US2879659A - Pin tumbler lock - Google Patents

Description

March 31, 1959 E. N. JACOB! 2,879,659

PIN TUMBLER LOCK Filed May 16, 1957 3 Sheets-Sheet 1 dwar'd NJacub'L March 31, 1959 E. N. JACOBI 2,879,659

PIN TUMBLER LOCK 3 Sheets-Sheet 2 Filed may 16, 1957 dwaq'c? .N'. Jacob-L March v1959 E. N. JACOB] 2,879,659

PIN TUMBLE R LOCK Filed May 16, 1957 3 Sheets-Sheet 3 Edward NJcabz United States Pate 2,879,659 N TUMBL L Kv Edward: N. Jacobi, Milwaukee, Wis., assignor to Briggs 8a. Stratton Corp., Milwaukee, Wis., a corporation of Wisconsin Application May 16, 1957, Serial No. 659,667 Claims. (61.; 70-364).

Thisinv ntio re nt s o p n. mbler ks of h yp wherein a. cylindrical plugfrnay be rotated between a loeked an cl an unlocked position by means of a key, and refersmore particularly to a pin tumbler lock wherein the key may be withdrawn from the plug when the latter is in its unlocked position as well as in its locked position.

In the well known pin tumbler lock a cylindrical plug having a key slot therein is rotatable in the bore of a sleeve, by means of a proper; key receivable in the key slot and. which causes movable pin tumblers carried by the sleeve to be released from locking engagement with the plug. Such relfiase of the pin tumblers is effected by means qf;-a row. as auxiliary spaced tumbler driversin the plug, constrained, to rotate therewith but individually movable radially relative to the plug. The tumbler driyers, are carried in. small transverse bores in the plug eni t ts. u ed u ac an t h ey l t an the inner end. portions, of the drivers, normally project int h h y ot o, b n d y a key n er ed her n In the locked position of the: plug each of the tumbler driyers isaligned with a pin tumbler in the sleeve, and when h h y no Pr s nt n. he p us th Pi u b er Pr j hom e ham er n l eve. p wa n o the driver bores to preclude rotation of the plug, the pin tumblers being individually biased inwardly to propel th m t ch l k g p s i n ,-v W en a PrQpet k y is inser ed; in e k y lo t aq un s the r v to positions, which their outer ends are flush with the curvedsurface of the plug, driving he tumblers, against the r yie d i s, t of the b r in h p us tn r the plug for rotatiqn away from its locked position.

As a key is inserted into or withdrawn from the plug, thelands on its notched, edge traverse the inner ends of th umb er drivers, and as umi pl g to be n, i locked position, the drivers are thereby propelled part Wsui tnt e nnib sr we l in he e ve, d placi the Pin. mb rs When he. p u s rota ed away r m t in hed pnsi inn, the ner sur a e f the s e e w l .e v naks outwar m vsn ent h drivers b yo d t e. curved. snrfase of. th p s an o eq en y h lands on the key cannot clear the drivers and the key cannot be withdrawn from the plug.

n ma y. ins a n in s h we er, i is de ra t P vide fo w hd awal of, the k y a a p ed e ned. nnlpcka pe tio Qt r tation i Pin One exped n her tofor e or d n. uch as wa o p i e n extra. s o Pin nr hle s n h sl eve, at an an la P s tiqn i which he ri rs. n he phig w ul a i with such. ext a p n. tumble w n h Pine as. ot ted tn the. p ede ermi ed nn n h d P i ionhis. xp di n expens e nd is dv n s o s'sincs i nn n y r r qh si he PrQY siQn. 0 ex ra. of tum e chambe in sleeve. b t a n e tn ed, h installation erein ntxtne e a setn nmhl andn nhle sprin s- BX hnrasti is n QblQE Qt the pr en inventio to provide a pin tumbler lock qfi the, character described wherein the key may be inserted into or withdrawn from ice the plug in either the locked or an unlocked position thereof, and wherein key releasing displacement of the tumbler drivers is provided ior at the unlocked position of the plug by very simple means whereby the drivers are permitted to move independently of one, another but are yieldingly confined against displacement out of the plug, and whereby the drivers are yieldingly. held with their outer ends flush with, the curved surface of the plug when the key is fully inserted, to thus enable rotation of the plug away from its unlocked position,

Another object of this invention resides in the provision, in a pin tumbler lock of the character described, of a simple unitary spring member mounted on the enterior of the sleeve by which each of the tumbler drivers is individually yieldingly biased inwardly of the plug toward a position at which its outer end lies within the curved surface of the cylindrical plug when the latter is in its unlocked position. v

