US1032636A - Bit-adjuster for rotary cutter-heads. - Google Patents

Description

E. G. WATKINS.

BIT ADJUSTER FOR ROTARY CUTTER HEADS.

APPLICATION FILED FEB.7,1911.

1,032,636. Patented July 16, 1912 0 INVENTOR 44/001 4) (J Attorney EDWARD G. WATKINS, OF GARDNER, MASSACHUSETTS, ASSIGNOR T SAMUEL J'- SHIMER & SONS, OF MILTON, MASSACHUSETTS.

BIT-ADJUSTER FOR ROTARY CUTTER-HEADS.

Specification of Letters Patent.

Application filed February 7, 1911.

Patented July 16, 1912. Serial No. 607,190.

' State of Massachusetts, have invented a certain new and useful Improvementin Bit- Adjusters for Rotary Cutter-Heads, and do hereby declare that the following is a full, clear, and exact description thereof.

In the rotary cutter head which is the subject of the Shimer Patent No. 874,871, December 24, 1907, the bit or blade adjusting means consists of a simple screw located at the back or inner side of the bit holder which is accessible only by the removal of the bit holder from the cutter head. i

The object of my invention is to provide a bit adjusting device for cutter heads of the type referred to, which will be conveniently accessible at all times without the removal of the bit holder from the cutter head and which will possess otheradvantages, and to this end my invention consists in the device constructed substantially as hereinafter specified and claimed.

In the accompanying drawingsFigure 1 is a perspective view of a rotary cutter head embodying my invention; Fig. 2 a section thereof on a plane transverse to the axis of revolution, but of onlyafragment of the head; Fig. 3 a section on the line 3-3 of Fig. 2; and Fig. 4 a detail view in perspective of one of the bit holders removed from the cutter head.

The type of cutter head to which my invention relates comprises a cylindrical body 10 having an axial hole or opening for the shaft or mandrel, and having in its periphcry a series of longitudinally extending channels or recesses 11, in each of which is placed one or more hit holders 12, in the form of a metal block that is provided with a bit receiving slot 13 extending from one edge inward nearly to the opposite edge so as to constitute a clamp for the bit 14 under the action of one or more bolts 15 whose threaded shank enters a threaded opening 16 in the bit holder while its head is adapted to engage the adjacent side wall of the cut-' ter head recess when the bolt is turned in the direction as for unscrew ng, and thereby exerts a thrust upon the bit holder whlch produces a pinching or clamping efi'ect ofv the two portions of the bit holder separated by the slots 13 upon the bit, as well as, at the same time securely holds the bit holder in its recess in the cutter head. In the embodiment of my invention that I have selected for illustration, there are two bolt holes 16, one near each end of the bit holder and in a thickened portion of the bit holder through which said screw holes pass, and situated between said screw holes in said thickened portion 17 is an opening 18 which forms a bearing for the outer end of a screw 19, the inner end of which has a bearing in a hole 20 in the cutter head body, the threaded portion 21 of the screw being of somtawhat greater diameter than the inner end that has its bearing in the hole 20 and extending between said inner end and the inner side of the thickened portion of the bit holder. Contiguous to the outer end of its threaded portion 21, the screw has a collar or annular enlargement 22 that forms a thrust bearing to prevent endwise movement of the screw outward while endwise movement of the screw inward is prevented by the shoulder that is formed at the inner end of the screw by the reduced bearing end thereof in the opening 20. Thus, though the screw 19 is free to revolve, it is prevented from endwise movement in either direction. Mounted upon the threaded shank 21 of the screwis a nut 23 having a radial projection or finger 24 that projects through a slot 25- nierely wide enough to accommodate it in the bit holder and bears against the inner edge of the blade 14. The nut 23 being prevented from rotating by the engagement of its lug 24 with the sides of the slot 25, it is compelled by the rotation of the screw to traverse along the screw, and, of course, by the contact of the lug 24 with the inner edge or heel of the blade 14, the blade 14 will be moved outward when the direction of rotation of the screw is such as to cause an outward movement of the nut. It will thus be seen that I have provided a simple and most efiicient blade adjusting device which will positively hold the blade in its adjusted position, and as the outer end of the screw 19 is exposed so that it is at all timesaccessible, such adjustment of the blade as .is necessary may most conveniently and quickly be effected.

Instead of the tongue or rib 7 on the inner side of the bit holder which is employed in Patent No. 874,871 to prevent the bit holder dropping out of the body -or cylinder 10 when the clamping bolts are loose, I provide in the rear wall of the holder a threaded hole 26 into which is screwed the inner end of a screw 27 passing through a hole 28 extending inward from the periphery of the cylinder or body 10. This arrangement is preferable to the rib and groove device of Patent No. 874,871, because it does not require as does the rib and groove arrange ment that the bit holder shall be slid endwise through the recess in the cylinder or body in applying it to or removing it therefrom, for which operation it is necessary to take the cutter head out of the planer. With the screw device, evidently, the operation of applying and removing the bit holder to the head can,- therefore, be much more conveniently and easily performed. The cylinder or body 10, shown in the drawings, is provided with the rib -receiving grooves so that such head, if desired, can'be used with bit holders having ribs, as in the patent above mentioned.

Having thus described my invention what I claim is- 1. The combination of a cutter head having a peripheral recess, a bit holder in said recess having an outwardly opening bit-receiving slot, a screw having a bearing in a thickened wall of said bit holder with its operating end outwardly exposed, and a nut on the screw engaging the inner end of the bit, confined to travel along the screw by the walls of a slot extending inwardly from the thickened portion of the bit holder.

2. The combination of a cutter head having a peripheral recess, a bit holder in the form of a block having a bit-receiving slot that extends outward, a screw having a bearing in said block at one side of said slot and a bearing in the cutter head, and a nut 1,osa,ese

on the screw having a bit-engaging lug, the lug projecting through a' slot in the contiguous wall of the block and engaging the sides thereof to prevent turning of the nut.

3. The combination of a cutter head having a peripheral recess, a bit holder in said recess in the form of a block having a bitreceiving slot that extends outward, the block, toward its outer end, having its wall contiguous tothe bit-receiving slot thickened, a screw having a bearing in said thickened wall with its operating. end outwardly exposed, a nut on the screw engaging the in nerend of the bit, said nut playing back and forth in a slot in the block extending inwardly from the thickened portion of the block wall, and a bolt passing through a threaded opening on the thickened wall at each side of said adjusting screw engagin the bit at oneend, and the contiguous wal. of the cutter head recess at the other end.

4. The combination of a cutter head having a bit holder receiving recess extending from the periphery of the cutter head inward, a bit holder having bit-engaging members on opposite sides of the bit, a bolt' engaging an opening in one of said bit-engaging members, and adaptedv to bear against the contiguous wall of said recess, and a bit holder engaging part situated in an opening extending inward from the periphery of the headand entering a hole inthe bit holder.

In testimony that I claim-the foregoing I have hereunto set my hand.

THATCHER B. DUNN, FLORENCE L. MOORE.

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