US934640A - Pneumatic tool. - Google Patents

Description

W. H. VAN SICKEL.

PNEUMATIQTOOL. i APPLICATION FILED FEB. 18, 1909.

Patented Sept. 21, 1909.

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UNITED sTATEs i' A'i Ei\rr oEEicE.

WILBER H. VAN SICKEL, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR '110` THOS. H. DALLETT C0., A CORPORATION OF NEW JERSEY.

PNEUMATIC Toor..

Application filed February 18, 1909.

To all whom it 'may concern:

Beit known that I,VVILBER H. VAN SICKEL, a citizen of the United States, residing at Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented a new and .useful Improvement in Pneumatic Tools, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part oi' this specication.

My invention relates particularly to certain improvements in the valve mechanism ot' pneumatic tools and by which the operation of the tool is made more rapid and certain, and also to cushioning the piston in its downward stroke independent of the shift of the valve.

Speaking generally: I employ a hollow valve in the valve chamber, the interior of which, through its open end, is in constant communication with the air supply. In the upper portion ot' the valve chamber is a lateral passage through the valve chamber which, in one position of the valve, is covered by the valve skirt. Vhen the valve moves to its other position, this passage is uncovered and receives air from the air supply. This passage terminates in a longitudinal passage leading to the upper portion of the piston chamber. In order to insure, with certainty, a full amount of air to act on the upper portion of the piston, I provide openings through the valve, which in the position of the valve, when the first mentioned lateral passage is uncovered from the valve skirt, communicate with a lateral passage through the valve chamber, opening into the longitudinal passage leading to the upper portion of the piston chamber. In the other position ot the valve these openings through the valve communicate with a lateral pas sage through the valve chamber communicating with a longitudinal passage to the lower portion of the piston chamber. The action of the air upon the piston to drive it down being most important, my new valve mechanism enables the air to act quickly upon the upperportion of the piston, and sufficient air is insured to give the desired power. All of this I obtain with simplicity ot' construction.

I will now describe the embodiment of my invention illustrated in the accompanying drawing and then point out the invention in l the claims.

Specification of Letters Patent.

rammed sept. 21, 1909.

Serial No. 478,710.

In the drawings: Figure 1 is a sectional view of a pneumatic tool embodying my invention with the valve and piston in one position. Fig. 2 is a similar view with the parts in the other position.

a is the valve chamber, o the valve therein. This valve is hollow, vthe interior of which valve is in constant communication with the pressure supply through its open end. The lower portion or head ot' this valve is provided with the flanges c so that the exterior of the valve at this point is ot' greater area than the interior portion at that point and the area of the valve skirt d.

c is a longitudinal passage extending from the upper end of the piston chamber /L to a point near the top of the valve chamber where it communicates with a lateral passage f, which lateral passage f is, in the position of the valve shown in Fig. 2, covered by the valve skirt d, and in the position shown in Fig. l it is not covered by the valve skirt.

g is a longitudinal passage extending from the lower portion of the piston chamber 7L to the lateral passage z' extending through the wall of the valve chamber.

j is a lateral passage extending through the valve chamber, and communicating with the piston passage e.

73 are ports or openings through t-he valve. In the position shown in Fig. l, these openings register with the passage j, and when in the position shown in Fig. 2, these open` ings 7c register with the passage z'.

Z is a chamber formed in the valve chamber and in constant communication with the exhaust passage m.

a is a longitudinal passage leading from an intermediate point of the piston chamber to the pressure supply.

