Positioning guide for rubber-like material rotary cutting machine

A positioning guide for accurately positioning and guiding lengths of elongated rubber, plastic and other resiliant stock material having a predominately cylindrical exterior surface configuration being fed along a feed path to a cutting machine having a rotary knive and a pair of endless drive belts flanking the feed path. The positioning guide is formed of an integral elongated plate-like body of a length greater than the span of the drive belts along the feed path having a straight guide bore extending therethrough of circular cross-section at its opposite end. The plate-like body has a width and thickness greater than the diameter of the guide bore at the ends and having a pair of opposite elongated flat-bottomed depressions each forming a relief cavity in top and bottom faces of a plate-like body for receiving the confronting reaches of the drive belts so that the stock material is exposed in the region of the depressions for driving and positioning contact with the confronting drive belt portions.

BACKGROUND AND OBJECTS OF THE INVENTION 
The present invention relates in general to guide devices for positioning 
elongated small diameter generally cylindrical exterior shaped material 
fed between a pair of drive belts along a feed path, and more particularly 
to a positioning guide for belt feed rotary cutting machines for cutting 
rubber and plastic small diameter material of such shape to a cutting 
station for high speed cutting. 
Heretofore, various devices have been proposed for feeding and cutting 
material such as rod-like continuous extruded bodies or similar tubular 
rubber or plastic stock wherein feed belts or similar feed members advance 
the material to a cutting station. Examples of these may be found in the 
prior Reinhart et al. U.S. Pat. Nos. 3,561,051 and 3,577,935 wherein 
continuous cylindrical extruded stock is fed to a cutter by a pair of feed 
belts. The Arnold et al. U.S. Pat. No. 3,423,497 discloses a similar type 
of feed arrangement for cylindrical continuous extruded stock, wherein the 
stock is advanced to a cutter by either a pair of grooved feed pulleys or 
a pair of similarly grooved endless feed belts. The Thorman et al. U.S. 
Pat. No. 3,530,536 also shows a pair of confronting feed belts and a 
cutter, the Hasten et al. U.S. Pat. No. 3,646,894 employs a similar pair 
of confronting endless feed belts, and the Borsvold U.S. Pat. No. 
3,690,796 shows a pair of continuous feed belts embracing opposite sides 
of a cylindrical product. However, none of these patents disclose 
structure which satisfactorily constrains the material along the 
predetermined guide path in the most critical span between the exit zone 
from the confronting closely adjacent portions of the feed belts to the 
cutter where small continuous lengths of generally cylindrical exterior or 
rod shaped material of rubber or plastic material of similar properties 
are highly subject to getting out of position and producing an improper 
cut. 
An object of the present invention is the provision of a novel positioning 
guide for extruded rubber or similar plastic small-diameter continuous 
lengths of generally cylindrical or rod-like stock material for 
effectively constraining the continuous feed material in the regions 
immediately adjacent the feed end and discharge end of the zone between a 
pair of elongated continuous drive belts and in the span between the exit 
end of the drive belt pair and a cutter to maintain precise positioning of 
the stock material at the cutter. 
Another object of the present invention is the provision of a novel 
material positioning guide as described in the preceding paragraph, 
wherein the guide forms an elongated plate-like body having cylindrical 
guide bores at the inlet and outlet ends of the body and wherein the bore 
communicates along the feed axis with an intermediate slot of a width 
corresponding to the diameter of the guide bores which is exposed above 
and below to the adjacent parallel reaches of two feed belts to permit 
effective feeding of the stock material to a high speed rotary cutter 
while maintaining the material precisely positioned along the feed path. 
Other objects, advantages and capabilities of the present invention will 
become apparent in the following detailed description, taken in 
conjunction with the accompanying drawings illustrating a preferred 
embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawings, wherein like reference characters designate 
corresponding parts throughout the several figures, the positioning guide 
of the present invention is illustrated in FIG. 1 and designated generally 
by the reference character 10, and may be generally described as an 
elongated plate-like body 11 of greater transverse horizontal width than 
vertical thickness, having a feed or inlet end 12 and discharge or outlet 
end 13 forming vertical substantially rectangular end faces in the 
illustrated embodiment, and having a central guide bore indicated at 14 
which extends entirely through the length of the plate 11 along the 
longitudinal center axis thereof. The plate-like body 11 may vary in 
vertical thickness as required by the diameter of the central guide bore 
14 and the small diameter generally cylindrical continuous length of 
material to be fed therethrough, and includes upwardly and downwardly 
facing elongated, hollowed out flat-bottom trough-like depressions or 
relief cavities 15,16 with concave end transition surfaces near the ends 
12, 13, which extend into and intersect the guide bore 14 along a major 
portion of the length thereof centered substantially on the longitudinal 
midpoint of the guide bore 14 providing a pair of upwardly and downwardly 
exposed slot formations 17, 18 over most of the length of the guide bore 
14. 
This positioning guide 10, as will be described more particularly 
hereafter, is designed to provide precisely guided support for materials 
such as small diameter extruded continuous stock material, for example 
rubber or plastic of similar deformable properties, as indicated generally 
at 20 in the drawings, which is to be fed between a pair of endless drive 
belts and advanced to the cutting station of a high speed rotary cutting 
machine or the like. 
