US2833173A

US2833173A - Rotary impact hand tool

Info

Publication number: US2833173A
Application number: US633107A
Authority: US
Inventors: Reginald J Aspeek
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-01-08
Filing date: 1957-01-08
Publication date: 1958-05-06
Anticipated expiration: 1975-05-06

Description

' May 6, 195s R. J. ASPEEK 2,833,173

VROTARY IMPACT HAND TOOL Filed Jan. 8, 1957 2/ ||I `IlZ Z L i United States .,'lih-is invention relates to fa hand tool and .more Apar;

ticularly toa self-contained hand tool. for tightening or Y loosening screws, bolts, nuts or the` like by the translation of the impact force of an axially movable mass into a rotational force.

v The prior art discloses a number `of axial impact screw driver or wrench-type hand tools which require the use of vtwo hands in their operation. That is, they must vbe) held by one hand while the other hand wields a hammer, the momentum of -the mass of the head of which is appropriately translated through the impact tool into the` desired threading orv unthreading rotational movement.V

It is an object of the present invention to provide'a self-A contained tooll which does not derive its impact force through an auxiliary 'implement such as.a-separately` wielded hammer head. Y

` ram member 12 is circular in cross-section.

2 designated-10. Thetool 10 comprises a square crosssection elongated Yshaft or stem 11. Slida'bly mounted on the vshaft or stem 11 is a tubular ram -member 12. In its retracted position, as shown in Fig. 1, the ram member extends substantially above the upper end of the shaft or stem 11. Contained within the hollow portion of the ram member 12 is a compression spring 13 adapted to restore and maintain the tubular ram member in its inoperative retracted position. The spring 13 reacts between the upper end 14 of the stem 11 and a threaded plug 15 closing the upper end of the chamber in the tubular ram member 12. I

The upper end of the tubular ram member 12 carries a heavy handle mass 16 which may be castiron molded to substantially the elliptical contour illustrated. It is an importantfeature of the present invention that it be understood that this handle mass 16 is a. connected or integral part of the tubular ram member 12. The'lower end of the tubular ram member -is provided with two helical lobes 17, the apexes of whichare 180"` apart. v

It will be noted that the central hole 18 of thetubular The ram member is Vthus freely rotatable about the stem 11.- A positioning means is provided to releasably maintain the ram member 12 in pre-selected positions relative to the stem 11. Referring toFignZ.. the tubular ram member In its preferred form the axial impact tool comprises an elongated stem encompassed by a tubular ram member slid-ably and rotatably journalled on the upper portion of said stem. 'The tubular ram members carries at its upper end a heavy handle mass. At its lower end,

the tubular ram member is provided with axially dependt ing helical lobes. is a tool bit adaptor having laxially extendinglob'es on the upper end thereof. The ram member lobes andthe tool bit adaptor lobes are normally in spaced axial rela- Secured to the lower end of said sternY l v tionship to each other, the -tubular ram member being;

vrelationship to the tool bit adaptor lobes when said lobes are axially spaced from one another. The predetermined radial relationship .is utilized .to predetermine the direc-y tion of rotation of the tool bit adaptor upon thehandle mass being driven downwardly to cause impact engage. ment of said opposed lobes such as will'cause rotation of the tool bit adaptor. y.

Further objects and advantages and the features of construction embodied in the present invention will be apparent from the following description l.and appended claims, reference being had to the accompanying drawing yforming a part of this specification wherein like reference numerals designate corresponding parts in the several views:

.Fig l` is a vsectional elevation of a ,tool fitted with an adaptor anda screw driver bit. v I

Fig. 2 is a sectionview takensubstantially through the line 2-2 in Fig.v 1 looking in' the direction of the arrows. Y.

'Before explainingin vdetail thepresent invention, yit to" be understood that the inventionis not limited irrits application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carried out in various ways.

