US2357004A - Lock device - Google Patents

Description

2 S heets Sheet '1 E. N. JACOB! Ldcx DEVICE Original. Filed Sept. 5, 1941 Aug. 29, 1944.

E. N. JACOB! LOCK DEVICE Aug. 29,

2 Sheets- Sheet 2 Original Filed Sept; 5, 1941 EdwardA/L/Eadbz Patented Aug. 29, 1944 LOCK DEVICE Edward N. Jacobi, Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee, Wis, a corporation of Delaware Original application September 5, 1941, Serial No. 409,611. Divided and this application April 3, 1942, Serial No. 437,547

22 Claims.

This invention relates to looks and refers particularly to door latch locks of the type shown inPatent No. 2,208,003, issued to E. N. Jacobi, July 16, 1940, and is a division of the copending Application, Serial No. 409,611 filed September 5, 1941. now Patent No. 2,318,490.

In lock devices of the type here under consideration, as well as in other tumbler looks, it is desirable that the cylinder be removable. Various devices have been employed in the past for removably securing the cylinder in its casing, but in general they all embody a spring pressed detent carried either by the cylinder or the easing and extending across the juncture therebetween to engage with an abutment or shoulder from which the detent must be freed to permit withdrawal of the cylinder.

It is also the practice in tumbler locks of the character described to retain the individual tumbler springs either by individual retainers or more suitably by means of a single retainer fixed to the cylinder with portions thereof disposed over the tumbler springs.

With a view toward minimizing the number of parts, the present invention has as one of its objects the provision of a novel manner of combining the functions of retaining the tumbler springs and removably holding the cylinder in its casing.

To this end, it is an object of this invention to provide a novel combined tumbler spring retainer and cylinder retaining member so designed and assembled with the cylinder that the reaction of the tumbler springs holds this combined retainer in an operative position projecting a lug or lip thereon beyond the wall of the cylinder for engagement with a retaining shoulder in the bore in the casing.

More specifically, it is an object of this invention to provide a combined tumbler spring retainer and cylinder retaining member which consists of a stamping set into a recess in the cylinder wall in such a manner that it may be considered to be floatingly disposed and biased to a position projecting its stop lug or lip beyond the cylinder wall by the reaction of the tumbler springs.

Another object of this invention is to simplify the construction of the individual tumblers.

Still another object of this invention resides in the provision of a novel cap for the end of the casing which is formed as a die casting and incorporates as an integral part thereof a protective boss projecting forwardly to partially embrace the protruding end of the cylinder and thereby prevent access to the combined tumbler spring and cylinder retainer in the locked position of the cylinder.

With the above and other objects in view, which will appear as the dscription proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a longitudinal sectional view through a lock device constructed in accordance with this invention;

Figure 2 is a cross sectional view taken through Figure 1 on the plane of the line 2-2;

Figure 3 is a perspective view of the lock casing per se;

Figure 4 is a perspective view of the combined casing cap and bolt retainer;

Figure 5 is a perspective view of the cylinder Figure 6 is a perspective View of the combined tumbler spring and cylinder retainer; and 30 tumblers.

Figure 7 is a perspective view of one of the Referring now particularly to the accompanying drawings, in which like numerals indicate like parts, the numeral 5 designates the door of a glove compartment, only the upper wall 6 of which is shown.

Extending down from the upper wall 6 directly adjacent to the door frame is a striker plate or keeper 1 behind which a toggle-like latch bolt 8 carried by the lock device indicated generally by the numeral 9 engages to secure the compartment door 5 closed. The lock device 9 is mounted on the door so that when the door is closed, the latch bolt automatically engages behind the striker plate or keeper.

The lock device comprises a casing l0 preferably formed as a die casting and having a bore I l to slidably and rotatably receive a lock cylinder l2. A longitudinal slot l3 through the top wall of the casing accommodates the latch bolt 8. The sides of this slot 13 are longitudinally grooved as at M to receive trunnions l5 formed as integral parts of the toggle-like latch bolt. These trunnions are held against the inner ends of the grooves l4 by-spaced arms 16 projecting rearwardly from and constituting an integral part of a casing cap IT.

This cap, like the casing, if preferably a die casting and has an annular part l8 from which the arms 16 project. The annular-part fits over the front end of the casing where it is clinched in place. The cap thus defines the mouth of the bore in which the cylinder is received with its front end protruding therefrom to project from the front face of the door panel as a push button.

