US2261565A - Sandblasting machine - Google Patents

Description

SANDBLASTINGMACHINE Filed No 13, 1939 2 Sheets-Sheet 1 lNVEN'i'OR 'FH.ROSEZZ8 ATTORNEY 1939 2 Sheets-Sheet 2 INVENTOR .FTHRoseZZe NEY F. H. ROSELLE SANDBLASTING MACHINE Filed Nov. 15

Nov. 4,.1941.

Patented Nov. 4, 1941 TAES r QFF! This invention relates in general to sand blasting apparatus, and in particular the invention is directed to improved mechanism in apparatus of the type described to feed the sand into the stream of compressed air.

Heretofore, the general practice has been to feed the sand from a tank or reservoir through a lead pipe into the lateral side of a T-fitting; said T-fitting being interposed in the compressed air line. This arrangement has been subject to the objection that there is a tendency for the sand to plug in the T-fitting during operation of the apparatus.

It is therefore the principal object of this invention to provide mechanism which is arranged to prevent plugging of the sand in any part of the apparatus, such object being accomplished through the medium of a unique sand and air mixing assembly.

Another object of the invention is to provide mechanism for the regulation of the proportion of sand mixed with the compressed air and fed into the hose and sand blast nozzle of the apparatus.

A further object of the invention is to provide means in the apparatus arranged so that the supply of sand can be entirely shut ofi when desired, so that air alone passes into the sand blast hose and nozzle.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly efiective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Figure 1 is a side elevation of the apparatus.

Figure 2 is a fragmentary sectional elevation of the apparatus.

Referring now more particularly to the characters of reference on the drawings, the device comprises a vertical and elongated tank or reservoir I, the bottom of which is of inverted frustoconical configuration, as at 2. This tank is supported by suitable legs 3, and is provided on opposed sides with carrying handles 4 which normally depend from pivots 5 carried by brackets 6, said brackets including stop elements 1 adapted to engage the inner ends of the handles and to limit outward and upward swinging movement of said handles to a horizontal position, as clearly shown in dotted lines in Fig. 1.

At its upper end, but offset from the vertical axis thereof, the tank I is provided with a filling neck 8 which includes a pressure-tight but removable cap indicated generally at 9.

I A compressed air supply hose l0 extends from the source of compressed air (not shown) to a point beneath the tank I, and from said point is connected with a fitting II on the bottom of the inverted frusto-conical portion 2 of the tank by means of an elbow l2, union l3, and nipple M; a valve I5 being interposed between the end of the hose I0 and elbow l2. A vertical nozzle or jet I6 is fitted within nipple M and extends from a flanged lower end I! secured in the union I3 upward to a termination within'the tank portion 2 some distance above fitting I l. r

A pipe l8 having an internal diameter somewhat greater than the diameter of the upper or discharge end of nozzle I6 is disposed axially and vertically in tank I; the lower end of said pipe I8 being disposed adjacent nozzle l6, while the upper end portion of the pipe slidably extends through and projects some distance beyond a packing gland I9 inthe upper end of the tank I. Within the tank I, the pipe I8 is slidably supported by means of a spider 20.

An upwardly opening cup 2| is formed integral with thenut 22 of packing gland l9, and surrounds a pipe I8 above said gland l9; this cup 2| at its upper edge being formed with an outwardly projecting annular flange 23. An exteriorlythreaded sleeve 24 is fixed on pipe l8 by means of a set screw 25, and extends upward about said pipe l8 from within cup 2|. A hand wheel 26 is threaded on sleeve 24 above cup 2|, and this hand wheel 26 is provided with an-annular collar 2'! secured in place by bolts 28; such collar engaging beneath cup flange 23.

At its upper end, pipe I8 is provided with a bell reducer 29 and a flexible hose 39 is connected at one end by suitable means insaid reducer 29. A swinging hose supporting bracket 3| is formed with a fork 32 mounted on pipe [8 between sleeve 24 and reducer 29; said bracket 3| above the fork curving upwardly and outwardly and at its upper end being formed with an eye 33 through which the hose 30 projects. This swinging bracket 3| prevents kinking or rupturing of the hose adjacent the reducer 29, and which would otherwise occur when the hose 30 was swung about during a sand blasting operation. The sand blast nozzle (not shown) is attached to the free end of hose 30 as is usual.

