US1171869A - Jolt ramming-machine. - Google Patents

Description

E. H. Mun/110110.05011.

R. s. MuMroRn, ExEcuTRlx.

JOLT RAMMING MACHINE.

APPLICATION HLED JUNE 17. 1915.

Patented Feb.15,1916. '5

2 SHEETS-SHEET 2 efk e@ UNTTE sTATEs PATENT OFFICE.

EDGAR H. MUMFORD. VDECEASED. LATE OF PLAITIELD. NEW JERSEY, BY ROSE S. MUMFORD. EXECUTBIX. OF PLAINEIELD. NEW JERSEY.

JOLT RAMMIG-MACHINE.

To IZZ Vwia-0m it may con/lern Be it known that Enma: H. Mt'nronmand useful Improvements in Jolt Ramming- Machines, of which the following is a specification.

rIhis invention has reference to machines for ramlning sand molds and particularly to that type of machine known as a jolt rammer in which the moving parts are operated by fluid pressure, the supply of pressure being controlled by automatic valve mechanism. One of the chief.objects ofthis invention is to provide a novel and improved form of fluid pressure control valve mechanism which will operate efficiently and accurately. j The foregoing, together with such other objects as may hereinafter appear or are incident to the invention are attained by means of alconstruction illustrated in preferred form in the accompanying drawings, wherein- Figure l lis a longitudinal section through a portion of a combined squeeze and jolt ramming molding machine such as shownin' copending application of Edgar H. Mumford, Ser. No. 19,931, filed April 8, 1915; Fig..j`2 is a sectioii similar to that of Fig. 1 showingta modification of the improvement; and Fig. 3'is a sectional view of another detailed modification of the improvement.

Improvements have been made in jolt ramming apparatus whereby the provision of n echanical means for positively shifting the valve controlling the supply of fluid pressure to the moving parts has been dispensed with, the control of the supply of fluid pressure being -had through the medium of fluid pressure actuated valve mechanism. The invention relates more particu- 'larly to an improvement in this latter form of mechanism.

For convenience of. illustration. the invention is shown as applied to a combined sqaeeze and jolt ramming molding machine. Only such parts of the apparatus are shown as are necessary to bring out theoperation of the improvement. Referring now to Fig. 1, the apparatus comprises a main casting olitbase 7 which is provided with an annularl'ups'tanding cylindrical portion S and Specication of Letters Patent.

Patented Feb. 15, 1m u.

A Application led .Tune 17. 1915. Serial No. 34.710.

with a centrally disposed cylindrical guide post il. The mold table supporting traine is carried on the plunger 11 mounted in the cvlindnhfal portion Si of the base. LThe plunger 11 is hollow and is provided with a centrally disposed c vlindrical portion 11a which surrounds and i's guided by the central guide post 9. The squeezing operations of' the machine are carried on by the introduction of fluid pressure into the cylinder S beneath the lower face of the plunger 11, but as this forms no part of this invention, further description will be dispensed with.

Referring now to the mechanism for carrying out the jolt ramming operations, it will be noted that there is a space in the cylinder 11 above the post 9 to provide a valve chamber 12, and that a valve block 13 is detachably secured by means of the studs 14 to the top of thepost 9. The valve block is provided with a passageway for conducti'hg fluid pressure to the interior of the cylinder 11a. such passageway being comprised of a horizontally extending inlet passage 15, a horizontally disposed discharge passage 16 separated horizontally 'by the wall 17, and the passage 18 in the all 17 which serves to connect the passages 15 and '16. A vertically movable piston valve A controls the opening 1S. such valve being provided with an upwardly projecting stem 19 which is of such length that it projects slightly above the top face of the valve block 13 when the valve is in lower or open position. T he lower face of the piston portion 20 of the valve is spaced away from the upper face of the post 9, for a purpose which will hereinafter appear.

