US 1474774 A
Description (OCR text may contain errors)
Nov. 20, 1923., MLWW'M R. w. FULLER BELT JOINT AND METHOD OF MAKING SAME Filed Nov. 14, 1922 Fatented Nov. 2%, 19233.
in r to it? r r i Prat .falbii U lililiQaEO MACHINE COMPANY, OF GEEENFIELD,
SSACEU'SETTS, A CORPORATION OF BELT JOINT AND FEET-HOD OF MAKING SA'ME.
Application filed November To all whom it may concern Be it known tnat l, RUFUS W. FULLER, a citizen of the United States, residing at Deerfield, in the county of Franklin and State of Massachusetts, have invented certain new and useful Improvements inBelt Joints and Methods of Making Same; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as Wlll enable others skilled in the art to which it appertains to make and use the same.
This invention relates to a belt joint and more particularly to a belt joint of the type illustrated in United States Letters Patent No. 944,658, and to a method of making the same.
One of the objects of the invention is to improve the belt joint shown in said Letters Patent and to add to its strength and durability yet without increasing to an objectionable degree the thickness of the belt at the joint. A further object of the invention is to provide a method whereby the improved joint may be made in an easy and expeditious manner.
To the above ends the invention consists in the improved belt joint and method of producing the same hereinafter described and particularly pointed out in the claims.
In the drawings illustrating the preferred embodiment of the invention Fig. 1 is a plan of an abrasive belt showing the abrasive surface and the locking fingers formed at j each end of the belt preparatory to joining these ends together; Fig. 2 is a perspective view showing the belt with the abrasive face downward and the fingers interlocked and in position ready to be pressed into the back of the belt to form the belt oint; and Fig. 3 also illustrates in perspective the belt with the abrasive face downward and with the belt joint in the jaws of the press by which the fibres of the fingers are pressed into the interstices of the fabric of the belt, a portion of the upper jaw of the press being cut away for purposes of illustration.
Abrasive belts comprise, in general a body portion of firmly woven canvas 01' other fabric or rubber, upon one side of which a surface coating of emery or other abrasive is adhesively secured. The end portions of the abrasive belt are joined to form anend- 14, 1922. Serial No. 600,979.
less belt arranged to travel over pulleys in a well-known manner in grinding machines,
the back or smooth surface of the belt com ing in contact with the pulley and the abrasive surface being positioned to engage the work being ground or polished.
Referring to the drawings, the improved belt joint is formed by means offingers 10 cut out or otherwise formed upon each end of the belt which are interlocked and lapped over upon the back 1910f the belt. Heretofore it has been the practice to soften the glue or cement by means of hot water or steam'andthen to press the fingers firmly onto or into the belt between smooth surfaces. Such a joint, however, has been found unsatisfactory not only because of its lack of strength and durability, but also because of the substantial increase in thickness at the joint. In the present invention, in order to secure a maximum gripping effect between the fabric of the fingers and the fabric of the back of the belt to thereby produce a belt joint capable of withstanding maximum strain, provision is made for removing the abrasive material from the surface of the fingers 10 as a preparatory step in forming the joint, so that when the fingers are lapped over upon the back of the belt, the contacting fabric surfaces, are in condition to be adhcsively and mechanically secured to each other in the most advantageous manner. A convenient manner of removing the abrasive material is to pass the end of the belt sidewise beneath an emery wheel or similar grinding tool, care being taken that only the abrasive material is removed, leaving a surface adhesive upon the face of the fabric. The ends of th belt are then brought together and the fingers are interlocked and adhesively secured in a lapping position upon the back of the belt.
In addition, it has been found desirable, in order to produce a belt joint. of maximum strength, to subject the fingers to the pressure of a knurled plate or similar device for forcing the individual fibres of the fingers down into the interstices or spaces between the fibres of the back of the belt to secure a mechanical gripping action between the fingers and the belt. This is of particular advantage in the case of abrasive belts, for
- the reason that the fabric is so closely woven 'the interlocked fingers and the shearing strength of theadhesive or glue. In testing belt joints formed according to the present method and those formed according to prior methods, such for example, as that disclosed in said patent, the improved belt joint has been found many times stronger. In addition to presenting a most desirable surface for the purposes of adhesively securing the fingersto the belt, the removal of the abrasive surface from the ends of the lingers assists in reducing the thickness of the belt joint so that a joint may be formed of practically the thickness of the body portion of the belt itself.
