US1605732A

US1605732A - Sand-blast machine

Info

Publication number: US1605732A
Application number: US524627A
Authority: US
Inventors: Herman F Hoevel
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-12-24
Filing date: 1921-12-24
Publication date: 1926-11-02
Anticipated expiration: 1943-11-02

Description

VNov. 2 ,1926.

H. F. HoEvEL SAND BLAST MACHINE Filed Deo. 221,v 1921 INVENTOR. ge/'maza //faeae/ m, @MM2/L www@ ATTORNEYS.

Patented Nov. 2, 1,926.

UNITED sTATEs HERMAN E'. HOEVEL, OF NEV YORK, N. Y.

SAND-BLAST y MACHINE.

Application led December 24, 1921. Serial No. 524,627.

My invention relates to machines for delivering sand or other material from a tank tothe place of use, and has particular reference to machines of the type in which a compressed medium such `as compressed air is admitted periodically to a chamber containing the sand or like material, Jfor the purpose of causing such material to be eX- pelled from such chamber.

An example of my invention is illustrated by the accompanying drawings, in which Fig. 1 is an elevation of the apparatusgFig. 2 is a vertical section;y Figs. 3 and 4 are diagrammatic vertical sections showing two different positions of certain cocks or valves.

`The interior construction of the blasttank may be of a well-known type, as shown in Fig. 2, where the tank 10 comprises a hopper 11 to receive thesand or other material through a screen 12, an upper compartment 13, and a lower compartment 14 from the outlet 15 of which the sand passes to the blast-pipe 16 which delivers a mixture of air and sand to the place-of use through a pipe or hose (not shown). Compressed air is supplied to the chamber 17 containing` the blast-pipe 16, in any suitable manner, for instance by a pipe 18, and a pipe 19 connects the said chamber 17.with the upper portion of the lower compartment 14, so that thefsame pressure will prevail in said compartment and in said chamber. A downwardly-opening spring-pressed valve 2O controls the connection of the hopper 11 with the upper compartment 13, and a similar valve 21 controls the connection of said vupper compartment with the lower Vcompartment 14. The upper compartment is also'adapted to be connectedalternately, at suitable intervals of time, with the outside air and with a source of compressed air respectively. l

According to the form of my invention .illustrated herein, this alternate connection of the upper compartment is'effected by the following arrangement and mechanism: KFrom the pipe 18 a branch conduit 22 carries the compressed air to the port 23 of a casing 24, said port registering at times (Fig. 3) with the passage 25 of a plug 26 mounted to turn in said casing. The passage 25 is adapted to register at the same time with another port 27 of said casing 24, this port communicating with a conduit 2,8. The latter is connected with the upper compartmentK 13 either directly or, as shown, by means of the upper portion of a pipe 29 communicating with said compartment at 30. A cock or valve is thus provided to control the connection of thecompartment 13 (through the pipe- 28) compressed air (through the branch conduit- 22). The lower portion of the pipe 29 has a valve-controlled or cock-controlled connection with the outside air as follows: The lower end of said pipe connects with the upper port 31 of a casing 32 in which is mounted to turn a plug 33v having a passage 34.l The casing 32 also has another port which isopen to the outside air either directly or through al short pipe 36. In one position (Fig. 4) the passage 34

registers withpboth ports

31 and 35, and the valve thus being open, communication `is established between the compartment 13 and the outside air, the pipe 29 thus forming a ventpipe; in the other position (Fig. 3), the valve is closed, that is to say, the compartment 13 has no connection with the outside air. It will be noted that both valves or with the source of cocks are of the very simple one-way construction, and, for the reasons explained below, this is a great advantage, particularly in regard to the valve 'controlling the connection of the compartment 13 with the outside air. At no time are

yboth plugs

26, 33 in the open position.

The proper operation of thev valves requires that when either of them is open, the other should be closed. To accomplish this automatically, I have provided the `tollowing mechanism, in the particular embodiment illustrated: The two movable members or

plugs

26, 33 are connected rigidly with

parallel arms

37,38, respectively, onel of which, 37, has a .pivotal connection at 39 with an `operating rod orbar 40 having a handleY 41. The bar 40 also has an upright slot 42in which is adapted to slide-a pin 43 on the arm 38, said pin being as far from the plug 33 as the connection 39 is from the plug 26. The rod or bar 40 is mounted to slide in a stationary guide 44, in which it can also rock slightly. It will be understood that the axes about which the

plugs

26, 33, turn, and the connections 39, 43, are parallel to each other. W

So far as described above, theapparatus will operate as follows: Let us assume that the valves are in the position shown in Fig.

