US1951169A - Mechanical power hammer - Google Patents

Description

March 13, 1934. H. scHwoB 1, 2

MECHANICAL POWER HAMMER Filed Aug. 15, 1932 Patented Mar. 13, 1934.

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PATENT OFFICE Application August 15,

9 Claims.

The objection of my invention is to provide a mechanical power hammer which is simple, durable and comparatively inexpensive to manufacture.

A further object is to provide a power hammer, preferably of portable construction, which is of the mechanical type, as distinguished from the pneumatic type.

Still a further object is to provide a mechanical power hammer for digging, drilling, tamping, crushing and riveting operations, which may also be used for breaking rock, cement and the like, the hammer itself being readily adapted to receive dififerent tools for these various operations.

Still a further object is to provide a hammer construction in which the hammer is driven me chenically from a source or power such as an electric motor, a gasoline engine or the like, the hammer being driven at a high rate of reciprocation from the source of power and acting much in the same manner as a pneumatic hammer, the structure being particularly adapted to perform any operations which pneumatic hammers are adapted to perform.

Still a further object is to provide a hammer construction in which a hammer is reciprocated through resilient connections from a cross head, the reciprocations being imparted to the cross head by a crank shaft and connecting rod driven from a source of rotating power.

Still a further object is to provide means for rotating the tool which is being used so that besides imparting a hammering movement to it, it can be'rotated for drilling operations and the like.

With these and other objects in view my invention consists in the construction, arrangement and combination of the various parts oi my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawing, in which:

Figure l is a front elevation of my mechanical power hammer.

Figure 2 is a vertical sectional view on the line 2--2 of Figure l.

Figure 3 is a rear elevation of the invention.

Figure 4 is a vertical sectional view on the line 1-4 of Figure 2 showing the operation of the hammer;- and Figure 5 is a horizontal sectional view on the line 5-5 of Figure 2 showing details oi construction.

On the accompanying drawing I have used the reference numeral is to indicate a hammer tube.

1932, Serial No. 628,860

Within the hammer tube 10, I provide a reciprocable hammer element 12. I provide an electric motor 14 for reciprocating the hammer element. 12 in the following described manner, although it will be obvious that other sources of power can be provided, such as a small internal combustion engine mounted in place of the motor 14.-

The motor 14 is mounted on a base 16, which in turn is secured to the upper end of the hammer tube 10. Through a belt connection 18 the motor 1 rotates a crank shaft 20. The crank shaft'20 is journalled in bearings 22 which are supported in a transverse sleeve 24 welded or otherwise secured to the hammer tube 10. v

A crank disc 26 is mounted on the crank shaft and is provided with a crank pin 28. A guide bar 30 is mounted longitudinally of and supported on the hammer tube 10 and a cross head A is reciprocable therealong.

The cross head A has perforated bearing flanges 32 surrounding the guide bar so and has ends 34 which are arranged on opposite sides of the hammer tube 10. A connecting rod 36 has its ends pivoted to the crank pin 28 and the cross head A respectively. From the description of the foregoing parts, it will be obvious that rotation of the crank shaft 20 will be converted into reciprocating movement of the cross head A. The stroke of the cross head A may be varied by placing the crank pin 28 in any desired opening 28a therefor in the crank disc 26. These openings are at different distances from the crank shaft 213.

Reciprocation oi the cross head A is trans mitted to the hammer element 12 by springs 38 and a link re. The link to is slldable through a rectangular opening 42 which extends through the center of the hammer element 12. The hammer tube 10 is provided with slots as, through which the link extends. The ends of the link are perforated and likewise the ends of the cross head A are perforated for the ends of the springs 38 to hook into.

