US3189104A

US3189104A - Percussion tools

Info

Publication number: US3189104A
Application number: US54864A
Authority: US
Inventors: Douglas W Jamer; Richard A Kirkham
Original assignee: Atlas Copco AB
Current assignee: Atlas Copco AB
Priority date: 1960-09-09
Filing date: 1960-09-09
Publication date: 1965-06-15
Anticipated expiration: 1982-06-15
Also published as: GB987104A; BE607933A

Description

June 15, 1965 D. w. JAMER ETAL 3,189,104

PERCUSSION TOOLS Filed Sept. 9, 1960 4 Sheets-Sheet l June 15, 1965 PERCUSSION TOOLS 4 Sheets-Sheet 2 \NVENTJOR lBY ATTORNY June l5, 1965 D. w. JAMER ETAL PERCUSSION TOOLS 4 Sheets-Sheet 3 Filed Sept. 9, 1960 June 15, 1965 D. w. JAMER ETAL PERCUSSION TOOLS 4 Sheets-Shea?I 4 Filed Sept. 9, 1960 United States Patent O 3,189,104 PERCUSSION TQOLS Douglas W. lamer, Upper Saddle River, and Richard A. Kirlrlram, Ringwood, NJ., assignors to Atlas Copco Aktiebolag, Nacka, Sweden, a corporation of Sweden Filed Sept. 9, 196i), Ser. No. 54,864 9 Claims. (Cl. 173-154) The present invention relates to percussion tools and more particularly to percussion toolsof the self-contained manually portable and operable type powered by an internal combustion engine. Still more particularly, the invention relates to tools of the above character in which the percussion blows transmitted to the tool bit are effected by a free hammer piston forming a part of the engine component of the tool, the return stroke of the piston being effected by the pressure of elastic iiuid generated by operation of the engine. In one general type of a tool of this kind elastic fluid utilized to effect the return of the free piston is provided by a portion of the combustion gases generated by the engine and bled under pressure from the combustion chamber of the engine for the purpose. In another general type of this kind of tool an air compressor is provided, which in a preferred embodiment of engine is formed in part by a compressor portion of a power piston having a power portion in addition to the air compressor portion.

Power tools of the kind under discussion are naturally considerably heavier than pneumatic hand tools of equally or greater power but are advantageously used in many situations where pneumatic tools, with their requirement for a supply of compressed a-ir from an outside source, art at a distinct disadvantage, since such outside source in the great majority of instances must be in the form of a portable engine or motor driven compressor, which is not only cumbersome and bulky but also involves a considerable capital investment. However, because of their greater weight as comparedwith pneumatic hand tools, many operators object to the use of the self-contained engine powered tools, particularly for certain uses requiring the manually lifting of the tool by the operator, as for example in pavement breaking or the drilling of test holes through street paving, such as asphalt, when searching for underground leaks from gas mains and the like. In such uses the operator when withdrawing the tool from a test hole or the like, must not only lift the weight of the tool but also overcome, by

' lifting the resistance to withdrawal of the drill steel through thick pavement of asphalt or the like, which may be considerable and add up to back-breaking labor. Also, self-contained units of the kind under discussion may desirably be used for purposes in which power feed of the tool bit is required if exhaustive manual effort on the part of the operator is to be avoided.

It is therefore the general object of the present invention to provide an improved percussion tool apparatus of the self-contained combustion engine powered type in which fluid pressure generated as the result of operation of the engine is utilized to perform functions in addition to any functions relating to the ope-ration of the engine per se, such additional functions being effective to lighten the load of manual labor imposed on the operator. In one of its aspects this general object is effected in accordance with the principles of the invention by the provision 3,189,104 Patented .lune l5, 19$5 of a mobile carrier for the tool, which carrier is adapted to support the weight of the tool and to move the tool relative to a iixed support or abutment through the actuation of fluid pressureactuated means activated by pressure iiuid generated as a result of the operation of the engine of theftool. In another of its aspects the invention contemplates the provision of a fluid pressure actuated feed leg connected with the tool for effecting power feed or retraction of the tool through actuation of the feed leg by pressure fluid generated by operation of the tool engine.

