US 1934252 A
Description (OCR text may contain errors)
NOV-7, 1933 J. N. BAKER BIT ROTATING DEVICE FOR RECIPROCATING TOOLS 2 Sheets-Sheet l Filed Feb. 2, 1951 Nov. 7, 1933. 1. N. BAKER BIT ROTATING DEVICE FOR RECIPROCATING TOOLS 2 Sheets-Sheet 2 Filed Feb. 2. 1931 Patented Nov. 7, 1933 UNITED STATES BIT `ROTATING DEVICE. FOR RECIPRO- CATING TOOLS James N. Baker, Towson, Md., assignor to The Black & Decker Manufacturing Company a corporation of Maryland Application February 2,
The invention relates to an automatic turning device which is adapted for use with a percussive tool or portable power-driven hammer, being particularly useful in turning a drill bit or the like operated by such a hammer or any type of reciprocating tool.
While the turning device is illustrated in connection with a hammer of a type in which the striker element is driven in reciprocation by Va motor-operated rotary crank and connecting rod, its use and application are by no means and in no way limited to this or any other type of hammer or percussive tool.
While the turning device is especially useful in connection with a star or similar drill or bit serving to rotate the drill as it is struck by the hammer, thus preventing clogging due to the accumulation of particles of cement, stone, etc. previously loosened by the drill, the invention is not limited in its application to this or any particular type of bit. Y
In the accompanying drawings I have illustrated a turning device embodying the features of the invention in the preferred form, the same being shown in connection with so much of a portable power-driven hammer as is necessary to a full understanding of the method'of constructing, applying, operating and using the turning device.
Figure 1 is a side elevation of a portable hammer selected for convenience as a vehicle for the illustration of the invention, the same being equipped with the turning device of the invention.
Figure 2 is a vertical central section taken on the axis of the hammer and broken away intermediately to shorten the structure for convenience of illustration.
Figure 3 is a section on the same line at right angles to Figure 2, certain ofl the parts Within the hammer barrel being shown in elevation.
Figure 4 is a transverse section on the line 4, 4 of Figure 2. I
Figure 5 is a fragmentary elevation showing one of the pawls and the manner of mounting and engaging the same, including the paWl carrier and ratchet. Y
Referring to the drawings by numerals, each of which is used to indicate the same or similar parts in the different iigures, the portable powerdriven hammer, to which the invention isapplied for purposes of illustration, consists of a hammer or gear case 1 to which is attached a barrel 2, and grip 1. The working parts include,
1931. serial No. 512,800
(o1. 25a-43) l in the form of hammer shown, an electric motor 5 which drives through bevel gear 6 `and pinion 7 a crank shaft 8 which operates a connecting rod 9 and piston'rod or thrust rod 10, which in turn reciprocates a pistonlike ram or striker member 11 which is shown as connected to the thrust rod or piston rod 10 by way of and by means of springsv 12. The' details of the hammer structure shown are, as already pointed out, in no Way material to the present invention, being shown merely to illustrate the application of the device to a convenient type of hammer.
The turning device in the preferred form, a shown, comprises a sleeve or tube 15which is mounted to rotate or oscillate within the barrel 2 and within which the piston or ram 11. slides and reciprocates in the operation of the hammer. This sleeve 15 is secured at its upper end to a collar 16, referred to .hereinafter as the ratchet shoulder or shelf 18, the same comprising in the form of the invention shown a portion of the upper surface of the barrel 2 where it projects inwardly from the lower edge of the gear or hammer casing 1 to which it is attached by flange 21. Tool bushing 20 is secured to the lower end of the sleeve or tube 15, and is suitably guided by engagement with a bearing surface 22 formed on the inside of the barrel for this purpose.
In the form of the invention shown'the sleeve 15 has a threaded connection with the ratchet collar 16 and with the tool bushing 20, respectively, being threaded into the insideof ratchet collar 16 at 16 and receiving the tool bushing 20 within the internal thread 23, but these parts' may be held in similar relation in any suitable and convenient manner. The tool bushing 20 is apertured centrally at24 in line with the axis, the aperture being adapted to fit the shank 25 ofthe drill or other bit and to hold the same in such manner as to prevent or substantially prevent rotation of the drill relatively to the bushing, or otherwise to cause the drill to rotate with the bushing.