The post 9 has a central chamber 21, from the upper portion of which an inlet port 22 extends to the upper face of the post opening at a point communicating with the downwardly extending end of the passage 15. Fluid pressure is introduced into the chamber 21 through an inlet pipe Q3. the supply of fluid pressure being controlled by any suitable form of valve mechanism(not shown) in the usual manner. An exhaust port or opening 2i is drilled in the wall of the cylinder 11, andthe valve block at one. end is spaced away from the inner wall of the cylinder 11!l to form a space 25 with which the port 24 comes into register, as will further appear. A restricted passage 15;L extends from the end of the passage 15 to the space beneath the lower face of the piston portion 2O of the valve A.

The operation of the apparatus is as fol lows, assuming that the parts are in the position shown in Fig. 1: F luid pressure is introduced into the chamber 21l through the supply pipe 23 and passes through the inlet port 22 into the passageway 15, thence` through the opening 18 around the valve stein 19 into the discharge passage 16, and thence into the chamber 127 causing the cylinder 11a and the plunger 11 of which the cylinder ormsa part, to rise, carrying the frame l10 upwardly. During this period of operation, the pressures on the opposite4 4faces of the lower portion of the valve A are substantially equalized as it will be seen tha-t the passage 15a permits an accumulation of pressure on the lower face of the piston 2() of the valve. Hoivevei',the pressure on the upper face of the stem 19 of the valve tends to hold the valve oil its seat. The parts continue their upward movement until the eXu haust port 24 in the wall of the cylinder 11a comes into register with the space 25, at.

which time the pressure in, the chamber 12 exhausts through lthe port 24, thereby causing a -rapid reductionof pressure above' the valve. The passage 1G is covered by the rising wall of the cylinder11"L just prior to the uncovering of the port 24.

The pressure accumulated beneath and acting against the lower face of the piston portion 2O 'of the valve then immediately causes the valve to move upwardly to close the valve opening 18, thereby cutting ofi the supply of fluid pressure from the cha-1nber 21. The plunger '11 and cylinder 11a fall, impacting on the upper face of the base 7. As' the partsmove downwardly, a tappet 19a in the end of the cylinder 11a cornes into Contact with the upper end of' the stem 19' of the valve and moves the valve to open position, after which the operation above described is repeated, and the rainming oit' the mold effected. v

-Some difiiculty hasbeen encountered in preventing the valve from prematurely moving upwardly 'to""close the opening 18, which obviously would result in an impairment of -the eciency of the device. To overcome this difficulty, the passage way 15 is formed so as 'to set up a peculiar swirling motion in the air as it flows therethrough, which causes the'air to act against the valve to hold'itlin lower or open position. To impart this swirling motion to the air, the annular wall of the passageway 15 is rounded as indicated at 26. It is diicult to define accurately just what effect therounding ot the wall'of the passageway 15 has on the'air 'assing through the passageway, but it has been found by experience that the eiect of so' rounding the wall adjacent to the valve r.ducted to the lower face of the valve. this form of apparatus, the port 2S is drilled annees passing through the opening 1S to draw the valve upwardly. This peculiar action ot' the currents of air maybe perhaps best gathered from inspection of Fig. 3.A In the construction therein shown, the rounding of the' passageway 15 is accentuated by providing a downwardly-turned lip 27 on the wall 17l adjacent to the opening 18. The piston portion 20 oi' the valve in this type has a loose tit and pressure accumulates beneath the valve by leakage. 'The valve in introduced into the valve block from beneath, the plate 28 being thereafter detachably secured in place.