Still another object of this invention resides in the provision of a pin tumbler lock of the type having a plug rotatable in the bore of a sleeve and carrying tumbler drivers, wherein the key may be inserted into and Withdrawn from the plug when the plug is in an unlocked position, and wherein each of the tumbler drivers may project into an aperture in the wall of the sleeve at the unlocked position of the plug to enable insertion and withdrawal of the key without danger of the, drivers being displaced out of the plug, such confinement of the drivers collectively being effected by the same unitary means whereby they are indiyidually biased to positions in which their outer end portions n? h ld flush with the. Curved es i. h Pl s so hat he p us may be rotated out of its unlocked position.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly d fine b the. ppe ded cla ms, it b n understood that such changes inthe precise embodiment of the hereindisclosed invention may be made as come within, the scope of the claims, i

The accompanying drawings illustrate one complete example of t Phy al em ndirne f th n e t n constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a de evntinna i w f sp n umble lock embodying the principles of thi invention;

Figure 2 is a cross sectional view taken on the plane of the line 2-2 in Figure 1,. showing the lock with its cylindrical plug in its locked position of rotation and with the key removed therefrom;

Figure 3 is a view similar to Figure 2 but showing the plug rotated to its unlocked position and with the key Withdrawn therefrom;

Figure 4 is a view similar to Figure 3 but showing a key inserted part Way into the key slot in the plug;

Figure 5 is a longitudinal sectional view taken on the plane of the line 5-5 in Figure 4;

Figure 6 is a perspective view of the spring member of this invention; 7

Figure 7 is a cross sectional view of the lock with a modified embodiment of the spring member of this in vention installed thereon, the view being taken through the rearmost tumbler of the lock;

Figure 8 is a separated perspective view of the modified spring member and detent tumbler shown in Figure nd Figure 9 is a fragmentary perspective view Of 3 9mm m d e embodim nt 9 t e. spr rns nh r- Referring now, more particularly to the accompanying drawings, in which like numerals designate like parts throughout the several views, the numeral 5 designates generally a pin tumbler lock comprising a sleeve 6 havmg a bore 7 therein in which a cylindrical plug 8 is rotatable. In a radial extension 9 extending lengthwise of the sleeve are a row of axially spaced pin tumblers 10, each movable radially in a tumbler chamber 11 which opens to the sleeve bore. Each tumbler is biased inwardly toward the axis of the sleeve bore by means of a coiled compression spring 12 confined between the outer end of the tumbler and a retainer 14 extending lengthwise along the extension 9 and which closes the outer ends of the tumbler chambers.

The plug 8 has a plurality of axially spaced driver chambers 15, in each ofwhich a driver 16 is confined for rotation with the plug and for motion radially relatlve to the plug, there being as many drivers as there are pintu'mbler's. The driver chambers open at their inner ends to a key slot 17 adapted to receive a key 18 where- 'by the plug may be rotated between its locked and unlocked positions, and in the locked position of the plug the outer end of each driver chamber aligns coaxially with one of the pin tumbler chambers so that when there is no key in the key slot the pin tumblers can project short distances into their adjacent driver chambers (as shown in' Figure 2) to preclude rotation of the plug out of its locked position.

When a proper key is fully inserted into the key slot, the inner ends of the drivers are engaged with the bottoms of notches 20 in the key, whereby the drivers are raised to positions in which their outer ends are flush with the curved surface of the plug, and each driver, in turn, moves its adjacent pin tumbler, against the bias of its spring, to a position clear of the driver chamber to free the plug for rotation to an unlocked position.

The mechanism thus far described will be recognized as entirely conventional, and it will also be recognized that as the key is inserted into and withdrawn from the key slot the lands 22 on its notched edge move the drivers outwardly as they traverse the inner ends of the drivers, momentarily carrying the outer end portions of the drivers substantial distances beyond the curved surface of the plug. In the locked position of the plug the drivers are free to move part way into the tumbler chambers, and the springs 12 by which the tumblers are biased inwardly yield sufiiciently to accommodate the displacement of the tumblers which is consequent to such dis placement of the drivers by the lands on the notched edge of the key. However, as the plug is rotated away from its locked position the wall of the sleeve normally confines the drivers against such displacement as would enable them to clear the lands of the key, thus preventing withdrawal of the key from the keyway.

