US795167A - Adjustable hollow mill. - Google Patents

Description

1%. 795,167. PATENTED JULY 18, 1905. 7

H. K. PORTER. ADJUSTABLE HOLLOW MILL.

APPLICATION FILED JUL-Y 2. 1904.

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PATENTED JULY 18, 1905."

H. K. PORTER; ADJUSTABLE HOLLOW MILL.

AIPLIOATIOK FILED JULY 2, 1904.

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No. 7e5,'167.

UNITED STATES- Patented. July 18, 1905.

HENRY K. PORTER, OF CHELSEA, MASSACHUSETTS.

ADJUSTABLE HOLLOW MILL.

SPECIFICATION forming part of Letters Patent No. 795,167, dated July 18, 1905, Application filed July 2. 1904. swarm. 215.044..

T (tZZ 1072,0217. zit vita-y concern.-

Be itknown that I, HENRY K. PORTER, acitizen of the United States, residing at Chelsea, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Adjustable Hollow Mills, of which the following is a specification.

My invention relates to turning-tools or milling-tools of the kind usually termed hollow mills, and is an adjustable hollow mill with attachments and advantages that will be explained; and the object of my improvement is to provide such a tool in which the cutters are readily detachable from the head or carrier in which they are operated and are adjustable therein radially and longitudinally and so constructed and arranged as to be unusually elfective in practical use. I attain the object stated by the construction illustrated in the accompanying drawings, in which Figure 1 is perspective of the tool embodying my invention. Fig. 2 is a front view of the same in plan. Fig. 3 is a rear view. Fig.

4 is a side elevation of the body of the tool with the clamping-band and knives removed and the shank broken off. Fig. 5 is a plan of the front face of the tool with the knives adjusted to cut a larger diameter and showing the means and method of adjustment. Fig. 6 is a plan of the front face of the tool with the knives removed. Fig. 7 is a central longitudinal section on line 7 7, Fig. 5. Fig. 8 is a perspective of one of the knives. Fig. 9 embraces two perspectives of the adjustingshims of unequal thickness. Fig. 10 is aperspective of an attachment to the tool termed a chip-guard.

Referring to the drawings, in which the various parts are numbered, the same number size required, but as illustrated is about four inches long exclusive of the shank and is hollow, being bored centrally in line with the axis of the tool from its front face to near the shank 22. The grooves in which the knives are held may be cut in the sides of the body at an angle of about ten to fifteen degrees with a plane passing through the axis thereof to give the cutters when held therein the proper rake, and the cutting edges when properly adjusted longitudinally are radial to the axis of the tool. The knives are constructed from commercial quadrate bars of steel of suitable dimensions and are properly shaped on their outer ends 23 24 25 26 and arranged to serve as effective cutting-blades when assembled and properly adjusted in the carrier, their interior corners 27 28 29 30 being slightly beveled to render the cutters selfcentering on the end of the stock operated upon. A plurality of knives is most effective and any practical number may be used; but I prefer to use four, having found that number in practical use on stock of various shapes themostdesirableandefficient. Nearlyopposite the inner end of the central hole bored in the body 13 are four clearing-holes 31 32 33 34:, bored at right angles thereto through the sides 18 19 2O 21, two of which, 31 and 34:, are clearly shown in Fig. 1. The bodies of the blades cross these holes more or less, according to the angles of the grooves, and are seen through them from the outside, but only partially obstruct the same without practical interference with the clearance of the central pocket or hollow from chips or other collections of debris that might gather therein. Through the several sides of the band 12 are threaded a number of clamping or binding screws, one half of which number turn against the body 13, while the other half turn against the blades held in the grooves of the body. Thus the blades are held firmly in the positions to which they are adjusted in their grooves, and the opposing screws which turn against the sides of the body counteract any tendency of those which press against the blades to distort the body. These opposing screws serve to resist the torsional strain on the body produced by the blade-clamping screws when the surrounding band fits loosely, as shown, and, as is obvious, they might be omitted if the band were closely fitted and fastened around the body. I prefer, however, to make the tool substantially as shown and to use two square-headed screws, or screws adapted to be turned with a wrench, against each blade, as screws with slotted heads which can be tightened only with a screw-driver do not exert sufficient pressure to hold the cutting-blades from being pushed back when in use. In practice the screws with slotted heads may be what are termed plug-screws and preferably do not project beyond the outer faces of the clamp sides through which they are turned. Those screws which act on the blades in pairs are 35, 37, 39, and 41 and those which oppose them, counteracting on the body in pairs, are 36, 38, 40, and 42. They are shown as being part of them square-headed, while the remainder have less prominent slotted heads, which might better be plugscrews, as above stated. This difference in the heads has no practical effect on the tool itself, but is thus made to somewhat contract the tool to avoid its interference when in use with the usual cutting-off tool in the crossslide employed on the same machine, and also to avoid contact with the finishing boxtool rest when the same is used on the screwmachine.

