US2524589A - Quarry drop hammer - Google Patents

Description

Oct. 3, 1950 G. D. BECKER QUARRY DROP HAmvIER Filed March 13, 1946 R O T N E V m Patented Oct. 3, 1950 V.UNITED VST'Ai'lTl PAT-ENT OFFICE.

i 2,524,589 Y QUARRY DROP HAMMER l-Georgel).Beclrer, Wauwatosa, Wis., assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation `oi' Delaware j Application Minchia 1Q4aseriai No. 654,071

This invention relates to improvements in rock breakers of the type in which a 'heavy body is 4dropped upon a large rock to break the rock into fragments. Anobject of the invention is to pro-v vide an improved drophammer head having a permanent massive iner-tiavbodyl and a replaceable impact or wearing shoe. l

-A further object is to provide a drophammer head for lcable attachment, in which the lifting cable is lattached directly V.to a replaceable wearing shoe rather thanvto the permanent massive inertia body.

Astill further object is to provide such a hammer head `in which a permanent massive body is safely held by a lifting cable without direct attachment thereto.

The above and still further objects may be carried into practical effect as described below with reference` to the drawing, in which:

Fig. l shows a moreor less schematic view of a rock breaker according to the present invention; Fig. 2 is an enlarged elevation of the drop hammerhead of Ythe rock breaker shown in Fig; l, with a fragment of the lifting cable;

Fig. 3 is a top elevation of the head shown in Fis. 2; 1 Y v i Fig. e is a longitudinal :sectional View of/ the hammer head taken on the line IV-IV fof' Figiv 3, the parts being shown displacedas in assembly; f Fig. 5 isa side elevation of the fimpact'shoe detail;

Fig. 6 is a detailed View of the shoe of Fig. 5 in section on the line VIwVI.

The type of rock breaker with relation to which this invention is an improvementris well known to the prior art. Such rock breakers consist, generally speaking, of a portable crane or derrick to the cable of which is attached a heavy piece of metal. The stone to be broken rests upon the the ground or the floor of a quarry. 'Ihe crane is placed in position so that the weight may be hoisted by the crane cable to a position directly over the rock to be broken. When the hoisting mechanism of the crane is released, the heavy piece of metal, cr hammer head, freely falls, striking and shattering the rock.

As these drop hammer type rock breakers have been used in the past, the cable is generally secured directly to a massive integral piece of metal. Such an integral piece of metal, used as al hammer, is worn away by repeated impacts with rocks until it is no longer heavy enough to be eiective when dropped from a reasonable height. And, before long, the head must be discarded with a resultant loss of a subs claims. (o1. zii- 291i stantial'percentage of the metal used. Another diinculty encountered in the prior art was .concerned with-the breakage of the cable where attachedV tothe hammer. The point of attachment w of` the cable was generally exposed and-subjectto wear,` and the cable itself was subject to seri- Y ous kinking and chang when iallingslack after impact.

The `present invention is primarily concerned with the construction of the drop hammer head,

, and its connection to the flexible cable used for hoistingthe same to position over a rock. Fig. 1 illustrates in general outline the hammer head I :ofi the invention attached to cable 2 of a portablefcrane 3 of suitable known type. Hammer l is shown as .suspended directly over a rock li, to

. bebroken. The crane 3 is equipped with suitable mechanism for hoisting the hammer l to an elevated position and for releasing the cable and permitting the hammer l to descend freely under theiniluence of gravity and deliver a rock breakingimpactyin a manner known to the prior art.

'-'Ihe hammer I and its attachment to the hoist ing cable 2 as shown in Figs. 2-6, includes a massive inertia `body 6, having a bore 'l enlarged at one end as shown at 8, and having its other end bell mouthed or ilared in a smooth curve as shownrat .9. Adjoining the enlarged portion 8 of the bore vis an annular seat Il, substantially coextensive with the end of the body 6. An impactashoe 12, of substantially'mushroom shape, lisiprovided-on its rear face with an annular seat I33suitably formed to t seat H on the end of the body 6 when the stem i4 is inserted in the enlarged-portion 8 'of the bore l. The stem klil. is of suitable cross sectional formation so that it nts closely the enlarged portion 8 of bore l, and is provided with an eye I6 to adapt it for engagement by the blight of lifting cable 2 as shown in Figs, 2, 3 and 4.