The cylinder is also preferably die cast and has an open transverse tumbler cavity I9 communicating with a longitudinal keyway 20. The side walls of the cavity have opposite grooves 2! extending across their full width to provide tumbler guideways in which the side edges of tumblers 22 ar slidably received.

At one edge of the cavity the cylinder is formed with bridges 23 which extend across the cavity .between the tumbler, guiding grooves 2|, These bridges, together with a similarly located ledge (not shown) on the inner or rear end of the cavity. provide lands in position to collide with spring rests 24 on the tumblers toalimit the stroke of .the tumblers under action of their springs 25.

The individual .tumblers, as best shown in Figure '7, arestamped from flat band stock and have their medial'portions recessed or cut out at one edge to provide a key opening 26. The spring rests 24 are projections-formed on the inner edges of the intermediate portions of the tumblers bent back 'ontothe intermediate portions as clearly shown so as to dispose the actual spring seats in line with the intermediate portions. The spring seats are pointed to enter the ends of the coil springs andprevent displacement of the springs.

Heretofore, the tumbler springs were held in place either by individual retainers or a common retainer secured in the cylinder, but in all instances in the past, the tumbler spring retainers were fixed .and generally were staked into the cylinder.

With the present invention, an entirely new form of tumbler spring retainer is employed, and

as a result the functions of retaining the individual tumbler springs and also removably securing the cylinder in the casing bore are pergated bar or strip 28 of a length greater than that of the tumbler cavity and having a plurality .of spring seats 29 formed thereon. These spring seats may be roughly defined as teeth bent laterally from one edge of the bar 28 and to guard against displacement of the ends of the springs from these seats, their extremities are bent inwardly as at 30.

To accommodate the retainer 21, the cylinder has an open slot 31 extending along one side of the tumbler cavity and continuing past the front end thereof. This slot receives the fiat bar or strip 28 with the front end portion thereof cate'dforw'ardly of the tumbler cavity.

At its rear end, the strip 28 has a projection 32 which enters a hole 33 in the inner end portion of the cylinder which closes the rear or inner end of the tumbler cavity. In this position the retainer 21 has its spring seats 29 disposed over the individual tumbler springs and as will be readily apparent, is free to swing on the fulcrum provided by the engagement of the projection 32 in the hole 33.

The retainer is thus substantially floatingly mounted and is free to move toward and from the surface of the cylinder in a direction substantialthe tumbler cavity, the retainer has a transverse arm 36 extending laterally in the same direction as spring seats 29, and at its extremity the transverse arm is bent down to form a fiat portion 31 parallel with the bar and provided with an extension 38 which lies directly opposite the front end portion 34.

This extension 38 like the end portion 34 is engageable with the inner surface of the cap 35, and to guard against binding, the edges of the end portion 34 and the extension 38 which engage the cap lie in a plane normal to the plane of the bar or strip 28, and the location of the retainer is such that these edges engage the cap at points equidistant from a median longitudinal plane passing through the axis of the cylinder and parallel with the plane of the bar or trip 28.

On the rear edge of the transverse arm 36 is an outwardly bent lip 39. This lip, in the free position of the retainer, projects beyond the surface of the cylinder to be engageable behind a shoulder 40 on the casing cap I! to thereby removably hold the cylinder in the casing bore.

In assembling the cylinder with the casing the lip 39 on the sprin pressed retainer is cammed in over the edge of the shoulder 40 by a cam surface 4| formed at the junction of the face of the annular part I8 with the cylindrical surface 42 of a boss 43 protruding from the front of the casing cap. The cylindrical surface 42 is concentric with the bore and is somewhat larger in diameter than the bore which allows for the annular chamfer which forms the ca surface 4|.

As clearly shown in Figure 4, the boss extends around only a portion of the'mouth of the bore and is in position to cover the exposed arm 36 of the retainer in the locked position of rotation of the cylinder. Hence, the retainer cannot be depressed to disengage its lip 39 from the shoulder 40 until the cylinder is turned to its unlocked position whereupon the exposed arm 36 is clear of the boss 43.

