US2101608A - Internal combustion hammer - Google Patents

Description

Dec. 7, 193 7.

E. R. BoDDlNGHoUsE INTERNAL COMBUST ION HAMMER Filed Aug. 13, 1954 v3 Sheets-Sheet l EmnwIwRodcmg/wwe,

Dec. 7, 1937. E. R. BODDINGHOUSE V2,101,608

INTERNAL COMBUSTION HAMMER Filed Aug. l5, 1934 3 Sheets-Sheet 2 Dec. 7, 1937. E. R. BODDINGHOUSE 2,101,608'

INTERNAL COMBUS TION HAMMER Filed Aug. l5, 1934 3 Sheets-Sheet 3 *f |n www.

t .i [mgm nlll a nl: lllllll II Emmons R. Boddinghc c i I alertes netrunner. oo L r hlco. Iii., assigner to Gas 'llool Patents orpotion, Chicago, lill., a corporation of Delaware.

Application August i3,

9 Claims.

This invention relates to improvements in internal combustion hammers.

One of the objects oi the invention is to provide a portable internal combustion hammer so constructed that the conduction of heat from the combustion chamberto the associated parts oi the device is limited and controlled for minimizing the harmful effect of such heat upon the associated parts.

Another object of the invention is to provide a hammer having such a predetermined relationship between the relative weightsmf the parts, the spring load and the hardness of the parts as will ensure durability and most emcient operation. Another object of the invention is to provide improvements in the cooling in construction affordingmore rapid dissipation of heat and greater strength in the entire device.

Another object of the invention is to provide a construction assuring the device greater ruggedness and durability.

Other objects and advantages of the invention inherently possessed by it will become apparen upon a perusal of this specication. Y Y

in the drawings:

Fig. l is a vertical axial section through a device embodying the invention;

Fig. 2 is a plan view oi the device;

Fig. 3 is a detail view in cross section through the cylinder and piston in the plane indicated at 3--3 in Fig. l;

Fig. 4 is a side elevation of the device from viewpoint ninety degrees removed angularly from that of Fig. l, a portion of the fuel tank and carburetor being broken away in section;o

Fig. 5 is an enlarged fragmentary detail in section through a portion of the fuel tank'and carburetor; i

Fig. 6 is an enlarged fragmentary detail in section in adifferent plane from the section of Fig. 5 showing the carbureton'mixing valve;

Fig. '7 is a bottom plan view'ot the f uel tank and carburetor unit; y

Fig. 8 isa side elevation, partly in section, showing a modified form of my invention; and Fig.

9 is an enlarged view showing the abutting relation of the return and cushioning springs.

The cylinder t is provided with cooling ns t which preferably extend in vertical planes-radiatresi, semi no. '139.553 (on. ics-'1) against one of the ilat surfaces on the spark plug li will serve to prevent the spark plug from becoming unscrewed.

The castings employed in this device, with the exception of the cylinder casting, are preferably made of steel.

at the top or the unsA o there is provided an annular shoulder it upon which rests a handle ring ld to which the handles lll are bolted. One of these handles serves as a conduit to receive the cable l5 which carries the electrical connections to the spark plug ll and the timer hereinafter to be described.'

The connectionv between the handles and the handle ring i3 is preferably effected through a heavy gasket it which isulates the handles from the heat developed in the-cylinder casting. The

joint between the cylinder casting and the handleI ring, although not provided with any gasket, -isl 4in itself a means of heat insulation since -any joint odors a high reluctance path to -the con-v ductance ci heat.

^ .lit the lower end of the cylinder casting is-the sro-called lower unit ll which closes the lower end of the cylinder and provides a bearing guide for theanvil member lt, into the socketed end of whichfthe tool ld is received. The tool is guided .in a htting it applied to the lower unit ll. Packing rings it surrounding the anvil it serve to prevent escape of gases downwardly from the sub-piston compression chamber 2t.

lt is important to note the location of the joint between the lower unit ll and the cylinder casting. This joint is located relatively high on the haer and is packed with a gasket llla to minimize heat conduction from the cylinder to the iuel ta and carburetor unit, which is supported from the lower unit ll in a', manner hereinafter tovhe described.

Thehandlering,cylindercasting,lower unit and tool guide are held in assembled relationship by -means of long tension bolts il. Annular 4shoulders il, above which these bolts are reduced in diameter, in connection with nuts t ia lrmly seat the unit lll against the bottom of the cylinder. A dat surface tl on each bolt fitting into corresponding recesses in the unit lll prevent these bolts from turning. Surrounding .the lower ends oi the tension bolts are heavy dsprings 22 seated upon heads tit and 2t and against the tool l Just below the nuts tia the tension bolts are provided with reduced portions 2id having diameters approximately one-half that of the lower com ci the lts. By reason of the presence of these reduced portions it is found that when the cylinder casting expands, due to heat during operation of the hammer, these bolts will stretch, particularly in the reduced portions 2id, and will return to their original length when the casting becomes cool. Thus the unit I1 and ring I3 will always be held seated very firmly upon the cylinder casting.

