other one of the side surfaces.
The circular cutter of the invention may be employed in an apparatus for cutting of elastomeric fabric material which includes a cutter support means, a shaft journalled in the support means for rotation, and a circular cutter having a bore 69;2 therein off-set from the center of the cutter, the shaft receiving the bore to provide an ecrentric mounting of the cutter on the shaft, means securing the cutter to the shaft for simultaneous rotation, drive means on the cutter support means connected to the shaft for rotating the shaft and the cutter continuously and simultaneously about the center of the shaft during the cutting of the material.
There is described and contemplated an apparatus in which the cutter may be employed that utilizes a carriage which is mounted on a support frame for reciprocal movement on a guideway.
A cutter support member carrying the cutter and its cooperative anvil is mounted on the carriage for movement therewith. The anvil is supported by the cutter housing in its reciprocal movement. Means are provided to pivot the cutter and the cutter support member along with the anvil out of the way so that as the cutter and anvil can be returned to the original starting position while the fabri~ material to be cut is indexed in preparation for the next cut. The rotating circular cutter is eccentrically mounted so that its rotating edge cooperates with the anvil to provide a downward shearing action in cooperation with the traveling anvil, which anvil is supported by the cutter support.
The support frame may be adjusted for the bias angle to be cut, ~r it may be adjusted for zero bias angle.

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Fig. 1 is a front elevational view of a bias cutting apparatus with a portion of the conveyor shown.
Fig. 2 is an enlarged elevational view of the carriage, cutter support, anvil and a portion of the guide bar.
FigO 3 is a cross-sectional view of the carriage and cutting means taken along lines 3-3 of Fig, 20 Fig. 4 is a fragmentary cross-sectional view of a portion of the carriage and cutter support showing the cutting support elevatedO
Fig. 5 is a side elevational view of the rotary cutter and a portion of the anvil.
Fig~ 6 is an enlarged cross-sectional view of a portion of the cutter and anvil taken along lines 6-6 of FigO 5, Referring to the drawings wherein like reference characters designate like or corresponding parts through-out the several views, there is shown in Fig. 1 an end-less conveyor belt that iq suitably supported at spaced 3L07~69~

- ends thereof by suitable rollers driven in a manner old and well-known in the art. The conveyor belt has an upper conveying run 10 and a lower return 11.
Suitable guide and support means are provided ,to guide the belt in its travel, including an up~er plate 12 to support upper run 10. Supporting framework shown general-ly in Fig. 1 includes a pair of spaced upwardly extending support members 16 and 17 with suitable supports includ-ing an upper cross support or I-beam 18 and a lower cross support 19. Lower support 19 has a pivot mounting 22 at its intermediate lower portion suitably ~ournaled in the floor Or the installation, about which the support framework can be pivo~ally adjusted. A plurality of spaced rollers 23 are suitably mounted on respective lower end portions of the supporting framework to facilitate the angular ad~ustment of the supporting frame and the bias cutting apparatus to be described. Cross support 18 extends across the entire width of the bias cutting apparatu~ and as shown in Fig. 3 supports a guideway or guideway member 24 having a plurality of ways thereon.
Mounted ~or reciprocal movement on guideway 24 i8 a carriage rneans 26 which includes side plates 27-27 and end plates 28-28 (Fig. 2). Suitably ~ournaled on carriage means 26 are a plurality of rollers 29 which rollingly engage the ways on guideway 24 to maintain carriage means 26 thereon and guide the reciprocal move-- ment of the carriage means 26 on the waye of the guide-way 24. Journaled on the lower one end portion of end plates 28-28 of carriage means 26 is a rod or ~haft 31 .. - i ~o~9z for pivotally supporting a cutter support member 32.
Cutter support member 32 has a pair of bosses integral therewith each having aligned bores in which is journaled a shaft 37. Shaft 37 has a pair of spur gears 38 (only one shown) suitably keyed to the respective end portion thereof. Shaft 37 supports a clevis for pivotal attach-ment to the rod end o~ piston rod 40 of a pneumatic - cylinder 41. The head end of pneumatic cylinder 41 is pivotally attached to a bracket means 43 which is part of the æide plate 27 of carriage means 26. The spur gears 38 meshingly engage stationary gear segments 44 (only one shown) that are rigidly secured to the respec-tive end plates 28-28 of carriage means 26. Upon actuation of the head end of cylinder 41, piston rod 4 is extended from the p09iti0nshown in Fig. 3 to that æhown in Fig. 4 whereby the spur gears 38 rotate clock-wise as shown in Fig. 3 pivoting the cutter support member 32 in a clockwise direction (as viewed in Fig.
3) about shaft 31 ~or a purpose to be described.
The lower portion of cutter support member 32 is centrally recessed to provide guideways which support an adjustable block 49. A motor 65 suitably secure~ to carriage means 26 has its output shaf-t connected to a sheave 66 whlch i6 in alignment with sheave 54. Sheave 54 has its output connected via suitable gears to drive shaft 550 A V-bel-t 67 is trained about sheaves 66 and 54, to provide the transfer o~ power from motor 65 to shaft 55 on which a circular cutter 60 i6 eccentrically mounted. The center of shaft 55 i8 deslgnated a~ "A"
in Figure 5, while the center of cutter 60 is designated as "B"~ The amount of eccentricity between centers A and 19;~74697~

