US2392097A

US2392097A - Reversible close quarter drill

Info

Publication number: US2392097A
Application number: US497167A
Authority: US
Inventors: Leon F Meunier
Original assignee: Chicago Pneumatic Tool Co LLC
Current assignee: Chicago Pneumatic Tool Co LLC
Priority date: 1943-08-03
Filing date: 1943-08-03
Publication date: 1946-01-01
Anticipated expiration: 1963-01-01

Description

Jan. l, 1946. L. F. MEUNlER REVERSIBLEVCLOSE QUARTER DRILL] EFiled'Aug. 5, 1943 s sheets-snee; 1

/9 ATTORNEY Jan. 1 1946.

| MEUNIER REVERSIBLE CLOSE QUARTER DRILL 3 sheets-sheet 5 Filed Aug. 5, 1943 Patented Jan. 1, 1946 UNITED STATES PATENT OFFICE REVERSIBLE CLOSE QUARTER DRILL Leon F. Meunier, Cleveland, Ohio, assignor to Chicago Pneumatic Tool Company, New York, N. Y., a. corporation of New Jersey Application' August s, 1943, serial No. 497,161 9 Claims. (emr-472) This invention relates to portable power driven close quarter drills or tools adapted for tapping, drilling, screw driving, reaming etc., andparticularly to reversing means for the mechanical drive thereof.

The general object of the invention is to provide a portable drill or tool of the type indicated with special reversing means capable of driving the drill in either direction at will, although the prime mover furnishing the power is capable of rotation only in one direction. The use of a unidirectional motor overcomes certain well known disadvantages of prior drills in which motors of the reversible type are resorted to. In the Case of a pneumatic motor, the reversing throttle structure and complicated porting arrangement add to the bulk, weight and cost of the drill. In an electric tool, on the other hand, the sudden reversal of power supply while the motor is running under its momentum would cause dangerous current surges, and therefore it is usually found necessary to provide a special brake to stop the motor mechanically before the switch can be thrown into reverse.

A specific object is to enable the operator to control both the reversing gears and the power connections to the motor by the manipulation of a single control element, which also forms a handle for supporting the drill.

Another object is to provide a portable power driven tool or drill with a practical type of reversing means which is reliable and durable despite the limited space available in such a tool, thereby eliminating any need for bulky or heavy conventional reversing devices.

A further object is the provision of a high ratio speed reduction mechanism to enable the drill spindle to be driven by a high speed, high frequency electric motor, with consequent freedom from vibration during operation.

It is also an object to embody. the principles of the invention in such a efiicient design of the parts of a portable power driven tool that lightness of the resulting assembly and accessibility of the interior for repairs as well as replacement of parts without sacricing efficiency, power or smoothness of operation will characterize the tool as a whole.

Other Objects and the various advantages inherent in the nature and construction of the invention and accruing from the application thereof in actual practice will appear more fully in detail as this specification proceeds.

In order to facilitate ready comprehension of the; no ve'l features and constructional details, theJ invention is illustrated in the accompanying drawings forming part hereof and in which:

Fig. 1 is,V a side elevation of a portable power driven close quarter. drill or tool made according to this invention and embodying the salient features thereof, the view indicating how the tool may be held in the handsv of an operator;

Fig. 2 is a vertical longitudinal section of the same tool serving to disclose interior details of construction and relations of parts;

Fig. 3 is a cross section of the apparatus taken on line 3-3 in Fig. 2;

Fig. 4 isanother cross section of the same taken approximately on line 4-4 in said Fig. 2;

Fig. 5 is also a cross section of said apparatus taken on line 5 5 in Fig. 2, looking rearward;

Fig; 6 is a fragmentary view, looking forward, showing parts of the apparatus disclosed in Fig. 5 occupying an intermediate or neutral position;

Fig.,7 is a further cross section of the apparatus taken on line 1-1 in Fig. 2 showing substantially the same parts from the side opposite that shown in Fig. 5; Y

Fig. 8 diagrammatically illustrates a different stage of operation of the movable parts shown in Figs. 5 and '7, the view being taken along line 8--8 in Fig. 2; v Y v Fig. v9 also illustrates[diagrammatically the same parts at an opposite stage of operation;