When the tool or drill I9 is engaged with the work and the weight of the entire device rests upon it, the anvil I8 will be supported free from the bottom 25 of the recess in the tool guide. The tool guide itself will absorb the impact of the piston whenever the work does not absorb it through the tool I9. The resistance, offered by Ithe tool guide to the impact of the hammer under such conditions may be varied by substituting stronger or weaker springs 22.

'Ihe timer for producing the spark is housed in a sleeve 21 inserted into the cylinder casting and carries a reciprocable piston 28 onthe inner end'of which is mounted a cam follower roller 29. On the outer end of this piston is positioned a spring 3l seated against a shoulder on the plate 32 for holding the cam follower 29 against its associated cam. The upper end of the contact spring is insulated from the hammer by being clamped between two insulating washers, as shown. The lower end of contact 33 normally rests against a post 34 made of insulating material. A camsurface 35 is provided along the skirt of the piston 36.

When the timer piston 28 is moved outwardly by the cam 35 it strikes the spring 33 and grounds it on the frame ofthe hammer, whereupon the ignition spark is created.

" jected.

The upper end of the piston is provided with a plurality of horizontal passages 39 which communicate with a recess 4I at one side of the piston. At the lower end of the downstroke of ber 42. At that instant communication is established between the combustion chamber 43 and the sub-piston compression chamber 28. The described communication is completed through the horizontal passages 39 and a plurality of vertical passages 44 disposed as shown.

The return spring 45 and the cushioning spring 46 are preferably wound in the same direction and have square ends which abut each other slightly below the top of the reduced portion of the anvil I8 as shown in Fig. 9.

Mounted on top of the device and extending downwardly through the top of the upper casting is a plunger 41 having an enlarged head 48 and a small head 49 at its lower end .which extends into the top of the combustion chamber. A spring 5|. resting upon the top of the casting and against the head 48, as shown, normally maintains this plunger in raised position. The plunger is employed for thrusting the piston downwardly when it is desired to start theA piston in operation. By locating the spring 5I on top of the fins rather than upon the top of the combustion chamber it is thus separated from the of the piston. check valve 59 which is normally held seated by a cylinder sufficiently to be shielded from temperatures that might adversely affect its temper.

The fuel tank which supplies the fuel for the combustible mixture is carried upon the device, extending part of uthe distance around the side of the device. The tank, designated 52, is supported wholly upon the lower unit I1 of the apparatus, and by reason of its location low on the device and because of the gasket |13 opposing downward conduction of heat, the fuel tank is found to be sufficiently shielded from heat produced by operation of the hammer to avoid any harmful evaporation of the liquid fuel carried in the tank. The gasket I1a and the jeint in which it is disposed together serve as a very efficient combined heat insulator. The lower unit is provided with a boss 53 upon which is fitted an appropriately shaped part 54 of the fuel tank. Bolts 55 serve to firmly unite the tank to the boss 53. A U-bolt 56 connected with the fuel tank and embracingthe sides of the device, as shown, assists in securing the tank in position. Carried byand partially contained within the fuel tank is a carbureting device which includes a screened air inlet 51 opening into a passage 58 for admitting air under suction created in the sub-piston compression space during the upstroke The air is admitted through a spring 6I. Suction lifts the valve 59 and as the air flows past it a charge of liquid fuel is drawn through a strainer 62 positioned within the bottom of the fuel tank through a passage 63 past a needle valve 64, thence through the regulating nozzle 65 into the air stream. The combustible mixture then flows into the passage 66, thence into a vertically extending recess 61 in the unit I1 adjoining the return spring 45. This recess delivers the combustible mixture into the subpiston compression space wherein it is compressed on the downstroke of the piston and thereafter transferred through the transfer chamber 42 upwardly into the combustion space 43 at the time the piston reaches the lower limit f its travel. The recess 61 cut back into the cylindrical passage in the lower unit I1 prevents the convolutions of the springs from interfering with the travel of this gas. Q

It is ,particularly worthy of note that the valve 59 and its mounting and the needle valve 64, its mounting and the strainer intake. 62 are unitarily mounted in a block 68, which is removable and replaceable as a unit and which when secured to the bottom of the fuel tank constitutes a unit with the fuel tank whereby the composite unit may readily be removed from the device and replaced. A cover 69 (see Fig. 5) is employed to surround the lower end of the valve 59.

