US2014233A

US2014233A - Lock construction

Info

Publication number: US2014233A
Application number: US732451A
Authority: US
Inventors: Henry F Keil
Original assignee: Keil Francis & Son Inc
Current assignee: Francis Keil & Son Inc; Keil Francis & Son Inc
Priority date: 1934-06-26
Filing date: 1934-06-26
Publication date: 1935-09-10
Anticipated expiration: 1952-09-10

Description

Sept. 10, 1935. H F. KEIL .Y 2,014,233

LOCK CONSTRUCTION INVENTOR ATTORN EYS Sept. 10, 1935. 4 H. F, KElL 2,014,233

LOCK CONSTRUCTION Filed June 26, 1934 l 2 Sheets-Sheet 2 INVENTOR BYHen KeL'Z m *QH/Mz ATTORN EYS Patented Sept. 10, 1935 PATENTT'OFFICE LOCK CONSTRUCTION Henry F. Keil, Scarsdale, N. Y., assigner to Francis Keil & Son, Inc., a corperation of New York Application June 26, 1934, Serial No. 732,451

33 Claims.

This invention relates to lock construction and more particularly to a key-controlled mechanism of the so-called cylinder type.

One of the objects of this invention is to pro- Vide a simple, inexpensive, and reliable lock construction of the. above-mentioned character and more particularly one that may be quickly and easily assembled, in the course of manufacture or which may be with facility and convenience disassembled for purposes of replacement, repair, or change of the parts or their relation and then reassembled. Another object is to provide a construction of the above-mentioned character that will be compact, inexpensive to manufacture, simple to operate, and that will be also foolproof. Another object is to provide a lock construction which is armored against drilling, or the like, in a simple, inexpensive and compact manner, and, moreover, without creating unsightliness of appearance. Another object is to provide a simple, inexpensive and practical connection between the key plug and operating bar and also to provide such a connection that is well adapted to meet varying conditions of practical use. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings in which are shown several of the various possible embodiments of my invention,

Figure l is a vertical central sectional view through the lock mechanism as it appears when installed in a door, or the like;

Figure 2 is a transverse sectional View, as seen along the line 2-2 of Figure 1;

Figure 3 is a plan view, as seen from the top in Figure 1, of the casing per se as the latter appears disassembled from the other parts shown in Figure 1;

Figure fi is an end View, as seen from the lefthand end of Figure 1, more particularly as seen along the line li--li of Figure 1;

Figure 5 is a plan View of the connecting bar;

Figure 6 is a sectional view, as seen along the line 'ii-5 of Figure 5, showing more clearly certain details of construction of the connecting bar;

Figure '7 is a detached side elevation showing the inner relation of the connecting bar with the key plug;

Figure 8 is a fragmentary central vertical sectional View, as seen substantially along the line 3 3 of Figure 4.-;

Figure 9 is a top plan view of a modified form of mechanism;

(Cl. 'Y0-47) Figure 10 is a front elevation thereof, as seen from the bottom in Figure 9;

Figure 1 is an end view, as seen from the left in Figure 9;

Figure 12 is a detached side elevation showing the interconnection between the connecting bar and the key plug;

Figure 13 is a plan view of the connecting bar;

Figure 14 is a sectional view of the connecting bar, as seen along the line I4-I4 of Figure 13, and

Figure 15 is a plan view of a member coacting to maintain the connection between connecting bar and related parts.

Similar reference characters refer to similar parts throughout the several views in the drawings.

Referring now tc the drawings and more particularly to Figure 1, I have there shown my lock construction as it might be applied to a door, or the like, for actuating, under the control of a suitable key, a bolt or latch mechanism I@ suitably mounted upon the door II, as upon the inside or left-hand face thereof, the key-controlled or lock mechanism being mounted in a hole I2 in the door I I, ina manner more clearly described hereinafter.