An anvil element id is loosely mounted in the lower end of the hammer tube 10. It receives the impacts of the hammer element 12 when in its position shown in Figure 4. These impacts are transmitted to a tool 48, or any other tool which might be inserted into the angular bore so or the anvil element 46.

v With respect to the operation of the hammer element, when the crank pin 28 starts upward on its travel it is going slowly at first, away from the anvil and is going most rapidly when it is in a position horizontal with respect to the crank higher than the crank pin tends to make it go, thereby increasing the length of the stroke of the hammer element.

The crank pin then starts to descend on the other side of the crank shaft, slowly at first until it is again horizontal when it is going at its fastest speed. This gives a corresponding downward jerk to'the hammer element which is somewhat arrested by the tension of the springs so that as the crank pin descends it brings the hammer element down with the speed not only of the descending crank pin but also of the reflex actior. of the springs and the blow of the hammer element is actually delivered when the crank pin is at the bottom of its stroke but the hammer element is farther down as illustrated in Figure 4, the springs permitting this. The anvil arrests the blow of the hammer element, which would swing on downthe hammer barrel (if the anvil were not there) until the springs could fully arrest it.

The element 46 has a flange 52 which normally rests against'the lower end of the hammer tube 10 when the tool 48 is held against the work to be done, the hammer element 12 at each impact causing the flange to be driven away from the tube.

In Figures 2 and 3 I. have shown a tool 48a, which may be used for hammering or crushing operations. It will be obvious that other tools, such as cold chisels and the like, may be substituted for either the tool 48 or 48a. Such tools would have angular shanks of the same cross section as the bore 50 so as to prevent their rotation relative thereto, yet permit and facilitate insertion and removal of the tools in the same manner as now done in connection with pneumatic hammers.

During some operations it is desirable to permit the tools to rotate, as they will naturally do on their own account. During other operations it is desirable to positively rotate the tools. To accomplish rotation, I provide the following described mechanism:

A sleeve 54 is screw threaded on the lower end of the hammer tube 10. It is provided with a flange 58. A rotatable plate 5 8 is positioned below it and is held in the position shown by a gear which engages the top of the flange 56 and which is bolted by bolts or the like 62 to the plate 58.

The plate 58 has a pair of key-like projections 64 which interflt with key-ways 66 formed in the anvil element 46. Thus the plate 58 and the .gears 60 are rotatable relative to the sleeve 54 and carry the anvil element with them.

For rotating the gears 60, I provide a shaft 68 suitably supported for rotation on the hammer tube 10 and having a spiral gear connection at '70 and 72 with the crank shaft 20' and a pinion 74 to mesh with the crank 60 Thus rotation of the crank shaft 20 will impart somewhat slower rotation to the plate 58 and the anvil element 48 as well as to the tool associated therewith.

The rotating device need not be used if such rotation is not desired. The sleeve'54 can be unscrewed from the lower end of the hammer tube 10 so that the assembly'of sleeve, plate 58 and gear 60 can beentirely removed when it is not desired to rotate the tool. 7

when an electric motor is used in connection with my hammer structure, a suitable switch,

I have shown handles 76 for the convenience of the operator in handling the structure and the switch can be located on one of these. When a small internal combustion engine is used as the source of power, an idler pulley for tightening the belt 18 can be provided, the belt being normally loose enough to permit rotation .of the engine without imparting rotation to the crank shaft 20.

These changes, as well as others, may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my for imparting reciprocations to said hammer element comprising a crank shaft, a guide longitudinally of said tube and mounted exterior thereof, a cross head reciprocable'therealong, a connecting rod connection between said crank shaft and said cross head, said cross head having ends on opposite sides of said hammer tube and resilient connections between said ends and said hammer element.