0 is an exhaust passage. n

p is a passage leading from the valvechamber below the valve head and opening into the piston chamber at two points, one point opposite the point of openingof pas- 100 sage a, the other point opposite the exhaust o.

rPhe operation of the tool is as follows: In the position shown in Fig. 1, the valve chamber below the valve is in communication with 105 the exhaust through passage p and exhaust o. The pressure supply in the interior of the valve holds the valve in the position shown. The pressure below the piston g is exhausted through exhaust o. The pressure enters lat- 110 soA eral passage f and passes by longitudinal passage e to the top of the piston, forcing the piston down. A supplemental supply of air is delivered on the top of the piston through the ports 7c, lateral passages j, and longitudinal passage e. When the grooved portion 1" of the piston reaches the opening of passage n, the solid portion has covered the opening t of passage p and exhaust 0. Pressure then passes to passage p through opening w and, by reason of the greater area acted on, the valve is moved to the position shown in F ig'. 2. In this position the skirt Z of the valve covers the passage f', and the ports or openings 7c no longer register with the passages y', and pressure does not pass through the passage e. The passage e however, is in communication with chamber Z and the pressure above the piston exhausts. The ports 7a, in this position of the valve, are in communication with the passage z', and pressure is admitted below the piston and it is lifted. This continues until the grooved portion of the piston passes beyond opening of passage nl and the solid portion of piston has passed beyond the exhaust 0, and covered opening w, at which time the pressure below the valve is relieved, and the constant pressure in the interior of the valve shifts it to the position shown in Fig. l. I also use certain means to cushion the piston in its downward movement. The admission of such cushioning being controlled solely by the movement of the piston. By this arrangement I am enabled to admit pressure below the piston independent of the shift of the valve, and thus allow pressure to act on the top of the piston for a greater time than is the case if the pressure admission below the piston is dependent upon the shift of the valve. For this purpose I employ the longitudinal passage y, having the port z opening into the piston chamber at a point at or near its lower end, and also having a port 10 opening where, when the piston groove r uncovers the opening or passage n, the piston groove will register with the port 10 and pressure will enter passage y and pass through port s to a point at or near the lower end of the piston chamber. By this arrangement, the admission of the air to cushion is in no way dependent upon the shift of the valve. Therefore, the piston, in its down stroke, can be held longer under the action of live air and be provided with cushioning, than if the admission of the air to cushion were dependent upon the shift of -the valve. Further, while initially the bushing 2 and striking portion of the piston make a snug lit, still under wear of use there is likely to be leakage at this point, which leakage is compensated for by the increased amount of live air admitted, in my construction, to the lower portion of the piston chamber.

Having now fully described my invention, what I claim and desire to protect by Letters Patent is:

l. In a pneumatic tool, a piston chamber, a piston therein, there being a longitudinal passage leading from the upper portion of piston chamber, a valve chamber, a hollow valve therein, said valve having a iange intermediate of its length limiting the movement of said valve in one direction, the interior of said valve communicating at its open end with the pressure supply, a lateral passage at one end of said valve chamber passing through the wall of said chamber and communicating with the longitudinal passage, said valve having a skirt which in one position of the valve covers said lateral passage, and in the other position passes beyond said passage, said valve having openings therethrough, there being a passage leading from the longitudinal passage, said valve openings registering with said lastmentioned passage when the lateral passage is uncovered by the skirt.

2. In a pneumatic tool, a piston chamber, a piston therein, there being a longitudinal passage leading from the upper portion of the piston chamber, a valve chamber, a hollow valve therein having a lower enlarged head, the interior of the valve communicating at its open end with the pressure supply, a lateral passage at the upper end of said valve chamber passing through the wall of said chamber and communicating with the longitudinal passage, said valve having a skirt which in the upper position oi. 'said valve covers said lateral passage, and in the lower position passes beyond said passage, said valve having openings therethrough, there being a passage leading from the longitudinal passage, said valve openings registering with said last mentioned passage in one position of the valve.

3. In a pneumatic tool, a piston chamber, a piston therein, there being a longitudinal passage leading from the upper portion of piston chamber, a valve chamber in line with said piston chamber, a hollow valve therein, the interior of which communicates at its open end with the pressure supply, a lateral passage at one end of said valve chamber' passing through the wall of said chamber and communicating with the longitudinal passage, said valve having a skirt, which in one position of the valve covers said lateral passage, and in the other position passes beyond said passage, said valve having openings therethrough, there being a passage leading from the longitudinal passage, said valve openings registering with said last mentioned passage in one position of the valve.

