File band

Jan. 13, 1942.

2,269,749

R. J. WILKIE

FILE BAND

Filed Sept. 16, 1940

<img file="US2269749A_D0001.tif" />

Robert J. Wilkie

<img file="US2269749A_D0002.tif" />

Patented Jan. 13, 1942

2,269,749

UNITED STATES PATENT OFFICE

3,269,749

FILE BAND

Robert John Wilkie, Minneapolis, Minn., assignor to Continental Machines, Incorporated, Minneapolis, Minn., a corporation of Minnesota

Application September 16,1940, Serial No. 357,001

Claims. (Cl. 29—79) turb the accuracy of the position of the file element with relation to its backup or support.

To this end it is another object of this invention to provide a file band wherein the attach5 ment of the individual file elements to the carrier includes a spacer leaf under an end portion of each file element and projecting therefrom to engage under the free end of the next adjacent file element so that the major portion of each file 10 element is held spaced from the carrier band per se.

With a view toward reducing manufacturing costs and precluding weakening of the flexible carrier band, it is another object of the present 15 invention to provide the spacer leaves with the band carried part of the complementary connections between the band and the ends of the file elements for preventing lateral shifting of the flies.

More specifically, it is an object of this invention to form the spacer leaves with outwardly projecting tongues which engage in grooves formed by sockets in the ends of the file elements.

25' With the above and other objects in view, which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particu30 larly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates two 35 complete examples of the physical embodiment of the invention constructed in accordance with the best modes so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a perspective view illustrating part of a file band constructed in accordance with this invention with one of the file elements removed to more clearly show the relationship of its socket to the tongue on the spacer leaf;

Figure 2 is a side view of a portion of a file band embodying this invention; and

Figure 3 is a view similar to Figure 1 illustrating a slightly modified embodiment of this invention.

Referring now more particularly to the accompanying drawing in which like numerals indicate like parts, the numeral 5 designates a flexible ribbon-like steel carrier band, the ends of which are adapted to be connected so as to 55 form one endless unit which, as is customary is

This invention relates to filing machines of the type shown in Patent No. 2,180,078, issued to Leighton A. Wilkie, November 14, 1939, and refers particularly to the file band thereof.

These machines are quite similar to the conventional band saw in that they have an endless file band composed of a plurality of file elements arranged end to end on a flexible endless carrier trained over spaced pulleys with one stretch thereof traveling in a vertical straight line through a working zone between the pulleys.

Inasmuch as the flies must be so secured to the carrier as to permit the carrier to flex as it travels around the pulleys, the flies are apt to shift, laterally with respect to the carrier and each other.

In the aforesaid patent interengaging connections between the ends of adjacent file elements are employed for the purpose of holding the ends of the file elements against lateral shifting. These connections are automatically established as the file band enters its straight stretches, so that as the band passes through the working zone the connections between the file elements are effective or operative.

So connecting the adjacent ends of the file elements undoubtedly aided materially in maintaining proper alignment, but was found not entirely satisfactory for while the file elements were thus interconnected with each other, their ends were free to shift with relation to the carrier band, which is the only laterally rigid part of the assembly.

It is therefore an object of the present invention to provide a file band so constructed that lateral shifting of the individual file elements is positively precluded not only with respect to each other, but also with respect to the laterally rigid carrier.

Inasmuch as these filing machines are employed for precision machining, every precaution must be taken to insure the file elements traveling in their intended path. In the past where the file elements were directly secured to the flat ribbon-like carrier band, the accumulation of chips or filings behind the file elements and consequently between the file elements and carrier band, constituted a serious threat to the maintenance of the desired accuracy. . . .

The present invention greatly minimizes this objection through the provision of a novel manner of securing the file elements to the carrier band whereby a substantial portion of the file element is held spaced from the carrier band so that the presence of chips or filings will not dis2 2,269,749 trained over the pulleys of the filing machine to be driven thereby.

Inasmuch as the construction of the filing machine forms no part of this invention it has not been shown, and if desired, reference may be had to the aforesaid Patent No. 2,180,078, for an illustration of one form of such a machine.

The flexible ribbon-like band 5 carries the file elements 6 which are preferably identical and consist of rigid rectangular bars having a front abrading surface and sockets or notches 7 at both ends in their under surfaces.

The width of the file elements is at least equal to that of the carrier band so that no part of the band projects beyond the file, and the backup support (not shown) which supports the file element as it crosses the working zone,. likewise is no wider than the file elements.

Each file element is secured to the flexible carrier band by two rivets 8 or their equivalent. The rivets 8 also pass through spacer leaves 9, preferably formed of the same material as the band 5 and interposed between the band and the file elements.

The location of the point of attachment of each file element to the carrier band and the relative position of its associated spacer leaf is such that the spacer leaf underlies only an end portion of the file element and projects a short distance therefrom.

It is the leading end of the file element with relation to the direction of motion of the file band which is secured to the carrier.

The projecting end portion of each spacer leaf has a lug 10 formed thereon which constitutes a tongue to engage in the sockets 7 and provide a tongue and groove connection between the ends of the file elements and the carrier band. This connection, as will be readily apparent, holds the adjacent ends of the file elements against relative lateral shifting, not only with respect to each other but also with respect to the file band by virtue of the nearness of the point of attachment of the spacer leaf to the carrier band. The lug 10 may be formed in any desired manner, but preferably consists merely of an outward protrusion struck from the metal of the spacer leaf itself.

The width of the lug should be as close to that of the sockets 7 as free running clearance will permit and by having the side walls of the sockets perpendicular with the rear and front surfaces of the file elements and the sides of the lugs sharply defined, the file elements will be securely held against any possible shifting.

By forming the lugs 10 on the spacer elements, it will be readily apparent that weakening of the file band is avoided, and likewise cost of production will be decreased due to the simplicity of stamping the spacer leaves in large quantities as distinguished from forming lugs directly on the carrier band.

The. spacer leaves, however, have another important function, namely, that of spacing the file elements from the carrier band, for being considerably shorter than the file elements, it is obvious that a substantial portion of each file element is spaced from the carried band at all times. This reduces the probability of inaccuracies resulting from the accumulation of chips or filings under the file elements during operation of the machine.

In some filing machines heretofore in use, the ends of the file elements were cut off obliquely in a transverse direction for the stated purpose of insuring smooth transfer from one file element to another.

This angular disposition of the juncture between the adjacent file elements under severe strain tended to shift the elements laterally and to avoid this possibility, the ends of the file elements are preferably either square as shown in Figure 1 or formed with an edgewise angularity as shown in Figure 3.

The latter construction provides, in effect, an overlap of the trailing end of the leading file element over the leading end of the next following file element.

' From the foregoing description, taken in connection with the accompanying drawing, it will be readily apparent that this invention provides an exceedingly simple but effective manner of making a file band for continuous filing machines which not only incorporates means for insuring proper alignment of the file elements, but also incorporates protection against loss of accuracy due to the accumulation of chips and filings under the file elements, and that it achieves the optimum of simplicity and economy in construction by utilizing the same means to perform both functions.