According to the preferred manner of producing the improved belt joint for an abrasive belt, the fingers 10 are died or out out of a strip of abrasive cloth. One end of the belt is then placed upon a plate on a grinding table being positioned by pins proecting from the plate which engage the bottoms of the spaces or notches between ad 'jacent fingers. The plate is then reciprocated on the table carrying the fingers transversely back and forth beneath an emery wheel which grinds off the abrasive from the surface of the tapered ends and shanks of the fingers without removing it from the widened bases. The other end of the belt is then similarly treated leaving the belt and fingersas shown in'Figure 1. The ends of the belt are then brought into a contiguous position and fingers l0 interlocked. The end end portions of the belt are then tacked or otherwise secured to a supporting frame 20 having a wire mesh 22 as a supporting surface. The surfaces of the fingers 10 from which the abrasive has ben removed and also the back of the belt are first provided with a priming coating of glue or similar adhesive and the frame 20 and belt are thereafterhung up to dry for several hours. After the priming coating has dried, a second or thicker coating of adhesive is applied to the surfaces of the'fingers and to the back of the belt and-the frame and belt are positioned between the jaws 9.6 of a press, (see Fig. 3). A. knurled plate 28 is interposed between the upper j awof thepress and the back of the belt, the belt being supported at the joint by the wire mesh 22, and the belt joint is then subjected to sufficient pressure to firmly impress or force the fibres of the fingers down into the interstices of the fabric of the back of the belt to eifec't an actual mechanical 1 gripping between the fingers and the belt. I
desirable. The belt joint is permitted to reseveral hours until dry. I The belt is then;
ready for use.
rLbelt joint formed in accordance with the present inventionhas no break or interruption extending continuously across the belt. The unground bases on opposite ends of the belt meet at their edges or corners leaving only small bare areas between the bases of the fingers, which areas are separated from one another and are arranged in staggered relation so that for all practical purposes a continuous abrasive surface at the joint is secured. 7
While the invention has been illustrated and described in its preferred form, it is to be understood that it may be embodied in other forms within the scope of the following claims.
1. A belt joint for abrasive belts comprising interlocking fingers upon contiguous ends thereof, from which fingersthe abrasive has been removed,leaving the original adhesive, the fingers being overlapped upon and adhesively secured to the back of the abrasive belt. V
2. A belt joint for abrasive belts comprisinginterlocking fingers upon contiguous belt, the fingers being provided with a series of projections impressed into the interstices oi the back oi: the belt to secure a mechanical s'rip betweenthe fingers and "body portion- Zir the belt.
l. T he method of joining contiguous ends 1 of an abrasive belt which consists in forming fingers upon both ends of thelbelt, removing the abrasive fromthe fingers, interlocking the fingers applying adhesive to the fingers and to the back of the belt, and thereafter subjecting the fingers to the pressure of a plate having projections thereon to impress portions o-f'the fingers into the interstices of the back of the belt. 7
The method of joining contiguous ends ofan abrasive-belt whichconsists in forming fingersupon both ends of the belt, grinding off @the abrasive from the fingers without .removing the original adhesive, interlockin and overlapping the fingers upon thebac of the belt', applying adhesive tothefingers and back of the belt, and thereafter subject ing the fingers to pressure to secure them to the back of the belt.
6. The method of joining contiguous ends 01 an abrasive belt which consists in forming fingers upon both ends of the belt, removing the abrasive from the fingers, interlocking and overlapping the fingers upon the back of the belt, applying adhesive to the fingers and back of the belt, and pressing the joint between rough surfaces to cause the fingers and belt to interlock at separated points.
7 The method of joining contiguous ends of an abrasive belt which consists in forming fingers with tapered ends and \videned bases upon both ends of the belt, grinding of? the abrasive material from the shanks and tapered ends of the fingers Without removing it from the bases, interlocking the fingers With the unground bases on the opposite ends of the belt meeting, applying adhesive to the fingers and to the back of the belt, and pressing the fingers and belt into close contact.
RUFUS W. FULLER.