US1860826A

US1860826A - Hammer rectilinear reciprocation

Info

Publication number: US1860826A
Application number: US386816A
Authority: US
Inventors: Erwin W Tschudi
Original assignee: Black and Decker Manufacturing Co
Current assignee: Black and Decker Corp
Priority date: 1929-08-19
Filing date: 1929-08-19
Publication date: 1932-05-31
Anticipated expiration: 1949-05-31

Description

I 5 Sheets-Sheet l E. w. TSCHUDI HAMMER RECTILINEAR RECiPROCATION Filed Aug. 19, 1929 May 31, 1932.

May 31, 1932. w T$HUD| 1,866,826

HAMMER RECTILINEAR REC IPROCATION Filed Aug. 19, 1929 3 Sheets-Sheet 2 May 31, 1932. E. w. TSCHUDI HAMMER RECTILINEAR RECIPROCATION .3 Sheets-Sheet :5

Filed Aug. 19, 1929 HA L.

. .EBWIN w. rscnUnronBnnrrrrona, MARYLAND, Assrenoa'roi THE iaLAcK & nncxna MANUFACTURING COMPANY, or TQWSON, MARYLAND, A. conroienrron or MARY- v iF-igureil.

Patented May 31, i932 "UNITED sures LAND 1 new.

PA E fl HAMMER aso rinrnnnn nnciraocn'rron Application filed August 19, 1929. Serial No. 386,816.

The invention relates to a powerdriven L-hammerof the type having a rotating driving wheel and .a-reciprocating'hammer piece,

.which isactuated bythe successive blowsof a striker on the wheel. The hammer piece delivers the blow to the tool and is returned The-present inventionirelates particularly. to

suchatoolin which the hammer piece recip .rocates. on. a rectilinear path.

In :the accompanying drawings 1 have illustrateda hammer embodying the features of the invention inthe preferredform.

In the drawings,.-Figure 1 is a vertical cen- -.tral-section;taken on theaxis of, the hammerpiece and'bit, the plane of the section being at right angles to the axis of the striker -wheel.

Figure 2 is asection on the line 22 of Eignre3is -;a section on the line 33 of Figure 1 looking downwardly. (Figure atis a section on the Fi ure 1. n

- igure 5 isan elevation of the tool on a line 44 of .reducedscale looking at the same in-the'oppo site direction :tothat in which Figure 1 is 'taken.

igure v6 is a fragmentary section similar ;t the section, Figure .1, showing. the same hammer having a striker wheel provided 1 with two striker members. 7

V fiFigure'? is an elevation corresponding to :Figure' 1 showing the hammer equipped with anelectric motor.

' Figure-8 is an elevation atrightangles to Fi ure 7.

eferring to the drawings by numerals,

mounted on ashaft'S, to which-it is secured .-in=;any=suitable manner, as by means of keys ;3. Theshaft: ismounted in suitable bean ;;ingsi4; in the fi'ameeor. casing; 1, which bearings may be. enclosed in bosses onthe inside of the casing and bearingat their ends on thesides of the wheel 2, which they serve to position. in Figure 1 includesa handle or grip35. In accordance with the preferred c on-,,

The casingin theform shown 55 I struction, one of the bearings 41: and the corresponding boss may beisupp'ortedona removable plate or coveri6, forming ar removable portion of the casing or frameand providing for the convenient removal, and replacement of the wheel 2. The cons truction also includes a hammer piece '8 mounted I i to reciprocate or slide on a rectilinearpath to which it is confined by a barrel 9 formed. in the frame or casing: l and extending from a point-10 in the'vicinity of the wheel and near one end of the horizontaldiameter to a point 12 near the end of the boss 11 wherethe barrel is closed by aplug 14 suitablybored at 15in alignment with. the axis of thebarrel 9 to receive the shank16 of abit 17 ;which extendsinto the path ofithehammer piece projections arefiat on the'si'de 19,t0ward the striker piece 8, saidflat surface 19 beingwith' one 7 actuate the hammer piece 8 which; striker;

preferably radial ornearly radial and-in in the presentinstance, is a holebored in i the. boss;11 of the casing. This bore is preferably at right angles or substantially at right angles to the horizontal diameter of.

hammer piece Sand at the other end against the plug 14L.- The coil of the helical spring atthe upper end is shownas encircling a;

strikingposition preferably at or nearly? at I right angles to the axis of the barrel 9, which,

barrel 9 and bearingationeendagainst. the '1 boss-21 at the end of the. hammer piece 8.

To position the hammer piece 8 at the end of its return stroke in the path of the'striker projection 18, a stop 22 is provided which may be of any preferred form. In the form of the invention shown itconsists of a lever 24 pivotedintermediately on a stud 25, seated 1. e. threaded or otherwise in the boss 11 par- I allel to the barrel 9. 'Ihis lever 24 extends .a t one end into the path of the hammerpiece 8 on its return stroke, pro ectlng over the.

end of the barrel 9, in which. position it rests on a ledge 26 at the top end of the barrel 11. The other end of the lever 24 is shown as provided with a downwardly disposed tail '28, which bears on the top 29 of the boss 11.

