US2083261A

US2083261A - Gas hammer

Info

Publication number: US2083261A
Application number: US67593A
Authority: US
Inventors: Thomas C Gray
Original assignee: Barco Manufacturing Co Inc
Current assignee: Barco Manufacturing Co Inc
Priority date: 1936-03-07
Filing date: 1936-03-07
Publication date: 1937-06-08
Anticipated expiration: 1954-06-08

Description

June 8, 1937. 'T. c. GRAY 2,083,261

, GAS HAMMER 'F'iied March 7, 1936 v 2 Sheets-Sheet 1 June 8, 1937. T. c. GRAY 2,083,261

GAS HAMMER Filed March '7, 1936. 2' Sheets-Shem; 2

-. Patented June 8, 1937 PATENT OFFICE GAS HAMMER Thomas 0. Gray, Evanston, 111., asslgnor to Barco Manufacturing of. Illinois 00., Chicago, 111., a corporation Application March '1, 1936, Serial No. 7.593

11 Claims.

This invention relates to improvements in internal combustion hammers.

Heretofore internal combustion hammers having springs for returning the pistons have had such return springs mounted inside of the cylinder below the piston. The springs so located are subject to considerable of the heat generated.

in the cylinder by combustion and are therefore liable to deteriorate by reason of the effect of such heat. Furthermore, the return springs so confined are not conveniently accessible for replacement. Another disadvantage of such an arrangement is that the confining of the spring in the cylinder below the piston necessitates pro- 5 viding a cylinder of considerable length.

In accordance with this invention the piston return springs are mounted outside of the cylinder,.thus making them more accessible, easier to keep cool, and making it possible to employ 20 a shorter cylinder.

Various other objects and advantages of the invention inherently possessed by it wil1 become apparent upon a perusal of the specification.

' In the drawings:

Fig. 1 is a central vertical sectional view of one form of the invention, and Fig. '2 is a central vertical section of another form of the invention.

Referring now to Fig. 1, the invention therein 30 shown includes a cylinder l in which a piston 2 is disposed. The piston is provided with a striking portion 3 adapted, at the lower end of the stroke of the piston, to strike the raised portion 4 of an anvil 5 which transmits the blow to a 5 tool 6 extending upwardly into the anvil. While a recess is provided in the anvil shown to receive the tool, it should be understood that a recess is not necessary as the bottom of the anvil may be otherwise shaped in the area in which it 40 contacts with the tool. 1

The tool, which may be a drill, tamper, concrete breaker, or other similar device, is retained by a tool guide I, abutting the lower end of an anvil housing 8 andheld yieldably thereagainst 45 by tension springs carried on tie rods whose upper ends are supported preferably on the handle ring, later described. These springs and tie rods may be similar to those disclosed in U. S. Letters Patent No. 1,997,072, issued April 9, 1935, 50 to James A. Mould.

In hammers of this type heretofore constructed, the piston return springs have been positloned within the cylinder below the piston, usually between the piston and the anvil. The present invention contemplates mounting the return springs outside of the cylinder. with this end in view, a rod 9 is connected inany suitable mannerto the upper end of the piston and extends through the top of the cylinder, being provided on its upper end with a head I I or some other suit-' able means for retaining the upper end of the return spring 12.. The lower end of the spring i2 is preferably seated on another spring which may be termed a cushioning spring l3, being heavier and stronger than the long spring and serving to dampenthe vibrations of the longer I spring. The short cushioning -spring surrounds a boss M on the top' of the cylinder and is held against lateral displacement thereby.

The head. ll reciprocates in a guideway I5 which may be either a cylinder or of other suitable construction to guide and steady the rod 9 in its movements, and also to form a protective guard around the enclosed moving parts. The cylindrical guideway l5 of Fig. 1 is provided with a cover plate l6 having a central aperture through which a tool or rod may be introduced to depress the head and the piston for starting purposes. A keyway l0 cooperating with a key 20 prevents rotation of the head.

While other means of controlling the ignition for the hammer may be employed, it is preferred to operate the timer or interrupter from the head II which, for this purpose, is provided with a cam surface l8 at one side. As the head reciprocates with the piston, the cam follower 19 will press the plunger 2| outwardly to cause a spark across the terminals of the spark plug 22. During normal operation of the device, the piston will not rise as high as the position which it occupies in the drawings because of the resistance offered by the combustible charge in the cylinder above the piston.

The anvil housing and anvil contained therein serve to close the bottom of the cylinder and afford between" the bottom of the piston and top of the anvil and housing a precompression space in which the combustible mixture will be comready to be compressed by the piston when the return springs raise the latter up again to firinner walls are shaped to avoid contacting the' vertical fins such as 29, 3| and others, not shown, which are provided onthe cylinder. The exact manner of mounting this tank and the form of the-carburetor employed for forming the mixture do not constitute a part of this invention, but reference may be had to the James A. Mould U. 8. Patent No. 1,997,072, issued April 9, 1935, for a disclosure of one suitable form of mounting for the tank and construction of a carburetor. It is sufficient to call attention to the fact that the combustible mixture will preferably be introduced into the precompression space through an aperture 32.