In both of the phases of the invention above noted it is a further object of the invention to make the fluid pressure actuated components such as the carrier or the feed leg readilyA attached` to or detachable from the percussion tool and a still further object is to so construct such components that the necessary control mechanismv therefor is carried by the detachable components, so that when they are detached by the weight of the tool, which may be used independently of such components, will be a minimum. A still further object of the invention is to provide a tool of -the kind described, to which different auxiliary components such as a carrier orV a feed leg may readily be interchangeably attached and be detached in accordance with the immediate use to' which the tool is to he put. Other and moreV detailed objectsof the invention and the manner in which they are attained,

' will become evident as the ensuing portion of this speciication, descriptive of, by way of example V but not limited to, suitable embodiments for carrying the invention into effect, proceeds.

In the accompanyingdrawings, forming a part of this specification: t

FIG. l is a perspective side elevation of one embodiment `of apparatus incorporating the invention;

FIG. ,2 is an elevation, partly in section and on enlarged scale, of the apparatus shown in FIG. l;V

FIG. 3 is a plan view of the portion of the apparatus shown Iin FIGS. 1 and 2 below the section line 3,-3 of FIG. 2; p

FIG. 4 is a view similar to FIG. `2 and on larger scale, of a portion of the apparatus shown in FIGS. 1 and 2 and with the View partly in elevation and partly in section through the axis of the engine cylinder;

FIG. 5 `is a fragmentary sectional view on still larger scale of a part of the apparatus, taken on the line 5 5 lof FIG. 4;

FIG. 6 is a fragmentary longitudinal section on enlarged scale'of one Vof the supporting units of the carrie shown in FIGS. 1 and 2; i Y

. FIG. 7 is a section on enlarged scale taken on the line 7-7 of FIG. 2; i

FIG. V8 is a similar section taken on the line 8 8 of FIG. 2;

FIG.V 9 is a side elevation partly in section of another example of apparatus embodying the invention;

FIG. 10 is a fragmentary section on enlarged scale taken on the line 10-10 of FIG. 9; and

FIG. 11 is a fragmentary view similar to the lower portion of FIG. 4, illustrating another form of engine component for apparatus embodying the invention.

Referring now to the drawings, the apparatus illustrated in FIG. 1 and related figures comprises a combustion engine driven percussion tool indicated generally at 3 10. In its major respects the tool is of known construction and advantageously may be of the kind disclosed in U.S. Patent No. 2,764,138, granted September 25, 1956, to G. L. B. Wahlsten et al.

As seen more particularly in FIGS. 1 and 4, the tool comprises an internal combustion engine having a power cylinder 12 of the air-cooled nned type in which there is operatively mounted a power piston 14 attached by means of a connecting rod 16 to the crank shaft (not shown) of the engine, the latter being located in the crank case 18 of the engine, to which the handles 20, to be grasped by the operator of the tool, are fixed and which also carries the fuel tank 22. As seen in FIG. 1 the crank case also carries a suitable starter the housing of which is indicated at 24 through the medium of which the engine may be started by the usual rope starter the handle of which is indicated at 26.

In addition to the power piston 14 there is also mounted in the cylinder 12 the free hammer piston 28 carrying at its lower end a flange 30 of larger diameter slidably mounted in a chamber 32 formed in an axial extension 12a of the cylinder 12, and further carrying a co-axially extending hammer portion 28a of smaller diameter, adapted to strike a tool such as a drill steel indicated at 34, the latter being carried by a casing extension 36 secured to the lower end of the cylinder 12, which extension also carries suitable means 38 for rotating the drill, the latter means being of known construction forming no part of the present invention and therefore not being described herein in detail.

The cylinder 12 is connected to crank case 18 through the medium of a casing part 40 having a bore of larger diameter than that of the bore of cylinder 12. The power piston 14 projects into the casing 40 and at the end of the piston opposite the combustion chamber is provided with an external flange 14a engaging the Wall of the bore of the casing portion 40, so that the chamber 42 is formed around the portion of the piston adjacent to the ange which may be for convenience referred to as a compressor portion of the piston as distinguished from the power portion of the piston operating in the cylinder 12. The chamber 42 forms the working chamber of an air compressor, atmospheric air being drawn into the chamber by way of the inlet port 44 and the springloaded inlet valve 46 and the compressed air being discharged from the chamber by way of the exhaust port 48 and the spring-loaded exhaust valve 50. Compressed air from the compressor is delivered by way of conduit 52 and

transfer ports

54 and 56 located, respectively, above and below the flange 30 on the hammer piston 28 to the air chamber 32, to effect the return stroke of the hammer piston, which is driven downwardly to impact the drill steel by the power stroke of the engine. The details of the manner in which this action is effected by the structure herein disclosed are all well known and fully disclosed in the aforementioned U.S. Patent No. 2,764,138 to which reference may be had for detailed description of the action of the engine, which per se forms no part of the present invention.