The lock mechanism includes a casing generally indicated at I3 suitably shaped, as bycasting, or the like, to provide a front or escutcheon plate I4, preferably circular (see Figure 2) from the rear or left-hand side of which, as seen in Figures 1 and 3, extends a cylinder-like housing portion I5 along the top of which extends a tumbler housing portion I6 (see also Figure e). The casing I3 is bored out through the cylinder portion I5 thereof, as at Il, in order rotatably to receive and mount the cylindrical key plug I8 whose forward or right-hand end (see Figure i) is of larger diameter formed as by the spaced peripheral shoulders I8-2, the latter having therebetween an annular groove ZI, the casing I3 being counterbored as at 22 to a larger diameter than the diameter of the bore I1 in order thus to accommodate the larger diametered portion ISB- of the key plug I8; this counterbore 22 is preferably accommodated within the thickness of the front plate le, the latter being made of suitable thickness for that purpose,

With the key plug I8 inserted into the bore and thus positioned as seen in Figure 1, the annular or ring-shaped shoulder I9 of the key plug Iii fits into the angle of the counterbore 22 and thus limits movement of the key plug I8 in a direction toward the left, as viewed in Figure 1, and in that position of the parts, the left or rear end of the key plug I8 is preferably flush with the left-hand end of the cylindrical housing portion I5, as better appears in Figure 1.

p The key plug I S is provided with a suitably shaped key slot 23 extending lengthwise thereof .and preferably throughout the lower half portion thereof (see also Figure 2) and a suitably crosssectioned key may thus be inserted into the key slot 23, the key being ysuitably serrated, notched or edged to coact with and control suitable tumbler devices which coact with the casing I3 to prevent or to permit rotation of the key plug I8? relative to the casing I3. In so far as certain features of my invention are concerned, these tumbler devices may take any suitable orlappropriate form and number and illustratlvely and preferably they are in the form of so-called pin` tumblers, as shown in Figure 1 and illustratively there are five sets.

Accordingly, the key plug I8 is provided with tumbler-receiving

recesses

3I, 32, 33, 34 and 35, these being generally cylindrical and extending from the upper face of the key plug I8 (with the latter in the position shown in Figures l and 2) down intov communication with the key slot 23 in order thereby to expose to the latter and to a key inserted therein the pin tumblers 4I, 42, 43, lill and t5 respectively received in the aforesaid recesses.

These tumbler pins are of suitably differing lengths, as is understood in the art, so that, when the proper key is inserted into the key slot 23, these tumbler pins ,are lifted (as viewed in Figure l) to bring their upper faces or edges substantially exactly to the periphery of the key plug i8 itself, thereby ejecting from the tumbler-receiving recesses in the key plug I8 the coacting pin tumblers 5I, 52, 53, 54 and 55 which theretofore had projected from the tumbler-receiving housing portion I6 of the casing I3 into the key plug recesses, thereby precluding rotation of the key plug.

These tumbler pins 5I, 52, 53, etc. are slidably mounted in tumbler-receiving recesses 6I, 62, 63, 64 and 65, respectively, the latter being formed as by casting or drilling, in the housing portion I6, opening at their lower ends into the bore I1. These tumblers are spring-pressed downwardly by

springs

1I, 12, 13, 14 and 15, respectively, the springs being interposed between the tumblers and the upper closing wall of the tumbler-receiving recesses; this` closing wall may be in the form of a plate 24 extending along the top of the housing portion IS between flanges I6a and I6b (Figure 4) of the latter, these flanges being burred or pressed over to hold the plate 24 in place. l

The tumbler-receiving recesses 3l, 32, etc. in the key plug I 8 and the tumbler-receiving recesses Si, @2, etc. in the casing I3 lare respectively alined when the key plug I8 has its ring-like shoulder or flange I9 bottoming in the counterbore 22 (Figure l) and this alinement is maintained by a plate member 25 (Figures l and 2) that is received within the ange I4 and that coacts with the annular groove 2I of the key plug I8.'

