US1880337A - Pressure fluid operated implement - Google Patents

Description

5 Sheets-Sheet 1 O. O.V APP Filed July 3l, 14926 PRESSURE FLUID OPERATED IMPLEMENT Oct. 4, 1932.

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RESSURE FLUID OPERATED vINUELEMENT Filed July 3l, 1926 3 Sheets-Sheet 2 INVEN TOR.

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Patented Oct. 4, 1932 PATENT OFFICE OLIVER 0. APP, F NEW YORK, N, Y.

PRESSURE FLUID OPERATED IMPLEMENT Application led July 81,

The implement to which this invention relates is an automatic hammer, operated by compressed air or other pressure luid, and designed for general use, either individually in portable form, or in multiple, as on rock tunneling machinesl having a rotary head carrying a plurality of the hammers. Generally speaking the hammer is of the character of that disclosed in my prior Patent #1,319,034, of October 2l, 1916, upon which this invention constitutes an improvement. While in one form'the hammer is valve controlled, certain features of my invention may be utilized in a valveless hammer.

An object of my invention is to provide a hammer which may be very sensitively controlled by pressure of the tool against the work. Another object is to eliminate the pos- `sibility of injury to the valve by reason of its positive actuation. Another object is to insure that the valve, which is biased to closed position, will positively move to shut oil' the air when the tool is not in contact with the 4 work. Another object is the provision of practical and elective means to vent the chamber in front of the piston and sleeve to relieve excess pressure before the piston and sleeve and to prevent dust and other deleteri- `ous matter from getting into the hammer.

closed system which will operate under any degree of moisture or pressure. Other objects are convenience a'nd economy in manufacture and assembly, simplicity and dura bility of construction, and reliability and facility in operation. Still other objects and advantages of my invention will appear from the following description.

In accordance with my invention the air at line pressure is led to an annular chamber around the control valve by a longitudinal passage along one side of the cylinder from whence it is delivered under control of said valve to va longitudinal passage in the opposite side of the cylinder leading to the piston Another object is to construct an entirely 1926. Serial 170. 126,170.

bg' a passage whose opening into the cylinder c am er is controlled by the piston acting as a piston valve. One or more exhaust openings are properly disposed in the c linder while'the space between the piston an .tool is 50 adequately vented by passages leading there v from to the exhaust manifold. Not only is this construction extremely simple, but it has also has the merit of locating the control .valve in the space within the-cylinder between the pis- 55 ton and tool and makes ossible the positive .actuation of the valve in oth directions, and

taken along line 4 4 of Figure 2;

taken along Fig. 5 is a sectional detail line 5 5 of Figure 2; v

Fig. 6 is a section on line 6 6 of Figure 2; 75

Fig. 7 is a section on line 7 7 of Figure 2;

Fig. 8 is a side elevation partly in section taken on line 8 8 of Fi re 7,

Fig. 9 is a section on` ine 9 9 of Figure 7 showing a'slightly modified form of valve 30' structure.

The hammer enerally is constructed of iron or other sultable material with a cyl-v inder housing 1 being internally cored to forma working cylinder 1 having two Sec- 85 tions of di'erent internal diameters, an intermediate annular shoulder 2 bein formed by the increase of the diameter ofg the cylinder beyond this shoulder. A correspondi ing piston 3 having turned portions to t '90 the cylinder sections is reciprocally dislength of the housing, except at the front end where the housing has a tool carrying member secured thereto by screws or any such means. This member will be described in detail later. v `The base portion 6 depending from housing 1 has a. narrow rib portion 21 and then flares out into a flat web portion 29 by which the device may be secured to any support by means of bolts or the like. The rear end of the cylinder is closed by means of a metal disk 8 held a ainst an internal shoulder inthe c linder y means of a' cap 9 threaded into t e end of the cylinder,l and having a compression screw 10 screw-threaded through the center of cap 9 anagcontacting with disk 8 (as illustrate in Fig. 1) which acts as a lock nutsecurely locking the cap 9.

