US2505678A - Reversible ratchet mechanism - Google Patents

Description

Patented Apr. 25, 1950 REVERSIBLE RATCHET MECHANISM Francis R. Kull, Rockledge, Pa., assignor to Standard Pressed Steel 00., Jenkintown, Pa., a corporation of Pennsylvania Application August 28, 1947, Serial No. 771,065

2 Claims.

This invention relates to ratcheting drive elements and particularly to a ratchet for hand tools such as mechanics wrenches.

' Ratcheting drives for wrenches in current use are unsatisfactory because, if suiiiciently rugged to withstand ordinary working forces, they are constructed of such a size as to prevent their use in locations where there is a minimum of working clearance for the wrench and its related parts. Furthermore, the construction of such devices renders them unsatisfactory because slippage frequently occurs and, in many types, the reversing mechanism soon becomes inoperative or is not adapted for quick manipulation. Frequently, in order to obtain sumcient strength, it has been necessary to incorporate the ratcheting device in the wrench handle itself, with the concurrent disadvantage that the handle is needlessly enlarged and expensive.

An object, therefore, of my invention is to provide a cheap but rugged reversible ratcheting drive for a socket wrench in which the ratcheting element has an outside diameter approximately the diameter of the socket employed with the wrench.

A further object of the invention is to provide a reversible pawl for a ratcheting wrench drive which is under compression during the application of driving torque.

A further object is to provide a pointed toggle action reversible pawl for a ratcheting socket wrench drive element.

A further object of the invention is to provide a transverse shaft for reversing the pawl in a ratcheting wrench element operable by a crown on the side of the element.

A further object of the invention is to provide a spring loaded pawl having a pair of 60 teeth tapered with respect to each other and adapted to be selectively engaged in the notches of a ratcheting wrench drive member by means of a manually operated crown on the side of the mem- Fig. 2 is a sectional view of the structure of Fig. 1.

Fig. 3 is a sectional view taken along lines 3-3 of Fig. 1.

Fig. 4 is a perspective view of the pawl and the pawl housing with the ratcheting member and easing removed.

Fig. 5 is an enlarged detail of the pawl and the ratcheting member diagrammatically illustrating the composition of turning forces.

Referring now more particularly to the drawings, a ratcheting drive element constructed in accordance with the invention has a pawl housing in in which is milled a transverse slot II, the sides of which form a pair of ears I2 and I3 having outwardly curved sides. Ear I2 is substantially thicker than ear l3 due to the fact that slot 1 I is offset from the center line of the housing l (Fig. 1) and in addition extends beyond the end of ear l3 to form an abutment M for pawl I and also a guiding shoulder I6 at the end of ear l2. Housing 10 extends oppositely to form a hexagonal shank IT in which are located notches l8 for reception of spring pressed retaining elements in the socket of the wrench or other member through which turning force is applied to the hexagonal shank. The housing is centrally drilled at is to accommodate helical spring 29 and steel ball 2|, which cooperates with the lower pointed end 22 of pawl l5 to urge the pawl to pivot on shaft 23 which is in turn supported in ears l2 and I3.

Pawl l5 has a somewhat diamond shaped configuration, the lower portion of which terminates in a 90 point providing a toggle action with steel ball 2|, whereas the upper portion of the pawl carries two outwardly facing 60 teeth 24 and 25 which are cut at an angle with each other. The upper portion of the pawl is milled away on a line parallel to the face of teeth 24 and 25 to form a reinforcing foot or compression member 25 which abuts the flat face of ear i2 and extension H in all positions of pawl [5. Hole 21 in the pawl has a raised flat 28 which is in alignment with flat 29 on shaft 23, thereby locking the pawl to the shaft and thus enabling the pawl to be pivoted by rotating the shaft.

Ratcheting member 30 has a circular hollow head 3| of the same outside diameter as housing 1 Ill and is designed to abut the ends of ears I! and I3. Head 3| of the ratcheting member carries on its inside periphery twelve broached teeth 32 between which are formed twelve notches 33 having sides set at an angle of with each other r (Fig. 5). Ratcheting member 30 likewise-extends" 3 in the opposite direction to form a hollow shank 34 having a hexagonal internal broach adapted to receive a socketed tool element or other driven element which engages the work pieces to which the turning torque is to be applied.

Circular casing 35 encloses ratcheting member 30 and housing It and serves to maintain these members in proper alignment with respect to each other. This is accomplished by the fit of annular lip 36 on casing 35 adapted to rotate on shoulder 31 of member 30, and rigid attachment between the opposite edge of casingziii which is peened to the main body portion of housing in. Slight turning clearance is, permitted between member 30 and casing 35, but thisclearance .is not great enough to permit noticeable end play or misalignment of members in and. 3 0. 23 extends through casing 35 and is permanently secured therein, after assembly of the ratchet elements, by means of washer 38 over which the shaft ts may be peened Crown-3 is secured to the opposite end of the shaft and fits in a circlh larly milled recess 40 on; the upper face. of casing 35.

