US2418893A - Sand-blast shield - Google Patents

Description

April 15, 1947.

Y P. F. M CORMACK 2,418,893

SAND-BLAST SHIELD Filed April 8, 1944 .2 Sheets-Sheet 1 fli y- INVENTOR.

Pattie/(17,122 Cozmack.

BY ATTORNEY.

April 15, 1947.

P. F. MccoRMAcK SAND-BLAST SHIELD Filed April 8; 1944 2 Sheets-Sheet 2 INVENTOF BYHTTOPNEY M A/We Patented Apr. 15, 1947 UNITED STATES PATENT ()FFlCE 1 Claim.

"This invention relates to-a shield or screen particularly designed for use in sand-blastin inscriptions on stones or monuments.

'It isthe generalobject of my invention toprovide an improved shield or screen for such purposes, so designed that a desired inscription may be easily assembled by inserting separate selected letter orfigure stencils in spaced slots or. openings in said shield.

An important object of my'invention relates to means for conveniently centering and securing a line of such assembled letter or figure stencils.

A further object is to provide a shield which may be built up of selected parts to provide any desired height of letter in. a given line. andany desired spacing .between two adjacent lines. I also provide improved means for holding the shieldinplace on. a stone or. monument and for preventing lateral displacement thereof during the sand-blasting operation.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claim.

Preferred forms of the invention are shown in the drawings, in which- Fig. 1 is a front elevation of one form of my improved shield as applied to a stone to be lettered;

Fig. 2 is a side elevation, looking in the direction of the arrow 2 in Fig. 1;

Fig. 3 is a partial front elevation to be described;

Figs. 4 and 5 are perspective views of types of guidebars used in the assembled shield shown in Figs. 1 and 2;

Fi 6 is a front elevation of a modified construction of shield;

Fig. 7 is a side elevation, looking in the direction of the arrow 1 in Fig. 6;

Fig. 8 is a bottom view, loo-king in the direction of the arrow 8 in Fig. 6;

Fig. 9 is a partial rear view, looking in the direction of the arrow 9 in Fig. 8 and Fig. 10 is a partial side elevation showing 2 cesses-22 alongtherear upper and loweredges thereof. The vguidebars ;20 are commonly pf greater width than .the bars 2| and are provided with dovetailed longitudinal channels 24 in their rear faces for a purpose to be described. I

In assembling my improved ,sand blast shield, it is convenient to locate one; ofthe guidebars 2-0 in a selected position on a stone S to receive the lower lineof stencils25; and fille piecesifi, as shown-in Fig. :3. This guidebar 20 may be temporarily secured in position by a .pair of clamps C. A row of letter and figure stencils 2:5 and filler pieces 26 is then assembled above the bar 20, after which a';bar.2| is positioned as indicatedv in Fig. l. The desiredinscriptionisthus progressively assembled, with asecond bar 20 forming the top of ;the,shie1d. .It will be understood that the bats 2| will be furnished ;in different widths, SO'aS, to -,provid any desired spacing between the lines of the inscription.

After the guidebars, stencils and filler pieces are thus assembled, the clamps C are removed and cross bars 30 are laid over the bars 2|] and 2|. The assembled guidebars and cross bars are then secured to the stone S by clamps C and CI.

The cross bars 30 each have a plurality of tapped holes 3| to receive thumb-screws 32 which are inserted in selected holes to engage the filler pieces 26. Preferably these filler pieces extend beyond the edges of the stone S, so that they may be easily reached and may be used to shift the assembled stencils to the right or to the left to accurately center the inscription. They may then be secured in centered position by tightening the associated thumb-screws 32.

Blocks of rubber 34 (Figs. 1 and 3) are desirably inserted in the dove-tailed channels 24 at the back of the outside guidebars 20. When compressed against the stone by the tightening of the clamps C and CI, these rubber blocks 34 efiectually prevent lateral shifting or displacement of the shield during the sand blasting operation.

It will be understood that th guidebars 26 and 2| and the cross bars 3|) may be made of any desired lengths, and that the guidebars 2|] and 2| may be of any desired widths, so that widely varying inscriptions may be assembled on stones of substantially different dimensions.

The guidebars 2D and 2|, the stencils 25 and the filler pieces 26 are all preferably formed of steel or other metal of substantial thickness, sothat they are well adapted to withstand the operation of the sand blast when it is directed through the Openings in the Stencils to produce the desired letters and figures.

It is a matter of substantial importance that the guideways between adjacent guidebars 20 and 2| are unobstructed for their entire length, and that the filler pieces 26 extend beyond the edges of the stone. With this construction, it is unnecessary to preliminarily ascertain the length of a line of letters or figures, as the assembly may be readily shifted as a unit to the right or to the left until it is correctly centered on the stone.

While the construction shown in Figs. 1 to 5 is well adapted to producing a variety of inscrip- CJI tions on stones of different sizes, the construction shown in Figs. 6 to 10 has advantages where inscriptions of identical letter heighth and identical line spacing are desired on a substantial number of duplicate stones, such as the stones used in military cemeteries.

For such purposes, I provide a shield comprising a body orplate 40 (Fig. 6) having transverse guideways 41 (Fig. 10) formed in the rear face thereof and having a slot or opening 42 overlying each guideway 4|. Side bars 43 are secured to therear side edges of the plate or body 40, as clearly shown in Fig. 8. These side bars 43 are spaced apart to clear the edges of the stone S and are provided with tapped holes to receive thumb-screws 44 which engage the rear faces of filler pieces 45 by which stencils 46 may be conveniently centered and secured as previously described.

A top bar 4'! (Fig. 10) on the back of the plate 40 is adapted to'engage th upper end of the stone SI and thus conveniently determines the vertical position of the shield on the stone. The shield with assembled stencils and filler pieces may be held in place on the stone by clamps C2 during the and blasting operation.

This construction is obviously somewhat more simple than the construction shown in Figs. 1 to 5 and is desirably used where a large number of stones are to be cut with substantially duplicate letter sizes and duplicate line spacings.

Having thu described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth. in the claim, but what I claim is: A sand blast shield comprising a unitary frame having parallel unobstructed transverse guideways in its rear face for letter and figure stencils and for filler pieces and having a sand blast opening through said frame associated with each guideway, said guideways bein entirely open and unobstructed at both ends, side bars secured to the rear face of said frame at the side edges thereof and bridging said guideways, clamping screws mounted in said side bars and behind said frame and effective to engage the rear faces of said filler pieces and to force them forward against the body of said frame to position a line of stencils in a selected transverse centered position, and clamping means efiective to secure said frame against the face of a stone.

PATRICK F. MCCORMACK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Lake July 4, 1876

Images