The ratchet collar 16 is rotatably supported, as already described, at the lower end of the hammer casing or gear casing 1 or a suitable extension 1' thereof which may be chambered at 26 for this purpose, providing a downwardly disposed annular shoulder 27 spaced well above the shoulder 18 already described. An internally shouldered shoulder by the lrelief spring 29 which may be otherwise referred to as the actuating spring of the rotative device.
Between the spring abutment ring 28 and the ratchet collar 16 is a pawl carrier or cylinder 30. This bears at its upper end "againstan Vouter downwardly disposed peripheral shoulderl 3l on the spring abutment ring 28, and at its lower end it may rest on the ratchet teeth 17 or be otherwise suitably supported. This pawl-carrying sleeveor.
cylinder 30 is provided at its lower end with pawls 32, see particularly Figure These pawls as' f shown are provided with circular heads 33 mount'- edge.
and connected to the sockets. urged kdownwardlyY into engageement 'with the teeth 17"of`l'the l ratchet collare 16 by springs 36. ,TheV pawl carrierl SQis'also slotted diagonally at 38,Figure, the lslotbeing inclined'toY the right andextending upwardlyfrom the bottom edgevof ,thecarrierz` This slot is engaged byv a pin y39 projecting outwardlyfrom 'the spring enclosing sleeve140rwhich is located-withinthe carrier and shouldered at its bottom edge at 4ll to support'the spring 29'the rsleeve" 40 in vturn resting at its lower edge on an annular shoulderf42 lformed on andnearthe upperfportion of the ratchetcollar 1 6. Y spring' sleeve -4ojris permitted to slide vertically-being normallyiheld down'lby tension ofjspringjZQjand is'h'elldlagainst rotation by an anchor vscrew 44 which isdriven through the gear 'casing Yor hammer casing i" for this purpose, and engages a verticalslot 45 inthe spring ysleeve 40,. ,This anchorfscrew 44 also passes throughfa rela'- 'tivelyj wide lslotv 146`-Vin thei'pawlV carrier 130 Vand limits'fthe rotation of theY latter; 'Shoulder ,'41 Yis formed on an inwardly disposed ilange47- which projectsv intothe upward or retraction path'ofth'e ramo n V e i. .In the operation of the l*iamrnerl the'v ramfor striker on 'its retraction or` upward` strokefcontactsy the.V ledge or flange 47 at the' lower end of thespring sleevej40, forcing'the sleeve upward againstzthe tension lof the spring l29 and Itending ftoclose the space 48between thejspring sleeve and vthe collar 2 8 -where asunicient vclearancejis provided. This upward.motion-ofthev spring sleeve whichisheld against rotation by the anchorl screw 44 andthe slot 45` engagedthereby, 'as it raises the pin `39 in avertical direction, serves-by engagement of thispin ewiththe inclinedl slot 387,",which may bev otherwisetermeda cam slotfin that it has a camlike operation, torot'atethe pawl carrierinclockwise directionQin accordance v,withthe form of the invention shown, the motion of the carrier being limited by the inclination of the slot 33 andcalso by the width of ,the Vslot 46 in the `carrier as shown in Figure 4. l i 1 This clockwise rotationy or oscillation of the carrier 30 causes the pawls *32j to engagethe ratchet teeth Vl''mo'ving the ratchet collar 16 and henceithe sleeve l5, tool Abushing A.and'thetool in clockwise rotation through an arc corresponding tothe upward motion of V the spring sleeve-i0v and the'inclination of the cam slot 38 in the carrier 30. When the ram' l1 again moves downwardly on theworking stroke,theY spring sleeve is released and moves downwardlyin response to the tension of the` spring 29. 'On this return motion of the sleeve, thefpin 39l engages spring abutment ring 28 is pressed up against this the opposite side of the slot 38, rotating the pawl carrier 30 through a corresponding step or oscillation in the opposite and in this instance in contra-clockwise direction, drawing the pawls 32 backwardly over the ratchet teeth 17 so that they are ready on the next upward or retraction stroke kof therarn'tojre-engage theratchet teeth and move .the collarl, the sleeve 15, the tool bushing V 20 and the tool 25 through a second step in clockwise rotation. By constant repetition of this foperation which is incident to the operation of the hammer, a step by step rotation is thus imparted vto the' tool`giving the desired automatic rotation of the tool whereby the tendency to clog with ed in circular sockets 34Y formedY 'inthewall (off. the pawl-carrying cylinder() near 'the lower! The pawls 32 project downwardly troni@ these sockets into and beyondslotsoiormedin the lower edge of the cylirn'lerfor this purposeV Theipawls are particles of cement, stone, etc. is completely oven come and thel edges are presented in new cutting positions to new portions of the material being cut. Y- Y I have thus described the preferred form of my invention for providing an automatic turning movement of the tool operated by a power hammeror the like; the description being specic as to the `details inorder that the manner of constructing theuinvention in the preferred form,
and operating, applying and using the same may be Vfully understood; however, the specic terms herein are used descriptively rather than in a limiting sense, the scope of the invention being defined in the claims.