As illustrated more in detail in FIG. 5, and as also disclosed in the aforesaid Patent No. 2,764,138, air which is delivered to chamber 32 as pulsations from the compressor is converted to a pneumatic pressure of relatively constant value maintained at predetermined desired pressure by virtue of a metering orifice S discharging a metered quantity of air to a zone of lower pressure, which air is advantageously used as shown in FIG. 5 for blowing chips and the like from the working end of the bit 34 to which the air passes by Way of the orifice 58 to the auxiliary chamber 60 and the bore 34a in the drill steel or bit.

In the particular embodiment illustrating the metering orifice 58 is shown as being formed in a removable plug, which readily permits orifices of different ow area to be employed in adjusting the action of the engine.

Any suitable form of flow adjustment however may be employed as, for example, the adjustable needle valve shown in the aforementioned patent. In the present instance, in accordance with one phase of the present invention, the plug 62 is advantageously provided with a second passage 64 leading to the exterior of the engine and adapted to deliver air without material restriction from chamber 32 to a conduit 66 for use hereinafter to be described, conduit 66 advantageously being connected with plug 62 by means of a readily disconnectible union 63 so that flow of air through the passage 64 may readily be blocked by a suitable plug replacing the conduit connection 66.

In accordance with one of the aforementioned aspects of the invention, there is provided, for use with a tool of the kind just briefly described by Way of example, a mobile carrier indicated generally at 70, comprising a base 72 which advantageously is in 'the form of a triangularly shaped base plate at the corners of which there are mounted

wheels

74 and 76, the latter being swivel or caster mounted to facilitate the manoeuvreability of the carrier. On the base plate 72 there are fixed, as by Welding, two spaced cylinder elements 78 of supporting units indicated generally at 8i). Cylinder elements 78 receive in sliding engagement suitably packed piston elements 82, the upper ends of which are connected to a tool holder indicated generally at 84. In the embodiment illustrated the holder 84 is in the form of a plate having horizontally extending arms 84a Welded at their ends to the upper ends of the piston rods, and an upper vertical extension 84h provided with suitable apertures adapted to receive threaded screws or studs to be screwed into suitable threaded sockets in the crank case structure of the engine for attaching or detaching the tool from the holder. The holder also advantageously includes a n downwardly extending extension or arm 84C bent at its lower end as shown at 84d to form an auxiliary or secondary support engaging the lower end of the casing extension 36 of the engine of the tool. Tool is also advantageously provided with an apertured lug S3 for a purpose hereinafter to be described. As seen in FIG. 2, when the tool is fixed on the carrier, lug S is not in use and projects through the opening 84e in arm 84C.

The conduit 66 connects the passage 64 and the plug 62 to the housing of a rotary three-Way plug type valve 90, seen in FIGS. 2, 7 and 8. This valve comprises a housing 92 having a cylindrical bore in which is rotatably mounted a plug .type valve member 94 adapted to be manually turned by means of a handle 96, the housing further being provided with a longitudinally extending internal manifold passage 98 with which the conduit 66 connects. As shown in FIG. 7 the valve member 94 is provided with an elbow passage 109 adapted in one posiion of rotation of the valve member to provide communication between the inlet manifold passage 98 and an outlet port 102 spaced 90 from the manifold 98 and communicating with a conduit 104. In the same transverse section of the valve housing as that at which the port 102 is provided, the housing is provided with a vent port 106,I the latter port being located diametrically opposite the passage 98.

As seen in FIG. 8 the valve member is provided at another transverse section with a second elbow passage 108 providing communication in the same position of the valve member as that shown in FIG. 7, between a vent port 110 located in the housing diametrically opposite the inlet passage 9S, and a port 112 located 90 away from passage 98 and diametrically opposite port 102 in the plane of FIG. 7, port 112 being in communication with a conduit 114.

