US2395681A - Ratchet mechanism - Google Patents

Description

Feb. 26, 1946. w. H, oDLUM ET Al.

yRATGHETy MEcHANIsM 4 Sheets-Sheet 1 l Filed Nov. 8, 1944 'INVENToRSQ v 'Qm/HdllwI/f Karl/@Pam Feb. 26, 1946. n l w, H, QDLUM ETAL 2,395,681

RATCHET ME'cHANIsM Filed Nov. 8, 1944 4 Sheets-Sheet 2 Feb. 26, 19-46. Vw. H. oDLUM ET AL,- 2,395,581

RATCHET MECHANISM Filed Nov. 8, 1944l 4 Sheets-Sheet 3 ,361 Kaw @Pm-72e,

www' 'l Feb.261'94s. WQ QDLUM ETAL n 2,395,681

RATCHET MECHANISM -FiIed Nov. 8, 1944 Y 4 Sheets-Sheet 4 Y, INVENTORS.v

Patented Feb. 26, 1946 RATCHET MECHANISM william n. odlum, wiifnette, and Kari A. Paine,

Park Ridge, Ill., assignors to Duro Metal Products Company, Chicago, Ill., a corporation oi Illinois Application November 8, 1944, Serial No. 562,464

' 8 Claims. (Cl. l15H2- 4.33)

This invention relates to ratchet; mechanisms, and particularly to those adapted to use for driv- 4 ingtools and the like. Y

It is a general object of this invention to provide an improved reversible ratchet-mechanism which is compact, rugged and well adapted to use for driving tools such as wrench sockets, screw drivers, bits and the like.

Another and more specic object of the invention is to provide a reversible ratchet mechanism having pairs of pawls for operation in each direction which function alternately to provide twice as many driving positions for the mechanism as there are ratchet teeth, thus establishing small angular driving increments while maintaining th'e strength of coarser teeth.

. The invention has for another object the provision of tooth angles on the pawlsfrelated in such a way to the normal direction of movement of the pawls and the direction of the driving force applied therethrough' that the application of driving force results in a componentof force urging the teeth of the ratchet and pawl into engagement. i

It is also an object of the invention to provide a reversible ratchet mechanism having a di'- rection control instrumentality protected against inadvertent operation.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings in which similar characters of reference indicate similar parts throughout the several views.

Figure 1 is a perspective view of a tool adapted for use in driving wrench sockets and the like, and-to which the ratchet mechanism of our invention is adapted;

Fig. 2 is a fragmentary bottom View of a portion of the tool shown in Fig. 1; f

Fig. 3 is a fragmentary top view of a tool suchl as is shown'in Fig. 1 and including a modification of a portion of the structure;'

Fig. 4 is a. f fragmentary sidesectional view showing a part of a preferred form of ratchet mechanism, made in accordance with our'invention, and having the section taken substantially onaline4-4 ofFig.1;

Fig. 5 is a sectional plan view of a ratchet mechanism embodying a preferred form of our invention, in which the section is'taken substantially on a line 5-5 of Fig. 4; 1 Figs. Sand 7 are top Aplan views of the internal parts of our preferred form of ratchet mechanism showing two different operating positionsof the mechanism; v

Fig.- 8is an explodedview of the ratchet mechanismV shown in Figs. 4 to 7, inclusive, illustrating the parts of the mechanism' in an orderly disas-` sembled relation;

Figs. 9and 10 are enlarged top plan views of parts of the disclosed ratchet mechanism.

Although it is understood that the ratchet mechanism disclosed herein may` be adapted to many uses and to other tools, it is in this instance disclosed in an exemplary association with a driving tool for wrench sockets and the like. In this adaptation, illust-rated generally in Figs. 1, 2 and 3, a preferred -form of the ratchet mechanism of our invention is disclosed in its association with a driving member comprehending a lever arm 22 having at one end a head'23 which houses the ratchet mechanism, and at its other end a grip 24 to which manual driving force is applied for actuating a tooll driving shank 25 in one direction or the other depending upon the angular position of a dirction control knob 26. A spring urged detent 21 of well known construction is preferably provided in the tool driving shank' 25 and projecting from one side thereof releasably to engage various driven tools such as wrench sockets.

