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Publication numberUS1511566 A
Publication typeGrant
Publication dateOct 14, 1924
Filing dateJul 12, 1923
Priority dateJul 12, 1923
Publication numberUS 1511566 A, US 1511566A, US-A-1511566, US1511566 A, US1511566A
InventorsGeorge L Kollock
Original AssigneeGeorge L Kollock
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electric hammer
US 1511566 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

Oct. 14 1924. 1,511,566

G. L. Ko|- l ocK ELECTRI C HAMMER Filed Judy 12, 1923 ATTORNEY Patented Oct. 14,- 1924.




-Application led July 12,

I To all 'whom t may concern:

Be it known that I, GEORGE L. KoLLocK,

la citizen of the United States, residing at a cam driven by an electric motor.

Another object resides in the novel construction of a double or duplex cam mechanism for operating the striking member,

said mechanism embodying one cam member r having a plurality of, roller bearings embedded in the bearing surface thereof and another cam vmember movable on said roller bearings. g l

Another object is to provide novel and elficient means for guiding the reciprocating striking element of the hammer said guiding means being arranged to absorb the torque that is transmitted by the cams to striking member without causing undue wear and without causing said striking mem- .ber to bind and thereby become less efiicient in operation.

With the above and -other objects in view .the invention consists in the novel features vof construction and comblnatlon of parts,

the essential elements whereof are recited in the appended claim and a preferred form of embodiment of which is hereinafter described and fully illustrated.

I accomplish these objects by devices illustrated in the accompanying drawings, wherein- Figure 1 is a view in longitudinal midsection of a tool constructed in accordance with my invention parts being shown in elevation and the striking member being shown elevated;

Fig. 2 is a fragmentary longitudinal sectional view in a plane at substantially right angles to the plane of the section of Fig. l; Fig. 3 is a view in cross-section on two different planes substantially on line 33- of Fig. 1; and l Fig. 4 is a view of one of the cam members showing the same as it may,A appear if laid out on a flat lain.

Referring to e drawings throughout 1923. Serial No. 651,028;

which like reference numerals indicate like parts, I have shown a housing comprising an upper cylindrical housing member 6 and a lower cylindrical housing member 7 that are detachably joined by a fitting ring 8. Y

The lower housing member 7 is provided'at the outer end with a tubular shank 9 of a smaller diameter which terminates in a convergent end l0 provided with an axial opening 11 herein is fitted 'a bushing 12 through which the end of a tool, not shown, may be inserted. Perforations 13, to permit a free inlet and outlet of air, are provided in the end l0 aroundthe opening l1.

The bottom end of the housing member 7 is internally counterbored where it joins the smaller shank 9 to form two shoulders 14 and l5 whereon a base 16 and a peripheral liange 17 of a suitable bearing vplatejmay rest, the base portion 16 being threaded into the counterbore, as more clearly shown in Fig. 2, said bearing plate is provided with.

'an upwardly protruding centrally arranged tubularbearing member 18.

An annular plate 19 is secured by screws 2O to the top of the flange 17 to form a more substantial support through which two diametrically opposite guide posts'. 2,1 and 22 that are parallel with the axis ,inofkg'the hammer may4 be threaded. The guide postsv 21 and 22 are supported attheir upper ends in a bracket 23 that is securedwithin the upper end of the housing 7.

, .A lower driven cam member24 is mounted on the tubular member 18 and 'is supported on a ball thrust bearing 25 that restson the base-plate 16. The lower cam member 24 is provided on its upper end with two relatively long cam surfaces 26 and 27 that arev inclined at a lesser angle and with two diametrically opposite abrupt oii'sets 28 and 29. The cam surfaces 26 and 27 are provided at a plurality of points with radially arranged rollers 30 rotatably disposed in segments of bearing sleeves'l that are embedded in the cam in a manner more clearly shown in Fig. 4 so that theperipheral portions of the rollers 30 will project a short ldistance above the plane of th surfaces 26 and 27. The rollers 30 and cam sleeves 31 are preferably tapered and are retained in place by a sleeve 32 that fits over the outside of the cam and is secured thereto.

A non-rotatable cam 33 shaped to fit the cam'24 is larranged to seat on the rollers 30 lll cylindrical shank 34, herein `termed a striking member, that extends downwardly lthrough the tubular bearing member 18 into the housing shank 9. The lower en d of the striking member 34 is provided with an annular groove, not shown, wherein is disposed a split ring 35that forms an annular flange on which a compression vspring 36 may rest. The upper end of the spring 36 ab-u-ts the plate 16.

A buHer spring 37 is disposed within an annular' recess 38 in the bottom of the shank 9, the recess 38 preferably being undercut or of larger diameter than. the interior ofthe shank 9, as shown, so that the buffer spring may be crowded down into said recess when compressed but will not-snap entirely out of the recess when expanded. The buffer spring is arranged to catch the striking member just before it reaches the end of its stroke and` thereby prevent damage being done to the several parts of the hammer;

The lower cam member 24 is externallyy provided with gear teeth 39 -that -meshes with internal pinion teeth 40 on the lower end of a jack shaft 41. The upper end of the jack shaft 41is secured to a gear pinion 42 which mesh with an idler pinion 43 which, in turn, meshes with a pinion 44 on the driven shaft 45 of a motor 46 which is disposed within the upper housing member 6 and may be any desired style and type of electric motor capable of generating enough power to operate the hammer.l A bracket 47 aii'ording a bearing 48 for the motor shaft 45 -between the' motor 46 and gear pinion 44 is provided in the 'housing member 6. The upper eIid of the jack shaft 41 is journaled in the bracket 23 and the lower end of said 'jack shaft 41 terminatesin a bearing stud v49 thatis journaled in the plate 19 and flange 17.