. The stud projects well above lever 24 and-a coil spring 30 encircles the stud 25, bearlng at one end against the bottom side .of the head 31 and at theother end against the top of the lever 24, around the hole '32 in the lever through which the stud extends.

or knocking at the end of theup or reverse 5i stroke. 7

" In the form illustrated in Figures 1, 2, 3, 4

and 5, the striker wheel 2 and particularly the striking projection 18 operates in an arcuate slot 34 formed in the upper end of the boss llinside of the casing, it being noted that the slot intersects the barrel 9 at the top, permitting the striker wheel proper to rotate in close relationship to "and with the hammer piece 8 in its" initial .or retracted position, as illustrated in Figure '1. The 'depth'of the slot 34 is further sufiicient to accommodate the striking projection 18 which, as already pointedout, projects be yond and outward more or less radially-from the peripheral surface of the wheel and into the path of the hammer piece 8, so that at each revolution v the energy stored by the wheel is imparted directly to the hammer piece which it engages at eachlstrokeprojecting it downwardlyto the lower end of the barrel where it dellvers a blow upon bit shank 16 and rebounds as hereinafter described. 7

In the form of tool shown in Figures 1, 2,

3, 4 and5, thestriker wheel shaft 4 may be driven by means of a flexible shaft 38 which as shown is connected direct to the striker wheelshaft 3 in anv suitable manner as means of the coupling 39.

In operation, the tool or bit 17 being placed in contact with the work, the striker wheel shaft 3 being rotated in any suitable manner as by means of the flexible shaft 38 ,the projecting striker member 18 comes in contact once in each revolution with the hammer piece'8 which is normally located in thepath ofthe hammer by the action of the spring 20, being positionedby means of the stop 22. After the first blow the hammer piece 8 is returned immediately by the recoil and by the action of the spring 20 to the posi of the shank 16 of the tool, delivering sharp blows or impacts which are repeated in rapid succession. In each instance the recoil of thehammer piece is quickenouglr'to return it to the path of the striker member projection 18 prior to the advance of the same on the next stroke, a H

The energy of the blow delivered to the tool 17 by'the hammer piece 8 depends on the speed of rotation of the striker wheel2 and on the diameter of the said wheel and upon the moment of inertiaof the striker wheel about its axis. 7 f

In Figure 6- I have shown a hammer-of similar construction to thatof Figurezh etc. except that in this instance the striker wheel 40 is provided with two-striking projections 41 and 42 wherebythe number of strokes or blows is increased or multiplieduby 2.. The

number of projections may be increased-to a maximum depending upon-the relationo'f the and constancy of speed of the

wheel

2 or 40.

In Figures -6 and 7 I have illustrated a portable'power driven electric tool embodying the percussive device alreadydescribed. This construction may bein' any proposed formras shown, there is a handle or grip member-45, to which is connected a'cable 46.

The grip member 47 contains switch mecha- IllSHlIlOi? shown operated by a trigger lever 48.

motor casing :01- housing 49 containing an electric motor :50. The motor -asshown is cooled byafan 51 secured to the lowerend of the motor shaft 52 and surrounded by perforations 53 in the gear casing 54. This gear casing 54 contains a train of reducing/gears 55, including a pinion 56,.which meshesfwith a gear 57 secured to'the striker wheel shaft speed of the hammer piece 8 to the' speed 2 The grip inember45 is secureditoa 58 on which is mounted the'strikerwheel 59 secured to the shaft to rotate therewith,*or the gear 5'? and striker wheel may be secured together. The striker wheel, in turn cooperates witha hammer piece 8 mounted to reciprocate in a' barrel 9 to cooperate with the tool 17, having a shank 16, thefi'h-ammer piece 8 being supported' and' returnedito its normal orinitial position by means ofa spring 20 'and bv'the recoil. The hammer piece 8 is located in the path of thestriker member'18 on thereturn stroke of thehammer piece by means of the stop22'whichis similar to the stop described inconnection with the machine, Figure 1'. T

The operationoffthe electrically driven percussion device is very. similar to that previously described except 'thatfnoi rotating shaft communicating with the outside is necessary to the operation of the tool, the tool being thrown into and out of operation instantaneously by the operation of the switch lever or trigger lever 48.

I have thus described specifically and in detail a power driven percussive device embodying the features of my invention in the preferred form in order that the nature and on a path which is substantially tangential to the path of the striker member, means for supporting a bit'in the path of the ram at one end of its stroke, a resiliently mounted stop means located at theupper end of the ram guide for checking the rebound of the ram at the opposite end ofits stroke and in the path of the striker member and resilient means for supporting the ram in contact with the stop, the stroke of the ram, as controlled by said guide, being so placed and of sufficient length to carry the ram entirely out of the path of the striker, permitting the striker to pass the ram on each full reciprocation.

2. The combination in a portable power hammer of a continuously rotating striker having a striking member rigidly mounted thereon with a striking surface which is substantially radial, a freely reciprocating ram with guiding means therefor enga ed by the ram in sliding relation, causing t e ram to move on a path which is mainly outside of and substantially tangential to the path of the striker member, means for supporting a bit in the path of the ram at one end of its stroke, a resiliently mounted stop means located at the upper end of the ram guide for checking the rebound of the ram at the other end of its stroke and near the point of tangency, resilient means tending to support the ram in contact with the stop, the path V of the ram as determined by the guide causing it to pass completely out of the path of the striker member immediately after con tact therewith whereby the striker member passes the ram on each stroke.

Signed by me at Towson, Baltimore County, Maryland, this 15th day of August,

ERW'IN V. TSCI-IUDI.