In F ig. 2 there is shown a slightly modied forni of construction which differentiates from that shown in Fig. 1 in the manner in which the fluid, pressure is conthrough the wall of thep'ost 9 so as to communicate with the chamber 21, and a second port 29 located above the port 2S extends in an upward direction trom a point above the port 28 opening into the space beneath the lower face of the valve parts. Mounted in the wall ofthe cylinder 11a is a spring-held member 30 having a groove 31 in its inner face, which groove serves to connect the ends of the ports 28 and 29 after the cylinder 11.a

has moved upwardly a predetermined distance. When these parts are brought into register, pressure flows from the chamber 21 through the port 28, groove 31 and port 29 to the lower face of the valve, the parts being so arranged that they are brought into register substantiallyzg simultaneously with the uncovering of the exhaust port 24:.

, It will be seen troni-the foregoing that the valve operates with great accuracy, which results in an increase in eiciency. Furthermore, the arrangement oit' the valve mechanism above the post 9 siinplizlies the whole structure as it obviatsthe necessity ont forming special openings or recesses for the introduction ofV the valve parts, and special ports which otherwise might be nec-- essary The location. of the valve parts above the post also gives added eiiiciency be cause the valve parts, by reason of their lo cation, are immediately subjected 'to the eii'ects of changes inpressure conditions.

1. The combination in a jolt ramlning machine of a-plunger member and a cylindrical member, relatively movable and provided with a fluid pressure chamber therebetween, one of said members being provided with an exhaust port, anadmission port for introducing fluid pressure to said chamber, a valve casing in said chamber, and a valve in said-casing for controlling said admission port, said val-ve being fluid pressure held in open position and being ygoverned as to its closing movement by thesaid exhaustI port when the latter is in registry with the said chamber.

2. The combination in a jolt ramming machine of a stationary plunger, va vertically movable cylinder mounted thereon, there being a fluid pressure chamber in the cylinder above the plunger and anexhaust port in the wall of the cylinder and an admission port in the plunger, a valve block mounted on the plunger andv lying in said chamber and provided with a passageway in communication with said admission port, and a. fluid pressure actuated valve in said block for controlling said passageway normally in open position and governed as to its closing movement when the exhaust port is brought into registry with the said chamber.

3. The combination in a jolt ramrning machine of a stationary plunger, a vertically movable cylinder mounted thereon, there beinga fluid pressure chamber in the cylinder above the plunger and an exhaust port in the wall of the cylinder and an admission port in the plunger, a valve block mounted on the plunger and lying in said chamber and provided with a passageway in communication with said admission port, and a fluid pressure actuated valve in said block for controlling said passageway normally in open position and governed as to its closing movement when the exhaust port is brought into registry with the said chamber, the wallof said passageway being rounded to direct the incomingI current of fluid pressure downwardly against the valve.

4. The combination in a jolt ramming machine of a stationary plunger, a vertically movable cylinder mounted thereon, there be ing a. fluid pressure chamber in the cylinder above the plunger and an exhaust port in the wall of the cylinder and an admission port in the plunger, a valve block detachably fastened to the top of the plunger and lying in said chamber and provided with a passageway in communication with said admission port, and a fluid pressure actuated valve in said block for controlling said passageway normally in open position and governed as to its closing movement when the exhaust port is brought into registry with the said chamber.

5. The combination in a jolt ramming machine of a cylinder member and a plunger member -relatively movable, means for admitting fluid pressure into the cylinder member to raise the plunger member comprising apassageway, and a fluid actuated valve controlling said passageway, the wall of said passageway being formed to direct the incoming current of fluid pressure against -a face of the valve to hold it in open position.

6. The combination in a olt ramming machine of a cylinder member and a plunger member relatively movable, one of said members being provided with an exhaust port, means for admitting fluid pressure into the cylinder member to raise the plunger member comprising a passageway, and a fluid actuated vertically movable valve controlling said passageway and open when in lower position, the wall of'said passageway being formed to direct the incoming current of fluid pressure against a face of the valve to hold it in open position and the valve being governed as to its closing movement by the uncovering of said exhaust port.

In testimony whereof I have hereunto signed my name.

ROSE S. MUMFORD, Eecutrz'a: of Edgar H. Mumford, deceased.

Copiesof thls patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C.

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