The cutting-blades, which are inclined to the radial planes coincident with their cutting edges and which project a little beyond the front of the hollow body, are adjustable radially in the tool by means of metallic shims of various thicknesses, ranging from one sixtyfourth of an inch or less to any desired thickness. Four shims are used of each thickness, one for each cutter; but the several thicknesses used may be such that combinations can be made which will enable the mechanic to cut therewith many sizes and to obtain all the nicety in degrees of adjustment that is required. Thus with shims of one sixty-fourth, one thirty-second, three sixty-fourths, and seven sixty-fourths combinations giving every sixty-fourth of an inch from one sixtyfourth to thirteen sixty-fourths can be made. Two of the shims, 43 and 44:, (shown in perspective in Fig. 9,) represent the form of the same. They are employed practically in the adjustment of the cutters by placing one or more of them of like thickness or like combination of thicknesses between each cutter and the bottom of the slot in which it rests, thus carrying the blades apart radially and uniformly to the required extent to effect the reduction of the stock operated upon by this tool to the diameter required.

Another device, 49, which I term a chipguard, (shown in Fig. 10,) may be employed. There are four of these guards, which are formed to turn the falling chips outward or away from the central opening into the body and also serve to protect the face of the body between the blades and the ends of the adjusting-shims from abrasion by the falling chips. They each comprise an adjustable slotted plate L9, adapted to be attached to the edge of the clamp 12, and an angular branch 48, fitted to be interposed between two adjacent blades and formed to turn away the falling chips and to protect the face of the tool from abrasion, as described.

My invention as above described constitutes an adjustable hollow mill which by reason of its novel construction and arrangement is unusually effective and rapid in its practical cutting operation, is easily adjusted to cut stock of various shapes, either cylindrical or polyhedral, and is comparatively cheap to construct and keep in-order.

What I claim as my invention, and desire to secure by Letters Patent, is

1. A hollow mill, comprising the combination of asquare, hollow body, terminating in a round shank; four grooves in the sides of the body; four cutting bars, or blades, fitted in the grooves; a band, or clamp loosely fitted around the body and blades; a suitable number of screw-bolts threaded into the band to be turned against the blades, and a like number to be turned against the body; all constructed, arranged and adapted to operate together, and relatively to each other, substantially as and for the purposes specified.

2. A hollow mill comprising the combination of a cutter-head adapted to be attached to proper actuating mechanism, and having a central longitudinal opening through the same; a plurality of grooves formed longitudinally in the exterior of the head around the central opening, and inclined to the axis of the head; a corresponding number of cutterbars having radial cutting edges formed on the ends thereof, and fitted in said grooves so as to permit the use therewith of measuringshims constructed and arranged to effect a radial adjustment of the bars as described; a surrounding band inclosing the bars and grooves; and a suitable number of retainingscrews threaded through the inclosing band, and arranged to operate against the cutterbars in opposition to the shims, all as and for the purposes specified.

3. A hollow mill comprising the combination with a suitable hollow body provided with a shank and constructed with recesses, of cutting-tools fitted to said recesses, chip-guards arranged adjacent the cutting edges formed at the ends of said'tools, means for securing the said cutting-tools in place, and means for securing said chip-guards in place.

HENRY K. PORTER. Witnesses:

T. K. CRAWFORD,

EUGENE HUMPHREY.

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