2. A power hanimer structure comprising a hammer tube, an anvil in one end thereof, a hammer element reciprocable in said tube and means for imparting reciprocations to said hammer element comprising a crank shaft, a guide longitudinally of saidtube and mounted exterior thereof, a cross head reciprocable therealong, a connecting rod connection between said crank shaft and said cross head, said-cross head having ends on opposite sides of said hammer tube, ears extending from said hammer element and springs connecting said ends of said cross head with said ears. 3. A power hammer structure comprising a hammer tube, an anvil in one end thereof, a hammer element reciprocable in said tube and means for imparting reciprocations to said hammer element comprising a crank shaft, a guide longitudinally of said tube and mounted exterior thereof, a cross head reciprocable therealong, a connecting rod connection between said crank shaftand said cross head, said cross head having ends on opposite sides of said hammer tube, said hammer element having a slot therethrough, a bar slidable through said slot and springs connecting the ends of said bar with the ends of said cross head.

4. A power hammer structure comprising a hammer tube, an anvil in one end thereof, a hammer element reciprocable in said tube and means for imparting reciprocations to said hammer element comprising a crank shaft, a guide longitudinally of said tube and mounted exterior thereof, a cross head reciprocable therealong, a connecting rod connection between said crank shaft and said cross head, said cross head having ends on opposite sides of said hammer tube, resilient connections between said ends and said hammer element, a rotatable plate mounted on said hammer tube and slidably and non-rotatably connected with said anvil and means for operatively connecting said rotatable plate with said crank shaft forrotating the former from the, latter.

5..A powerhammer structure comprising a through, a

hammer guide, an anvil at-one end thereof, a

hammer element reciprocable along said guide and means for imparting reciprocation to said hammer element comprising a crank shaft, a cross head reciprocable longitudinally of said guide, a connecting rod connection between said crankshaft and said cross head, said cross head having ends on opposite sides of said hammer guide, said hammer element having a slot therebar 'slidable through said slot, and springs connecting the ends of said car with the ends of said cross head.

SJA power hammer structure comprising a hammerguide, an anvil at one end thereof, a hammer element reciprocable alongsaid guide and means for imparting reciprocation to said hammer element comprising a crank shaft, a cross head reciprocabie longitudinally of said guide, a connecting rod connection between said crank shaft and said cross head, said cross head having ends on opposite sides of said hammer 'guide, resilient. connections between said ends and said hammer element, a rotatable plate mounted on said hammer guide and slidably and non-rotatably connected with said anvil, and means for operatively connecting said rotatable plate with said crank shaft for rotating the former from the latter.

'7. A power hammer structure comprising a her tube, an anvil in one end thereof, a hammer element reciprocable in said tube and means for imparting reciprocations to said hammer element comprising a crank shaft, a guide longitudinally; oi said tube and mounted exterior thereof, a cross head reciprocable therealong, a

connecting rod connection between said crank,

shaft and said cross head, said cross head having ends on opposite sides of said hammer tube, resilient connections between said ends and said rotating it upon rotation connection between said rotating hammer element, a d rotatable means operatively connected with said crank shaft and slidably and non-rotatablyconnected with said anvil for of said crank shaft.

8. A device of the class described comprisin an impact element guide, an impact element reciprocable along said guide and means for imparting reciprocation to said impact element comprising a rotating shaft, a cross head reciprocabie longitudinally of said'guide, an operative shaft and said cross head for imparting reciprocations to said cross head, said-cross head having ends on opposite sides of said guide and resilient connectingmeans between said ends and said impact element, said connecting means extending through said impact element and slidable therethrough to equalize the tension of said means on said; impact element. 1

9. A device of the class described-comprising an impactoelement guide, a tool in one end thereof, an impact element reciprocable along said guide and means for imparting reciprocation to said impact element comprising a rotating shaft, a cross headreciprocable longitudinally of said guide, an operative connection between said rotating shaft and said cross head for imparting reciprocations to said cross head, said cross head having ends on opposite sides of said guide, resilient connecting means between said ends and said impact element, said connecting means extending through said impact element and slidable therethroughto equalize the tension of said means on said impact element and rotatable means operatively connected with said rotating 11o shaft and slidably and non-rotatably connected with said tool for rotating it upon rotation of said rotating t.

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