The non-rotatable cam 33 is provided with semi-circular guide members 50 thatfit over the guide posts 21'and 22 and prevent rotation of said cam 33 when the cam 24 is rotated. This particular mechanism for resisting the torque due to the rotation of cam 24 has been found to be exceptionally efIicient and durable and to be free from any binding effect that might tend' to lessen the efficiency of the hammer.

.The `upper housing member 6 is provided with a suitable handle -51 having an inlet 52 for electric circuit wires 53 by which electric current is supplied to the motor 46, and

suitab e switchmechanism operated ger piece 54 for controlling the flow 4of such electric current.

Th'ecam member' 24 rotates at relatively high speed and therollers 30 adjacent they abrupt `shoulders 28 and 29 Aare near enough to said shoulders so that there will be no sliding 4contact between the two cam members at. the time the shoulder portions of the upper cam member drops from the corresponding -shoulders 28 and 29 of the lower cam.V

In operation, when the motor is rotated, rotary movement will be transmitted through gear pinions 44, 43, 42, jacks'haft 41, and gears 40 and 39 to the lower cam to impart a rapid succession of upward movements to cam 33 and striking member 34 each of which m-ovements will compress the spring 36 which will expand and drive the striking member outwardly to strike a blow each time the upper cam -member 33 drops from the abrupt shoulders 28 and 29 of Ithe lower cam member 24.

The foregoing description and accom anying drawings clearly7 disclose what now consider to be a preferred embodiment of my invention bu-t it will be understood that this disclosure is -merely illustrative and ber rigidly secured to the housing and rest-- ing on said shoulder, an axially arranged tubular bearing member on said fitting, a cam rotatably mounted on said bearing member, a striking member reciprocable within aid tubular member, another cam secured to the upper end of lsaid striking member and arranged to engage with and be reciprocated by said-first na-med cam, acollar forming an extei-nal flange at the lower end of said striking member, a com-pression spring arranged to bear against said collar, guide posts e'xtending axially of said casing,means on said lupper cam for slidably engaging said guide posts to prevent rotation of said upper cam, a gear on the periphery of said lower cam,

a Jack. shaft mounted for rotation in said'I housing, a pinion onv the lower end of said jack shaft meshing with said ear, a pinion on the upper end of said jack aft; a. motor mognted in said housing and having a driven Ishaft arranged axially of said housing, a pinion on said motor shaft, and an idler gearA interconnecting the pinion on said motor shaft and the jack shaft.

In witness pinion on the upper end of the whereof, hereunto subscribe my name this day of July, A. D. 1923.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2436450 *Oct 24, 1942Feb 24, 1948Price Vernon LPercussion tool
US2643649 *Aug 20, 1949Jun 30, 1953Tarwater Railway Supply CoElectric tie tamper
US2794621 *Jun 11, 1951Jun 4, 1957William D SellersDrilling attachments
US2834384 *Aug 2, 1955May 13, 1958Cascades Plywood CorpVeneer joggers and jointers
US2905034 *Apr 18, 1958Sep 22, 1959Turner Ralph MReciprocatory impact hand tool
US3080008 *Mar 2, 1959Mar 5, 1963Hendrickson John JDrive mechanism for rotary impact drill
US3123156 *Apr 16, 1959Mar 3, 1964 gapstur
US3315643 *Sep 9, 1963Apr 25, 1967Eratico Rose RWriting implement mechanism
US3513918 *Aug 15, 1968May 26, 1970Hughes Tool CoSafety improvements in cam-and-spring operated impact tool
US4343456 *May 16, 1980Aug 10, 1982Galtek CorporationPlastic control valve
US7032687Sep 23, 2002Apr 25, 2006Mk-Produkter Mekanik & Kemi AbPercussion device
US7690274Nov 18, 2004Apr 6, 2010Thermo Fisher Scientific OyPipette with a tip removing mechanism
US7717191Nov 21, 2007May 18, 2010Black & Decker Inc.Multi-mode hammer drill with shift lock
US7717192Nov 21, 2007May 18, 2010Black & Decker Inc.Multi-mode drill with mode collar
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US7987920Apr 26, 2010Aug 2, 2011Black & Decker Inc.Multi-mode drill with mode collar
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US20070012466 *Feb 10, 2006Jan 18, 2007Stefan SellHammer
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US20090126954 *Nov 21, 2007May 21, 2009Black & Decker Inc.Multi-mode drill with an electronic switching arrangement
US20090126955 *Nov 21, 2007May 21, 2009Black & Decker Inc.Hammer drill with hard hammer support structure
US20140338945 *May 8, 2014Nov 20, 2014Robert Bosch GmbhHand tool device
EP0477576A2 *Aug 29, 1991Apr 1, 1992Robert Bosch GmbhImpact drilling machine
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U.S. Classification74/56, 173/203, 74/567
International ClassificationB25D11/10
Cooperative ClassificationB25D2211/065, B25D11/102
European ClassificationB25D11/10B