For example, the positioning guide of the present invention may be 
advantageously used with a high speed rotary rubber cutting machine such 
as the Versa-Cutter model 45 high speed cutter/puller machine produced by 
Foster and Allen, Inc., a subsidiary of Plastics Machinery Co., Inc. of 
Summerville, N.J., which is illustrated in FIG. 2 and indicated generally 
by the reference character 22. That machine is generally described as a 
rotary knife cutter wherein the knife cutting action is performed by a 
heavy motor drive fly wheel on which may be mounted one, two or four 
blades, with the fly wheel operating at variable speeds in the range from 
one hundred to one thousand rpm's permitting variation of cutting rates 
fron about one hundred cuts per minute to about four thousand cuts per 
minute. In the cutting machine of the illustrated example, the machine 
consists essentially of a large diameter cylindrical fly wheel, shown at 
23 in FIGS. 3 and 4, having a plurality of cutter blades 24 fixed at 
circumferentiallly spaced positions about the perimeter of the fly wheel 
and mounted within a generally cylindrical safety guard 25 located 
adjacent a puller assembly indicated generally at 26 formed of a pair of 
endless belts 27, 28 positioned by associated endless belt drums 29a,b and 
30a,b respectively. The belt drums and belts are positioned so that the 
adjacent flat reaches or horizontal adjacent confronting portions 27a, 28a 
span a substantial length of the material feed path, indicated generally 
at 31, over a distance, for example approximating about twelve or fourteen 
inches, just before delivery of the stock material 20 to the cutting 
station defined by the fly wheel 23 and blades 24. A pair of aligned 
stationary bushings 32, 33 spaced apart a distance just adequate to 
accommodate the thickness of the cutter blades 24 therebetween and having 
central cylindrical bores therethrough of a size to just accommodate 
passage of the stock material 20 are supported by frame members 34 
flanking the cutting plane transversed by the blades 24. The controls for 
the cutting machine are housed in a single eye level console indicated at 
35 in the typical rotary cutting machine herein illustrated, providing 
digital displays to indicate either cutter rpm or revolutions between 
knife extensions and a counter for recording the number of pieces cut from 
the stock material. 
As illustrated in FIG. 3, the discharge end portion 13 of the plate-like 
body 11 has a pair of laterally extending apertures mounting ears or 
projections 13a through which mounting screws may extend, indicated for 
example at 36, to fix the discharge or outlet end 13 of the positioning 
guide to the stationary endlet bushing 32 of the cutting station, and the 
opposite or feed end 12 of the positioning guide body 11 is also provided 
with laterally extending apertured mounting ears 12a to receive mounting 
screws for fixing the feed end to adjacent stationary frame members of the 
cutting machine 22 (not shown). 
It will be seen from the side elevation view of FIG. 4 that the thinned 
elongated intermediate portion 37 of the positioning guide 10 thus 
provides upwardly and downwardly facing flat bottom depressions or relief 
cavities 15, 16 whose upstream and downstream end transition surfaces, for 
example 15a and 15b, conform to the shape of the confronting surfaces of 
the drive belts 27, 28 which lie nearest the feed path of the stock 
material and are designed to engage and feed the stock material to the 
cutting station. Since the depressions or relief cavities 15, 16 intersect 
and, in effect, cut through the guide bore 14 along horizontal chords of 
the cross-sectional circle defined by the guide bore 14 leaving only the 
elongated slot indicated at 17, 18 through which the stock material 20 
protrudes into engagement with the drive belts, the stock material is 
effectively constrained laterally along its proper guide path by the side 
edges of the intersected bore 14 and are constrained vertically by 
engagement with the drive belts 27, 28. The downstream end portion of the 
guide bore 14 adjacent the discharge end 13 and the zone between the two 
downstream drive belt rollers or drums 29b, 30b and the upstream bushing 
32 thus defines a completely enclosed circular guide bore which provides 
precise guided material support in this most critical span along the stock 
material feed path. 
While the positioning guide of the present invention has been described 
primarily in conjunction with feeding of cylindrical stock which is either 
solid material of circular cross-section or tubular material having a 
hollow center, it will be appreciated that other rubber-like continuous 
lengths of material can be cut at high speed and effectively guided so 
long as the predominant external surface shape of the material is 
substantially cylindrical, although it may be interrupted as in material 
of substantially "C" shaped cross-section and the like. The dimension of 
the guide, both as to its length, width and vertical height, and the 
diameter of the guide bore, will of course be selected to suit the 
dimensions of the particular extruded material to be cut. For example, 
this guide structure with suitably dimensioned guide bore may be used 
effectively to cut material of various sizes from about 3/32 inch outer 
diameter to 11/2 inch diameter while maintaining the full advantages of 
the invention herein described. 
While only one specific and detailed exemplary embodiment of the invention 
has been specifically illustrated and described, it is recognized that 
other changes or modifications may be made by those skilled in the art 
without departing from the spirit and scope of the invention as defined by 
the appended claims.