Moreover, even though through deft manipulation it would be possible to depress the free end of the retainer to disengage its lip 39 from the shoulder, removal of the cylinder could not be effected in the locked position of rotation as the projecting ends of its tumblers would collide with the back of the annular part of the casing cap.

Rotation of the cylinder is limited to by the complementary shape of the inner end of the cylinder and the bottom of the casing bore. Also by virtue of the relative shape of the inner end of the cylinder and the bottom of the bore, the cylinder cannot be depressed in the fashion of a push button in its locked position of rotation. It must be turned to its unlocked position and when so turned the cylinder may be depressed to rock the toggle bolt on its trunnions and retract the same from engagement with the keeper or striker plate I.

As in the patent hereinbefore mentioned, the bolt is biased to its operative keeper engaging position by a spring 44. This spring presses the inner arm 45 of the bolt against the end of the cylinder and thus pushes the cylinder forwardly to hold the lip 39 firmly against the shoulder 40.

Attention is directed to the fact that the location of the fulcrum about which the retainer 21 swings lies inwardly, that is closer to the axis of the cylinder than the lip 39. lip 39 resulting from its engagement with the shoulder 40 thus tends to rock the retainer toward operative position rather than camming it inwardly out of engagement with the shoulder, and it is also to be observed that the transverse arm 36 which carries the lip 39 is braced by its engagement with the walls of the cylinder recess in which it fits.

With the cylinder in its locked position of rotation, retraction of the bolt is positively prevented by a foot 46 formed on the bolt and engaging the side of the cylinder.

In its unlocked position, a recess 41 in the side of the cylinder aligns with the foot 46 to accommodate it and permit retraction of the bolt by inward depression of the cylinder in the normal manner.

If perchance the bolt spring 44 does not project the bolt to its operative position, turning of the cylinder to its locked position of rotation positively earns the bolt outwardly as the end 48 of the recess 41 rides under the foot 46 From the foregoing description, taken in connection with the accompanying drawings, it will be readily apparent that this invention provides a lock device especially adapted for use on glove compartment doors which has substantial advantages over similar devices heretofore in use in that it positively secures the toggle bolt against retraction when the cylinder is in its locked position of rotation and simplifies the design of the lock mechanism by combining the tumbler spring retainer and the cylinder retainer.

I claim:

1. In a lock having a bored cas ng, a cylinder and spring pressed tumblers carried by the cylinder and cooperating with the casing to secure the cylinder against rotation: means for removably securing the cylinder in the casing comprisin a shoulder on the casing; a part connected with the cylinder and restrained against endwise movement with respect thereto but free to move radially, said part being engageable with the shoulder and having'means reacted against by all of the tumbler springs so that the tumbler Pressure on the springs collectively bias said part to its operative shoulder engaging position.

2. In a lock of the type having a casing and a lock cylinder removably mounted therein and equipped with spring pressed tumblers engageable with the casing to secure the cylinder against rotation: a tumbler spring retainer assembled with the cylinder in a manner enabling limited radial movement of a part thereof in the direction of the thrust of the tumbler springs so that said tumbler springs yieldingly project the retainer radially outwardly of the cylinder; and a shoulder on the casing behind which a portion of said spring retainer engages to hold the cylinder in the casing bore.

3. In a lock of the type having a casing and a lock cylinder removably mounted therein and equipped with spring pressed tumblers engageable with the casing to secure the cylinder against rotation: a tumbler spring retainer assembled with the cylinder in a manner enabling limited radial movement of a part thereof in the direction of the thrust of the tumbler springs so that said tumbler springs yieldingly project the retainer radially outwardly of the cylinder; and a shoulder on the casing behind which a portion of the sprin retainer engages to hold the cylinder in the casing bore, said spring retainer being depressible against the force of the tumbler springs to disengage the same from said shoulder and free the cylinder for withdrawal.

4. A look of the type having a bored casing with a lock cylinder removably mounted therein and equipped with spring pressed tumblers cooperable with th casing to secure the cylinder against rotation, characterized by the provision of: a common tumbler spring and cylinder retainer biased by the tumbler springs to a position operable to secure the cylinder in the casing.

