US2576190A - Excelsior knife - Google Patents

Description

Nov. 27, 1951 F. H. PHILLIPS -2,576,190

EXCELSIOR KNIFE Filed July 19, 1949 2 SHEETS-SHEET 1 l V i I H i 4 J r/ f I I l 0 0 IE. 1 I 5 o o I l //vv/vr0z FRANK ll. fl/ll-l/FS waflwzw F. H. PHILLIPS EXCEILSIOR KNIFE Not 327, 1951 Filed July 19, 1949 Patented Nov. 27, 1951 UNITED STATES PATENT OFFICE This invention relates to a knife for use in cutting excelsior. Specifically, the knife of this invention is secured in an excelsior cutting machine and is reciprocated over a wood bolt to remove strips of excelsior from the bolt on each advancement of the knife over the same.

An object of the invention is to provide an improved knife for an excelsior machine which will cut ridges of varying height in a bolt to provide for more satisfactory and uniform cutting of excelsior from the bolt.

Another object of the invention is to provide a knife for an excelsior cutting machine constructed such that it will produce ridges of different height on a bolt to provide a degree of compressibility to the surface engaged by the cutting plate of the machine and thereby permit of easier adjustment of the cutting depth of the knife, and provide a certain amount of leeway in setting the knife so that it will out correctly at every stroke.

Another object of the invention is to provide a knife for an excelsior cutting machine in which the knife is formed with a series of parallel grooves having round bottoms to provide a reinforcement to the shoulder of the teeth, and to provide for a feather-edge cutting by the cutting edge of the grooves to permit more satisfactory operation of the knife on a greater variety of woods, and particularly soft woods.

Further objects and advantages will become apparent from the drawings and the following description.

In the drawings:

Figure 1 is an elevational view illustrating the operational position of a knife relative to a bolt.

Figure 2 is a plan view of the cutting plate holding the knife.

Figure 3 is an end view of the cutting plate.

Figure 4 is a plan view of the knife for the excelsior cutting machine.

Figure 5 is an enlarged plan view of a portion of the knife of Figure 4 to more clearly illustrate the construction of the grooves in the face of the knife.

Figure 6 is a cross-sectional view taken along line 6-6 of Figure 5.

Figure 7 is a cross-sectional view taken along line 1-| of Figure 5.

Figure 8 is a cross-sectional view taken along line 8-8 of Figure 4.

Figure 9 is a cross-sectional view of a bolt i1lustrating the surface thereon after being worked upon by the knife of this invention.

In Figure 1 there is illustrated a cutting plate ill of an excelsior cutting machine that carries the knife II. The knife II has grooves 112 in theshank 13 thereof through which are placed bolts M for securing the knife II to the tool-head IE on the cutting plate ID.

The cutting plate H3 is provided with the guides 6 that guide the reciprocating movement of the cutting plate in the excelsior cutting machine.

' A wood bolt 20 is positioned against the cutting plate In and is urged against the same, and advanced toward the same, by any conventional apparatus well known in this art.

As the cutting plate reciprocating over the bolt 20, grooves 25 provided in the knife H remove wood shreds from the surface of the bolt, in the manner well known in the art.

The knife I l of this invention is provided with the series of parallel grooves 25 in one face of the knife. The working end of the knife is provided with a bevelled surface 26, as shown in Figure 6, whereby the grooves 25 in the face of the knife form a series of teeth 21 that remove wood shreds from a bolt to produce excelsiors.

The grooves 25 in the knife are arranged in groups 250, that are each separated from the other by a second groove, 25!) that is deeper than the grooves 25a. The bottoms 28d and 28b of the grooves 25a and 251) are all rounded, as shown in Figure 8, thereby providing radiused shoulders 30 at each vertical edge of the respective grooves which thereby strengthen the lands 3| between all of the grooves.

In Figure 5 it will be noted that the grooves 25a and 25b of different depth, produce teeth 32 of different length. Also, the round bottom of the grooves 25a and 25b provide radiused shoulders 35 between each of the grooves and the teeth 32 thereby strengthening the teeth 32.

When the knife I l works upon a bolt, such as the bolt 20, a ridged surface is produced on the working face 40 of the bolt. The deep grooves 251) produce high ridges 4012 on the bolt while the shallower grooves 25a. produce ridges 40a slightly less in height than the ridges 4%.

As shown in Figure 3, the ridges 401) are those that are primarily engaged by the cutting plate [0, and since these ridges are few in number, and since the wood itself has a degree of resiliency, there will be provided a degree of resiliency between the bolt 20 and the cutting plate Ill. This resiliency between the bolt 20 and the cutting plate is taken advantage of at the time the knife is set for the correct depth of out. Since the bolt 20 is urged against the cutting plate ID by suitable pressure rolls, the resiliency of the several high ridges 40b will permit a certain degree of leeway in setting the knife H for its depth of cut. This is of particular advantage since the prior methods of cutting all grooves to the same depth presented ridges of all the same height to the cutting plate, so that the relatively rigid surface provided by the ridges of all the sam height made it extremely difficult to set a knife at'the correct desired depth, this being particularly true when producing wood Wool.

Since the high ridges 401)- on the bolt when" by the various depth grooves will not be precisely in alignment with one another across the knife, a more uniform cutting of the bolt is obtained, andsofter woods can be used.

By using a knife of the construction described herein, the useful life of the knife is increased since the teeth are greatly strengthened and thus breakage of the teeth is largely eliminated, such breakage requiring costly re-grinding of the cutting edge and excessive removal of useful tool material, which greatly reduces the tool life.

Having thus fully described my invention. what I claim as new and desire to secure by Letters Patent is:

1. A knife for an excelsior cutting machine having a bevelled edge forming a cutting edge and having a plurality of parallel grooves in its face that cooperate with the bevelled cutting edge to form a plurality of cutting teeth, said grooves including grooves of deeper depth than the other of said grooves, said grooves of deeper depth being spaced periodically across the face of the knife.

2. A knife for an excelsior cutting machine having a bevelled edge forming a cutting edge and having a plurality of parallel grooves in its face that cooperate with the bevelled cutting edge 't'o'form a plurality of cutting teeth, said grooves being arranged in groups in which all of the grooves inthe respective groups are of the same depth and in which the groups are separated from one another by a groove of deeper depth REFERENCES, CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Number V 7 Ward .1 May 31, 1898

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