The vertically extending heat radiating fins 9 add considerable strength to the entire device Without unnecessarily increasing the weight thereof. Vertical channels between these vanes enable the heated air to rise and escape readily. The handle supporting ring being mounted at the top of these vanes and having apertures therethrough, as shown in Fig. 1, is itself maintained fairly cool. The plunger supporting spring I being supported above() the rest of the structure adornos am sides oi' the cylinder casting, is a further aid in saving the fuel tank from becoming too hot.

A cover Il for the filling opening for the fuel tank is provided, as shown.

For returning the piston it is preferred to use the combined action of the springs d and tt' although one spring alone or more than two springs might be used.

The battery and coil for supplying the ignition current will be connected with the cable l5 Aand supported either apart from the hammer or upon it. o I

By delivering the freshly formed fuel mixture into the lower end of the cylindrical channel in the unit' il, the adjoining portions of the springs are cooled and their heat is thereby carried away by the combustion charge. 'Ihe channel l'l is provided to prevent these springs from blocking the ecient delivery of the fuel but ould not be so wide as to permit the springs to enter thereinto. The upper end of the return spring is cooled by the-gases owing into the vertical passages tt, while the remainder of this spring is exposed to cooling by the gases in the middle portion of the sub-piston compression space.

In the operation of the device the piston is 4returned after the power stroke by the combined action of the springs t5 and dt and the rebound which occurs from the impact of the striker por- `tion of the piston upon the reduced portion of the anvil.l In order that the anvil and hammer may have the necessary durability and may cause the desired rebound, they should each have aV minimum hardness of 60 scleroscope.

The maximum A"spring load referred to herein is that force in pounds required to force the piston manually down into contact with the anvil.

I have discovered that the maintenance of a predetermined ratio between the piston weight, the scleroscope hardness of the striker portion oi the piston and of the anvil, and the maximum spring load of the return springs is essential to efiicient operation of the hammer as a whole. rIhe scleroscope hardness of the striker portion till and the anvil preferably should, not fall below` a minimum of 60 scleroscope. "The mamirn'umD spring load in pounds of the return springs should not exceed thirty times the weight in pounds of the piston. When-these ratios are maintained, the device will have the rapidity of action required for its work and excessive vibration will not be imparted to the entire device.

While the piston is shown as comprised 'of two parts assembled permanently together, it is contemplated that the striker portion may be originally cast or otherwise formed integrally with f the upper portion of the piston.

Fig. 8 shows a modified form of my invention which has the same internal operating parts as the preferred form shown in Fig. l, but involves a different external assembly of the cylinder, the

anvil housing and the handles. In the modiiied form' the lower end of the cylinder is clamped directly to the upper end oi the anvil housing while the handle ring is supported wholly on the long outside tension bolts rather than upon the cylinder fins. This modied form of the harnmer comprises a cylinder tl on the. outer surface of which is a plurality of outwardly and longitudinally extending iins t2. The upper ends of these fins are formed as shown to pass within a handle ring t3, this ring not being supported upon the iins but merely lightly contacting the edges thereof. ahamd `and construe .-r te..

ring of Fig. l, ving insulating strips ad and handles tt.

At opposite sides the handle ring is provided with lugs, one of which te is shown, through which the outside tgnsion bolts pass. The bolt tl, shown in Fig. 8, is provided with a shoulder just below the lug, upon which the lug seats, and

a nut te clamps the two together. The lower end of the tension bolt l extends through the flange t@ on the cylinder casting and through the wall of the anvil housing or lower unit 9i. It will be understood that a piston and an anvil, together with return springs similar 'to those shown in Fig. 1, are employed in this modled form of the invention. 'Ihe rod tl extends upwardly through the lower unit 9i, passing into a boss Q2 at which point is located a shoulder 93 on the rod, together with a corresponding recess in. the lower unit and a flat surface 9d on the side of the rod cooperating with a corresponding iiat sided recess to prevent turning oi the tension bolt. A pin 90 may be driven through each bolt @l just above the ange t9 to prevent downward movement oi the bolt.

A tool'guide t5 is yieldably supported on the tension bolt tl and its mate on the opposite side, as in the preferred embent. One of the compression springs @t is shown resting.

against the nut @I and a bossld on the tool guide.

In order to secure the cylinder casting and the lower unit iirmoly together without undue conduction of heat from the cylinder to the anvil housing, I have provided a pair of bosses 9B and 99 at the lower marginal portion of the cylinder casting and cooperating bosses itl and iti on the anvil housing. Short bolts itt and ltd passing through these bosses secure the two parts iirmly together. A heat insulating gasket idd at the juncture of these two parts prevents any un-` duly extensive conduction of heat from the cy l' inder casting to the anvil housing. This precaution is important in order that the fuel tank, which is supported Wholly on the anvil housing,

as is the case in the preferred embodiment, may

be protected from the heat generated by the operation of the hammer. The lower end of the cylinder, where the lugs are lcatel', naturally is kept relatively cool by reason of the iuel mixture flowing through the sub-piston compression space within the lower end oi the cylinder.

