US509301A - Cutter-head - Google Patents

Description

. (No Model.) 7

H. ERNSBERGER.

CUTTER HEAD.

No. 509,301. Patented Nov. 21, 1893.

772. K Wad/Ma,

UNIT D STATES PATENT OFFI E.

HARMEN 'ERNSBERGER, or NORTH CREEK, onto.

*. CUTTER-HEAD.

SPECIFICATION forming part of Letters Patent No. 509,301, dated November 21, 1893. Application filed January 7, 1893. Serial No. 457.599. (No model.) i

To all whom it may concern:

Be it. known that I, HARMEN ERNSBERGER, a cltizen of the United States of America, residing at North Creek, in the county of'Putnam and State of Ohio, have invented certain new and useful Improvements in Cutter-Heads, of which the following is a specification, reference being had therein-to the accompanying drawings.

My invention relates to an improved cutterhead for planing-machines, and possesses the following characteristics: The construction of the head is such that I am enabled to secure the cutters therein without forming slots or bolt-holes in it; to place more cutters in a head of a given size than has heretofore been practicable; to so secure the cutters in the head that the strain on the cutter for the time being in contact with the board to be planed is transmitted throughout the entire head,

thereby avoiding all danger of the latter breaking at any of its sockets; to secure the cutters inthe head in such a manner that they will be supported at their cutting-edges on both sides, whereby all possibility of the cutters springing is avoided, and also in such a manner that the cutters will make a shaving or draw out, in contradistinction to what is known as the scraping cut; and, furthermore, by the peculiar construction of the head and cutter-fastenings I am enabled to use cutters until they have been worn away to less than one-third their original length.

In the drawings, Figure 1 is a perspective view of a cutter-head of my improved form. Fig. 2 is an end view of the same. Fig. his a detail View of the fastening device, showing the parts separated.

Referring to the drawings, A is a cutterhead, having gudgeons l and circular cuttersockets 2, in which latter are secured cutterknives B, of a curvature corresponding to that of the sockets. The knives are secured in place in the sockets by fastenings 0, each of which consists of clam p-blocks '0, held apart by a bolt 4:, threaded at 5 and provided with a not 6, as will be fully understoodfrom Fig. 3. Each clamp-block has a central'bolthole 7, into which the ends 8 of the bolt 4 project, a bolt-head 9 being formed on .the bolt a short distance from one end. When the knife is put in place, the nut 6 is screwed up on the bolt 4, the. clamp-blocks are placed on the ends of the bolt, and the whole device slipped into the end of the knife socket. One clampblock is set to bear against the knife, an the other block to bear against the inner si e of the knife-socket, after which the nut 6 is screwed so as to tighten up the clamp-blocks and hold the knife firmly against the head.

It is apparent that as the cutting-edge'of one -knife strikes thelumber the strain will be borne in the first place by the portion a of the head between the knife-sockets; and, in all the forms of heads with which I am acquainted, this portion was of'necessity made heavy enough to carry all the strain whereas by my construction the fastening device of the next following knife'is made to act as a brace to sustain the portion a by transmitting the strain to the, next following portion a, which in turn is braced by the fastening device following it, and so on throughout the seriesuntil at last a portion .of the strain is actually transmitted to the fastening device of the knife then in contact with the lumber, thereby helping to hold the knife solidly and preventing all vibration. It Will thus be seen that I am enabled to make the portion a of a minimum thickness, which enables me to place more knives around the periphery of the head than if the portions a were compelled to be of a thickness suitable tobear all the strain unaided, as in the usual forms of heads.

Moreover, by this construction, being on abled to place the knives closer on the periphery of the head, a greater number of cuts is made per revolution of head than-in the old forms,whereby I am enabled either to feed the lu mber through the machine ata fasterrate for the same number of revolutions of the head, or to run the head at a slower'speed for the same rate of feed of the material. Again, the

portions a being made. smaller than in the old form of head, a cutter-head of my construction is much lighter for the same number of knives, and in consequence I can revolve the head much faster without the centrifugal force bursting the head than where the por- Lions a are made heavy, thus permitting the lumber to be fed faster than when the old forms of heads are used.

As the only part of the knife which need project beyond the head is the cutting-edge,

it is plain that I may hold the knife as close to its extreme edge as I desire. This advantage not only prevents vibration of the knife, but takes all undue strain off the fastenings.

It will be seen that as the knives wear at the edge or are ground away in sharpening, they may be pushed out so as always to project the-same, until they are almost entirely used up, and only enough remains to permit the clam p-blocks to hold them, when they may be removed and new knives inserted.

In a cutter-head using the form of fastening-device herein described, the bolte is arranged diametrically of the socket, and in order to keep the fastening device from being thrown out by centrifugal force when the head is revolving I make the circular sockets soas to contain more than one hundred and eighty degrees of arc, whereby the centrifugal force merely tends to tighten the fastening device and holds the knife tighter.

As in my construction the knife is not slotted, it is much stronger, easier constructed, and, as before stated, may be almost entirely used up before replacing with a new knife.

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

1. The combination, with a cutterhead having a series of knife-sockets and intervening solid portions, of a series of knives and a series of' strain-transmitting securing devices, each of which latter serves to hold a knife in its socket, the securing device abutting against the front surface of its respect: ive knife and against the rear surface of the solid portion ofthe head forward of that knife.

2. The combination, with a cutter-head series of strain-transmitting securing-devices arranged diametrically of the knife-sockets, each device abutting against the front surface of a knife and against the rear surface of the solid portion forward of that knife.

4. The combination, with a cutter-head having a series of knife-sockets and intervening solid portions and a series of knives in said sockets, of a series of strain-transmitting securing devices for holding the knives in their respective sockets, each of said devices comprising a bolt provided at one end with a block, which bears against the front surface of one of said knives, and at the other end with a screw-threaded nut, which bears against the rear surface of the S0116. portion of the head forward of that knife.

In testimony whereofI affiX my signature in presence of two witnesses.

HARMEN ERNSBERGER.

Witnesses:

WM. HUNTER MYERs, M. O. MASSIE.

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