As shown more clearly from FIGS. 2, 6, 7 and 8, conduit 194 leading from port 102 is provided with branches 10411 and 1Mb which are fixed to the respective piston elements 82 and communicate with longtudinally extending passage 1116 located in the rod portions of the piston elements and terminating at ports 1118 situated in chambers 121i located above the pistons.

Conduit 114, leading from port 112, is similarly provided with branches 114a and 114b connected to the respective piston elements and communicating with passages 122 in the rod portions cf the piston elements :and terminating in transversely extending passages I124 providing outlets communicating with the chambers 126 located below the piston elements.

As will be evident from the figures, valve 90 operates to connect the pressure chambers in both cylinders in parallel with the source of pressure liuid derived from conduit 66, and also no vent the chambers -to atmosphere.

Withthe valve in .the position shown in FIGS 7 and 8,

air under pressure is delivered by the supply conduit 66, conduit 104 and its branches, and passages 116 to the chambers 12) above the piston elements, to thereby cause the pistons to move downwardly in their respective cylinders and lower the holder and its attached tool relative to the base of the carrier. This downward movement is permitted by the fact that in this position of the valve the chambers 126 below the piston elements are vented to atmosphere by the

passages

124 and 122, the conduit branches and conduit 114 and vent port 11u. If the valve plug 94 is turned 90 in counterclockwise direction from the position shown in FIGS. 7 and 8, pressure fluid will be admitted from the supply conduit 66 via the manifold passage 9S, conduit 114 and its branches to

passages

122 and 124 to chambers 126, to raise the pistons in the cylinders, this action being permitted by venting the air from chambers 120 via passages 116 and conduit 104 and its branches to port 106.

In positions of rotation of the valve plug 94 intermediate the two positions just described, communication between the cylinder chambers and both the pressure fluid supply and the vents is cut off so that the supporting element of the carrier may be maintained in any desired fixed position.

As will be seen from the foregoing, the above described mechanism provides for selective raising or lowering of the supporting component of the carrier, and with it the tool, relative to the base of the carrier, by simple manipulation on the part of the operator of the three-way control valve 90.

As will be evident from FIGS. l and 2, the tool when mounted is located with th-e `axis of the working cylinder and of the tool bit, which may for convenience be referred to as the axis of impact, located within the confines of the triangular area defined by the location of the three carrier wheels, thus giving the maximum of stability to the apparatus, while at the same time permitting the tool to be tilted away from a vertical impact axis by pivoting the carrier about the axis of the two major wheels 74. In the embodiment shown the base is in the form of a triangular at plate having an opening 12S located in alignment with the axis of the tool bit-to permit passage of the tool through the base of the carrier. Obviously, other specific forms and shapes of bases may be employed for mounting the wheels and providing the required support for the units Si).

The operation of the above described apparatus is largely obvious. Assuming for example that the apparatus is to be used for the purpose of putting down Itest holes through an asphalt pavement, for the purpose of detecting the source of leakage of gas from underground mains or the like, the mounted tool may readily be wheeled to the area to be explored, with the tool bit lifted above the level of the Working surface, and, with the engine in openation and making :available -a supply of compressed lair at the conduit 66, the tool may be power fed tothe working face by appropriate manipulation of the control valve to admit pressure fluid to the cylinder elements of the carrier above the pist-on elements therein .in order to drive the flatter downwardly to lprovide the power feed. It will be evident that the value of the downward force which can be exerted on the -tool bit by the apparatus along is limited to the total weight of the tool and the carrier, but if desired the normal weight of the carrier, since it does not have to be lifted or carried by the operator, may be increased by the use of removable lead ballast or the like. The feeding torce applied to the cylinder may of course be augmented by downward force manually applied by the operator of the tool. Obviously, if desired, power feed of the tool downwardly may be omitted entirely if force manually exerted by the operator is sufficient and the labor involved not too onerous.

Assume that a test hole has been drilled by the tool bit through asphalt pavement. In such instances it has been found that as a general rule withdrawal of the tool through the asphalt often requires the exertion of a considerable withdrawing force, and in the present instance this required force is provided by the carrier, by the simple manipulation of the control valve to admit compressed air generated by operation ofthe engine to the chambers 126 below the pistons, thus utilizing the reverse of the power feed to withdraw the tool bit from the test hole and relieve the operator of both the manual labor of lifting the tool and the additional labor of providing the force necessary to pull the bit from the bore it has created.