Not only is such alinement of the respective tumbler-receiving recesses and tumblers in the casing and key plug achieved and maintained but also, as later pointed out hereinafter, the resultant fixing of the axial position of the key plug il relative to the casing I3 and more particularly relative to the bored-out cylinder portion I5 thereof is made to coact in controlling and maintaining the interconnection, at the rear or lefthand end of the key plug I8 of the connecting or operating bar 28 which extends into the bolt mechanism Iii; this unique coaction may be achieved by illustrative constructions and arrangements as are hereinafter described in greater detail and according to which the interconnection between key plug and connecting bar may not only be reliably maintained but may also be shiftable or capable of quick and easy rearrangement tomeet certain of the varying conditions of practical use pointed out hereinafter. The above-mentioned plate member 25 may, furthermore, andin accordance with such coacting features of my invention, be made to maintain assembly of key plug with respect to the casing while the above-mentioned interconnection is changed or shifted even though the member 25 otherwise aids in maintaining disconnection of the connecting bar from the key plug, thus preventing spilling of, disassembly of, or interference with, the relatively minute and otherwise numerous parts, such as the tumbler pins, springs, and the like, while on thev other hand, the member 25 assures proper coaction between the cylindrical housing portion I5 of the casing, the connecting bar itself, and the rear end of the key plug.

More specifically, there is formed in the front plate I4 a slot or guideway 26 (Figures 2 and 3) whose width, as viewed in Figure 2, preferably is somewhat greater than the diameter of the fro-nt or flanged (IQ-20) end of the key plug I8 and Whose depth or vertical dimension is preferably Such that it extends from the peripheral face of the front plate I4 downwardly preferably toabout the axis of the counterbore 22, thereby intersecting the counterbore. Into this slot 26, which may be cast or otherwise formed, is snugly and slidably fitted the above-mentioned plate member 25, the latter being made preferably of hardened steel or other suitable hard metal capable adequately to resist the action of a tool such as a drill, or the like. The plate 25, shaped as is better shown in Figure 2, has its lower edge 25a cut or shaped on a curve whose radius is the same as the radius of curvature of the bottom of the annular groove 22 (Figure l) between the shoulders L11-20 of the key plug I8, annular groove 22, plate 25, and plate-receiving slot 26,

being of substantially the same thickness or di- 4 mension (as seen in Figure 1) so that the lower edge portions of the plate 25 ride into the annular groove 2I with sumcient snugness to prevent movement in an axial direction of the key plug I8 while permitting freedom of rotation of the latter, and the plate 25 being received within the slot 26 with sufficient snugness to prevent play of the plate 25 relative to the casing I3. Thus, the key plug I8 is dependably held in assembled relation to the casing I3 and the above-mentioned alinement of the respective tumbler recesses and tumblers dependably maintained.

Thevertical or side edges of the slot 26, as seen in Figure 2, are preferably parallel and equidistantly spaced from a vertical line drawn through the axis of the key plug I8 in which case the plate 25 will be seen to be symmetrical. Though plate 25 is received within the slot 26 with sufficient snugness or tightness of ft, so as to be securely held therein by frictional contact with the walls of the slot, nevertheless, I prefer to lock the plate 25 in position and for that purpose I may employ a screw 21 (Figures 1, 4 and 3) threaded into and through that portion of the front plate I4 that is to the rear of the slot 26 so that, by tightening up the screw 21 it clamps the plate 25 between itself and the front wall portion of the slot 26 itself. In that position and because of the hardness of the material of the plate 25, the latter gives a protection to the lock mechanism that is of great practical importance. The expanse of the plate 25 both Vvertically and horizontally (see Figure 2) is such as to form a substantial barrier against access, as by drilling through the front plate lll, to the` tumbler-receiving housing portion I6, and thus it becomes impossible to drill into the housing I5 in order thereby to drill away or dislodge the tuinblers 5|, 52, etc., and thereby endeavor to achieve rotation of the key plug I8.