Fig. 10 is a plan view of the apparatus of Figs. 1 and 2 with the top removed to reveal interior detail, an intermediate portion of the length being broken away;

Fig. 11 is an enlarged perspective view showing a pair of gear segment-levers of Figs. 5 to 9;

Fig. 12 is a fragmentary horizontal section of the apparatus of Fig. 2 as taken on line l2-I2;

and Y f Fig. 13 is another fragmentary horizontal section of the same taken on line I3-i 3 in the same Fig. 2. Y

Figs. 10, 12 and 13 are drawn to a smaller scale than Figs. 3 to 9 inclusive but to a larger scale than Figs. 1 and 2.1 Y

VThe same references parts throughout the views.

In power driven tools of the portable type and especially in close quarter drills utilizing ratchet lever and pawl means for rotating the tool spindie, it is very desirable to enable reversal of rotation of the tool spindle at will. Ordinarily this would entail use of a reversible motor or, if a nonreversible motor were used, conventional reversing mechanism would be included which is more 'orless bulky-and heavy. and notV well suited for indicate the same or like* It is therefore proposed to avoid reversing. the.

motor and instead. introduce a very eifective and simple reversing device which is combined with a ratchet drive, together with complete remote control of the apparatus involved winch substantially fulfills the foregoing objectswhile avoiding the mentioned disadvantages,r and in addition Y forming a practical solution-toseveral'l problemsin this eld.

Hence referring again to the drawings, in the that said pawls may be withdrawn within the Section outline of said spindle as particularly evident in Figs. 10 and 12.

Further each pawl 55 and `56 is retained in assembled association with the spindle, primarily by the same having an enlarged cylindrical rear end 59 occupying a corresponding seat 60 in the body of the spindle which allows the pawl to swingA from withdrawn position in pockets or recesses 51 or 58 within the spindle outline out into active contact with the teeth of internal ratchet 45. Each pawl is also confined in position by the walls of the pocket in which it is located, and in each case a spring 6I is preferably recessed in the rear wall of the pocket involved and also in the corresponding pawl so as to tend to swing said pawlout into active engagement with the practice of the invention an electric motor generally indicated at I4 is enclosed within a. casing I5 (Fig, 2) and comprises a rotor I6 mounted on a shaft I'1 which is rotatable in bearings I8 and I9. Ihe shaft I1 carries upon its. forward end a. pinion 2l) axially retainedv on` theshaft by a collar 2l: and meshing with aV gear 22 fixed ona transverse "shaft 23. In order to ventilate and cool the motor: during operation, a conventional fan 24 is xed on the motor shaft I1 within a plurality of peripheralopenings 25. at one. end ofthe motor casing I5 and tends to drawk out air passing through the motor fromv a plurality of rear side openings 26 in said casing. Rearwardly the motor bearing I8 has an outer race 21 retained in position by means of a plate 28 held by a screw 29 on the rear wall 30 for the motor casing, While the front bearing I9 has the outer race 3| thereof retained` in place in the forward end Wall or;

partition 32 by means of a plate 33` held on said Wall by a screw or screws 34. Ther front end wall or partition 32 is secured by bolts 32- (Fig. d4) to. the. end of motor casingV I5 and to said partition is' attached a ratchet drive casing 35 by any suit-- able means known in the art and' provided

witht bearings

36, 36 for the transverse shaft 23 which may be termed the drive shaft.`

Upon this drive shaft a spur gear 31 isI rigidly secured which` meshesi with a larger gear 38Lfxed. on a crank-shaft 39 rotated in bearingsy 4d, 40. mounted in

casing.35inparal1elismwith bearings

36, 36. Y

The crank-shaft 39 is formed with twocorrespondingly opposite cranks 4I, 42 individually oscillating a pair of similar ratchet members 43 by means of bearing blocks 44 slidablymountedbetween gibs I2l and I3 (Figs. 2, 10 and 12) forming the rear ends of said members, while the otheror forward ends of the latter are each formed with an internal ratchet 45. Each ratchet surrounds a rotary tool spindle 46 mounted in anA upper bearing 41 and a lower bearing 48 located in the forward end or head 49. of casing 35, thev lower bearings being removably held in position by a screwed ring 50 which also allows removal of the tool spindle for replacement or repairs. The latter spindle is of more or less conventional construction, and is recessed'to receive the lower end of a feed screw 5I supported in a collar 52 fitting into the upper hub portion 53 of casing head 49.

