US 3609925 A
Description (OCR text may contain errors)
Oct. 5, 1971 M. COMELLA-RIERA 3,609,925
GRINDING DISC Filed July 22, 1969 United States Patent 01 id:
Patented Oct. 5, 1971 3,609,925 GRINDING DISC Manuel Comella-Riera, Barcelona, Spain, assignor to Telas y Papeles Abrasivos, S.A., Barcelona, Spain Filed July 22, 1969, Ser. No. 843,332 Claims priority, application Spain, July 20, 1968, 1 83 Int. Cl. B24d 11 B24b 55/02 US. Cl. 51402 1 Claim ABSTRACT OF THE DISCLOSURE The present invention relates to a grinding disc. If the entire active surface of such a disc is made in a single piece, the grinding power of the disc is unsatisfactory, because of the intense abrasion of the active layer; the grinding power decreases noticeably even after the initial wear. Up to the present time, the active surfaces of grinding discs have generally been divided into sections by intersecting channels, each channel being uninterrupted. This sort of arrangement makes it difiicult for the cooling liquid to distribute itself evenly over the different areas of the disc, and also limits the grinding power. The objects of the present invention is to solve these problems by providing a grinding disc made up of superposed layers of suitable granular substances conveniently held together by resins. Because of this arrangement of the abrasive material in superposed layers, the abrasive grains are distributed more uniformly in each of the layers, which substantially increases the grinding effect of the grains and the life of the grinding disc.
The main feature of this grinding disc is that the abrasive material is cut by uniformly spaced radial channels and by channels transverse to these. This feature improves the properties of the disc, because all the channels together form a cooling network which allows air currents as well as the cooling liquid to circulate. On the other hand, the abrasive layer has a greater grinding capacity because it is divided into sections.
Thus this configuration has noteworthy practical effects that improve the grinding discs efficiency.
The following is a detailed description of a preferred embodiment of the grinding disc, the subject of the present invention, referring to the attached drawings, which show an example of this embodiment of the invention.
In these drawings:
FIG. 1 shows a plan view of a grinding disc according to the present invention.
FIG. 2 represents an enlarged elevation view of a radial section IIII across the disc shown in FIG. 1.
As shown in these figures, the grinding disc that is the subject of the present invention includes a carrier 1 provided with a central opening 2 and several radial cuts 3, in a known form. The purpose of the central opening and radial cuts is to insure that the disc firmly engages the driving shaft and centers on it.
The rest of the disc comprises a circular layer on top of the carrier, this circular layer consisting a conglomerate 4 of superposed layers of abrasive material, held together by suitable resins.
This conglomerate is cut by a plurality of transverse channels 6 intersecting uniformly distributed radial channels 5, in such a way that no transverse channel meets another transverse one, but they rather alternate or are staggered with respect to each other.
These radial and transverse channels together make up a multiply connected network, and provide the advantageous characteristics discussed above. The circular layer is supported on the peripheral zone of the carrier 1. Although the abrasive layer is relatively thick, the disc is flexible at the perimeter, because the material of the carrier 1 is preferably of a fibrous nature.
On the other hand, the fact that the grinding conglomerate is in the form of layers has the result that the grains, in contrast with those in most conventional grinding discs, remain active during the entire useful life of the disc, since the reaction of the material on which the disc acts causes the grains to be successively detached and the lower grains, which have not yet become worn, to become flush with the surface.
For the cooling liquid, which is generally water, the above described configuration of channels 5 and 6 furnishes a network of conduits running over all the surface of the disc, improving the efficiency of cooling, which perceptibly decreases the Wear of the disc, thereby prolonging the effective life of the disc.
From the above discussion it is clear that it is possible to increase the driving speed of this disc without concern for the heat that is usually generated when conventional discs are used.
1. A grinding disc comprising an active surface composed of a plurality of layers of abrasive material, bonded to each other and to carrier by means of suitable resins, said active surface being divided into sections by a plurality of radial channels of uniform width distributed uniformly over said surface, and by a plurality of transverse channels, each said transverse channel connecting two adjacent radial channels, but no two said transverse channels meeting each other at a radial channel, said transverse and radial channels together forming a continuous multiply connected network allowing the flow of air and cooling liquid.
References Cited UNITED STATES PATENTS 2,804,733 9/1957 Hurst 51-209 X 1,692,635 11/1928 Drake 51-2092 1,622,942 3/1927 Chase 51209.2
JAMES L. JONES, JR., Primary Examiner US. Cl. X.R. 51266