US2865149A - Work holding attachment for grinders - Google Patents

Description

Dec. 23, 1958 M. SOAVE WORK HOLDING ATTACHMENT FOR GRINDERS Filed 00%. 1. 1952 3 Sheets-Sheet l A? z INVENTOR.

ATTOPA/[F Dec. 23, 1958 M. SOAVE 2,865,149

WORK HOLDING ATTACHMENT FOR GRINDERS Filed Oct. 1, 1952 3 Sheets-Sheet 2 INVENTOR. M4260 50/4 1 5 Dec. 23, 1958 M. SOAVE WORK HOLDING ATTACHMENT FOR GRINDERS Filed 001:. 1, 1952 3 Sheets-Sheet 5 INVENTOR.

MA/PCO 50,4 VA

70/P/VE7 United States Patent WORK HOLDING ATTACHMENT FQR GRENEEKS Marco Suave, Hicksvilla N. Y.

Application October 1, 1952, Serial No. 312,527 3 Claims. (Cl. 51 -217 This invention relates to improvements in work holders for grinding machines.

More particularly, the invention is concerned with work holding attachments for grinders of the type in which the work is ground against the fiat face of the grinding wheel, and a work support in the form of a tiltable table is provided, permitting the work to be moved in parallelism with the grinding surface. In such machines, the work support is adjustable through a certain angle, to permit grinding at a desired angle with respect to the surface of the work support. In the usual machine of this type and used for miscellaneous grinding, as, for example, in pattern shop work for the shaping of various pieces of'wocd, the work is held on the rest by hand and given the required traverse movement with respect to the wheel by hand. Adjustment to precise angles is difiicult and the accident rate, due to fingers coming in contact with the wheel, is high.

It is an object of the invention to provide an attachment for grinding machines, permitting an extremely wide angle of adjustment, together with ease and accuracy of adjustment beyond what can be obtained with the conventional tilting work rest.

A second object of the invention is to provide a work support in which the work holding surface could be considerably shortened in the direction at right angles to the grinding surface, permitting the grasping of the work rearwardly at the edge of the Work supporting surface and in a position where danger of dama'geto the fingers should thework slip is minimized.

Still another object of the invention is to provide a work holder attachment having a full range of adjustability and holding the work in such a manner as to obviate any possibility of injury to the fingers, even when grinding small work pieces.

An attachment embodying the invention in a preferred form will now be described with reference to the accompanying drawing, and the features forming the invention will then be pointed out in the appended claims.

In the drawing:

Figure 1 is a side elevation of the attachment, positioned on a grinder, indicated in phantom;

Figures 2 and 3 are side elevations on a large scale and showing the attachment in two different positions of adjustment;

Figure 4 is a plan View of the attachment, with parts broken way to show the structure more clearly;

Figure 5 is a plan view of the attachment, removed from the machine and laid flat;

Figures 6 and 7 are perspectives, showing a work holder used with the attachment of previous figures; and

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Figure 8 is a perspective showing the attachment with the work holder positioned in a grinding machine, indicated in phantom.

In Figures 1 to 3 and 8, the grinding attachment of the invention is indicated in position in a grinder 1, having a grinding wheel 3, work support 5 and the usual slotted sectors 7 for pivotally supporting the work support, and the usual devices 9 for locking the work support in any desired adjusted position. The attachment includes a bed plate 11 which seats on the work support 5 as indicated, with downwardly extended flanges 13 which are fixed to the bed plate, abutting against the rearward edge of the work support 5.

Upper boards or plates 15 and 17 hingedly connected together at 19 are provided for-supporting the work, and may be adjusted to a variety of positions as hereinafter explained in detail. The forward edge of the plate 15 is provided with hooks 21, which engage under the work support 5 on each side of the grinding wheel. The bar 21 passing through the hooks 21 and axially and slidably rotatable therein may be provided together with wing screws 21 for fixing it in desired position. This bar has its ends bent at an angle as shown, and may be utilized for locating the device widthwise of the grinder wheel. The elements 15 and 17 are further supported along their hinge line by a pair of supports 23, the upper "ends of which are hingedly coupled together at 25 and the lower ends of which are pivotally fixed to nuts 27 on the threadedshaft '29, which is journaled in the bedjpl'ate 11. The threading is right and left hand, so that the lower ends of the elements 23 may be brought togetheror spread apart for raising or lowering the point of support of a hinge line between the boards -15 and 17..

