US1404337A - Clamping support for grinding machines - Google Patents

Description

B. BETHKE.

CLAMPING SUPPORT FOR GRINDING MACHINES. APPLICATION HLED MAR.'I0. 1920.

1,404,337, Patented Jan. 24, 1922.

IBERNHABD BETHKE, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO LUTHER G BIND R MFG. 00., 0F MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

CLAMPING SUPPORT FORGRINDING MACHINES.

Specification of Letters Patent.

Patented Jan. 24, 1922.

Application filed March 10, 1920. Serial :No. 364,715.

To all whom it may concern:

Be it known that I, BERNHARD BETHKE, a citizen of the United States, residing at Milwaukee, county of lvlilwaukee, and State of Wisconsin, have invented new and useful Improvements in Clamping Supports for Grinding Machines, of which the following is a specification. My invention relates to improvements in clamping supports for grinding machines and other small manually driven tools adapted to be secured to a bench or table. The object of my invention is to provide means whereby a grinding wheel or other rotative tool may be supported to revolye about an axis oblique to the front margin of the bench or table, and driven by a crank which revolves in a plane oblique to such margin, the machine being adequately secured and rigidly held to such bench or table, notwithstanding its oblique position. It is a further object of my invention to provide means whereby grinding wheel mechanisms and similar devices may be not only supported in the oblique position above mentioned, but may also, with equal facility,

be clamped to the table or bench in the ordi-.,

nary manner, with the tool supporting arbor or shaft at right angles to the front margin of the support.

In the drawings Figure l is a plan view of agrinding wheel clamping support embodying my invention, showing the same as it appears in use with the grinding wheel arbor obliquely disposed.

Figure 2 is an elevation of the mechanism, including the clamping support.

Figure 3 is a sectional view, drawn to a plane on line 8 of Figure 2.

Like parts are identified by the same reference characters throughout the several views.

The grinding wheel casing 1 may be of any ordinary type. The casing illustrated is provided with a driving shaft 2 having an exterior crank 23. The driven shaft or arbor 4- supports the grinding wheel 5, and is driven from the shaft 2 by a gear wheel and pinion, indicated by dotted lines at 6 and 7. All of these parts, however, may be of any ordinary construction.

But it will he observed that the casing 1 is supported by a base plate 10, preferably formed integrally with the bottom and front wall of the casing, but this base plate 10 is of peculiar contour. It is of a generally triangular form, with the right hand side margin 10 extending forwardly to an apex 10 located at the'right of'a vertical plane through the axis of the crank shaft 2. The left hand margin has one portion 10 extending from the left hand side of the casing toward the vertical plane of the crank shaft, along a line which is substantially parallel to the margin lQ-of the table or bench when the device is secured to such table with the arbor 4, at an angleof approximately 45 to the table margin. Between the portion 10 of the base plate margin and the apex 10', the base plate margin is outwardly curved, as indicated at 10 and this outwardly extending portion of the plate is provided with a depending arm 13 having a horizontally extending extremity 141, which projects underneath the table or bench, and through which a clamping set screw 15 passes, the upper end of this set screw being provided with a swiveled clamping head 17 adapted to engage the under surface of the table or bench, whereby the set screw may be utilized to draw the clamping plate 10 forcibly downwardly on the upper surface.

It will be observed that the form of the clamping plate 10 is such that the right hand marginal portion 10 extends inwardly upon the surface of the table along a line substantially at right angles to the margin 12 of the table, although the base plate margin is preferably slightly curved for the purpose of attractive design. 'lherefore. space is provided at 16 for the crank handle, the same being allowed to turn without striking either the base plate or the table.

On the other side,(i. e.,the left hand side), the contour of the base plate 10 is such as to interfere to a minimum extent with the manipulation of tools and devices of various kinds which are being subjected to a grinding operation. The fact that the grinding wheel revolves in an oblique plane is of great importance for the reason that many tools, such as chisels and long knives, or other tools with long handle, are frequently of such character that in order to get the best results the handles must be swung down wardly across the plane of the table, and un less the grinding wheel is located in an oblique plane suflicient clearance cannot be obtained.

Where ordinary clamping plates are employed, the desired adjustment of the grinding wheel cannot be secured,-at least with out greatly weakening the clamping engagement with the table. This is true for the reason that when the casing is rotated to the oblique position, the clamping arm corresponding with the arm 13 will strike the table on the right hand side,whereas the upper clamping plate will be entirely out of contact with the table on the left hand side, and the clamping pressure being exerted considerablyto the right of the center of gravity of the machine, considerable vibration results in operation, and the fastening becomes very insecure.

By my improvement, the clamping arm '13 is brought to the left, and the clamping pressure is exerted centrally, i. e., substantially directly below the center of gravity of the machine. The wide bearing area of the clamping plate upon the table at the points most distant from its front margin 12 and from the point at which the arm v13 is located, is also a factor in securing rigidity and stability for the support.

The larger area of the clamping plate is provided at the right hand for the reason that the majority of users operate the grinding machine with the right hand, and hold the tool with the left hand. Therefore, the described contour of the clamping plate provides clearance for the tool at the side where clearance is normally desired.

I claim A. clamping support for grinding machines and similar tools, comprising a base plate of substantially triangular contour, a gear casing carried by said base plate adjacent one of the triangular sides, said gear casing having a driving shaft bearing arranged at an acute angle to another of said triangular sides, and a clamping armextending downwardly from said last mentioned side and beneath said base plate.

In testimony whereof I afiix my signature in the presence of two witnesses.

BERNHARD BETHKE.

Witnesses v 7 LEVERETT C. WHEELER, 0. O. WEBER.

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