As further will be evident, the apparatus provided by the present invention does not in any way detract from the general utility of the tool itself, no appreciable weight being required to be added to the tool to enable it to be used in conjunction with the carrier, since the latter carries all of the auxiliary equipment, such as the conduit system and the control valve necessary to make the apparatus effective. If the tool is to be used alone, the only change in its construction required is either replacement of the plug 62 having the metering orifice 56 with a similar plug in which the passage 64 is omitted, or by using a simple closure plug to close the opening resulting from breaking the union connection 68 in order to detach the tool from the carrier.

The same principles as above described may also readily be employed in order to provide a power feed for a tool of the character described, for use in other applications where work is to be performed against a vertical or comparatively slightly inclined working face and where the use of a carrier such as that just described would be impractical. A

In such cases the tool 10 may be advantageously provided, as shown in FIG. 9, with a power feed leg indicated generally at 130, comprising a cylinder element 132 and a piston element 134. In this embodiment the cylinder element 132 is provided at one end with an axially extending flange or projection 136 adapted to be bolted to a cooperating lug, such as lug 88 on the housing 138 of the tool 10.

Bolt 142 provides a readily detachably hinged connection between the tool and the feed leg, and the force required to move the feed leg about its pivot may be adjusted byl varying fthe pressure exerted on the spring washer 146. Obviously other forms of joint may be employed.

The construction of the feed leg per se is of known form, the piston rod 134:1 projecting through a suitable gland in the lower end of the cylinder 132 and having attached lthereto the usual spiked foot 14S.

In the embodiment shown the construction of the tool and its engine component is the same as that previously described and in the present instance compressed air is delivered via a flexible conduit from the chamber 32 in the casing extension 36, to V the three-way valve 919 mounted on the feed leg cylinder and having

conduits

152 and 154 connecting respectively with passages 156 and -158 in the feed cylinder for supplying pressure fluid to adriano/iE tion with lthe embodiment in which the tool is used in conjunction with ythe wheeled carrier. Power feed, and if required, power retraction of the tool bit is effected by manipulation of the valve 90 to either project the piston rod 134:1 from cylinder 132 or retract it into the cylinder.

The provision of the lug 88 on the casing of the tool together with the provision of suitable threaded bores for receiving the fastening studs 86 for attaching the holder element of the carrier shown in FIG. 1, provides ready means for selectively and detachably combining the tool with different components of auxiliary equipment, without involving any increase of size or appreciable increase in weight of the tool. This tool may readily be used either alone as a self-contained manually operable unit, or as a power fed or retracted unit supported independently of the operator by a mobile carrier, or provided with a separate power feed leg.

In the embodiment shown in FIG. 9 the feed leg is illustrated as being supplied with pressure fluid for its operation by way of a flexible conduit 150. However, other known means of conducting pressure fluid from the source of supply to the feed leg through the hinged connection may be employed.

While in the embodiments hereinbefore described by way of example the principles of the invention have been illustrated as being applied to a form of tool in which pressure fluid for actuating the hammer piston on its return stroke is compressed air generated by a separate compressor incorporated in the engine component of the apparatus, the invention is not to be considered as limited -to apparatus in which the pressure fluid is compressed air separately generated by the engine.

In the art, it is well known to provide combustion engine powered percussion tools of the free hammer piston type in which the return stroke of the hammer piston is effected by the pressure of partially expanded combustion gases bled from the combustion chamber of the engine and utilized for the purpose. The present invention is equally well adapted to this known type of tool as well as to the type of tool herein disclosed in which the pressure fluid for returning the hammer piston is compressed air, and in FIG. 11 there is more or less diagrammatically illustrated in fragmentary fashion, a portion of the lower or hammer piston end of an engine cylinder 164 in which there is located the free hammer piston 166 returned upwardly on its return stroke in well known fashion by means (not shown) embodying passages in the casing portion 16S of the tool which also carries the bit 170. As illustrated in this figure, combustion gases under pressure may be bled from the cylinder through a lpor-t 172 located to be uncovered by piston 166 before it reaches the end of its power stroke, to admit combustion gases under pressure to the feed conduit 174, in which there i-s preferably located an expansion chamber 176 -to reduce or damp different pressure pulsations, in order that pressure fluid at relatively constant pressure may be delivered through conduit 17S for the purpose of actuating either a carrier or a feed leg, such as those hereinbefore described, in lieu of the compressed air employed in the apparatus herein disclosed in detail.