The ratchet members are oscillated atl their rear ends by the cranks 4I, 42 to` which they are connected and in order to translate their oscillations into torque impulses imparted to the drill spindle, the latter is provided with two groups of

centrifugal pawls

55, 55 and 56,` 56 recessed into pockets 51 and 58 in the sides ofthel spindle so ratchet surrounding the spindle. If then one set of pawls consisting of pawls 56, 56 as shown in Figs. 10 and 12 are free to swing out and engage internal ratchet 45r as urged byfsprings 6I, assuming'that: the. motor is actively driving crankshaft 39, thevlatter` will rapidly oscillate ratchet membersv 43 and by means of said pawls 56 engaging the ratchets within said members will consequently rotate spindle 48 in clockwise direction.

Shouldv the mentioned set of pawls be withdrawn into their pockets by suitable means and the other set consisting'ofpawls'55, 55 be released instead, the oscillation of the ratchet members, although still continuing in the same manner as indicated', will nonetheless cause the spindlev to be rotated by said pawls in the opposite or counterclockwise direction. While merely two opposed sets of pawls may be arranged to form a group to'bek operated byl bothratchet members, it

is preferred to use. two such groups of pawls in superimposed relation, one group for each ratchet member, with. the lower group extending to the bottom of each pocket 51 or '58' in the spindle While theupper group rests directly on the lower group and extends up to the inner race 63 of bearings 41 (Fig. 2), thereby preventing axial displacement of the pawls in both' groups.

Thus far it has beenA disclosed hcwthe motor, by'causing continuous rotation of the crank-shaft and' therefore also continual oscillation of the ratchet members, thereby causes rotation of theI tool spindle 46. It is consequently now'in order to consider the. means for controlling the direction of rotation of the spindle caused by the oscillation of the ratchet members while the motor rotates exclusively in one direction. To this end, spindle'46 carries a gear 64 keyed thereto at 65 so as to be positively rotated therewith, said gear meshing with a pinion 66 splined by a key 61: in a keyway 62 on a vertical reversing shaft, 68 which is parallel with the spindle and rotatable therebyin a lower bearing 69 and an upper bushing 10 fixed in casing 35 in a position intermediate the spindle andcrank-shaft 39; Reversing shaft 68 is axially slidable and formed with a reduced portion 1I surmounted by a widehead 12 at the upper end thereof. Referring to Figs, 2, 3 and 13, a rack 131which is bifurcated rearwardly by a 'slot 14' straddles the reduced portion 1I and is positively displaced in axial directions withsaid shaft due to its association with the reduced portion between head' 12 and shoulder 15 dening the upper and lower limits of said reduced portion. While the rack is thus assembled with the reversing shaft, the latter is rotatable with the reduced portionv thereof in slot 14 of the rack and in order topositively hold said rack against rotationI with the shaft, the rack in all' positions of axial displacement is located between the sidesof an open vertical slot 16 in the upper end of bushing 18.

As may best be seen'in Figs. 3 and 13, a sector leverl 11 meshes with the rack and is xed on the forward end 18 of a transmission shaft 19 (to be further described hereinafter) said end 18 being square and fitting a corresponding square hole in said lever to ensure positive rotary movement of the latter with said shaft. This rotary movement is limited to partial rotation with corresponding limited rise or fall of the rack as well as vertical shaft 68 for the purpose of determining the direction of rotation of the spindle.

Upon shaft 68 is areversing pinion 88 meshing with a pawl selecting or reversing camgear 8| rotatably mounted on the spindle 46 and provided with an integral sleeve 82 which virtually forms an integral hub slidably mounted on aforesaid reversing shaft, while a transverse reversing pin 83 projects rigidly from the side of said shaft and extends slidably into an oblique slot 84 in said sleeve. The mentioned cam gear 8| is located on an intermediate level in which the same may engage about both the upper and lower groups of pawls and has Iupon its inner periphery a group of opposite cam recesses 81, 81 and 88, 88 so relatively spaced apart with respect to the location of the pawls, as to be capable of alternatively releasing pawls 55 or 56 into engagement with the ratchets 45 and cause the oscillation of the ratchet members to eect rotation of the spindle in, clockwise or counterclockwise direction accordingly.