In the drawing there is illustrated, by way of example, a preferred embodiment of the impact tool, generally 12 is provided with a pair of diametrically opposed pinsl 19. The pins 19 are yieldingly maintained in engagement with .the stem faces bymeans of a steel spring band or circular clip 20 exteriorly embracing the tubular Aram member. Also carried on the exterior of the vtubular ram member 12 is a sleeve 21 which may be slilablymoyed downwardly over the band or clip v20.y When-so positioned, the pins 19 are rmly held against outward movement and lock the tubular ram member 12and the st em 11 against relative rotational movement. 1 f

The lower end of the stem 11 has secured thereto a tool bit adaptor 22 provided with a pair of helical ylobes237 on the upper end thereof. Thel 'apexes of the lobes 23 are'also spaced 180 apart, as were the apexes of thelob"e`s` 17 on the lower end of the tubular-ram member `12.

It will be noted that the apexes of the one set of lobes 17 are displaced relatively to the vapexes-'of the4 other set of lobes 23. This displacement is preferably 45circular degrees. This relative displacement is 'always maintained through the control that the'pins 19exert on the posi- 'tionng of the tubular ram member Y12. on the shaft or stem 11. The diametrical axis of the pins -19`is so positioned relative to the location of the apexes of the vlobes 171that the latter are always maintained at al 45"A displacement relative to the apexes of the lobes ,23 which are in iixed relationship to the shaft `or stem 11.y I i The l toolv bit adaptor' 22 may be'of any. conventional type adapted tonen-rotatably hold Ya tool such as alscrew driver bitz4. `1

lImpact tools are particularly useful for sta'rting'gscrews, bolts, nuts or the like which resist turning movementby an" ordinary rtool because of damaged ',tlireads orbecause l they have become' frozen in position'by corrosion; v'To dislodge-such a'screw', bolt, nut or the like with'the iinwill be rotated in th'e proper direction. `Avs4 `shown inl 1, `engagementy of ythe lobes 1.7` with .thel'lbes '231 will-'resultl in thetool bit being rotated ina 'countercloc'k-f wise direction. Should it -be desired to have the tool bit 24 rotate in a clockwise direction, it is only necessary to rotate the tubular ram member 12 ninety degrees in either direction relative to the stem 11. The spring clip` 20 will permit the pins 19 to move outwardly'a suicient distance so that the tubular ram memberv 12 may be rothe square corners of the stem, they` will snap back into` position so as to align the lobes 17 in proper relationship to the lobes 23. V

The tool having been set so that the tool bit `will be turned in the proper direction, the'head 25 offthe toolbit is then engaged with the object to beloosened. The handle portion or mass 16 is then-graspedand manually driven downwardly. The momentum ofthe vmasstiwill" be transmitted through `the tubular ram member 12 to the' adaptor 22. Because `of the helical relationship of the lobes 17 to the lobes 23, a component of the impact force will tendtto causethe adaptor to rotate. Inasmuch as the adaptor is rigidly secured to the end of the stem 1l, the stem `11 will also tend to 'be rotated relatively tothe tubular ram member 12. The pins 19 will permitthis since they will be driven outwardly against the tension of the `spring clip4 20. However, the degree of travel caused by the helical relationship of the lobes is such that the relative rotation caused is less `than 90 and it will not `be necessary to reset the tool in order to repeat the impact movement. t t f The `tool embodying the present invention has'the particular-advantag`e that the weight mass 16 is a partof the tool. Therefore, only one hand is 'needed to manipulate the tool. `Thisrisa highly desirable characteristic when the tool is `to be used under conditions where there is insutlcient room toswing a'hammer.

After `the object to be un'thre'aded has been loosened, it is Iorilylnecessary to drop thesleeve 21 down over the spring clip 20 thereby locking: Athe tubular ram member 12 to the stem 11 `and the tool may then be used as a conventional device to complete the removal of the threaded object.'