In operation, a quantity of sand is disposed in tank I through filling neck 8, and cap 9 is then secured in place in pressure-tight connection with said neck. Thereafter, said valve I5 is opened and the compressed air from hose l passes through vertical jet I6 and blows into the lower end of pipe I8. As the compressed air blows through into the lower end of pipe I8, it carries with it a quantity of sand from the tank I, the lower end of said pipe l8 being spaced above the upper end of nozzle l6 somewhat and so as to permit the sand to so pass into said pipe l8.

In order to regulate the amount of sand being carried into pipe l8 by the force of the compressed air from jet l6, said pipe I8 is raised or lowered as desired, and this is accomplished by rotating hand wheel 26; rotation of the hand wheel 26 causing the sleeve 24 and connected pipe IE to raise Or lower, depending on the direction of rotation of the hand wheel 26.

During operation of the apparatus, a head of compressed air builds up in the upper portion of tank I above the surface of the supply of sand, and when the valve I is shut off to stop operation of the device, such head of compressed air would force a plug of sand into nozzle I6 and upward into pipe I8 if means were not provided to relieve such head of air. To provide such relief, a bleed opening 34 is formed in pipe [8 at a point adjacent the upper end of tank I. When the valve I5 is closed, the head of compressed air in the tank I immediately bleeds out through opening 34 and thus no plug of sand occurs in jet H5 or pipe l8.

If it is desired that compressed air alone shall pass into pipe 18, the hand wheel 26 is rotated in a direction to lower pipe l8 until the lower end of said pipe projects over the upper end portion of nozzle l6, and rests on the bottom or lower end of tank portion 2.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

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

1. In sand blasting apparatus, a sand receiving tank, a vertical nozzle projecting into the tank through the bottom thereof, a pipe projecting through the upper end of the tank and depending to a termination at its lower end adjacent but normally spaced from said nozzle, the

nozzle and said pipe being disposed in axial alignment, means mounting the pipe for vertical sliding movement, and manually operative means 5 to effect such movement from exteriorly of the tank.

2. In sand blasting apparatus, a sand receiving tank, a nozzle in the tank, means to supply compressed air to said nozzle, a pipe extending into the tank and terminating at one end in adjacent axially alined relation to the discharge end of said nozzle, means mounting said nozzle and pipe for relative axial movement at their adjacent ends, and manually operative means to effect such movement from exteriorly of the tank.

3. In sand blasting apparatus, a sand receiving tank, a nozzle in the tank, means to supply compressed air to said nozzle, a pipe extending into the tank and terminating at one end in adjacent axially alined relation to the discharge end of said nozzle, means mounting the pipe in connection with the tank for axial movement at said one end, and a hand member movably mounted in connection with the tank exteriorly 25 thereof and operative to effect said axial movement of the pipe at said one end.

4. In sand blasting apparatus, a sand receiving tank, a nozzle in the tank, means to supply compressed air to said nozzle, a pipe extending into the tank and terminating at one end in adjacent axially alined relation to the discharge end of said nozzle, and means mounting said nozzle and pipe for relative axial movement at their adjacent ends; said last named means comprising a sleeve fixed on the pipe exteriorly of the tank, and a hand wheel threaded on said sleeve and mounted in rotatable but axially immovable relation to said sleeve.

5. In sand blasting apparatus, a sand receiving tank, a nozzle in the tank, means to supply compressed air to said nozzle, a pipe extending into the tank and terminating at one end in adjacent axially alined relation to the discharge end of said nozzle, and means mounting said nozzle and pipe for relative axial movement at their adjacent ends; said last named means comprising a sleeve fixed on the pipe exteriorly of the tank, a hand wheel threaded on said sleeve, a packing gland on the tank through which said pipe slidably extends, an outwardly facing cup formed with said packing gland and surrounding the pipe, the inner end of said sleeve projecting into said cup, an annular flange formed on and projecting laterally outward from the outer end of said cup, and an annular collar on the hand Wheel and engaging under said flange.

FREDRICK H. ROSELLE.

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