From the foregoing it will be evident that the principles of the invention may be embodied in different specific forms of apparatus and it further will be evident that certain features and advantages of the invention hereinbefore described, may, if desired, be used to the exclusion of others.

It is therefore to be understood that the invention is intended to embrace all modifications and variations of apparatus falling within the scope of the appended claims.

What we claim is:

1. In apparatus of the character described for powering a percussion tool and for supplying pressure fluid for driving -auxiliary feeding means and the like to be used with said tool and having a combustion engine with a combustion cylinder` and an auxiliary cylinder coaxial therewith, the combination which comprises a motor piston reciprocable in said combustion cylinder, a radial flange on said motor piston reciprocable therewith in said auxiliary cylinder for compressing fluid in said auxiliary cylinder, a hammer piston reciprocable in said combustion cylinder -and driven by combustion in said combustion cylinder imparting impact to said percussion tool, a receiving chamber adjacent said hammer piston for receiving compressed fluid from vsaid auxiliary cylinder and for supplying said fluid to said hammer piston for the return thereof -after each impact stroke, a conduit in flow communication with said auxiliary cylinder and said receiving chamber for carrying compressed fluid from said auxiliary cylinder to said receiving chamber, a connection disposed `in said receiving chamber with said connection having a passage disposed therein for supplying pressure fluid to said auxiliary means, and adjusting means in said connection for maintaining the said pressure fluid in said receiving chamber at a predetermined constant pressure.

2. Apparatus as recited in claim 1 in which said connection is a screw threaded plug screwed into said receiving chamber Iand removable therefrom for replacement therefor by a blocking plug when no auxiliary feeding and the like is to be used with said percussion tool.

3. In apparatus of the character described for powering a percussion tool and for supplying pressure fluid for driving auxiliary feeding means therefor and having a combustion engine with a combustion cylinder and an auxiliary cylinder coaxial therewith, and a pressure fluidoperated auxiliary feeding means -adjacent thereto, the combination which comprises a motor piston reciprocable in said combustion cylinder, means driven by said motor piston and reciprocable therewith in said auxiliary cylinder for compressing fluid in said auxiliary cylinder, a hammer piston reciprocable in said combustion cylinder and driven hy combustion in said combustion cylinder imparting impact to sai-d percussion tool, a receiving chamber adjacent said hammer piston for receiving compressed lluid from said auxiliary cylinder and for supplying said fluid to said hammer piston for the return thereof after each impact stroke and for supplying pressure fluid to said auxiliary feeding means, a pipe in flow communication with said auxiliary cylinder and said receiving chamber for carrying compressed fluid from said auxiliary cylinder to said receiving chamber, a connection disposed in said receiving chamber with said connection having a passage disposed therein for supplying pressure fluid to said auxiliary feeding means, adjusting means in said connection for maintaining the said pressure fluid in said receiving chamber at a predetermined constant pressure, and conduit means in flow communication with said connection and said auxiliary means for carrying said pressure fluid from said receiving chamber to said auxiliary feeding means.

4. In apparatus of the character described for powering a percussion tool and for supplying pressure fluid for driving the feeding mechanism of a wheeled carrier upon which said tool is held and fed, and having a combustion engine with a combustion cylinder and an auxiliary cylinder coaxial therewith, and a wheeled carrier for holding the said tool in a substantially vertical position over the surface to be worked, the combination which comprises a motor piston reciprocable in said combustion cylinder, means driven by said motor piston and reciprocable therewith in said auxiliary cylinder for compressing fluid in said auxiliary cylinder, a hammer piston reciprooable in said combustion cylinder and driven by combustion in saidl combustion cylinder imparting impact to said percussion tool, a receiving chamber adjacent said hammer piston for receiving compressed fluid from said auxiliary cylinder and for supplying said fluid to said hammer piston for 'the return thereof after each impact stroke and for supplying pressure fluid to said feeding mechanism, a pipe in flow communication with said auxiliary cylinder and said receiving chamber for carrying compressed fluid from said auxiliary cylinder to said receiving chamber,

a connection disposed in said receiving chamber with said connection having a passage disposed therein for supplying pressure uid to said feeding mechanism, adjusting means in said connection for maintaining the said pressure fluid in said receiving chamber at a predermined constant pressure, a tool holder disposed on said carrier' for holding said tool, laterally spaced apart extensible supporting means on said carrier having cylinder elements fixed -to the base thereof, piston and rod elements disposed in said cylinder elements with said rods connected to said holder, conduit means in flow communication with said connection and said extensible cylinder elements on said carrier, and control valve means in said conduit means for controlling the supply of pres sure fluid from said connection to said cylinder elements.