The; no ches; 3 3 in, head 3iformed between teeth 32- have sides setat 60 angles with each other. This construction insures that, regardless otthediameter of; the head iii of member 3%, one-.sideoftwo notches will at some time be parallel with the sides of; slot H Teeth 3.2, and 32": in Fig, 3 have one Side parallel and in line with the inner-face of'ear l3and; the positionof these two teeth determines. the location of slot II in housing- Hi, It will thus be apparent that when pawl 15 ispivoted in; slot l l, on, shaft 23- as an axis, either'tooth; 24 or teeth 25 will engage in the notch of head 3 {which-is oppositethe 111831; mum pivoting positionoi" the pawl. Turning the crown 39 against the action or"; spring 26, serves; to snap pawl i-Einto opposite notches in member 3 depending upon the direction of relativerotation between members 3%. and: itwhich may be desired. With this-construction itis possible to permit. rotation in either direction merely by holding pawl i5 inwa-substantially vertical position so that neither tooth-i l nortooth 25 en. sages memb r 30 t al Referring now to Figs. 2 and 3;, it will be evident, that: rotation o=:member ID- in a clockwise direction tends to lock; pawl 15, withrespect to member; 3!) and therefore driving forc is trans. mitted from member to member 3!). Counter;- clockwiserctation Qf member H3, however, causes pawl i i-"topivot, on shaft 23; thereby; permitting; amtchctine: action n i ection. The op site ratcheting efiect is; readily; achieved by re-, versingthe position of'the pawl I with. respect to member 30; so; that the pawl will bear against face 3.22" instead of' face 322., In this. position .0 1n .er-clockwise;turning f; m mber I!) transor ue to; member. 3.0;. whereas clockwise ur ing f m mber It; produces. the ra chetin action. Spring: 29, acting throushball: 2!. con-- tinu sto urge t e-tooth. 25. or; 25; a the; case-mar e; i to succ ssive; notche oi: member 35, durin theratcheting-actiom. Fig. 5 illustrates in greater de aiithe peculiarly ood; ratcheting a d; c ng. resultswhi h are btained p ma y meansoi; he s ape and location of; the notches;. -3 3 in membertfl. as well as. the teeth 24;; and: 2,5 in. pawl, 15, Clockwise rotation of; member 9; inE-ie 5 produces 'a; turns.

' ing, force upon the membettfi Whichmayi for the:

purposes, of: our us ration; be eontidered'to be 7 ents hated atapointQ. andiurth direction, 05;

in 'member 30.

a line drawn normal t the radius of head 3| at point 0. The pawl l5, in this position, is permitted to move on its pivot only in the direction 0Q in Fig. 5, and it will be apparent that there is no component of force S reacting upon the pawl in the direction 0Q. However, there is a component OP reacting on the pawl in the opposite direction, and another component reacting'in the direction OR. These tworeactions of the turning force S combine to lock pawl l5 more tightly Furthermore, the reaction forces upon the pawl are not imposed upon theshaft Shaft 23but directly upon the ear l2 and extension I4.

' The greater the turning force applied to member the greater-will be the locking action of tooth 25-with respect tomember 30.

Counter-clockwise rotation of member I 0, however, produces an entirely opposite eiTect, as diagrammatically illustrated in Fig. 5. In this case the sum of the turning forces on the member 30 may b repre ented s concentratedat pQintYB and a ing in adirection a right: angles, to a radius of the head; 3| at pointB. For-c now has a component, C actingin; the direct on BC which by. reaction uponthe-toothifi tends to; disengage the tooth from notch 33, thereb cans-l. ing pawl iito pivot on-shaftZB.

The ofi-center'location ofislot I I not onlypro vides for parallel engagementof teethl iand. .5; with suitable notchesin head 3] but also.- permits:

' strengthening of ear 12 in order to better ith stand the forces transmitted through pawl l5- the manner-described;abovee The ratchet driveischeapto manufacture,- and; of extremely ruggedconstruction. It; is adapted; to be used not-only, for hand tools such-as socket. wrenches, but be applied to. any driving: mechanism. in which one way driving torque is. required.

Whilecertain novel features or theinvention are disclosed herein inconsiderable detail with" respect to certain-particular forms of theiin en1' tion, itis not'intended thattheinvention be lim ited to such details since many-changes andmod! .ifications may well be made withoutdeparture from the spirit ortheinvention: initsbreadoSt aspects. I

I claim: 7

l. A ratcheting device compris ng a pawl houses ing havingapair of cars forming side walls. for the housing, oneof said ears being. thicker than;- the other ear, a pawl pivotall-ysupportedbetw said walls, ahollow, rotating member adapted to abut the endsof said ears, ,a guideon one ofisaid;

ears, extending into thehollow portion or the ratcheting member to provide alie ment for said; member, a, plurality of, notches around the interl portion of the rat h ting member; and ateeth: on one; end of the pawl for-engagingone Qi-gfiflidj notches, the shape ot the. notches andztooth being suchthat turninsforce,- applied throuehrthap wli to-the ratcheting member; a ne direction solves intotwo components, one of which fore thepawl into tighter; enga ement with; the: S l

pawl agai t. the: larger carand-suide tetransmita the turnin forceto the.h0l1sing. 7 2. A ratcheting device comprising a pawlhousa ine'h vine a pa t ars,iorminasidewalls o e h i a; ne o aid ears :beinethic t the-othere 17-,.a pa l:p vo al vsupportedbetweche it s idwalls, a ho low-- ro a ing memberadeptedtez abuttheends of said ears aguide 1 one efsaid ears extending into: 11. 185. hollow.- portion 9f; 5 1- ratcheting member to provide alignment fog-said 5 6 member, twelve 60' notches around the internal portion of the ratcheting member, and a 60 REFERENCES CITED tooth on one end of the pawl for one The foliowing references are Of reCOrd in the of said notches, the shape of the notches and file of thls Patent: tooth being such that turning force applied UNITED STATES PATENTS through the pawl to the ratcheting member in one direction resolves into two components, one ber Name Date 266,865 Miles Oct. 31, 1882 of which forces the pawl into tighter engagement with the notches and the other f which com- 719303 Thlbert 1903 1,087,316 Packer Feb. 17, 1914 presses the pawl against the larger ear and guide 10 1 808 268 st ewart June 2, 1931 to transmit the turning force to the housmg. 2,020,883 Gagne NO 12, 1935 FRANCIS R. KULL. 2,407,558 Kress Sept. 10, 1946

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