Referring to the more detailed disclosure of the ratchet mechanism embodying our invention, as shown in Figs. 4to 10, inclusive, the head 23 has an annular opening 28, on the -wall of which opening is a predetermined number of axially disposed internal ratchet teeth' 29. The inner ends-of the teeth are substantially fiat or slightly concave, so that together they provide a bearing rotatably supporting driven member 36. A retaining ring issecured against a shoulder 32 in a counter-bore 33 at one end of the opening 28 'by a rolled edge 34 at the end of the head 23.

This retaining ring 30 h'as an opening 35 through which a shoulder portion of the driven member 36 projects with a small clearance allowance around the surface 39 of the shoulder. A cylindrical body'31 comprises the part of the driven member 3S which is disposed within the opening 28 and has bearing engagement with the ends of the ratchet teeth 29. An end bearing surface 38 is provided by one end of the body 31. The bearing surface 38 on the driven member 36 co-acts with the adjacent plane surface of th'e retaining ring 3l) to provide'endwise support for the driven member.

Referring to Figs. e and 8, an axial cylindrical bore 42 in the endof the driven member 33 opposite the tool driving shank 25 rotatablysup ports a stud 43, which stud has a cylindrical body 44 at the outer end of which are axially disposed, in superimposed relation, a square shank 45, a circular extension 6:5 and a second square shank 41. The circular extension 46 passes through a circular openingr 48 in a second retainer ring 49; the second retainer ring being secured in a counter-boren in the end ofthe head 23 opposite the retainer rnehy rolled edge 52. Clearance is desirably provided between the extension 46 and the retainer n'ng 49 to avoid the possi bility of turning the stud 43 during relative movement between the driving and driven members and lto insure ease of separately rotating the stud. Having reference to Figs. and; '8,.paralle1 transverse slots 53 and 54; are provided in the end of the cylindrical body opposite the tool driving shank 25, and are preferably spaced equidistantly from opposite sides of thel axial bore 42. The slots 53 and 54 are desirably rectangular in section and have beveled or lleted corners such as andl 56- forstrengthening the structure; 'Alpaiir 5?' andi 58 and another 5S anct '60 of oppositely disposedj pawls are slidably mounted in the slots 53 and Mthe oppositely disposed Bair of pawl's 5T and 58.- respectively. having opposed lengitudinalbores B2 and G3i, and thel pair ofIV oppositely disposed pawls 591 and 6U have opposed longitudinal boresf l and` E5, respectively,which opposedJ1 bores retain the ends of compression springs 66' andg 6T. The oppositely disposed pairs off pawis 1in` each: of the slots 53 and dfare biased-apart and toward the ratchet teethfibyjthe Springs'anet. Y Y

The pavrlsm" and`A 58, 53 and: 60) are desirably paired diagonally for cooperative operation. iin controlling the driving5 ofv` the dven'memfber-fln either of the two directions. That is, dfametrically opposed pawls, such as 5'!S and 69; ilo` opposite ends of the dilterent Vsiots" preferably control the actuation of the driven member in one direction.; while the diagonally opposectpawls 58 and 5S theopposite direction.