Downwardly extending flanges 31 in the rearward edge of the board 17 pivotally carry the slotted members 33 and35. The slot of the member 33 receives a stud 37,-

and the member 33 may be locked in any desired position with relation to the stud by a wing nut 39. The slotted link 35 receives a stud 41, similarly equipped with a wing nut 43. By adjusting these various parts,

the boards 15 and 17 may be positioned in a variety of positions, as later described in more detail. Stops 45 are also provided for positively locating the device. If the board 17 is rocked about the upper ends of the supports 23 in a counterclockwise direction, it'will be apparentthat stops 45 will then come against the beveled rear edge of the member 11, thus limiting the forward movement of the member 17.

The board 15 may support the work W directly as indicated in Figure 1 and may also support the work holder as shown in detail in Figures 6 to 8. For this purpose, theboard 15 is equipped with a rack 47 along. each of its side edges, andv a guide stud 49, and with a substantially semi-circular trough or support 51 carried by members 53 which have slotted forwardly extending portions 55 engaged'under the stud 49 and in which there is journaled a shaft 57 to which are fixed pinio-ns '59 forming'a parallel motion adjustment, by turning the handle 61 at one end of the shaft 57. The trough 51 may thus be adjusted toward and away from the grinding wheel along the board 15 as desired.

' The board '15 may be provided with lugs 15' having bars 15 as shown, to permit mounting 'of the member by bolting to any available members, if desired Thework holder of Figures 6 to 8 comprises a work support plate 63, the forward edge of which rests on the board 15 and which may be adjusted as will now be described. Legs 65 pivo-tally attached to a round bar 67 which sits in the trough 51 are in turn pivotally attached to the plate 63 by means of pins 69 passing through the upper ends of the arms 65 and also through bearings 71 attached to the plate 63. Elements 73 pivoted coaxially with the lower ends of the legs 65 carry rotatable poppet nuts 75, through which screws 77, turnable by means of the wing heads 79, pass. The screws 77 are restrained from moving axially with reference to the upper ends of the legs 65 but are mounted for rotatable swinging movement with reference thereto. A slotted sector 81 cooperating with a wing nut 83 and stud fixed to the center leg 65 permit locking the legs at a given angular position with reference to the bar 67.

Four work clamps 85 are provided, their rearward ends being located by means of pins 87 received in sockets in the plate 63. Member 89 is provided for each pair of clamps 85, the member 89 receiving a stud 91 equipped with a wing nut 93. By backing off the wing nut 93, the clamps may be released, lifting their forward ends and turning the wing nut 93 will draw the clamps down to hold the work W securely against the plate 63 as shown in Figure 8. By tightening wing nuts 79, the plate 63 may be locked together with its supporting structure so as to form a rigid, set support.

The attachment just described is capable of a great variety of uses, depending upon the work to be done and the grinding angle.

As will be apparent from Figures 1 and 2, the rest of the grinder itself may be set at a given angle and the attachment utilized in such a way as to position the work support board at a much higher angle, thus giving practically any range. of adjustment desired. The angular adjustment being by means of the crank 29 and operating on a toggle system, is easily accomplished to an extremely high degree of accuracy.

The attachment may also be flattened out as indicated in Figure 3, the angle of the support board 15 to the grinding wheel being the same as that of the surface of the machine rest 5. Any intermediate position of adjustment is obviously available.

The usual machine rest 5 is of considerable width, as measured perpendicularly to the grinding surface, so as to be capable of supporting relatively wide as well as narrow work pieces. In consequence, in grinding fairly short or narrow pieces, the operator is compelled to hold them on the flat surface of the work rest and press them toward the grinding wheel, so that there is nothing to stop his hands from striking the grinding wheel should the work piece slip. The board 15 may be considerably narrower than the work rest, giving in the position of Figure 1, an edge at the hinge line between boards 15 and 17, against which the hands of the operator may stop should a work piece, such as the piece W indicated in Figure 1, slip.