5. In apparatus of the character described for powering a percussion tool which can be used manually or upon a supporting and feeding means, and for supplying pressure fluid for driving the feeding mechanism of said supporting and feeding device upon which said tool can be held and having a combustion engine with a combustion cylinder and an auxiliary cylinder coaxial therewith, and a wheeled carrier upon which said supporting and feeding means is disposed, the combination which comprises a motor piston reciprocable in said combustion cylinder, a radial flange on said motor piston and reciprocable therewith in said auxiliary cylinder for compressing fluid in said auxiliary cylinder, a hammer piston reciprocable in said combustion cylinder and driven by combustion in said combustion cylinder imparting impact to said hammer piston for driving said percussion tool, a receiving chamber adjacent said hammer piston for receiving compressed fluid from said auxiliary cylinder and for supplying said compressed fluid to said hammer piston for the return thereof after each impact stroke and for supplying pressure fluid to said supporting and feeding means, a pipe in ow communication with said auxiliary cylinder and said receiving chamber for carrying compressed fluid from said auxiliary cylinder to said receiving chamber, a removable screw-threaded plug screwed into said receiving chamber and removable therefrom for replacement therefor by a blocking plug when the said auxiliary supporting and feeding means is not in use, adjusting means in said screwthreaded plug for maintaining the said pressure fluid in said receiving chamber at a predetermined constant pressure, a base disposed on said mobile carrier, a tool holder disposed on said mobile carrier and axially spaced from said base for detachably holding said percussion tool, expansible supporting means disposed on said carrier with one end thereof connected to said base and the other end thereof connected to said tool holder for moving said tool holder toward and away from said base, conduit means in flow communication with said plug and said expansible supporting means for supplying compressed fluid from said plug to said expansible supporting means for moving said tool holder with said percussion tool disposed thereon toward and away from said base, and valve means disposed on said tool holder in said conduit means for controlling the supply of pressure iluid from said connection to said expansible supporting means.

6. Apparatus as recited in claim in which said base is triangular in shape with wheels disposed at each of the points of said triangular shaped base, and with the percussion tool mounted on said holder with the axis of impact thereof located within the area of the triangle defined by said Wheels.

7. Apparatus as recited in claim 5 in which said expansible supporting means comprises two spaced apart piston andA cylinder units on said mobile carrier with one end thereof disposed on said base and with the other end connected to said holder, and said holder comprises a bridging element connecting said units.

8i. In apparatus of the character described for powering a percussion tool and for supplying pressure iuid for driv- 10 Y ing auxiliary feeding means and the like to be used with said tool and having a combustion engine with a combustion cylinder and an auxiliary cylinder coaxial therewith, and a pressure iiuid actuated extensible feed leg pivotally connected to said tool with cylinder and piston elements, one of which is connected to said tool and the other of which is providedwith a foot adapted to engage a fixed abutment spaced from the working face to be engaged by said tool, the combination which comprises a motor piston reciprocable in said combustion cylinder, a radial iiange on said motor piston and reciprocable therewith in said auxiliary cylinder for compressing fluid in said auxiliary cylinder, a hammer piston reciprocable in said combustion cylinder and driven by combustion in said combustion cylinder imparting impact to said hammer piston for driving said percussion tool, a receiving charnber adjacent said hammer piston for receiving compressed uid from said auxiliary cylinder and for supplying said fluid to said hammer piston for the return thereof after each impact stroke and for supplying pressure fluid to said feed leg, a pipe in ow communication with said auxiliary cylinder and said receiving chamber for carrying compressed fluid from said auxiliary cylinder to said receiving chamber, a connection disposed in said receiving chamber with said connection having a passage disposed therein for supplying pressure fluid to said feed leg, adjusting means in said connection for maintaining the said pressure liuid in said receiving chamber at a predetermined constant' pressure, conduit means in flow communication with said connection and said cylinder and piston elements in said feed leg for conveying pressure fluid from said receiving chamber to said feed leg, and valvemeans in said conduit for admitting pressure liuid to said cylinder in said feed leg for the extension thereof and for feeding said tool thereon toward a surface to be worked.