During use the cylinder casting will become heated and will naturally lengthen but this tendency to lengthen is not in any way restricted by the handle ring, as the iins may" slide upwardly therewithin and return equally easily when cooling. 'I'here is, therefore, no increase or decrease of tension upon the tension bolt tl and its counterpart on the other side of the hammer by reason of expansion or contraction of the cylinder. Therefore the reduction in area of the tension.v bolts, as shown in Fig. 4, is not neces-v sary in this embodiment. In fact, these tension bolts may well he made much Ymore sturdy as they must sustain wholly or nearly so thethrust imparted 'between the lower end of the hammer and its handles.

It should be understood that the constructions herein shown and described have been selected for the purpose of illustrating the invention, and not for the purpose of indicating its limits. Various modifications of the invention and its parts may be made without a departure from the scope of the invention, particularly as it is deed in the appended www ing a cylinder and cooling ns thereon extending outwardly therefrom longitudinally of the cylinder to a point above the cylinder, an anvil, an anvil housing below the cylinder, a tool guide below said housing, a handle ring seated upon the upper ends of said fins above the cylinder and constructed to permit air circulation therethrough between the ns. and means cooperating with said ring and tool guide for retaining said ring, cylinder, anvil housing, and tool guide in assembled relation.

3. The combination of a cylinder and a spring returned piston therein, a separable lower unit seated against the lower end-of said cylinder and insulated therefrom, a fuel` tank supported on said unit and an anvil carried by the unit, a tool guide seated against the inner side of the unit for receiving impact from the anvil and yieldable thereunder away from said unit, cooling fins on said cylinder extending outwardly therefrom longitudinally of the cylinder and extending thereabove, a handle ring supported on the top of said fins near their outer extremities so as to permit clrculation'of air between said iins and through said ring, and means cooperating with said ring for rigidly supporting said unit and yieldably supporting said tool guide.

4. In an internal combustion hammer having a cylinder and a spring return piston therein, an anvil housing at the lower end of said cylinder, heat insulating means disposed between said cylinder and housing, radiating iins on the cylinder projecting radially therefrom and' extending longitudinally thereof above the upper end' of said cylinder, a handle supporting member mounted upon the top of said fins near the outer extremities thereof so as to permit air flow through said member, a tool guide below said housing, and means connected to said member ior rigidly supporting said housing upon the cylinder and yieldably urging the said tool guides against the lower end .of said housing.

5. An internal combustion hammer comprising a cylinder, a piston reciprocable therein, radially disposed ilns extending longitudinally` of said cylinder and beyond the upper end thereof, asplunger rod guide located above the cylinder and coaxially therewith, the upper ends of the spacesl between the fins being open to provide for air circulation around the cylinder and guide, a plunger. rod extending through said guide and the cylinder head `and having at its upper end provision for hand operation of the rod, and a spring interposed between the upper ends of said fins and the hand provision on the rod whereby said rod is yieldably retained in raised position.

6. An internal combustion hammer comprising a cylinder, a spring returned piston reciprocable therein, cooling fins extending radially from the cylinder and projecting longitudinally thereof above the upper end of the cylinder, a starting plunger extending from within the cylinder to a position above the top of said fins, a plunger guide disposed axially of said cylinder at the upper end of the iins, a handle ring disposed circumferentially of the fins at their upper ends so as to leave unobstructed air passages defined by said fins, said guide and said ring, and a spring mounted above said fins in the path of said air flow for holding said plunger in raised position.

'1. An internal combustion hammer comprising a cylinder provided with cooling fins extending radially outwardly therefrom and projecting longitudinally of the cylinder above the upper end thereof, handle supporting means, and a plunger guide carried by said fins above said cylinder and constructed to afford unobstructed passages between said ns to facilitate unrestricted upward flow of air between said fins. A

8. An internal combustion hammer comprising a cylinder equipped with radially projecting longitudinal disposed radiating iins extending above the upper end of the cylinder, an anvil housing at the lower end of said cylinder, a tool guide abutting the lower end of said housing, a handle ring seated upon the upper ends of said ns, tie rods extending between adjacent fins and through said ring, said housing, and said tool guide, said rods having shoulders engaging said housing and nuts threaded thereon above said ring whereby said ring, cylinder, and housing are rigidly clamped together, said rods being of .re-

duced diameter adjacent to the cylinder to facilitate longitudinal expansion and contraction thereof in conformity with variations in the cylinder length whereby rigidity of the assembly is maintained without injury to the said rods,vand springs interposed between the headed lower ends of said rods and said tool guide to yieldably hold said guides against said housing.

9. An internal combustion hammer comprising

Images