their outer ends the pawls 5T, 58, 5a: and 60; respectively, have teeth. w; 65', Tui and TI adapted to mesh with the ratchet teeth: 25;'- the teethI VGti and mi ci! the pawls 'land 593 being similar; and the teeth G9 and Tlf or' the pawls Sli andlv 611i being similar: orden to decrease the increments xsi-movement et the dritti-ligg-V memberswhich are necessaryto passirom. one driving position to the nextwithoitt increasingV the number of' ratchet teeth, theteeth, suchA as 6:3

control the-actuation of the driven member in' accessi the teeth Il of the pawl B0 (Fig. 10), the faces T3 are the driving or force-carrying faces. Faces 'I4 and 15 of the teeth 'IU and 1|, respectively, are paWl-moving or (Jamming faces. It is to be understood that the relations of the teeth and sur faces of the paWls 5'5 and 58 are similar. The cci-acting. ratchet teeth are desirably symmetrical to. provide like operating characteristics.. in both directions. Also, the pawl teeth are preferably fully engaged when in mesh with the ratchet teeth for driving the driven member.

In; addition to the details of the relations of the pawl and` ratchetteeth which have beendis cussedgit sfpertinent to note that, as is illustrated in. Fgs.. and III, the driving faces T2 and 73 0f the pawl teethi are angularly disposed so as to vary from parallelism with the side faces of the pawlsin a direction that the transmission oi driving force through the driving faces creates a resultant component of force tending to urge the pawi teeth into, engagement the ratchet teeth. Ins other words, the faces' TZ ci the pawl 59 vary from parallelisxrrv from the side faces t6. and 't1 of the pawfl in amounts indicated by angles o: and 1I. The resultant summation and direction of the. transmitted: components of force is suche that thepawk is urged: longitudinally of the sides 'I6 and 'H towardithelraltchetteeth- The same is true. of the. pawls, such as 6u', wherein the faires 'mi of thee pmol' teethx vary from parallelism with; the side: faces 1:& and 119E by' angles aand-d. i l

To: changes osi thedircctioxr oli or eration of the disclosed ratchet mechanisrncr a re taziiner ptate 8E tFigs. 4,. 6,. 7x and 8= 'having diafmetrically opposed peripheral slots d2 and as' and a square central: opening 84ris carried by the square shank. om the stud? 43. adiacenti the end ot the driven member for rotation with the stud 40 relative tothe ring 8f and; driven member as.

and 1t, ot the di'ametrcally' opposedoperating pairs,- ct pawlsr are differently positioned on. the pavvls. so as alternately to mesh` fully for driving action with thefratchet teeth.. Desirably, the -teetlrotone ot the pawls, such: as 51; of oneof theoperating pairs, such as 5T andi 6H, fully mesh with the ratchet; teetln at: haltr the .distance of 4movement necessary for the. teeth of the other -pawL such as Edicto pass between successiveratchet teeth. This; relation of the teeth of thee dia.,-

metri-cally opposed operating pairs'. of pawls; per- 'mits the'use of heavier' and.' consequently stronger ratchet teeth, While providing twice-as many orperativef driving positions. of theV driving member relative lto the driven member asithere are ratchet teeth. Y 1

The diierence-inrthe teeth:` on the paws is illustrated by comparison of the large plan. views of' Figs. 9 and` 1G.. In these views, also, certain angular, relations of the tooth faces are disclosed. Faces 12 of the teeth T81 ontheV pawl 59 (Fie. 9) are the'drivingy orforce-carrying faces: while on The ends of the siot.v 8e2: are adapted; to, engage and as which proieet outwardly trom the top surfaces of the opposed. pfrwlsZ 51 and 5c in the slot 53. Likewise, the ends of the slot 8'3 are adapted toengage pins si and 8B, which projectontwmrdly' imm the top surfaces 0f the op posed pamflsf. 5% and 5.8:.- The lengths of the slots 82 and 83 are preferably such' in a;y neutral position alli four ofthe parvis.. 51 and 58 5% and 60' are held ont. oil @easement with. the ratchet teeth 251. However, operation theretainer plate 81k engages the: pins; of diam-atrioallyopposed op erating pairs of pavv'lsi torender those pawls. inoperative; while; the other diametrically opposed operating: pair of` pawls is. free toren-gage the ratchet teeth. The; inoperative pavvls,y in each instance, serve as substantially stationary anchors; for the ends; of." the compression springs 6B and 6l', which spring bias the operative pawls toward.. the ratchet teeth.