In order to ensure retention of pin 83 in useful association with reversing shaft 68 an outer sleeve 85 is mounted upon sleeve or hub 82 exteriorly of said pin and extends between pinions 88 and 88.

As already intimated the two ratchet members 43 oscillate uniformly in the same manner irrespective of the resulting direction of rotation of the spindle or of which set of pawls is active, and both members have a large clearance opening 86 to allow said members full freedom to oscillate without contact with sleeves 82 or 85 or with bushing 18.

It is evident that if transmission shaft 19 is turned -counterclockwise (looking forward) so that sector lever 11 in meshing with rack 13 will raise reversing shaft 88 with its pin 83, the latter pin will rise through slot 84, and due to the oblique form of the same, the 'sleeve 82 and pinion 88 will be partially rotated toward the left from the position shown in Fig. 3, or angularly displaced in clockwise direction (looking downward) with respect to reversing shaft 68 and the lower pinion 86.

The mentioned pinion B6 is prevented from rotating upon said reversing shaft as it is slidably splined to the same. As pinion 88 meshes with gear 64 and the latter is fixed on the spindle, and as pinion 88 meshes with reversing cam gear 8| surrounding the spindle, the effect of the angular displacement or partial rotation of pinion 88 will be that cam gear 8| meshing therewith will valso be partially rotated or angularly displaced on the spindle 46 in counterclockwise direction into a postion wherein pawl clearance orcam recesses 81 in the cam gear will register withvthe outer extremities of pawls 55 and allow the same to swing out into active engagement with ratchet 45, causing the ratchet members to rotate the spindle*` inA counterclockwise direction. fltheptransmissionshaft 19'with its sector lever Tris partly-rotated -in clockwise direction the wise direction with respect to said reversing shaft 88 and pinion 88. This will cause corresponding rotation or-angular displacement of cam gear 8| in clockwise direction so as to assume the position indicated in Fig. l0 wherein cam recess 88 will register with the ends of pawls 56 so as to release the same and allow them to swing freely out into operative contact with ratchets 45 and allow oscillation of the ratchet members to cause clockwise rotation of the spindle. The cam recesses 81 are properly spaced from the cam recesses 88 to ensure that when one set of pawls is released for contact with the ratchets the other set is swung back by the form of the interior cam recesses of the cam gear into the pawl pockets within the outline of the spindle and are therefore idle. I

The ultimate control of the motor and the setting of the Vdirection of rotation of the spindle will now be considered and may actually be termed a remote control of the operation as a whole. l

A control casing 89 is secured to the rear 38- of the motor casing I5 and within the same is fixed a supporting plate 98 by means of screws 9| or the like and carrying an electric service switch 92 provided with a snap switch arm 83 projecting rearwardly through said plate 98. The motor is connected to the switch and both the motor and switch also connected to a current cable 94 in well knownmanner (not shown in order to avoid obscuring the View) the cable issuing from a rear hub 95 on casing 89 to the outside for connection with the electric mains. In the raised position of the switch arm shown in Fig. 2 the current is assumed to be off and the motor idle, and hence any means serving to draw said switch arm down into a low position will thereby turn on the current and start the motor. As this motor is non-reversible no facilities for reversing the same are necessary nor are in fact any further facilities for electrically or mechanically controlling the motor required.

On the other hand, a single manual control about to be described is used for simultaneously controlling operation of the motor and determining the direction of rotation of the drill or tool during operation.

Upon the end 96 of control casing 89 (Figs. 1, 2 and 10) a hub 91 projects rearwardly and within the latter is rigidly secured the end of a sleeve 98 serving as a support for a manually rotatable operating sleeve 99, a screw |88 being screwed into the outer extremity of supporting sleeve 98 and provided with a flange |8| serving to retain sleeve 99 axially against displacement on said supporting sleeve. rWithin the latter sleeve is mounted a rotatable control sleeve |82 extending from thevend screw |88 beyond the casing end wall 96 and terminating within said end wall in a one tooth gear sector or cam disc |83 and rigidly connected for simultaneous rotation with the outerl manually rotated sleeve 99 by means of a stud or screw |84 which extends inwardly from said manual sleeve 99 into control sleeve |82 through a transverse clearance slot |85 in the supporting sleeve 98.