Y Iclar'nzfgfm 1. Angaxial; impact type "rotary tool comprising an elongatedetem atleast a portion of whichis of square cross``section,`a tubular ram member slidably and rotatably journlledon the upper portion'of said stem, an integral heavy handlemass carriedkon the upperend Aof saidV ram-member; thelower end fof said ram member being provided with a 'pair of axially depending diametrically positioned helicalflobes, a tool bit adaptorhaving a pair of axially upwardly extending diametrically positioned helical lobes o'npthe upper end thereof, 'said' pairs of lobesgbeing normally in axially spacedzrelationship to each othei-jand'lpositioning means effective to maintain `saicl ramdneniber in'a pre-selected position on said stem whereby the apexeslof the ram: lobes are normally radially displaced ononfe side or the other o f the apexes of the tool bit adaptor lobes, said radial relatio11' ship determiningthel dire'ctiorliV ofrotation: of the tool bit adaptorpon the handlemassfbeing driven downwardly to cause' impact engagementiof said opposed `lobesfsuch as willresult in rotationpofpthe tool bitfadaptor, said,V

positioning means comprising diametrically t opposite pins carried in `said v#ram "member ,radially engagedwith oppo-.

site faces of the stern square portion, and s prin'gmeans encircling l'sad ram membernormally yieldingly, maintaining said pins in sternengagingsipos'ition elongated stem` atleastfa portiontoflwbichis of square cross-section, a tubular ram memberslidably and ,rotatf ably journalled on the upper portion ,of said stem, an

integralheavy handle mass carried `println; `upper end of Vpositioned helical lobes on the upper end thereof, said pairs of lobes being normally in axially spaced relationadaptor upon the handle mass being driven downwardly to cause impact engagement of said opposed lobes such as will result in rotation of the tool -bit` adaptor, and spring means contained within said ram member and compressed against the upper end of said stern to retract i the same after completion of the impact stroke, said positioning means comprising diametrically opposite pins carried in said ram member radially engaged with opposite faces of the stem square portion, spring means encircling said ram member normally `yieldingly maintaining said pins in stern engaging position, and a sleeve encircling said ram member and positionable over said spring means to non-yieldingly maintain said `pins in stem engaging position.

3. An axial impact type rotary tool for turning a threaded object, comprising an elongated stern at least a portion of which is of square cross-section,` a tubular ram member `slidably `and rotatably journalled on the uppervp'orti'on of said stem, an integralheavy handle mass carried on the upper end ofsaid ram member, the lower `V end of said ram member being provided with a pair of axially depending diametrically positionedhelical lobes, a tool lbit adaptor'having a pair of axially upwardly extending diametrically positioned helical lobes on the upper end thereof, said pairs of lobes being normally in axially spaced relationship to each other, positioning means effective to maintain said ram member in a pre-selected position on said stem whereby theapexes of the ram lobes are normally radially displaced approximately 45 on one side or the other of the apexes of the tool ybit adaptor lobes, 'said radial relationship determining the direction of rotation of the tool bit adaptor `upon the handle mass being driven downwardly to cause impact engagement of said opposed lobes such as will result in rotation Vof the tool bit adaptor, spring means contained within said ram member and compressed against the upper end of said stem to retract the same after completion of the impact stroke, and sleeve means positionable to block such movementof said pin means as would permit relative rotational movement of the ram member about Said stern, said positioning means comprising diametricallyu opposite pins carried in said ram member radially engaged with opposite faces of the stemsquare portion, spring means encircling said ram member normally yieldingly maintaining said pins in stem engaging position,`

and a sleeve encircling said ram member and positionable over said spring means to non-,yieldingly maintainA saidpins in stem engaging position.

2,010,616 Walsh Aug. 6, 1935 2,631,484 Spielman Mar. 17, 1953 2,633,042 Halverson Mar. 31 1953 2,635,497 Spielman Apr. 2l, 1953 2,638,806 Spielman May 19, 1953 FOREIGN PATENTS 61,912 France Dec. 15, 1954 710,707 Great `Britain June 16, 1954 .1,009,278

Prancev- Mar. 5, 1952