4. In a pneumatic tool, a piston chamber, a piston therein, there being a longitudinal passage leading from the upper portion of piston chamber, a valve chamber, a hollow valve therein, the interior of which communicates at its open end with the pressure supply, a lateral passage at one end of said valve chamber passing through the wall of said chamber and communicating with the longitudinal passage, said valve having a skirt which in one position of the valve covers said lateral passage, and in the other position passes beyond said passage, said valve having openings therethrough, there being a passage leading from the longitudinal passage, said valve openings registering with said last mentioned passage in one position of the valve, there being a passage leading from the lower portion of the piston chamber, said passage communicating with the valve chamber, said valve openings registering with said communication in the other position of the valve.

5. In a pneumatic tool, a piston chamber, a piston therein, there being a longitudinal passage leading from the upper portion of the piston chamber, a valve chamber, a hollow valve therein having a lower enlarged head, the interior of the valve communicating at its open end with the pressure supply, a lateralpassage at the upper end of said valve chamber passing through the wall of said chamber and communicating with the longitudinal passage, said valve having a skirt which in the upper position of said valve covers said lateral passage, and in the lower position passes beyond said passage, said valve having openings therethrough, there being a passage leading from the longitudinal passage, said valve openings registering with said last mentioned passage in one position of the valve, there being a passageleading from the lower portion of the piston chamber, said passage communicating with the valve chamber, said valve openings registering with said communication in the upper position of the valve.

G. In a pneumatic tool, a piston chamber, a piston therein, there being a longitudinal passage leading from the upper portion of piston chamber, a valve chamber in line with said piston chamber, a hollow valve therein, the interior of which communicates at its open end with the pressure supply, a lateral :passage at one end of said valve chamber passing through the wall of said chamber and communicating with the longitudinal passage, said valve having a skirt, which in one position of the valve covers said lateral passage, and in the other position passes beyond said passage, said valve having openings therethrough, there being a passage leading from the piston passage, said valve openings registering with said last mentioned passage in one position of the valve,

there being a passage leading from the lower end of the piston chamber, said passage communieating with the valve chamber, said valve openings registering with said communication in the other position of the valve.

7. In a pneumatic tool, the combination with the piston chamber and piston having a cut-away portion therein, the valve chamber and valve therein, of a passage in constant communication with the air supply, a passage from the piston chamber to the valve chamber for shifting the valve in the downward movement of the piston, and a passage admitting air below the piston in the shift of said valve, of a second passage leading to the lower portion of the piston chamber, the cut-away portion of the piston, in the downward movement of the piston, independent of the shift of the valve, connecting the constant air passage and the said second passage leading to the lower portion of the cylinder.

8. In a pneumatic tool, the combination with the piston chamber and piston having a cut-away portion therein, the valve chamber and valve therein, of a passage in constant communication with the air supply, a passage from the piston chamber to the valve chamber for shifting the valve in the downward movement of the piston, and a passage admitting air below the piston in the shift of said valve, of a second passage leading to the lower portion of the piston chamber, the cut-away portion of the piston, in the downward movement of the piston, connecting the constant air passage with the passage to the valve chamber to shift the valve, and with the said second passage to the lower portion of the cylinder. v

9. In a pneumatic tool, the combination with the piston chamber and piston having a cut-away portion therein, the valve chamber and valve therein, of a passage in constant communication with the airfsupply, a passage from the piston chamber to the valve chamber for shifting the valve in the downward movement of the piston to admit air below the piston, of a passage leading to the lower portion of the piston chamber, the cut-away portion of the piston, in the downward movement of the piston, first connecting the constant air passage with the passage to the valve chamber and then the constant air passage with the passage to the lower portion of the piston chamber.

In testimony of which invention, I have hereunto set my hand, at Philadelphia, on this 16th day of February, 1909.

VILBER H. VAN SICKEL. lVitnesses M. M. HAMILTON, E. E. WALL.

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