With the attachment of Figures 6 to 8, substantially complete protection for the hands is obtained, together with a delicate and exact control over the grinding. The angle being set, it will not be disturbed by turning the handle 61 to advance the work holder toward the face of the grinding wheel, nor will it be disturbed by a traversing movement of the work holder, which is maintained in parallelism by the bar 67 sliding in the trough 51. The operator may thus give the required traversing movement to the work by sliding the work holder back and forth with one hand, and feeding the work toward the grinder by turning handle 61 with the other. Since the pressure of the hand will be exerted downwardly toward the board 15 rather than toward the grinding wheel, there is no danger of fingers being brought into contact with the grinding wheel.

The attachment of the invention is capable of use with a wide variety of grinding machines, including both disc and belt grinders and having different work table adjustments or no work table adjustment. The advantages will be apparent by considering its use with a grinder of the very common type in which the Work table is adjustable between a range of approximately 10 above the horizontal for an open cut and 45 below the horizontal for a closed cut, or thereabouts.

Considering first the open cut, the attachment of the invention readily permits grinding at an angle 68 above the horizontal (providing a bevel of 22), and, as above pointed out, provides accurate control and minimizes the possibility of injury to the fingers, while permitting operation on pieces ranging from extremely small parts, too small to be held by the hands, to large pieces of the approximate size of the work table.

Even for open cuts at slight angles, and within the range of the existing machine, the attachment of the invention has a marked advantage in that the work rest may be horizontal and solidly held by both bolts, whereas if the work table itself is placed at an angle, one of the bolts 9 must be removed, so that the work table no longer furnishes a solid and firm support.

For closed cuts, the attachment of the invention permits increasing the angle from that provided by the work rest of the machine, or about 45, to about 70 or In this case, the wing nuts 39 and 43 are loosened, and the attachment in fiat condition (Figure 3) is swung up, so that the front edge of board 15 rests against the grinding wheel frame, and is then fastened in place by tightening the nuts 39 and 43, the members 23 supporting the hinge line.

In many cases, as where the part being ground is a flat board or metal plate, the edge may be ground at desired angle by either an open cut or a closed cut. In other cases, however, as where the two faces of the Work piece are not flat, or where the ground surface must be accurately related to one of the surfaces, it is not possible to select as between open and closed cutting, and in his case, it will be apparent that the attachment of the invention enormously increases the capacity of the machine, permitting a full range of operation with wood and metal parts of practically any size and shape.

What is claimed is:

1. A work supporting attachment for grinding wheels,

comprising a support board adapted to fit on the work rest of a grinder, a pair of boards hinged together, means for adjustably supporting the said pair of boards on the support board, at a selected position in a range betweena position where the pair of boards lie flat on the support board and a position with the hinge line at a predetermined elevation from the support board and each of the pair of boards slanting downwardly toward the support board therefrom, and a trough for slidably supporting a work holder and a parallel motion supporting the trough on one of the boards parallel to the hinge line for move-- ment toward and away from the hinge line.

2. An attachment according to claim 1, in which the parallel motion comprises a rotatable shaft, a pinion fixed to each end of the shaft and a cooperating rack for each pinion mounted on the support board.

3. A work holding attachment for grinding machines, comprising a board, means for attaching the board to the work rest of a grinding machine, a trough, means mounting the trough on the board and including a parallel motion for adjusting its distance from an edge thereof, a work holder comprising a work support plate and means for clamping a piece of work thereto, and means for sup porting the work support plate at an angle to the said board and with one edge resting thereon, the last said.

means including a bar in the trough and slidable therealong, whereby the work holder is slidable for traversing a work piece held therein, legs supporting the oppo site edge of the plate from the bar and pivotally connected to the plate, and means for adjusting the angle of References Cited in the file of this patent UNITED STATES PATENTS Daniels May 29, 1855 Klaber Oct. 6, 1874 Sargent Mar. 20, 1883 Strehl Feb. 26, 1907 10 Strehl Dec. 5, 1922 McCollough Feb. 5, 1924 6 Gaimpeter Feb. 14, 1928 Markaroff Sept. 1, 1936 Amendola Aug. 21, 1951 FOREIGN PATENTS Great Britain July 8, 1913 Denmark June 21, 1923 Sweden Nov. 23, 1948 France July 10, 1928 France Sept. 16, 1935

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