5. As an article of manufacture: a lock cylinder having a keyway opening to a transverse tumbler cavity; tumblers slidable in said cavity; springs yieldingly biasing the tumblers to operative locking positions from which they are retractible by a key inserted into the keyway; a tumbler spring retainer carried by the cylinder and against which the tumbler springs react, said retainer having limited movement in response to the thrust of the tumbler springs; and means on said spring retainer projectable beyond the surface of the cylinder in response to the spring thrust to provide adepressible cylinder retaining abutment.

6. In a lock: a casing having a bore and a cylinder retaining shoulder; a cylinder in the bore;

tumblers carried by the cylinder; spring means 7 biasing the tumblers to operative cylinder securing positions; and a cylinder retainer having a part engageable with said shoulder and biased to its operative shoulder engaging position by said spring means.-

7. In a look: a cylinder having a bore and a cylinder retaining shoulder; a cylinder in the bore; tumblers carried by the cylinder; tumbler springs biasing the tumblers to operative cylinder securing positions; a common spring retainer carried by the cylinder against which all of the tumbler springs react; and means mounting said spring retainer on the cylinder in a manner enabling a portion thereof at least to move radially with respect to the cylinder, said portion having a part engageable with the cylinder retaining shoulder, and said reaction of the tumbler springs against the retainer biasing said part of the retainer radially outwardly into operative engagement with the shoulder.

8. In combination: a lock cylinder having a longitudinal keyway opening to a tumbler cavity; tumblers slidable in said cavity with parts thereof engageable by a key insterted into the keyway; individual tumbler springs biasing the tumblers to predetermined positions from which they are retractable by the key; a single spring retainer mounted in the cylinder and extending past the tumblers providing spring seats against which the individual tumbler springs react, said spring retainer having limited pivotal motion about one end thereof in the direction of the thrust of the springs so that the tumbler springs yieldingly urge the retainer toward the surface of the cylinder; and a part on said spring retainer projecting above the surface of the cylinder to provide a cylinder retaining stop abutment, said part being depressible below the surface of the cylinder upon application of pressure on the retainer against the tension of the tumbler springs.

9. As an article of manufacture: a lock cylinder having a longitudinal keyway opening to a transverse tumbler cavity; tumblers in said cavity; springs acting on the tumblers and biasing them to predetermined positions from which they are retractable by a key inserted into the keyway; a single spring retainer mounted in the cylinder and extending longitudinally past the several tumblers with parts thereof providing spring seats against which the tumbler springs react; a pivotal connection between one end of the spring retainer and the cylinder allowing pivotal movement of the retainer in the direction of the spring thrust so that the tension of the springs reacting against the retainer tends to project the retainer outwardly of the cylinder; a cap on the opposite end of the cylinder with a portion disposed over the adjacent free end of the spring retainer to limit its spring propelled outward projection; and means on said spring retainer projecting above the surface of the cylinder in the position of the retainer defined by its engagement with the cap, said means providing a cylinder retaining stop abutment which is depressible below the surface of the cylinder by depression of the free end of the spring retainer against the tension of the tumbler springs.

10. As an article of manufacture: a lock cylinder having a longitudinal keyway opening to a transverse tumbler cavity; tumblers in said cavity; springs acting on the tumblers and biasing them to predetermined positions from which they are retractable by a key inserted into the keyway; a single spring retainer mounted in the cylinder and extending longitudinally past the several tumblers with parts thereof providing spring seats against which the tumbler springs react; a pivotal connection between one end of the spring retainer and the cylinder allowing 4 pivotal movement of the retainer in the direction of the spring thrust so that the tension of the springs reacting against the retainer tends to project the retainer laterally outwardly of I the surface of the cylinder in the position of the retainer defined by its engagement with the cap, said means providing a cylinder retaining stop abutment which is depressible below the surface of the cylinder by depression of the free end of the spring retainer against the tension of the tumbler springs; and cooperating shoulders on the spring retainer and the cylinder adjacent to said projecting part to brace the retainer against force applied thereon axially of the cylinder.

11. In a lock of the type having a removable cylinder provided with a plurality of key operable tumblers: a combination tumbler spring retainer and cylinder retaining member comprising, a stamping having a flat bar of a length to extend past all the tumblers in the cylinder, said fiat bar having one end formed to have a pivotal connection with the adjacent portion of the cylinder, a plurality of spaced tooth members projecting laterally from one edge of the bar to provide tumbler spring seats; and a laterally projecting arm on said edge of the bar having an outwardly projected lip thereon for engagement with a stop shoulder on the casing in which the cylinder is mounted to removably hold the cylinder in the casing.