In the lock of this invention the key may be withdrawn from the plug at a predetermined unlocked position of the plug, and this position, as well as the locked position, is preferably established by cooperating abutments on theplug and on the sleeve, not shown, but the nature of which will be familiar to those skilled in the .art. To enable withdrawal of the key at the unlocked position of the plug, a wall portion of the sleeve is apertured, as at 24, to accommodate the outer end portions of the drivers during insertion or withdrawal of the key, as the lands on its notched edge propel the drivers outwardly. A unitary comb-like spring member 25, serves the dual purpose of confining the drivers against displacement out of the plug (while yieldingly permitting them to be propelled outwardly into the aperture 24 sut'ficient distances to clear the key lands) and of returning the drivers to their retracted positions when the key is inserted all the way into the key slot, yieldingly holding the drivers with their outer ends flush with the curved surface of the plug so thatthe plug may be ro- "t ated away from the unlocked position;

v The spring member (see Figure 6 comprises an elongated body portion 26 extending lengthwise between .a

substantially,

. of any of the pin tumblers 10.

4 1 pair of axially spaced shoulders 30 on the exterior of the sleeve. A plurality of resilient spring fingers 27, one for each of the drivers 16, extend laterally in one direction from the body portion of the spring member and a lever arm 28 projects in the opposite lateral direction therefrom. Longitudinally aligning recesses 31 in the shoulders 30 loosely, receive tab-like trunnions 32 on the ends of the body portion. of the spring member to rockably mount the spring member" on the exterior of the sleeve with the extremities of its spring fingers projecting through the aperture 24 in the sleeve to engage the outer ends of the drivers when the plug is brought to its unlocked position of rotation. The outer end portions of the fingers are bent, as at 35, to ofiset their tips radially inwardly of the plane of the remainder thereof so that marginal edge portions of the sleeve adjacent to the aperture 24 will not interfere with engagement of the finger tips with the drivers.

Attention is directed to the fact that the recesses 31 have sides which converge in a direction away from the aperture 24, and that they have narrow abutments 31' at the apexes of their convergent sides which are engageable by the edges 32 on the trunnions remote from the spring fingers to fulcrum the spring memberfor rocking motion about an axis lengthwise thereof and parallel to that of the plug.

To maintain the trunnions properly seated on their fulcrums and to help maintain the fingers in biasingengagement with the drivers, the spring member is biased in the direction to rock the finger tips inwardly toward the plug by means of a coiled compression spring 37 confined between the lever arm and the sleeve. The coiled spring is seated in a pocket 39 in the sleeve and is further steadied by a rivet-like pilot 38 on the spring member. The biasing force of the coiled spring should be such that when all but one of the spring fingers are raised by outward propulsion of drivers during key insertion or withdrawal, all of the raised fingers will have to flex so that said one finger will continue to confine its driver within the plug. Obviously, instead of using a separate coil spring reacting between the spring member and the sleeve, the spring could be made as an integral part of the spring member.

Thus each of the fingers of the spring member may fiex individually as its driver is propelled outwardly by the lands on the notched edge of the key during insertion or withdrawal of the latter, while the remaining fingers resiliently hold their drivers inwardly. When the key is in itsifully seated position in the key slot, the spring fingers hold the drivers in the plug, with their inner ends engaging the bottoms of the key notches and with their outer ends flush with the curved surface of the plug, so that the plug may be rotated away from its unlocked position.

To further assure that the drivers will be held in the plug as theypass out from under the tips of the spring fingers, the inner surface of the sleeve wall has a small chamfer, as at 41, adjacent to the aperture 24 and by which the end of any slightly projecting driver is cammed into the plug as the plug is rotated away from its unlocked position.

In installations where the lock is subjected to severe vibration, or where the plug carries a part which tends to rotate it away from the unlocked position, one of the spring fingers may be provided with an inwardly projecting detent tumbler 42, as shown in Figures 7, 8 and 9. This detent tumbler projects partway into the driver aperture therebeneath when the plug is in its unlocked position of rotation, securely holding the plug against rotation out of said position. Preferably the detent tumbler is carried by the rearmost spring finger, so that the key must be inserted all of the way into the key slot to displace the detent tumbler and free the plug for rotation, the action of the detent tumbler being the same asthat the fingers;

The detenttumbler illustrated in. Figures 7' and 8' is substantially U-shaped in cross section and has a trans: verse slot 43 in the legs oi the U, opening to the edges thereqf; in which the free end portion of the rearmost spring finger 44 is'engaged. Said spring finger 44 is substantially flat along its entire length, rather than. having itsouter end portions bentinwardly like the rest of Edge portions ofthe aperture 24' in the sleeve guide the detent tumblerin endwise motion and, hold;- it in engagement withthe tip portion of the rearmost spring finger.