It willV be understood from an inspection of Fig. 4 that the hammer l may be readily assembled and disassembled. In assembly, the end of a cable 22 is inserted through the bell mouthed end 9 of bore l, passed through eye it and through bore l in the reverse direction to form a bight. The cable end may then be secured to the standing part .as shown at I1, or in any other suitable known manner. Impact shoe l2 may then be placed in operative position with its annular seat I3 engaging seat ll of the body 6, and stem i4 inserted in the enlarged portion 8 of bore 1, with the point of cable attachment protected by the body B.

It will be clear that when a strain is placed on the cable 2, the impact shoe l2 will firmly engage the end of body 6, and cable 2 will act on the sides of the more constricted part of the bore l lifting the body 6 andmaintaining the entire hammer I in a proper striking attitude, so long as it is freely pendant. The bell mouth 9 of the bore l guards against any bending of the cable 2 around a sharp edge, or any chang of the cable, at the top of head 6 during hoisting, and tends to guard against chang and kinking of the cable when falling slack after a rock breaking impact of the hammer.

When the impact shoe I2 becomes nearly worn away it may be discarded before any damage has been done to the permanent body 6, and a new impact shoe may be fitted, only a Small percentage of a properly designed impact shoe being discarded as waste material. In the event that the impact shoe becomes sufficiently worn away, so that its head can no longer transmit to body 6 sufficient force to lift the same, there is no danger that, if the head of the impact shoe l2 should be shorn away during a hoisting operation, the heavy body 6 might plunge ydownward endangering the lives of any men who might be working underneath it. Such danger is avoided by so forming the bore 1 that the stem I4 can not, if detached, pass through the bore l in the direction of the cable 2, but must jam against the constricted part of the bore above the enlarged portion 8, and prevent the accidental descent of the body 6.

While the body 6 has been shown as a substantially cylindrical casting it will be understood that its outer form may be, if desired, streamlined or of any suitable external form, the only limitations being that, where one cable is used, the bore l should pass through the center of gravity of the body 6, and the bore 1 must be sufficiently constricted intermediate its length so that the interior surface of the bore will bear against the standing part of the cable when freely pendant, maintaining the hammer I in proper striking attitude with the impact shoe facing downwardly.

While a particular form of the invention has been described and illustrated in the drawing, it will be understood that the invention is intended to include such modications and equivalents as may readily occur to persons skilled in the art, within the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In a drop hammer, a massive inertia body having a bore extending therethrough, said bore being enlarged at one end for a portion of its length, a shoe seat on said body adjoining said enlarged end of said bore, a mushroom shaped impact shoe adapted to engage said seat with the stem closely fitting said enlarged portion of said bore, an eye in said stern adapted to receive in lifting relation a lifting element inserted from the end of said bore opposite said enlarged portion.

2. In a drop hammer, a massive inertia body having a bore extending therethrough, an impact shoe tting and substantially covering one end of said body and having a stem extending into one end of said bore for a portion of the length thereof, a flexible lifting cable extending into said bore and engaging said stem in lifting relation and means in said body to prevent passage of said stem through said bore in the direction of said cable in the event of said stem becoming detached from the remainder of said shoe.

3. In a drop hammer, a massive inertia body having a bore extending therethrough, an impact shoe fitting and substantially covering one end of said body and having a stern extending into one end of said bore a portion of the length thereof, a flexible lifting cable extending into said bore and engaging said stem in lifting relation, said bore being constricted intermediate its length to form a guide surface cooperating with said cable to maintain said body in a striking attitude when said body is freely pendant on said cable.

GEORGE D. BECKER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 9,036 Reaney June 15, 1852 320,818 Sharpneck June 23, 1885 465,153 Bloomer Dec. 15, 1891 565,030 Quinan Aug. 4, 1896 668,998 Napier Feb. 26, 1901 839,246 Williams Dec. 25, 1966 1,240,821 Carezza Sept. 25, 1917 1,926,962 Rotinoff Sept. 12, 1933 2,140,724 Stefan Dec. 20, 1938 2,228,513 Frisbie June 14, 1941 FOREIGN PATENTS Number Country Date 147,696 Great Britain June 23, 1921

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