3, thus admitting compressed air to the upper compartment 13, and preventing the escape of such air therefrom to the outside, since the valve plug 33 shuts off communication from said compartment to the outside air. The compressed air in compartment 1,3 also holds the valve 2O closed, so that at this time no sandcan pass to the said compartment from the hopper 11. The pressure of the air in compartment 13 now being the same as in the lower compartment 14, the weight of the sand in compartment 13 will open the valve 21 so that a charge of sand will be transferred from the upper compartment to the lower compartment, from which it is fed, continuously, to the blastpipe 16. After a certain lapse of time, the rod 40 will loev operated to shift the

valve plugs

26, 33 to the position shown in Fig. 4, thus stopping the supply of compressed air to the upper compartment 13, and connecting this compartment with the outside air 'through the vent-pipe 29. Since the .lower compartment 14 is always connected with the supply of compressed air, it follows that the valve 21 will now be held closed tightly, so that no sand will pass at this time from the compartment 13 to the compartw ment 14. On the other hand, since atmospheric pressure now prevails both in the hopper 11 and in the upper compartment 13, the valve 20 will be opened by the weight of the sand which has previously accumulated in the hopper l1, so that the upper compartment will receive a new charge of sand. It will be understood that, as usual in apparatus of this type, there is preferably a continuous Supply of sand to the hopper 11. at such a rate that a suiiicient charge accumulates therein between successive openings of the valve 20.

At such times as the compressed air escapes from the upper compartment 13 to the outside air immediately after the plug 33 has taken the position Fig. 4, some dust and frequently some sand, will reach the valve plug 33 and its seat, and on account of this, these parts will wear out quicker, and require renewal oftener than the plug 26 and casing 24, which it will be noted are not in the. path of the dust and sand that may escape with the air at the time communication is established between the compartment 13 and the outside air. A very high-grade cock may therefore be employed at 24, 26, since its renewal will hardly ever be required. As stated above, the

parts

32, 33 constitute a one-way cock of the usual very simple and inexpensive construction, and I may employ at this point (32, 33) a cheap grade of cock so that the cost of renewal will be low.

As I have mentioned above, the rod 40 should be operated periodically to effect a reversal of the positions of the

valve plugs

26, 33. In order that'the attendant may be informed of the proper times for effecting this reversal, I have shown a time-indicator connected operatively with said rod and constructed as follows: The bar or rod 40 has a projection 45 the upper end of which is connected by a link 46 with a rack bar 47 sliding in stationary guides 48, the teeth of said rack bar being in mesh with a gear wheel 49, operatively connected with a sand-glass 5U, for instance by mounting said sand-glass directly on said wheel, or on some part, such as a support 51, connected with the wheel rigidly. In any event, the connection of the rack bar 47 with the sandglass is such that at each operation of the bar or rod (whether to the right or to the left), the sand-glass will be turned over to bring its lower (full) half back to the upper or starting position. The time required for the passing of the sand from the up per half of the sand-glass to the lower half may be, for instance, ten minutes. In this case, ten minutes after every operation of the rod 40, the operator will find that the upper half of the sand-glass is empty, and this will remind him it is time for again operating said rod. It will be understood that at one operation the rod 40 will be moved toward the left, at the next operation (say, ten minutes later) it will be moved toward the right, and so on in regular alternation. Stops 52 adjustable lengthwise on the rod 40, may variably limit its motion in either direction.

Various modications may be made without departing from the nature of my invention as set forth in the appended claims.

I claim:

1. A pressure tank for sand-blast apparatus and the like, a device for controlling the alternate connection of a chamber of the tank with the outside air and with a source of gaseous medium under pressure, a sandglass, and means, operatively connected with said controlling device, for inverting the sand-glass. y

2. A pressure tank for sand-blast apparatus and the like, separate cocks having plugs to turn about parallel axes and controlling the connection of a chamber of said tank with the outside air and with a source of gaseous medium under pressure respectively, parallel arms connected operatively with said plugs, a rod attached to said arms loosely by connections which compel said arms to remain substantially parallel to each other but permit the rod to change its inclination, and a stationary guide in which said rod has both longitudinal and rocking mobility.

3. A pressure tank for sand-blast apparatus and the like, a device for controlling the alternate connection of a chamber of the tank with the outside air and with a source of gaseous medium under pressure, a longitudinally movable rod for operating said controlling device, a rack connected with said rod, a support mounted to turn and operated by said rack, and a sand-glass carried by' said support and inverted by the movement thereof.

4. A pressure tank for sand-blast apparatus and the like, separate cocks having plugs mounted to turn, and controlling the connection of a chamber of said tank With the outside air and with a source of a gaseous medium under pressure respectively, arms con` nected operatively and positively with said plugs and mounted to rock, and a movable actuating rod positively connected with both of said arms to impart a simultaneous roeking movement to such arms and to the plugs connected therewith to positively rock said plugs to and from their open and closed positions.

5. In a sand blast apparatus, a tank having a pair of compartments, valve means movable to two different positions, in one of which a gaseous medium under pressure is admitted to one of said compartments, and in the other of which the gaseous medium is shut off from said compartment and the outside air is admitted thereto, and an indicatingl device operatively associated with said valve means for movement therewith to indieate the expiration of the normal maximum period of time said valve means should remain in either of said positions.

In testimony whereof I have signed this specification.

HERMAN F. HOEVEL.