Asshown irrig;y 6. thefpawls 51 and. 610 are held in an inoperative position. awa-y from the ratchet teeth 2t by the retainerplate 8D. In; this position, and. as viewed 'm the drawing.. the driving force istransmitted through the pawls 58 and 59 which; parels. are alternately effective to drive the driven member 36 in a. ciockvvise direction. Force applied to the; driving member in the clockwise directionV is transmitted through the driving faces et the pawl teeth.- 'tll and 1t. Rotation of the driving member im the opposite direction cams: the respective pawls mwardly-against the biasing: torce-s1 off. the springs its. and to cause 'the ratchet teeth 231:01l passl over the ,surfaces 0f the pawl teeth. z .y

' the driving member When the retainer plate 80 is inthe position shown in Fig. 7, the pawls 58 and59 are held in an inoperative position away from the ratchet teeth 29 and the pawls 51 and S0 are biased by the springs 66 and 61 into engagement with the ratchet teeth. In this position, and as viewed in the drawing, the ratchet mechanism is operative to transmit driving force from the driving to the driven member in a counter-clockwise direction.

In order to hold the retainer plate 80 'in the operating position, illustrated in Figs. 6 and 7, the stud 43 has angularly disposed plane intersecting surfaces 90 and 92 (Figs. 4 and 5) cut into the surface of the cylindrical body portion thereof in predetermined angular relation with respect to the square shank 45 which carries the retainer' plate. A ball detent 93 is longitudinally movable in a radial bore 94 in the body portion 3l' of the driven member and biased toward engagement with the plane surfaces 90 and s2 by a compression spring 95. One end of the compression spring 95 engages the ball detent, while the other end is retained in the bore 94 by an axially disposed pin 96.

Mounted on the second square shank 41 for controlling the angular position of the stud 43, and consequently the position ofthe retainer plate Bil, is the direction contro] knob 26; the knob being secured in position by a screw 91 or other suitable means. Rotation of the direction control knob 26 turns the stud 43 to positions such that one or the other of the plane surfaces 90 or 92 is engaged by the ball detent 93. 'The action of the ball detent holds the stud in the position to which it is operated and hold the retainer plate in one or the other of the positions shown in Figs. 6 and 7 to control the direction of operation of the ratchet mechanism. In either of these positions the pins 85, 8B, 81 and 88, whichever pair is engaged by the retainer plate, act to limit the rotation of the retainer plate and stud.

In the modification illustrated in Fig. 3, the retainer ring 49 is provided on its outer surface with an outwardly projecting circular flange 98 surrounding a direction control knob 99 and eX- tending to a height above the surface of the control knob. This flange S8 protects the control knob 99 from accidental or inadvertent operation while permitting the user of the tool to rest one hand on the outer surface of the ange during the use of the wrench.

From the foregoing description it may be understood that we have provided an improved reversible ratchet mechanism adapted to uses such as the use in driving tools. The mechanism is easily controlled to determine the direction of operation by the manual actuation of the control knob. When desired thecontrol knob may be protected from any accidental or inadvertent operation by a surrounding flange such as that shown in Fig. 3. The ruggedness of the driving parts of the ratchet mechanism is maintained without sacrificing the advantages of small operating increments by the use of pairs of alternately effective operating pawls for each direction of operation.

In addition to the foregoing advantages of our ratchet mechanism, the positions of the pawls and their respective directions of movement, as well as the positions of the pawl teeth, are so selected that the application of driving force to results in a component of force effective upon the driving pawl tending to hold that pawl in closeiengagement with the ratchet teeth.