The cam disc |83 carries upon its periphery a single gear tooth |88 adapted to mesh with a corresponding single tooth space |81 in an intermittent gear sector or lever |88 secured on the,

same will cause the rack and the reversing shaft rear .end of. transmission` shaftI 1:91 already: men.-V tioned. At, the sides of the'. tooth space; w11: the: gear sector-isv formed. with. two. similarprole; portions m9 I'I0', either oneof-,which will remairrj at rest-adjacent. to the outer. circularr peripheral. portion IfII of disc' |.03= and- Will ,prevent further rotation of the gear sector by-saidcam disc-after the singleI tooth |f06- has engaged in: the. tooth space- I-l and shifted said disc by rotation, from an intermediateY neutral.. position indicated in Fig. 6,. to either side as. indicated in Figs. 8 and 9. The. manual control of transmission shaft just described forms-i a1 remote; control of the previously I described-reversible ratchet drive mechahisrnvfor the tool` spindle. butv simultaneouslyv controlsoperation ofthe switch 92 as well. Thusa. pair offzxed boltsor. posts H2, I-I3 projectrearwardly from the switchV supporting plate 90 withincontrol: casing;A El!)vr and serveas pivot mountings for' a. pair of. gearI sector levers H4, I I pivoted at their outer ends on saidV posts, andv being. provided. at their.l inner adjacent. ends. with mutually meshingl gear teeth H6, II'I: respectively, so. that. both levers. positively follow each other in their pivotal movements. about their pivot posts I2, |I3. A switch lever |I8 isfalsomounted upon post II3v and secured. in rigid association with' gear sector-leverA I I5 by means of a pin- IlSwhichfnot. only extends: into said levers LIE and H8 but in addition also projects. rearwardly. from sector. lever H5:l intoa clearance recess |20 cut into` the junction. of the gear sector or cam. disc Ia lwith the control sleeve L02. The mentioned. pin. He alsov serves another purpose than' carrying. along lever |I8 with sec-v torlever. I-I5A as willalso appear.v A corresponding-pin I.2I. projects rearwardly in similar fashionfrom the sector lever |14 into mentioned clearance recess |20, while between the-two pins I I9 and I2|r is an inwardly projecting cam |22 integral with control sleeve I 02 and cam disc |03 and-occupyingpart of said recess. 'Thentocomplete the switchoperating mechanisnrthe switch lever. has an open slot or recessl |23 atv the inner free end thereof for. receiving thesnap switch arm 93 of switch- 92.

It. will now. be evident. that. when the. tool as a whole is held in. operative position by the left hand indicated'at |24 in Fig. 1 and the-right hand |25'fseizes the manual operating sleeve 99, a quarter. turnof. said sleeve to the left will cause inner control sleeve I 02 and sector or disc |03starting fromv the neutral. position. of Fig. 6,.to shift first tothe-position shown in Figs. 5 and' inwhich the tooth |05 has just. left the corresponding tooth space |.0'| inl lever |08. and set the latter inA position with its proiile portion. I l0 incontact with. the circular peripheral portion I.I.| of the camv disc |03, which effects a partial clockwise rotation. of transmission shaft 19; At the for.- ward end of theshaft the gear sector 'l'l meshing with'rack 13 is correspondingly rotated with shaft 'IQ-and will lower thev rack with its shaft 68 intoy the position of Fig. 3, causing the. pin 83. by descending to the bottom of obliqueslot. 84 to rotate. sleeve or hub 82 and reversing pinion 80 counterclockwise. The pawl selector or cam. gear 8| will thereby be rotated in. clockwise direction. to assume the position shown in. Fig. 10 with pawls 56- actively engaging the internal ratchets 45V` of ratchet members 43 preparatory todriving tool spindle 45 in. clockwise direction.