In the embodiment shown in Figure 9 the detent tumbl'cl eomprisesa pin 42 having a reduced diameter end port-ion projecting through a loosely fitting lengthwise extending slot45 in the tip portion. of the rearmost, spring finger and: peened; over to secure it to the finger. The slot permits the pin to slide lengthwise relative to. the

spring finger so that the pin canaccommodate itself to the aperture 24 in the sleeve and can cam itself laterally into the rear driver chamber when the plug is rotated to the unlocked position.

With both of the modified spring members, just described the detent tumbler prevents inadvertent unauthorized rotation of the plug; out of the unlocked position, as by the use of a screw driver or coin inserted into the key slot, as well as preventing inadvertent rotation of the plug due to vibration or the like.

From the foregoing description taken together with the accompanying drawings it will be apparent that this invention provides a pin tumbler lock having predetermined locked and unlocked positions at either of which a key is insertable into or removable from the plug, and which lock has a simple and inexpensive unitary spring member whereby each of the tumbler drivers is individually yieldingly biased inwardly of the plug toward and beyond a position at which the outer end of the tumbler is flush with the curved surface of the plug when the latter is in its unlocked position.

What is claimed as my invention is:

1. In a pin tumbler lock comprising a cylindrical plug having a key slot in which a key is insertable and having a row of axially spaced tumbler drivers which are movable radially relative to the plug by insertion or withdrawal of a key, but which are constrained to rotate with the plug: a sleeve having a bore in which the plug is rotatable between locked and unlocked positions, the wall of said sleeve being apertured to accommodate the outward projection of the drivers which occurs as a consequence of withdrawal of the key from the plug in the unlocked position thereof; a row of axially spaced pin tumblers in said sleeve, each yieldingly biased toward the plug and located to be aligned with one of the drivers in the locked position of the plug; a spring member comprising an elongated body portion having a resilient finger for each tumbler driver projecting therefrom in one lateral direction, the spacing of said spring fingers lengthwise of the body portion of the spring member corresponding to the axial spacing of the drivers, and said spring member having a lever arm projecting in the opposite lateral direction from its body portion; means rockably mounting said spring member on the exterior of the sleeve with the rocking axis extending lengthwise of the body portion and substantially parallel to the axis of the sleeve bore, and disposing the free ends of the spring fingers in registry with the apertured portion of the sleeve wall and with the drivers in the unlocked position of the plug; means reacting between the sleeve and the lever arm of the spring member to bias the spring member about its rocking axis in a direction urging the free ends of the spring fingers toward the exterior of the sleeve; and tip portions on the free ends of said fingers, extending from the undersides thereof and projectable through the apertured wall portion of the sleeve so as to have inwardly biasing engagement with the drivers when the plug is in its unlocked position, said fingers permitting yielding movements of the drivers outwardly into. said apertured wallportion of the sleeve when a' key is inserted into or removed from the key siet, but confining the drivers against; displacement out or the plug and urging the drivers to positions in which their outer ends are substantially flush; with thecurved surface of the plug when the key isinplace in the plug; so that the latter may be rotated away from its unlocked. position.

2. In apin tumbler lock comprising a cylindrical plug having akey slot in which. a key is insertable and having a row'of axially spaced tumbler drivers which. are movable radially relative to the plug byv insertion or withdrawal of: a key, but which are constrained to rotate with the plug: a, sleeve having inwardly biased pin tumblers, and having a bore in which the plug is rotatable between an unlocked position and a locked position in which the drivers align with said tumblers, a wall portion of the sleeve being apertured to accommodate outer end portions Qff the drivers to enable withdrawal of the key from, the plug when the plug is in its unlocked position; a spring member comprising an elongated body portion, a plurality 0f resilient spring fingers extending laterally in one direction from said body portion and spaced from one another lengthwise of the body portion in correspondence with the spacing betweenv the drivers, and a lever arm extending laterally in the opposite direction from the body portion; cooperating means on the exterior of the sleeve and on the body portion of the spring member rockably mounting the latter on the sleeve with the rocking axis extending lengthwise of the body portion and substantially parallel to the axis of the sleeve and with the free ends of the spring fingers in juxtaposition to the drivers through the apertured wall portion of the sleeve when the plug is in its unlocked position of rotation; and spring means reacting between the lever arm and the sleeve for biasing the spring member to a position of rocking motion in which its spring fingers yieldingly permit radial movement of the drivers to enable insertion and removal of a key into the key slot in the plug when the plug is in its unlocked position, but confine the drivers against displacement out of the plug and hold the drivers with their outer ends substantially flush with the surface of the plug to enable the plug to be rotated away from its unlocked position.