Formed in the base portion 6 below the cylinder are a plurality of longitudinally extendingr ducts or chambers for the admission rand delivery of air and for exhausting they `various chambers, these ducts being closed at theirextremities by flush plugs wherever they are not connected to supply or discharge lines. On one side below the cylinder there is an exhaust duct 11, open at its rear end to the atmosphere or to an exhaust line, extending substantially the full length of section 6 but having near its forward end a bale or partition wall 14 which forms an independent chamber 15 for purposes to be described hereafter. The c linder has two "ports 12, 13 near its ends cylinder from duct 11 is `a duct or means of which'duct 11 communicates wit the cylinder to exhaust the two chambers in the ends of said cylinder, these ports being spaced suiciently in from` the ends of the Aciyl'linder to provide cushioning chambers t erein.

Cored in the base 6 transversely across the assage 16`which constitutes the intake cham r and is connected at its rear end to the high 20 (Fig. 7) which is continuous through the entire length `,of the center rib portion 21 of base 6. This passageway 20 communicates with the cylinder at a proximately its longitudinal center throug a port 22 (Fio. 6) fromjwhich port air may pass `througi either port or 26 into by-passes 23 and 24 according to the position of piston 3. The piston, due to its decreased ortion 4, acts as a piston valve and closes eit er port 25 or 26 so that air may only be1 admitted to compression chambers in the cylinder to the rear of the piston throu h port 27 or to the front of the piston throug ort 28. The by-passes 23, 24 as Well as the c amber 20 are extended throu h the entire length of the base in order to ena le the passages to be cleaned if occasion arises and ma be plugged at the extreme ends with flush p ugs.

In any horizontal cylinder and piston there is usually a tendency for the piston to come to a state of equilibrium at the so-called dead-center osition and to overcome this objectionable gature, which prevents eas starting of the iston, the present c linder 1s constructed wit one portion of a, arger di-k ameter than the other as clearly shown in Figs. 1, 2 and 3. This results in a larger area upon one side of the piston y causing the piston to be moved toward one end of the cylinder... As an additional aid in this respect the two ports 25 and 26 are formed with leaks 32 and 33 made, for example, by a milling tool.

A small pin hole 23a is drilled connecting the extreme end of the cylinder with the bypass 23 to create a leak to avoid sticking of the piston in its extreme rear position.

The front chamber 34 of cylinder 1 surrounding the forward portion 5 of the piston,

the hammer end of the piston, including the ( ports 17 and 19, and housin the valve 18 may be termed a valve cham r and is also slightly enlarged at one section, namely, the forward end to bias the valve to maintain it normally in its forward position.l Within the valve chamber and surrounding the forward end of the piston is a hollow cylindrical slide valve 18. The valve is desi ed with an upstanding annular channel o suicient size to embrace the two ports 17, 19 to establish communication between them and with a flat section of suicient size to prohibit the passage of air between these two ports by covering one port and has suicient clearance around the forward end of the-piston to allow leakage of air forward and out at the tool. This leakage will prevent any foreign matter from entering and getting into the mechanism. The chamber 34 may be of the proper diameters to receive the valve as shown in Figs. 1, 3 and 8 or the bore may be enlarged to receive first a renewable sleeve 35 (Fig. 9) which will have ports coinciding with ports v17, 19 which sleeve will receive the valve 18.

Forward of the valve in chamber 34 is a thrust collar 36 of hardened steel, or some other material, which contacts with the valve at one end and with the tool 37 at the other tical portionfthereof to prevent any back Y tached pressure being accumulated forward of the collar.