While We have illustrated a preferred embodiment of our invention, many modifications may be made without departing from the spirit of the invention, and we do not wish to be limited to the precise details of construction set forth, but desire to avail ourselves of all changes within the scope of the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

l. A ratchet mechanism comprising, in combination, a driving member including a head having an annular opening and a predetermined number of internally disposed ratchet teeth facing said opening, a driven member having a cylindrical-body rotatably supported in said opening and a projecting tool driving shank, said body having in the end thereof opposite said shank a pair of parallel transverse slots substantially equidistantly spaced on each side of the central axis of the cylindrical body, pairs of oppositely disposed pawls slidably mountedA in said slots and having teeth adapted to engage said ratchet teeth, compression springs between said pairs of pawls biasing the pawls toward the ratchet teeth, the diagonally disposed pawls in different slots each being adapted to prevent rotation between the driving and driven members in one direction upon engagement with the ratchet teeth, the teeth of said diagonally disposed pawls being so 'positioned that they are alternately effective to prefvent rotation between the driving -and driven members in said one direction whereby the number of driving positions ofthe driving member relative to the driven member foreach direction of rotation is twice the number of teeth, and means including a retainer plate for selectively holding diagonally disposed'pawls in inoperative positions to determine the direction of operation of the ratchet mechanism.

' 2. A ratchet mechanism comprising, in combination, a driving member including a head having an annular opening and internally disposed ratchet teeth, a driven member having a cylindrical body rotatably supported in said opening and a tool driving shank, said body also having in one end thereof a pair of similar parallel slots, two oppositely disposed pawls slida-bly mounted in each of the slots, said pawls each being adapted to engage said ratchet teeth to prevent rotation between the driving and driven members in one direction and being Valternately arranged so that the pawls in each slot are adapted to prevent rotation between the driving and driven members in both directions, the alternate pawls being so related to the ratchet teeth that they are alternately effective to prevent rotation between the driving and driven members in one direction thereby to provide two ratchet steps for each ratchet tooth, means for biasing the pawls toward the ratchet teeth, and means for selectively holding alternately disposed pawls in inoperative positions to determine the direction of operation of the ratchet mechanism.

3. A ratchet mechanism comprising, in combination, a driving member including a head. having an annular opening and internally disposed ratchet teeth, a driven member having a cylindrical body rotatably supported in said opening and a too-l driving shank, said body also having in one end thereof a pair of slots, two oppositely disposed pawls slidably mounted in each of the slots, said pawls each being adapt- 4 ed'to engage said ratchet teeth to prevent rotar' tion between the driving and driven members in one direction and being alternately arranged, the alternate bands being so related to the .ratchet teeth that they `alternatefy engage .said teeth' thereby :to provide two ratchet steps for each ratchet tooth, means for biasing the nawls toward the ratchet teeth, and means for selectively holding alternately ,disposed pawls in inoperative positions to determine the direction of .operation of the ratchet mechanism.

4. A ratchet mechanism comprising, .in combination, a- `driving member including a head having an annular opening and internally disposed ratchet teeth, a driven member having a cylindrical body rotatably supported in said opening and e tool driving shank, said body also having in one end thereof a pair of slots, two oppositely disposed .pawls slidab-ly -unmounted yin each ci the slots, ,resilient means `disposed between two pawis in each slot for biasing the pawls toward the ratchet teeth, said paw-1s each being ,adapted to engage said ratchet teeth to prevent rotation between the driving .and driven members in one direction, the pawls vor preventing rotation between the `driving and driven members .in one direction 'being alternately arranged -circurnferentially of the cylindrical body with those for preventing relative rotation of the driving and driven members in .the opposite direction, and means for selectively holding alternately disposed pawls in inoperative positions to determine ,the direction of operation o f the ratchet mechanism. l