9. In apparatus of the character described for powering a percussion tool and for supplying pressure fluid for driving auxiliary feeding means and the like to be used with said tool and having a combustion engine with a combustion cylinder and an auxiliary cylinder coaxial therewith, and a iiuid pressure actuated extensible feed leg with a cylinder element pivotally connected to said tool and a piston element having a piston rod adapted to engage a surface spaced from the working surface of said tool, the combination which comprises a motor piston 4reciprocable in said combustion cylinder, a radial flange on said motor piston and reciprocable therewith in said auxiliary cylinder for compressing fluid in said auxiliary cylinder, a hammer piston reciprocable in said combustion cylinder and driven by combustion in said combustion cylinder imparting impact to said hammer piston for driving said percussion tool, a receiving chamber adjacent said hammer piston for receiving compressed fluid from said auxiliary cylinder and for supplying said uid to said hammer piston for the return thereof after each impact stroke and for supplying said fluid to said cylinder element in said feed leg, a pipe in flow communication with said auxiliary cylinder and said receiving chamber for carrying compressed fluid from said auxiliary cylinder to said receiving chamber, a connection disposed in said receiving chamber with said connection having a passage disposed therein for supplying pressure uid to said cylinder element in said feed leg, adjusting means in said connection for maintaining the said pressure iiuid in said receiving chamber at a predetermined constant pressure, a conduit in flow communication with said connection and said cylinder element for conveying said pressure fluid from said receiving chamber to saidcylinder element, and valve means disposed on said cylinder element in said conduit means for admitting pressure to said cylinder element to extend said feed leg in a direction imparting feeding movement to said tool.

(References on following page) Dobbs 173-154 10 Zeiser 175-201 Wahlsten et a1. 123-7 Read 173-159 Seawright 173-153 Larcen 175-129 BROUGHTON G. DURHAM, Primary Examiner.

CHARLES E. OCONNELL, BENJAMIN HERSH,

Examiners.

Claims

1. IN APPARATUS OF THE CHARACTER DESCRIBED FOR POWERING A PERCUSSION TOOL AND FOR SUPPLYING PRESSURE FLUID FOR DRIVING AUXILIARY FEEDING MEANS AND THE LIKE TO BE USED WITH SAID TOOL AND HAVING A COMBUSTION ENGINE WITH A COMBUSTION CYLINDER AND AN AUXILIARY CYLINDER COAXIAL THEREWITH, THE COMBINATION WHICH COMPRISES A MOTOR PISTON RECIPROCABLE IN SAID COMBUSTION CYLINDER, A RADIAL FLANGE ON SAID MOTOR PISTON RECIPROCABLE THEREWITH IN SAID AUXILIARY CYLINDER FOR COMPRESSING FLUID IN SAID AUXILIARY CYLINDER, A HAMMER PISTON RECIPROCABLE IN SAID COMBUSTION CYLINDER AND DRIVEN BY COMBUSTION IN SAID COMBUSTION CYLINDER IMPARTING IMPACT TO SAID PERCUSSION TOOL, A RECEIVING CHAMBER ADJACENT SAID HAMMER PISTON FOR RECEIVING COMPRESSED FLUID FROM SAID AUXILIARY CYLINDER AND FOR SUPPLYING SAID FLUID TO SAID HAMMER PISTON FOR THE RETURN THEREOF AFTER EACH IMPACT STROKE, A CONDUIT IN FLOW COMMUNICATION WITH SAID AUXILIARY CYLINDER AND SAID RECEIVING CHAMBER FOR CARRYING COMPRESSED FLUID FROM SAID AUXILIARY CYLINDER TO SAID RECEIVING CHAMBER, A CONNECTION DISPOSED IN SAID RECEIVING CHAMBER WITH SAID CONNECTION HAVING A PASSAGE DISPOSED THEREIN FOR SUPPLYING PRESSURE FLUID TO SAID AUXILIARY MEANS, AND ADJUSTING MEANS IN SAID CONNECTION FOR MAINTAINING THE SAID PRESSURE FLUID IN SAID RECEIVING CHAMBER AT A PREDETERMINED CONSTANT PRESSURE.