Valve 18 being biased to its forward posi` tion by reason of the difference in diameter of the two sections of chamber 34, creating a greater pressure at one end of the valve, is constantly urged forward into Contact with the thrust collar and forces this element into engafrement with the tool` thereby forcing the tool forward. The inner rear end wall 38 of the chamber 34 serves to separate the cylinder proper from the chamber 34 and also to limit the rearward motion of the valve andassociated mechanism. .c

Secured to the extreme forward end of cylinder -1 by means of bolts or the like is a tool chuck or support internally bored so as to present the shank of theoperating tool, such as arock drill, r inalignment with the hammer. The chuck is also bored to receive a transverse pin 41 which protrudes slightly beyond ,the inner bore of the chuck to engage an annular recess 42 in the end of the tool to limit the longitudinal movement of the tool and to revent the toolfrom becoming deiiom the chuck. The pin is removably retained within the small bore' by a retaining spring clip 43 surrounding the chuck and seat-mg in an annular roove -cut in the outer peri hery of the chuc If 'it is esired to make the system a closed one so that the hammer may be pperated under any atmospheric conditions or even when submerged in water a stuffing box 37 may be constructed around the tool holding packing 37 In Athe im lement illustrated the box and packin is sliown as being placed on the outer end o? the chuck to prevent any foreign matter vfrom entering into the valve mechanism through the clearance around the tool and in addition to this a small hole is made l establishing communication with the chamber 34 and the exhaust chamber gin"A order to relieve any back pressure that may build up within the chamber 34.

The operation of the hammer is as follows Air at' high pressureis admitted to duct 16 through a eonnection'at its rearl end and is passed forward to port 17.` Assuming the tool to be in its most -rearward position as shown in Fig. 1 it will be seen that thrust collar 36 and valve 1R are also in their most rearward position therebyV permitting the air to be passed through ports 17 and 19 and into Thrust collar 36 has a series of holes 36 drilled through the forward verblow chamber 15 from whence it is passedinto chamber 20` and into the cylinder through ports" 22.` With the piston shown inA Fig. 1 the air'still at line pressure is by-passed through port 26, by-pass 24 and port 28`into the cylinder compressionv chamin the `position ber in front ofpiston 3. The air'then drives the 'piston rearwardly uncovering exhaust port 13 from which the au' is vexhausted from the forward end of the cylinder into the exhaust chamber 11. As the piston is moved rearwardly it closes port 26 and establishes communication between port 22 andbyfpass 23 through port 25 and thereby admits the air at line pressure through port 27 to the cylinder at the rearward end of `piston 3 thusy lmparting a reciprocatory motion to the pistoncausing it to strike the end of the tool at each forward stroke and impart a working to it. The port 12 connects the rear portion ofthe cylinderto the exhaust chamber 11 to exhaust the cylinder on the return stroke of thepiston.

The above operations were described upon the assumption that the tool was in its most rearward position.` 'However'under normal inoperativeV conditions valvel 18. and asso ciated parts are forced into their most forward position due to the difference in diameters ofthe two sections of the valve chamber 34 which creates a larger surface u on oneside of the valve thereby forcing it orward and with the valve in its forward position port 17 lis closed by the valve thereby preventing air at line pressure from entering port 19, and consequently the piston remains A idle and inoperative.

If the tool is in engagement with hard material, it will generally not at first be driven out materially by the stroke of the hammer and the-valve 18 will therefore remain open because of the engagement of the collar 36 with the outer end of the valve and the above described operation will be rapidly repeated until the rock or other material against which the hammer impinges is broken of. Vhen this occurs thehammer is driven out to the positionl shown in Figure 3 andthe valve Awill follow vit by reason of the differential, pressure upon it and thereby shut off the air by closing port 17 and stop the hammer.

It will be noted that the force of the blow delivered to the tool depends upon thefnature of the material which isbeing worked. If the material is comparatively soft the` hammer drives the tool rout relatively farther than is the case' when working on hard material and since'the valve is partially closed by such actuation of the parts, the next and succeeding blows will be lighter in character untilethe valve is driven 'out sufficiently far to completely shut off the air; while if the material is hard so that it is substantially unyielding the blows continue rapid and of full violences-until the material' breaks` off and` Y closed position carryin permits the tool to move out and thus close the valve. In other words the hammer works onl so-long as the tool is against the work an is forced inwardly enough to open the valve and the blows are in proportion to the work required to be done. When there is no work in front of the tooll or when, in the case of a portable implement, the device is removed fromY the Work the parts automatically assume the inactive position shown in Figure 3, the outward movement of the valve to the tool with it if necessary. The operat1on of the device is again started merely by applying the tool to the work. The importance of this will be appreciated in connection with atunneling machine Where a plurality of tools are employed upon a revolving head, by reason of which characteristic each tool does only the work which it is called upon to doin the movement of the head and ceases to function as soon as it is free from engagement with material to operate upon.