5. A ratchet mechanism comprising, in `comlbination, a driving member including a head having an annular opening and internal ratchet teeth, a driven member having a cylindricalbody rotatably supported in said opening, said body having a cylindrical opening in one end and slots in `said end on opposite sides of the opening, pairs of pawls slide-ble in each of said slots, said pawls each being adapted' to engage said ratchet teeth to prevent rotation between the driving and the driven meniberg` in one direction, a part of said pawls Apreventing said rotation in one direction and a part in the other, means biasing 'said pawls toward engagement with said ratchet teeth, astrid rotatably supported in said cylindrical opening, detent means for releasably holding said stud in either of two angularly diierent positions, a. retainer plate lcarried "by `said stud for Arotation therewith, and ,means 'for providing lost motion connections between said retainer plate land selected ones of said pawls in each of the twoV positions of said stud to hold said selected ones of thepavvls in inoperative positions in each of said stud positions, thereby to determine the direction of operation of the ratchet mechanism.

6. A ratchet mechanism comprising, in combination, a driving member including a head having an annular opening and internal ratchet teeth, a, driven member having a cylindrical body rotatably supported in said opening, said body having a cylindrical opening "in one end and slots in said end on opposite sides of the opening, pairs of 'pawls slidable in each of said slots, said pawls leach being adapted to engage said ratchet teeth to `prevent rotation between the driving and driven members `in one direction, a part oi said Rawls preventing said .rotation-in .One .direction and a part inthe other, means biasing said pawl-s toward, engagement with said ratchet teeth, a Stud rotatably supported in said cylindrical opening, datent :means for releasably holding said stud .in either oi two angular-1y dii-erent positions, a retainer plate carried by said stud for rotation therewith, -means providing lost motion connections between said retainer plate and selected ones of said pawls in each of the two positions of Said stud to hold said selected ones of .the pawls in inoperative lpositions in each of said stud positions, thereby to determine the direction of operation of the ratchet mechanic a nianualli7 operable knob means secured to the stud for turning the stud to said Positions, and guard means surrounding said knob means to prevent inadvertent turning thereof.

7. A ratchet `me::hanisrn comprising, in combination, relatively rotatable driving and driven members, one within the other, one of said menibers having ratchet teeth thereon and the other carrying pairs of paw-ls, each of which parvis is linearly movable and adapted to engage the ratchet teeth to prevent the relative movement between said Amembers in one direction, one of said pairs of pawls being adapted to prevent said relative ymiwernentin one direction and the other of said pairs preventing rrelative movement in the other direction, means biasing the parvis toward engagement with the ratchet teeth, the pawls of each pair being so related to each other and to the ratchet teeth that :they are alternately engageable with the ratchet teeth ,at separate relative angular positions of said members to provide twice as many positions oi engagement in each direction of relative movement .as there are ratchet teeth, and manually opera-bie -rneans tor selectively rendering said pairs of 'pa-wis `inoperative to determine the direction tot operation of the ratchetmechanism.

8. A ratchet mechanism comprising, in `combin nation, a driving member including a head having an annular opening kand internally .disposed ratchet teeth, a driven member having a cylindrical body rotatably -supper-ted in said opening., Said body having in one end thereof .a pair .of parallel slots, :two oppositely disposed parvis slidably mounted :for linear movement in each .of said slots, said :pawls each including a toothed end having angularly ,disposed tooth surfaces ,adapted to :engage said ratchet teeth to prevent relative rotation between lthe driving and driven members in one direction, said pa-wls being divided into pairs and each pair being adapted to prevent relative rotation of the members in o-ne of the two directions .of relative rotation, said angularly ldisposed tooth surfaces of `each pawl being so related an gularly to the direction of linear 4movement of the pawl and the surfaces of the 'ratchet teeth engaged thereby that torque applied :to the head of the driving member effects a resultant component of force on the engaged paw] tooth urging the pawl toward the ratchet teeth, resilient `means normally biasing the pawls toward the ratchet teeth .and means for rendering pre-selected pairs of said pawls inoperative to determine the direc tion vof operation of the ratchet mechanism.

WILLIAM H. @DL-UM. KARL A. PAINE.

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