3. In a pin tumbler lock comprising a cylindrical plug having a key slot in which a key is insertable and having a row of axially spaced tumbler drivers which are movable radially relative to the plug by insertion or withdrawal of a key, but which are constrained to rotate with the plug: a sleeve having inwardly biased pin tumblers cooperable with the drivers, and having a bore in which the plug is rotatable between an unlocked position and a locked position in which the drivers are aligned with said tumblers, a wall portion of the sleeve being apertured to receive the outer end portions of the drivers in the unlocked position of the plug to enable removal of the key therefrom; a spring member comprising an elongated body portlon and a plurality of resilient spring fingers extending laterally in one direction from said body portion and spaced from one another, lengthwise of the body portion, distances corresponding to the spacing between the drivers; cooperating means on the exterior of the sleeve and on the body portion of the spring member mounting the latter on the sleeve for rocking motion about an axis extending lengthwise of the body portion and substantially parallel to the axis of the sleeve bore, disposing the spring member with the tips of its fingers adjacent to the outer ends of the drivers, through the apertured portion of the sleeve wall, when the plug is in its unlocked position of rotation; and means reacting between the body portion of the spring member and the sleeve to bias the spring member toward a position of rocking motion in which the tips of the spring fingers engage the drivers to yieldingly prevent their displacement out of the plug while permitting'movement of the drivers tok enable withdrawal and insertion of the key when the plug is in its, unlocked position,..and to hold the drivers flush with the surface of'the plug to enable the plug to be rotated away from its unlocked position.

4. A pin tumbler lock of the type comprising a bored sleeve having a row of pin tumblers mounted for individual movement therein toward and from the axisof the sleeve, and a cylindrical plug rotatable in .the bore of the sleeve between a locked and an unlocked position and in which a row of key operable tumbler drivers are confined for rotation with the plug and for tumbler actuating movement radially relative to the plug, and wherein movement of the drivers beyond the cylindrical surface of the plug is produced by insertion of a key, into a key slot in the plug or upon its withdrawal therefrom: characterized by the fact that a wall portion of the sleeve is apertured to receive outer end portions of the drivers in the unlocked position of rotation of the plug to enable the key to be withdrawn from the plug; and further characterized by the provision of means for preventing displacement of the drivers out of the plug through said apertured wall portion thereof and for yieldingly urging them inwardly of the plug to enable rotation of the plug out of its unlocked position by its key, said means comprising a unitary spring member having an elongated body portion laterally rockably mounted on the exterior ofthe sleeve, a plurality of resilient springfingers extending in one lateral direction from said body portion atlengthwise spaced intervals therealong, each of said spring fingers having means at its tip engageable under flexing bias with one of the drivers through the apertured wall portion of the plug, and a biasing arm extending in the opposite direction from said body member, intermediate its ends, and engaged with the sleeve to maintain inward bias upon all of the spring fingers while permitting them to flex independently.

5. The lock of claim 1, further characterized by a detent tumbler on the free end of one of the spring fingers of said spring member projecting into the sleeve and adapted to enage in the plug when the latter is in its unlocked position and the key is withdrawn therefrom, and by which detent tumbler rotation of the plug out of its unlocked position is prevented.

References Cited in the file of this patent UNITED STATES PATENTS 1,261,089 Yawman Apr. 2, 1918 FOREIGN PATENTS 831,208 Germany Feb. 11, 1952 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 2,879,659 March 31;, 1959 Edward. N Jacobi It is herebj certified that error appears in the -printed specification of the above "numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 28, for "auxiliary" read axially eg Signed and sealed this 21st day of July 1959 Attest:

ROBERT C. WATSON KARL H, AXLINE Commissioner of Patents Attesting Oflicer UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION March 31, 1959 Patent No. 2,879,659

Edward N. Jacobi appears in the-printed specification' It is hereby certified that error oorrection and that the said Letters of the above "numbered patent requiring Patent should read as corrected below.

Column 1, line 28, for auxiliary" read axially Signed and sealed this 21st day of July 1959.

Attest: KARL H, MIN ROBERT C. WATSON Commissioner of Patents Art testing Oflicer

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