US283197A - Saw-plate and inserted saw-tooth - Google Patents

Description

` (No Model.)

J. J. BOWEN. A

r SAW PLATE AND INSERTED SAW TOOTH. No'. @$3,197. A Patented Aug. 14, 1883.'

Wkfwsses I 'Mwewm UNITED STATES` JOHN J. BOWEN, on sAN PATENT OFFICE.

FRANCISCO, CALIFORNIA.

SAW-PLATE ,ZAND msi-:RTED SAW-TOOTH.

' SPECIFICATION forming part of Letters-Patent No. 283,197, dated August 14, 1883.

,Application tied December es, 1ste. (No model.)

To Illu/hom, t may concern: i

\ Beit known that I, JOHN J. BOWEN, of the city and county of San`Francisco, State of California, have invented Vcertain new and useful Improvements in Saw-Plates and Inserted Saw-Teeth; and I do hereby declare that the following is a full, clear, and exact description thereof. A

My invention relates more particularly to that class of saw-plates and inserted saw-teeth in which a crescent-shaped tooth is turned into a` circular recess in the edge of the sawplate, so that one end will form the cuttingpoint. Latterly these teeth have been-improved bycutting off the cutting end of the crescent-,shaped plate and inserting a'removable cutting point or bit in place of the portion removed in such manner that the crescentshaped .piece serves as a holder for the bit.` My invention is app'licable, however, to any form of inserted teeth, but is niost beneficial where narrow bits are used.

It consists in cutting "an irregular-shaped piece out of the saw-plate just back of the cutting point or bit and inserting inthe recess` thus formed a patch-plateV the back edge ofwhich fits the irregularities-ofthe recess, while itsfront edge conforms to the shape of the recess in which the saw tooth or bit is secured. The object and functionsof this inserted patch will be hereinafter described.

`I Eteferring to the 4accompanying drawings, Figurel shows the concave tooth-socket and patch ready tobe inserted. Fig. 2 shows a section of a saw-platehaving two teeth complete and one incomplete. j A

Let A represent the saw-plate. The edge of this saw-plate is provided with recesses atl regular intervals apart,'in which the inserted teeth are fitted.

B is the crescent-shaped tooth-holder, `which is inserted in the recess in the saw-plate by being turned into the recess, and is heldin place by a V- shaped dovetail in the usual way.`

C is the inserted bit or removable cuttingpoint. Just back of the cutting-point C, I cut out of the saw-plate an irregular-shaped piece,

so as to form an opening or recess, which eX- tends down into the plate as far as or below the point where the bit C extends, and in the recess thus formed I t a patch, D, the back edgefof which the irregular shape of the edge of the recess, while its front edge conforms to the shape p of the'recess in which thetooth or the toothholder' and bit are secured. The irregular shape of theback edge of the patch-plate fitting in the corresponding edge of the recess enables me to lock the patch in place by means of a rivet or key-pin, fi, which passes through a hole made on the line of juncture at Vthe lower edge of the patch. It is therefore immaterial what particular irregular shape the patch iitsagainst; but I prefer an S shape, as more convenient to make, and because it has no angles or sharp corners. The back edge of the patch is dovetailed-into the back edge ofthe recess in the usual way. This arrangement holds the tooth or bit with an elastic grip, which prevents it from being displaced. The special'oflice of thepatch, however, is to permit of that portion being renewed when it becomes worn or broken. |Ihe sawdust, passing back from the throat of the tooth, soon wears' the sides of the saw-plate thin at this point; but by inserting the patch-piece it receives the wear, and `can be renewed when desired, thus preserving the plate. The frequent removal and replacement of the saw tooth or bit also wears the edge of the recess, so that the tooth or bit becomes loose, in which condition it is liable to come out. This diiii- `culty is also remedied by the patch-plate, as a new one can beinserted at any time, thus keeping the teeth tight.

VIn case a tooth or bit should strike against a hard substance when passing through a log,

instead of breaking the plate, as heretofore,

- the patch-piece only will Vbe broken, and the saw can be repaired by inserting a new patch.

Having thus described my invention, what I claim, and desire to secure by Letters Patent,

1s n i The saw-plate A, having a recess formed in it directly behind the cutting point or bit, the back edge of which is irregular inshape, in combination with a patch, D, the back edge of which corresponds with and iits the back edge of the recess, while its front edge conforms with the curve of the recess in which the saw-tooth fits, the tooth-holder B, and the re- IOO movable cutting-point C, substantially as speci- In witness whereof I have hereunto set my hand and seal.

p JOHN J. BOWEN. [Ls] W'itnesses:

JOHN D. GAGNON, AMBROsE M. WILLIS.

Images