12. In a lock of the character described: a combination tumbler spring retainer and cylinder retaining member comprising: a stamping of sheet metal having a flat bar with a plurality of comb-like teeth projecting laterally from one edge to provide spring seats, and an arm projecting laterally from said edge and terminating in a fiat portion parallel with the bar, said flat portion and the adjacent end of the bar having edges lying in a common plane normal to the plane of the bar to provide locating shoulders and a lip on said arm providing a shoulder engaging portion to hold the cylinder in the casing.

13. In a lock of the character described: a casing having a bore and a shoulder at the mouth of the bore; a cylinder in the bore; tumblers carried by the cylinder; springs for the tumblers, said cylinder having a longitudinal groove therein extending past the tumblers, the rear end of said groove being formed as a socket; and a combined tumbler spring and cylinder retainer in the form of a sheet metal stamping and having a fiat bar received in said groove with one end thereof hooked in the socket so that the retainer has pivotal movement in its groove toward and from the cylindrical surface of the cylinder; projections on said bar engaging over the tumbler springs so that the springs react against said projections and yieldingly urge the retainer outwardly of its groove; means at the free end of the retainer limiting outward movement thereof; and an arm projecting laterally from the bar at its front end and having an outwardlylprojecting lip thereon engageable with said shoulder to retain th cylinder in the bore, depression of the front end of the retainer against the tumbler springs disengaging said lip from the shoulder to free the cylinder for withdrawal.

14. In a lock of the character described: a cylinder having a keyway opening to a tumbler cavity and having a longitudinal slot parallel with the keyway and extending past the tumbler cavity and having another similar longitudinal slot at the opposite side of the keyway located only at the front end of the cylinder, said slots being joined by a transverse recess at the front end of the cylinder which extends across the keyway; tumblers in the tumbler cavity; individual tumbler springs; and a spring retainer in the form of a sheet metal stamping having a fiat bar disposed in said first-named longitudinal slot and having spring seats projecting laterally therefrom and disposed over the tumbler springs so that the tumbler springs react thereagainst and yieldingly urge the retainer outwardly of the slot; an arm extending laterally from the front end portion of the bar and disposed in said trans verse recess at the front end of the cylinder; a fiat portion on the outer end of said arm parallel with the bar and disposed in said second-named recess; an outwardly extending projection on said arm providing a cylinder retaining stop abutment; and means for holding the retainer assembled with the cylinder and limiting its tumbler spring propelled outward projection while permitting depression thereof to depress said cylinder retaining stop abutment beneath the surface of the cylinder.

'15. In a look: a casing having a bore; a lock cylinder mounted therein and provided with spring pressed key operable tumblers j a tumbler spring retainer pivoted in the inner end of the cylinder and extending longitudinally past all of the tumblers to have its front end terminating adjacent to the front end of the cylinder; means on said tumbler spring retainer against which the tumbler springs react in a direction tending to swing the front end of the retainer outwardly of the cylinder; means for limiting such outward swinging movement of the retainer; and a stop on the front end of the retainer projecting beyond the surface of the cylinder in the normal free position of the retainer.

16. In a lock: a casing having a bore; a lock cylinder mounted therein and provided with spring pressed key operable tumblers; a tumbler spring retainer pivoted in the inner end of the cylinder and extending longitudinally past all of the tumblers, to have its front end terminating adjacent to the front end of the cylinder; means on said tumbler spring retainer against which the tumbler springs react in a direction tending to swing the front end of the retainer outwardly of the cylinder; means for limiting such outward swinging movement of the retainer; and a stop on the front end of the retainer projecting beyond the surface of the cylinder in the normal free position of the retainer, said stop being radially farther from the cylinder axis than the pivoted inner end of the cylinder so that pressure on said stop toward the rear of the cylinder tends to swing th retainer outwardly.

17. In a look: a casing having a bore; a cylinder in the bore provided with spring pressed tumblers; a tumbler spring retainer mounted in the cylinder with its inner end pivotally connected with the inner end of the cylinder so that the retainer is free to swing about its inner end toward and from the surface of the cylinder; means on the retainer providing spring seats against which the tumbler springs react and by which the pressure of the tumbler springs acts to swing the retainer outwardly of the cylinder; a finishing cap applied to the front end of the cylinder and having a part extending over the front end portion of the retainer to limit outward swinging movement of the retainer; and a part on the front end of the retainer projecting outwardly therefrom to extend beyond the surface of the cylinder in the normal free position of the retainer and provide a depressible stop engageable with a shoulder on the casing for removably securing the cylinder in the bore.