, Also the manner of securing the anvil housing rigidly on the bottomof the cylinder and the manner of yieldably supporting the tool guide 'I also do not constitute a part of this invention. And again reference may be made to the abovementioned Mouldpatent to ascertain how this may be done, if desired. It will be noted that in that patent the tension rods which retain the anvil housing and'also yieldably support the tool guide are themselves secured upon the handle ring and they may be so supported here.

The handles 33 and 34 by which the tool is held are secured to a handle ring generally designated as 35 which rests upon a shoulder 36 provided on 35 the cooling iin structure, This handle ring may be secured upon that shoulder in any suitable manner, for example, by the tension bolts just above referred to.

Fig. 2 shows another form of the invention,

40 differing from Fig. 1 only in the manner of op-' erating the timing mechanism. The details of. construction of this form of the invention, insofar as they resemble the form disclosed in Fig. 1, need not therefore be described. It suffices to state that this form of the invention includes a cylinder 4|, a piston 42, a rod 43 connected'in any suitable manner to the top of the piston, return springs 44 and 45, and a head 46 secured in any suitable manner, as by threads, to the top of the 50 rod for holding the return springs under compression, as illustrated. In this form of the invention, the head 46 is not employed to actuate the timing mechanism.

The piston 42 is provided with a striking portion 41 which imparts the blow of the piston to the I anvil 48 which transmits the blow then to .-thtooi 49.

A timing plunger II having a cam follower I2 riding in a groove- 53 on the outside of the piston wall will be thrust outwardly by the cam surface 54 provided at the'lower end of the groove to cause a spark to .occur across the terminals or the spark plug II. By removing the cover plate 56 and the spring retaining head 46, the return springs may easily be replaced whenever desired, and the tension of the springs may be regulated by adjustment of the head on the rod or by the employment of The cylinder I'l operates as does the cylinder xmllgofligi 1, both as a guide for the spring retaining head'an'd also as ashield surrounding the v 'It iscontemplated that the fuel tank Ql will 7" be mounted .cnthe anvil housing 69 in the or similar manner as is the fuel tank of Fig. 1, the fresh charges of fuel being-"admitted into the precompression space belowthe' piston through an aperture 5|.

It should be understood that the drawings and specification. disclose and describe merely two embodiments of the invention, but other varla-- tions of the invention are possible andare contemplated and included within the scope of the appended claims.

a The invention above shown and described is claimed as follows:

1. In an internal combustion power hammer, a cylinder, a piston therein, a spring mounted outside of the cylinder, and means operatively conon said piston.

2. A power hammer comprising a cylinder and a piston therein, a spring mounted outside of 'the cylinder, and means operatively connected with the spring and with the piston for retracting the piston in the cylinder after each powerstroke, said means comprising a longitudinally movable rod on said piston.

3. In a power hammer, a cylinder and a piston therein, a spring mounted outside of the cylinder and substantially coaxial therewith, and means extending through a wall of the cylinder connected with the piston and operatively connected with the spring for moving the piston in one direction, said means comprising a longitudinally movable rod.

4. In a power hammer, a cylinder and a piston therein", a spring mounted outside of the cylinder, and means extending through one end of the cylinder connected with the piston and operatively connected with the spring for moving the piston in one direction in the cylinder.

5. In a power hammer, a cylinder and a piston therein, a spring mounted outside of the cylinder, and means extending axially through said spring and operatively connected to one end thereof and further connected with the piston for moving the piston in one direction in the cylinder.

6. In a power hammer, a cylinder and a piston therein, a spring mounted outside of the cylinder, means operatively connected with the ton therein, a rod connected with the top of the piston extending through'the top of the cylinder, a spring mounted outside of the cylinder operatively connected with said rod and held under compression thereby, an ignition system for lgniting a combustible mixture in the cylinder, and means connected withsaid rod for controlling the spark in said-system.

9. In a powerhammer, a cylinder and a piston therein, a rod connected with the top of the piston extending through the top of the cylinder, a spring mounted outsideof the cylindenmeans connected with said rod holding said spring under e,oss,ae1 3 compression, and means for varying the com- 11. In a. power hammer, a cylinder and a pisspression-ot said spring. ton therein, a spring supported on the top of said .10. In a power hammer. a cylinder and a piscylinder and rising thereabove and adjustable ton therein, a spring supported on the top of means connected with said piston and holding said. cylinder and rising theteabove, and means said spring under compression for returning the 5 conficted with said piston and holding sairL piston after each power stroke. spring under compression for returning the piston after each power stroke. THOMAS C. GRAY.