B is desi~nated as "e"; however, the eccentricity of the cutter relative to anvil 70 is twice this. The eccentric mounting of the cutter 60 on shaft 55 gives the cutter 60 a rapidly rotating shearing action re-lative to the anvil. As seen in Figure 6, the circular cutting edge 56 of the cutter 60 ha~ a downward direction relative to the insert 71 of anvil 70, which is a rapidly rotating shearing action as the cutter is mo~ed linearly across the fabric material supported by a guide bar to be described. As seen in Figures 5 and 6~ the cutting edge 56 lies in a plane that contains one planar side surface 57 of cutter 60 while the edge 56 tapers in-wardly toward the other planar side surface 58 of cutter 60. Suitably secured to cutter support member 32 is an L-shaped bracket member 68 with its lower end portion having a laterally horizontally extending anvil 70 that - is suitably recessed to receive an lnsert 71 which may - be made of carbide.
Cutter support member 32 has bracket means 75 suitably secured thereto, which bracket means 75 has bores therein threadedly engaged by set screws 77. The respective end portions o~ set screws 77 abuttingly en-gage the block 49 to adjust its lateral position on the guideways 1~8 in the cutter support membër 320 Such block 49 may carry self-aligning bearing to permit the adjust-ment of block 49 by set screws 77. The anvll 70 is moved parallel to the edge of a guide bar 80 over which the fabric mateIial moveR while the upper conveying run 10 moves under the bar 80.

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The intermediate upper portion o~ I-beam 18, as shown in Figure 1, supports a variable speed motor - 82 having its output connected to a sprocket chain 83 which in turn is connected to carriage 26 and controls the reciprocation of the carriage on the guideway member 24 by suitable controls and limit switches old and well- :
known in the artO
In the operation of the apparatus described, the fabric material i8 advanced over the guide bar 80 by the upper conveying r~n 10 and, after sufficient material has advanced, the conveyor is stopped in preparation for the cutting of the fabric. Upon stopping of the conveyor beltg motor 82 is energized which thereby moves carriage 26 across guide bar 80 while cutter 60 is rotated at a high speed through the output of motor 65 which transfers its output to the V-belt 67 and thence to shaft 55. The cutting edge 56 of the eccentrically :
mounted cutter 60 is parallel to the cutting edge of anvil 70 and substantially abutting.the side surface thereof as seen in Figure 6. The cutting edge of cutter : 60 performs a snipping action which is a downward move-ment of the linear cutting edge across the fabric due to its eccentric mounting~ such that the Kevlar cords em-bedded in the fabric are cut effectively without fraying the ends thereof as the carriage 26 is moved linearly across the fabric to be cut. Upon completion of the cut~ motor 82 i~ denergized and the head end of cylinder 41 i8 pressurized! which action rotates the shaft 37 and spur gears 38 which mesh with stationary gear segments ~.

~6~7~692 Such action causes the gears 38 to roll up gear seg-ment 44, pivoting the cutter support 32, along with the cutter 60 and anvil 70 out away from the guide bar 80 about shaft 31 to permit the advancement of the fabric material as the carriage 26 is returned to its initial starting position by motor 82 through suitable limit switches and controls old and well-known in the art.
Upon return of the carriage to its initial starting position, the rod end of cylinder 41 is pressurized and returns the cutter support member 32 and anvil 70 to the lowered position such that anvil 70 is in engagement, a position relative to the cutter 60 and the guide bar 80 for the next succeeding cut~
Various modifications are contemplated and may obviously be resorted to by those skilled in the art with-out departing from the described inventi~ , as herein-after defined by the appended claims, as only a preferred embodiment thereof has been disclosed.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A circular cutter for use in cutting rubberized fabric, said cutter having a circular body with a circular outer peripheral cutting edge, said circular outer peripheral edge having a center on said body, a mounting bore in said body for mounting said cutter on a shaft for rotating said cutter, said body having a pair of oppositely disposed side surfaces, the center of said mounting bore being eccentric relative to said center of said body, said cutting edge being planar with one of said side surfaces of said body, and said cutting edge tapering to merge with the other one of said side surfaces.