Proceeding with the manual rotation of operating sleeve 99 and. its sector or-diso |03y from they appearing in Figs. 5` and'x 7V tothat indicatedin broken lines.in'F..8..it.w1ll' be noted that: while sector lever |08 and shaft. 19 remainin their attained positions, the interior cam: |22 within controlsleeve linzengagesagainst pin H9 (see 6.) on gear-.sector lever H51 and therebr brings: the same downward and with itthe. switch lever 8; This operation-carriesithe switch arm 93 down' and thereby operates the-switch to close: the circuit ofthe motor which immediately re.- sults in operation ofthe tool with the spindle and the. tool carried thereby rotating in clockwise direction until manual sleeve99 is returned clockwise tov starting positiom when the inner control sleeve I-02 disc |03: and sector |08- will resume their original neutral positions indicated in Fig. 6. The switchy arm- 93 is. assumed vtobe.A self-restoring so that if' released saidv arm- Will return automatically upwardand thereby break the circuit: by.- opening the switch. Such move.- ment of. the; switcharm may be caused by spring means built into the: switch (not shown). butzthe mentioned upward movement will thus carry 1ever H81: and sector, lever |-|5 upward with the switch: arm, and as sector lever I|I|y meshes with sector lever I-I5, the latter willl lilewise be restored to vupperinitial position. shown in Figs. 5

and 7, with pins ||-9y and: |'2I disposed. in their upper positions and interior cam |22. inl neutralintermediate position as indicated in said. Fig.6.

When it is desired to operate the tool with. a drill, tap or die rotating; in counterclockwise direction,A turning the operating sleevey 99` and thereby the inner control sleeve- |02. and` disc. I03 to the position indicated in Fig. 9.- willcause ro-l tation of sector |08 and transmission shaft 'I9 in: counterclockwise direction,v raising the rack.v '|-3f and shaftv 68.With its pin 83 at the front end of the apparatus` This rotates sleeve 82 clockwise so that simultaneous rotation of its` pinion will correspondingly rotate cam gear 8| counterclockwise to release pawls. 55 intov cam recesses 8-1 in. saidgear for contact with ratchetsk 45. 'Ihe spindle 46 is thenconditioned for counterclockwise rotation uponsubsequent oscillation of'. the ratchet members 43, by rotation of crankshaft 39 through the drive shaft Z3y by the motor. Continued turning. of. the manual operating sleeve; 99 to the right. brings interior. cam. |22V into, contact with pin Ilon sector lever I.|4. and lowers the latter into the position. of Fig. 9, which corresponds tothe position said sector lever occupied in Fig. 8. In. this case. sector lever H4 has brought downv sector lever H15 with the same and thereby also switchlever IIB, with the result that switch arm 93 has also been. operated downward to-close the switch as beforerthe motor being thereby started to rotate the drill or other tool in the intended counterclockwise direction; It is therefore of no consequence. in which direction the operating sleeve. is rotated` for starting the motor; as in any case the motor will bev positively started to operate in its one. direction while the specific direction. in which the manual sleeve. is turned will instead dter.-

mine.l the.- direction in which thev operating tool' will: be driven by the motor through the alterable interior drive mechanism within the tool. casing.

It; is of course desirable to have. the operating sleeve.- self-restoringto. intermediate neutral position when released by the hand, sothat thechoice. of. the; direction of. rotation ofL thetool is asreadily made: with.` respect to one. direction. as in the opposite. directon-,- while alsoincluding. the release and-.opening of theelectric. switch.. For this' purpose the end screw 100 has a hollow projection 126 into which the rear end of'a plunger 121 slidably extends, the other end of the latter terminating in a head 128 engaging against a transverse pin 129 projecting atboth ends through a pair of longitudinally disposed operating slots 130 in supporting sleeve S8. This Din is resiliently urged forward toward the forward extremities of slots 130 by means of a spring 131 mounted on the plunger between head |28 and screw 100,7and also extends through opposite pairs of V-slots 132, 133 in the manual operating sleeve 99 and inner control sleeve 102 A(Figs. 2 and 10). The apex of the angle in each V-slot is directed forward so that said pin will bear against the inclined edges of the slots and tend to cam in the outer and inner slots into a neutral central position under pressure of spring 131 when the operating sleeve is released by the operator. The outer sleeve 99 is recessed Iby a reduced portion 134 in order to accommodate a ferrule or covering ring 135 serving to conceal the mentioned slots and retain pin |29 in place and thereby iinish theappearance of the operating sleeve.