' What l claim `as new and desire to secure by Letters Patent isz' i f. i 1'. Ihe combination with a power hammer having a reciprocating ram of a spring having an abutmentspaced backwardly from the ram in the direction of the retraction stroke, an opposite,
yielding abutment for said spring in the path of the ramon saidstroke whereby said yielding abut- YInvent* is lreciprocated by theram and spring, `means 'Vforpreventing rotation of said yielding abutment, a rotary pawl carrier and pawls, means forimparting an oscillating motion to said pawl carrier from said yielding Aabutment as it`recip rocates, aratchet rotated by the pawls and ref. ceivin'gja step by step rotation therefrom, a tool bushing-and means connecting the ratchet Vto the toolbushing to rotate the latter; Y A
2. rifhecombination with a power hammer have ing'ia reciprocating ram of a spring havingjan `abutment spaced backwardly fromr the ram in the direction of the retraction stroke, an opposite yielding abutment for'said spring in the pathiofrtheram on said stroke whereby said yieldingabutment is reciprocated by theram and springjmeansfor preventing rotation of said yielding abutment, a- Yrotary pawl carrier rand pawls, means for imparting an oscillatingmovtion to said pawl carrier from said yielding abut` ment as it `'reciprocatesy a ratchet rotated by the pawlsand receiving a step by step rotation thereffrom, va tool bushing and means connecting the 'ratchet tp `the tool bushing to rotate the latter,
said connecting means beingjin the formof a tube lenclosing theram.
' 3. The combination with a power hammer having a reciprocating striking member of a spring pressed-"abutment moved in opposition to the cured at one end to the ratchet ring and enoircling the striker, and a. tool bushing secured to the other end of said tube.
4. The combination with a. power hammer having a reciprocating ram of a spring pressed member moved in opposition to the spring by the retraction stroke of the ram, said member being returned by the action of the spring, means for preventing rotation of said member, a pawl carrier, means for oscillating said pawl carrier from said member, means for limiting the oscillatory motion of the pawl carrier, pawls carried thereby, a ratchet receiving a step by step rotation from said pawls, a tube secured at one end to the ratchet and encircling the striker, a tool bushing secured to the other end of said tube and an abutment supporting said spring oppositely to said member, said abutment and said ratchet serving as opposed stops for preventing motion of the pawl carrier in the direction of reciprocation of the ram.
5. The combination in a portable power hammer having a reciprocating ram of a member in the path of the ram to be operated by the return stroke of the ram to move in the direction of retraction of the ram, a spring moving said member in the opposite direction whereby said member is reciprocated in the direction of the path of the ram, means for oscillating said member about the axis of the ram as it is thus reciprocated, and ratchet and pawl mechanism operated by said member as it oscillates to impart a step by step rotary motion to the tool.
6. The combination in a portable power hammer having a reciprocating ram` of means in the form of a sleeve in the path of the ram to be operated by the return stroke of the ram to move in the direction of retraction of the ram, a spring moving said sleeve in the opposite direction,where by said sleeve is reciprocated in the direction of the path of the ram, means for oscillating said sleeve about the axis of the ram as it is thus reciprocated, and means comprising a ratchet and pawl mechanism operated by said sleeve and a ram guide carrying a tool support at one end and one element of said ratchet and pawl mechanism at the other end for communicating a step by step rotary motion to the tool.
7. The combination in a portabley power hammer having a reciprocating ram of means in the form of a sleeve in the path of the ram to be operated by the return stroke of the ram to move in the direction of retraction 0f the ram, a spring moving said sleeve in the opposite direction, whereby it is reciprocated in the direction of the path of the ram, means for oscillating said sleeve about the axis of the ram as itis thus reciprocated, and means comprising a ratchet and pawl mechanism operated by saidl sleeve and a ram guide in the form of a tubular member carrying a tool support at one end and one element of said ratchet and pawl mechanism at the other end for communicating a step by step rotary motion to the tool.
- JAMES N. BAKER.