It is obvious that various `modifications may be made in the construction shown in communicating therew1th, said valve chamber having sections of different diameters, air ducts having passages leading from a source of fluid under pressure to a port in the valve chamber and from a port in the valve chamberto the cylinder, a valve slidably mounted in the valve chamber having sections corresponding in diameter to the sections of the valve chamber and a reduced central portion uniting the sections, the reduced portion of the valve being adapted to overlie the port in the valve chamber communicating with the passage leading from the source of fluid 'under pressure to the valve chamber and theport in the valve chamber communicating with the passage leading from the valve chamber tothe cylinder, and a tool extending into the lvalve chamber .and adapted when a force is exerted thereon to move the valve against the unbalanced force acting on the sections thereof. f

2. A fluid pressure operated implement comprising a cylinder, a piston operably mounted in the cylinder, a valve housing in front of the cylinder having a valve chamber coaxial with the cylinder and air ports communicating therewith, said valve chamber having sections of different diameters, air ducts having passages leading from a source f 'of fluid under pressure to a port in the valve chamber and from a port in the valve chamber to the cylinder, a valve slidably mounted in the valve chamber having sections corresponding in diameter to the sections of the valve chamber and a reduced central portion uniting the sections, the reduced central portion of said valve being equal to the distance between the outer edges of the port Ain the valve chamber communicating with the passage leading'from the source of fluid under pressure and the port in the valve chamber communicating with the passage leadin from the valve chamber to the cylinder, an a tool extending into the valve chamber and adapted when a force is exerted thereon to movethe valve against the unbalanced force `acting on the sections thereof.

3. A fluid pressure operated implement comprising a cylinder, a valve housing in front of the cylinder having a valve chamber coaxial with the cylinder and air ports communicating therewith, said chamber having sections of different diameters, a piston operably mounted in the cylinder and having a reduced end portion extending into the valve chamber in front of the cylinder," air ducts having passages leading from a source of fluid pressure to a port in the valve chamber and from another port in the valve chamber to the cylinder, a valve slidably mounted on the reduced end of the piston inthe -valve chamber having sections corresponding in diameter to the' sections of the valve chamber and a reduced'central portion uniting the sections, the reduced -ce'ntral portion-being adapted to overliethe port in the valve chamber communicating with thepassage leadin from the source of fluid under pressure an the portin the valve chamber 'communicating with the passage leading to the cylinder, and means to hold a tool free lto lreciprocate in front of the reduced end of the piston, the

tool having a shoulder adapted to abut against the end of said valve and move the l valve with the tool against the unbalanced force acting on the sections thereof.

4. A fluid pressure operated implement comprising a cylinder, a piston reciprocally disposed .therein and forming chambers in the front and the rear of the piston, the piston having a reduced central portion forming with the .Y cylinderwalls an intermediate chamber, air ducts leading from said intermediate chamber to the chambers formed in the front and the rear of the piston, a valve housing lin front of the cylinder having a valve chamber coaxial with the cylinder and air ports communicating therewith. said valve chamber having sections of different diameter, air ducts having passages leading from a source of fluid under vpressure to a port in the valve chamber and from a port in the valve chamberto the intermediate chamber formed in'thecylinder, a valve slidably mounted in the valve chamberfhaving sections corresponding in diameter to the sections of the valve chamber anda reduced central portion uniting the sections, the reduced portion of the valve being adapted to 5 overlie the port in the valve chamber communicating. with the passage leading rom the source of Huid under pressure to the valve chamber and the port in the valve chamber communicating with the passage leading 10 rom the valve chamber to the cylinder, and a tool extending into the valve chamber and adapted when a force is exerted thereonto move the valve against the unbalanced force acting on the sections thereof.

35 Y In witness whereof, I hereunto subscribe m signature. e

y OLIVER O. APP.

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