While the motor casing 15, reversing drive casing 35 and control casing 89 have been specically described as adjacent casings connected into a series, such construction is merely a convenience and hence for the purpose of this invention these casings may be considered generically to be a single casing, that is, the casing of a power operated tool as a whole.

It is self-evident that the various operating parts of the apparatus may be made of any suitable metals or alloys and that the casing, for example may be` made of. a light metal or alloy or even of any suitable plastics in order to lighten the tool as a whole. On the other hand the pawls may be increased or decreased in number and located in the ratchet members and contact with ratchet teeth on the tool spindle if so desired, and if a common snap switch is used without a self-restoring arm the gear sector levers may instead be restored by spring means raising the same to neutral or idle position upon erating sleeves to neutral idle position. Other modifications within the purview of the invention may be resorted to as found best in practice and according to the scope of the appended claims.

What is claimed is:

1. In a portable power driven toolA having a casing with a rotatable tool spindle journaledv therein and a uni-directional motor having switch means and providing the power for driving the tool spindle, the combination of reversible driv-"" ing means for transmitting the drive of the motor to said tcol spindle in either direction, including at least one ratchet member oscillating adjacent to the tool spindle when operated by the motor, at least two oppositely disposed pawls associated with the tool spindle for individual operative engagement with said ratchet member for rotating the tool spindle in one direction by means of one pawl and alternatively in the opposite direction by means of the other pawl during operation of said ratchet member. a movable reversing member closely associated with said tool spindle for retracting one pawl into a recess within the outline of' the latter spindle and simultaneously releasing the opposite pawl for engagement with the ratchet member and vice versa, and a manipulative member for operating said switch means after moving said reversing member to select the direction of rotary movement to be imparted to said tool spindle.

2. In a portable power driven tool having a casreturn of the op-fI rotating the spindle in clockwise or counterclock- Y vwise direction according to the pawl engaging with said ratchet, said operative means oscillating one portion of said ratchet member and thereby partly rotating the latter aboutsaid spindle, means resiliently urging said pawls toward said ratchet for engagement therewith, a cam associated with the spindle and capable of adjustment from one position in which said cam holds one pawl inactive in its recess while allowing the other pawl to engage freely against the ratchet, and to another position in which the cam allows the one pawl to engage freely against said ratchet while holding said other pawl inactive in its recess,V and manually operated means movaJble in opposite directions from an intermediate neutral position for adjusting said cam to either position of adjustment at will, the manuallyv operated means tending to return to neutral position when released.

3. In a portable power driven tool having a casing with a rotatably mounted tool spindle located at one end of the casing, drive means for causing rotation of the spindle, and a rotatable cam having means associated therewith for controlling the direction of the'rotary movement imparted to said tool spindle by said drive means, the combination of manually. operated means for rotating the camincluding amanually controlled 4Q member accessible upon the other or far end of said casing remote fromsaid one end of the latter, a transmission shaft extending a distance through said casing, means associated with the forward end of the shaft for communicating rotation thereof t'o the cam for selecting the direction of4 rotation intended for the tool spindle, and means associated with'the other end of said shaft for communicating movement of the manually controlled member to said shaft to partly rotate the latter and thereby control the direction of rotation imparted by the drive means to the tool spindle.

4. In a portable power driven tool having l'a casing with a rotatably mounted tool spindle', drive means for causing rotation of the latter, and a rotatable cam having means associated therewith for controlling the direction of the rotary movement imparted to said tool spindle by said drive means, the combination oi a gear embodying said cam surrounding the tool spindle and mounted to be independently rotatable about the same, a pinion meshing with said gear and having a hub forming a sleeve, a reversing shaft vslidably supporting said pinion and its sleeve, a

pin on said reversing shaft projecting into a cam slot in said sleeve, a second pinion slidably splined on said shaft for longitudinal movement of the shaft with respect to said pinions, a second gear mounted on the tool spindle for positive rotation therewith, and a lever engaging a portion upon said shaft and capable'of axially sliding the latter with respect to said pinions and thereby causing angular displacement of the iirst mentioned gear with respect to the tool spindle and the second gear upon said tool spindle, and

a manually operated member connected to said lever .for operating .the ilatter Vat will.

