US1341545A - Motor-operated rotary hammer - Google Patents

Description

R. E. COVERT.

MOTOR OPERATED ROTARY HAMMER. APPLICATIQM FILED NOV. 23, 1.917. RENEWED 05c. 30, 1919.

1,341,54 Patented May 25,1920.

NITED STATES RALPH E. COVERT, 015 DETROIT, MICHIGAN.

MOTOR-OPERATED ROTARY HAMMER.

Specification of Letters Patent.

Patented May 25, 1920.

Application filed November 23, 1917, Serial No. 203,647. Renewed December 30, 1919. Serial No. 348,376.

To all whom it may concern:

Be it known that I, RALPH E. Covnn'r, a citizen of the United States, residing at Detroit, in the county of lVayne and State of Michigan, have invented certain new and useful Improvements in Motor- Operated Rotary Hammers; and I do hereby declare the following to be a full, clear, and eXact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to a motor operated rotary hammer.

The object of the present invention is to provide a simple, practical and eflicient motor operated rotary hammer of strong, durable and inexpensive construction designed for riveting and various other purposes and capable of being readily operated by an electric motor.

Vith these and other objects in view, the invention consists in the construction and novel combination of'parts hereinafter fully described, illustrated in the accompanying drawing and pointed out in the claims hereto appended; it being understood that various changes in the form, proportion, size and minor details of construction, within the scope of the claims, may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawing:

Figure 1 is a side elevation of a motor operated rotary hammer constructed in accordance with this invention.

Fig. 2 is a sectional view through the easing of the rotary hammer.

Fig. 3 is a similar view on the line 3-3 of Fig. 2.

Like numerals of reference designate corresponding parts in the several figures of the drawing.

in the accompanying drawing, in which is illustrated the preferred embodiment of the invention, the motor operated rotary hammer comprises in its construction a casing l composed of sections 2 secured together by bolts 3 or other suitable fastening devices and having a central bearing opening 4 for the reception of a driving shaft 4 of a rotary driving member or hammer 5. The rotary driving member or hammer '5 is centrally secured to the shaft 4* and it extends through a central space 6 of the casing to a substantially annular passage 7 which forms a race way. The annular passage is provided with circular inner wall 8 arranged concentric with the shaft and it has an outer wall consisting of a concentric portion 9 and eccentric portion 10. The raceway receives heads 11 of the rotary hammer or driving member which is adapted to actuate balls 12. The casing is provided at the eccentrically arranged portion 10 of the passage with an opening 14 for the reception of a rivet set or tool 13 having a head 15 which is adapted to engage the rivet and which also is engaged by a shoulder 16 formed by an enlargement of the opening 14 and adapted to limit the inward movement of the rivet set or tool. The rivet set or tool is provided with an inclined or angularly disposed inner end 17 which projects inwardly into the raceway into the path of the balls, as clearly illustrated in Fig. 2 of the drawing, and the said inclined or angularly disposed face is adapted to eliminate rebound of the balls and the eccentrically arranged portion of the outer wall provides siniicient space for the balls to pass the rivet set and gain sufficient speed to enable them to pass in front of the rotary member or hammer. A ball is arranged at each side of the rotary hammer or driving member, which has each of its heads cooperating with one of the balls. The balls are driven around the raceway and they strike the rivet set or tool and produce an intermittent driving of the same similar in effect to a pneumatic hammer. The balls 12 are moved through the raceway 7 by being engaged by the heads 11 of the hammer, the balls during this movement being in loose contact with the hammer head. When one of the balls engages the inner end of the tool 13. its movement is momentarily stopped, and this ball is then struck by the head 11 of the hammer a blow of great force so as to impart a downward or outward impulse .to the tool, the ball thus acting to transmit the blow of the hammer head directly to the tool in much the same manner as if the tool were struck squarely upon its inner end by a manually operated hammer. By having the ball entirely free from the hammer head, and only in loose contact therewith. a blow of much greater force is obtained than is possible in rotary hammers of ordinary construction in which the heads of the hammer itself are movable radially, or substantially so, of the operating shaft so that these heads have merely a wiping effect upon the inner end of the tool so as to tend to force it outwardly by centrifugal force, but do not exert any positive hammering effect.

The shaft 4* is adapted to be actuated by an electric motor 18 which is connected at 19 with the hammer casing, and while the motor is shown directly connected with the shaft 4P any suitable gearing may of course be employed for increasing or diminishing the number of revolutions of the shaft. The hammer casing is provided with a handle 20 and is adapted to be manipulated in the same manner as a pneumatic hammer. In the operation of the device, the head of the rotary driving member or hammer strikes a ball to drive the same around the raceway with Su cient speed to enable the balls to contact with and deliver a blow to the rivet set and pass'in front of the cooperating hammer head. The centrifugal force will cause the balls to hug the outer wall of the passage and the inner end of the rivet set projects into the path of the balls but is located beyond the path of the actuating heads of the rotary hammer or driving member. Any suitable means may be employed for limiting the outward movement of the rivet set when desired.

What is claimed is:

1. A motor actuated rotary hammer including a casing having a raceway, a shaft journaled in the casing, a rotary hammer carried by the shaft an extending into the raceway, a ball free from the hammer open ai i th ra way and g ged y S i hammer, and a tool member protecting into the path of the ball.

'2. A motor operated rotary hammer in eluding a casing having a substantially annular'raceway provided with an eccentri- 1 en arged p r e ota y ha tending into the casing, a harnmer carried by h me yp 'h a e per t n h raceway, a ball free from the hammer and engaged thereby operable in the raceway,

and a vibratory member located at the e'coentrically enlarged portion of the said raceway and projecting into the path of the ball and located beyond the path of the hammer.

3. A motor operated rotary hammer including a casing provided with a substan tially annular raceway having an enlarged eccentrically arranged portion and provided thereat with a peripheral opening, a rotary shaft extending into the casing, a rotary hammer carried by the shaft and operating in the raceway, a ball also operating in the raceway and actuated by the hammer, said ball being free from the hammer and a vibratory member operating the peripheral opening and extending into the path of the ball and located beyond the path of the hammer or driving member, said vibratory member being provided with an inclined or angularly disposed inner face adapted to eliminate rebound. i i

'4 A motor actuated rotary hammer including a casing having a substantially annular raceway provided with an enlarged eccentrically arranged portion, said casing being provided thereat with a peripheral opening, a rotary shaft extending into the casing, a hammer member centrally connected to the shaft and provided at its ends with heads operating within the raceway, balls also operatingwithin the raceway and located at opposite sides of the hammer, said ball being free from thehammer, and a vibratory member extending into the path of the balls and located beyond the path of the rotary hammer.

In testimony whereof I afiiX my signature in presence of two witnesses' DAVE LEVIN, L. l/V. Omi.

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