18. A look cylinder having a transverse tumbler cavity communicating with a longitudinal keyway, the opposite walls of the tumbler cavity having grooves forming tumbler receiving guideways; tumblers disposed in said cavity with their edges received in the grooves, said tumblers having portions projecting from their sides to provide spring rests; tumbler springs engaging said spring rests on the tumblers; means against which said springs react to yieldingly urge the tumblers in one direction and bridges between the tumbler receiving. grooves and extending across the cavity in line with said spring rests on the tumblers to be engaged thereby and limit spring propelled motion of the tumblers.

19. A look cylinder having a transverse tumbler cavity communicating with a longitudinal keyway and a slot extending beyond one end wall of the cavity to provide an undercut ledge, said tumbler cavity being open at the top and having spaced bridging members a ross the bottom, the spaces between said bridgingmembers providing for the projection of tumblers the side walls of the cavity having tumbler guiding grooves in line with the spaces between said bridging members; tumblers having their edgesguided in said grooves; a spring rest projecting from one face of each tumbler and disposed over the adjacent bridging member to engage therewith and limit endwise movement of the tumblers in one direction; tumbler springs engaging said spring rests and yieldingly urging the tumblers in said direction; a retaining memberin the open top of the cavity with one end thereof engaged under the undercut ledge; and spring seats on the retaining member against which the tumbler springs react in a direction to hold the retaining member engaged with said undercut ledge.

20. A look cylinder having a transverse tumbler cavity communicating with a longitudinal keyway and a slot extending beyond one end.

wall of the cavity to provide an undercut ledge, said tumbler cavity being open at the top and having spaced bridging members across the bottom, the spaces between said bridging members providing for the projection of tumblers, the side walls of the cavity having tumbler guiding grooves in line with the spaces between said bridging members; tumblers having their edges guided in said grooves; a spring rest projecting from one face of each tumbler and disposed over the adjacent bridging member to engage therewith and limit endwise movement of the tumblers in one direction; tumbler springs engaging said spring rests and yieidingly urging the tumblers in said direction; a retaining member in the open top of the cavity with one end thereof engaged under the undercut ledge; and spring seats on the retaining memberagainst which the tumbler springs react in a direction to hold the re- I taming member engaged with the undercut ledge;

the spring rests on the tumblers having projections to engage in the ends of the springs and the spring seats on the retainer having portions engaging over the ends of the springs to hold the same against the side of the cavity whereby said side of the cavity and the adjacent sides of the tumblers form spring guideways in which the springs are held conjointly by the spring rests on the tumblers and the projections on the retainer.

21. In a lock device of the character described: a casing having a bore open at its front end; a finishing cap for the front end of the casing comprising an annular part secured to the front end of the casing to define the mouth of the bore; a boss on the front of said annular part extending partially around the mouth of the bore and having a curved surface concentric to the bore but of larger diameter, the juncture of said curved surface with the face of the annular part being bevelled to provide a cam surface leading to the mouth of the bore, and the back of the annular part adjacent to said bevelled cam surface providing a shoulder.

22. In a lock device of the character described: a casing having a bore open at its front end; a cap on the front end of the casing, said cap having an annular part secured to the casing and defining the mouth of the bore, the back of said annular part providing a stop shoulder; a cylinder in the bore with its front end protruding from themouth of the bore; a spring biased cylinder retaining detent on the cylinder engageable behind said shoulder to removably secure the cylinder in the bore; and a boss protruding from the front of the cap, said boss having a curved surface concentric to the bore but larger in diameter than the mouth of the bore, said curved. surface covering the protruding part of the cylinder to prevent access to the spring biased. detent on the cylinder until the cylinder is turned to a position at which the detent is clear of said boss, and the junction of the curved surface of the boss with the face of the cap being bevelled to provide a cam leading to the mouth of the bore for automatically depressing said detent during insertion of the cylinder into the bore.

EDWARD N. JACOBI.

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