i5. .A portable power rdriven :tool comprising lan elongated .casing having a rotatable tool .spindle journaled in one -end thereof., a non-reversible driving motor in said casing, ,reversible vdriving .means driven by the motor and operatively fassociated with the tool spindle and capable of transmitting driving movement from vsaid motor 'to said tool spindle .for .rotating .the .latter `in -clockwise -or counterclockwise direction, said reversible driving means having an adjustable member controlling the ydirection of rotary movevment imparted .to .the tool spindle by said driving means, a manually operated control member .accessible upon the other or far end of the casing and Aadjustable to either one of two extreme positions to determine said direction of rotation vof the 'tool spindle, a gear sector rotatably adjustable withsaid control .-member, zasector lever :engaged by said gear sector and shiftable thereby into-.either oneof two extreme opposite positions, a `transmission member connected to said :sector lever extending toward the rst mentioned end of Ithe casing, and adjustable means associated with said transmission member within said end of the casing for-communicating changes of adjustment yof said sector lever and transmission member lto the 4adjustable :member of said reversible driving means for ultimately determining the .direction of rotation of the tool .spindle by adjustment of said manual 'control member.

6. A portable power 'driven :tool including a casing, a tool 'spindle :rotatably :mounted :in .one

portion .of .said casing, a non-reversible motor associated with said casing, reversible vdriving means in said `casing driven .by said motor, :an adjustable member .operatively associated with said .driving means and rcapahle .of adjustment to two Vextreme opposite Apositionszfor controlling corresponding clockwise or counterclockwise .rotation vof said tool spindle by said .driving means according to the .attained position :of said adjustable member, va `manual control member accessible upon .another portion of the .casing and shiftable to either one -of `two Ypositions for .initially determining the direction of rotation fof said tool spindle, motor control :means within said casing .serving to Vcontrol .operation of said motor, transmission Ymeans extending from the vicinity of said manual lcontrol 'member toward said driving means, adjusting means operable by said transmission Vmeans for adjusting 'the 'adjustable member to one of its two elective posi tions, means operatively associated with said control member for operatingssaid rtrnns- :mission .means lthereby ultimately vcontrolling :the direction lof rotation iof said .spindle :by means o'f said manual fcontrol member vand .for :allowing further shifting of the latter control member `beyond y'either of its two eiective Dositions for operating .the transmission means, and .further Ameans 'associated with vsaid .manual control member effective to operate said motor -con- .trolmeans upon adjustment of :said manual con- .'trol member beyond 'either fof said two effective positions thereof after having initially 'determined the direction :ci rotation to `be imparted to the tool 4spindle `by the driving means.

"LA portable power driven tool according `to Aclaim 6., -wherein `the non-reversible motor is `an electric motor and motor control means in- 'cludes electrical means (of vthe Yclass lconsisting 'of -electric circuit ,breakers and switches.

1.8. A .portable #power driven .tool according Yto claim v`6, wherein the casing is elongated with "the tool spindle rotatably mounted in one end thereoi andthe manual control member is located `at the other end of the casing, and wherein the transmission means includes 'a partly rotatable -shaft extending 'lengthwise through the major portion of the length of 'said casing from the vicinity koi the manual -con'trol member to thel vicinity ofthe driving .means,fsaid partlyrotatable `shaft being `controlled at the one end by .said manual control lmember and lat the other 4end communicating its movement to said `driving means.

T9. Aportable drill comprising ia casing; a :uni-

- directional Velectric motor supported thereby; n

vswitch for said motor; a tool .spindle supported for movement in opposite directions :relative to the casing; a transmission between said motor and spindle including reduction gearing and .selectively .operated reversing means for 'controlling 'the direction of rotation of the spindle; 'a handle '-for supporting said fcasing and having u sleeve rotatable in either .direction away from 7a neutral position; motion transmitting means responsive to a relatively :slight Aturning Amotion of the sleeve away from neutral position for operating the 'reversing means; and motion transmittingmeans responsive to a relatively greater turning motion vof the sleeve away from neutral position for closing the electric switch; whereby the Voperator may rst select the direction of `rotation and Vthen start the Vmotor by continued kturning movement of the sleeve `in `the same di- 4rection.

LEON F. MEUNIER.