With the fixing of the rotatable key plug i8 in position within the casing I3, as above described, there has simultaneously been brought aboutalso a fixing of the interconnection of the connecting bar 28, which extends to the left into operative engagement with the bolt mechanism Ik) (Figure 1), to the left or rear end of the key plug i8. The connecting bar 28, conveniently in the form of a. stamping of heavy sheet metal, is substantially T-shaped, as is better shown in Figure 5, having at its end transversely projecting lugs 28a and 28h, the latter, however, being bent in opposite directions out of the plane of the bar 28 itself, as is better shown in Figure' 6, giving the bar 28, therefore, an effective T-shape, either as viewed in Figure 5 or as seen from the top in Figure 5, the left or rear end of the key plug I8 is provided with a T-slot I8"L (see Figures 8 and 7) open-ended at both ends, and into the T-slot ite the connecting bar 28 is slid, the throat of the T-slot being of a width substantially equal to the thickness of the connecting bar 28, the oppositely curved ears or lugs 28a-J8b of the connecting bar being thereby made to extend into the wider or base portion of the T-slot |8e, the connecting bar 28 being thus non-rotatably connected to the key plug I8 and also held against separation therefrom by movement in the direction of the axis of the key plug I8 itself. But the opposite open ends of the T-slot |8e, terminating as above mentioned in the peripheral or cylindrical face of the key plug, are now closed (see Figure 8) by the cylindrical portion |5 of the casing I3, so that movement of the connecting bar 28 along the T-slot |821, thus to disengage the bar from the key plug, is prevented.

It frequently happens, however, in practice, because of Variations in type or construction of the bolt or latch mechanism lil (Figure l) that the relation of the operating or connecting bar 28 to the key plug I8 has to be changed. For example, assuming that the key plug I8 and the casing I3 have the normal or locked positions shown in Figure l, the bolt mechanism It) may be of a type or kind or may be so positioned that the plate of the connecting bar 28 has to be vertical while, on the other hand, due to such factors as above-mentioned, the mechanism l!) may be of a type that requires the plane of the connecting bar 28 to be horizontal and hence displaced from what might be the requirement under other conditions or with another type of bolt mechanism |8. Or, stated differently, the slot in the roll-back or like device in the mechanism l0, depending upon the position cf the latter, the type or construction of the latter, and other factors, and which slot is to receive the connecting bar 28, extends either vertically or horizontally, and the key-controlled mechanism must be made to meet these possible conditions without necessitating the impracticable rotating of the entire casing I3 through 90.

Accordingly, I provide for meeting this peculiar condition and hence, referring now to Figure 4, I provide another T-slot |8b in the rear end of the key plug I8, T-slot |85, however, extending at right angles `and thus intersecting the abovementioned T-slot E821, as is clearly shown in Figure 4. Into either of these T-slots, therefore,

the operating bar 28 may be inserted, and in order to give access to the open ends of the T- slots I8a and ith, without requiring disassembly of the key plug i8 from the casing I3 and' related parts, I provide in the upper rear portion of the housing portion I5 (see now Figures 3 and 4) and immediately1 to the rear or left of vthe tumbler housing portion I6, a slot |5ab whose peripheral extent or dimension is preferablyat least-equal to the largest cross-sectional dimension of the T-slot |53a or |811.

Extending about this left or rear end of thecylindrical housing portion I5 and thus intersecting the slot l5a is an external peripherally extending groove It?b (Figures 3 and 4) and in this-external peripheral groove Ib is seateda split ring 29 made of a spring wire tending to contact and hence acting always to grip the cylindrical housing portion I5. As is betterr` -shown in Figure 4, adjacent one end of the split ring 29, the latter is provided with an inwardly directed U-shaped bend 28a suitably dimensioned to snugly fit into the slot HSE (see Figures 3 and 4) and substantially fill the gap caused by vsaid slot |5a, at leastv in so far as the slot l5@ permits vmovement in a radial direction oftheconnecting bar 28 along a T-slot |8a or |81. Accordingly, the portion 29a of the split spring ring 29 substantially closes the slo-t I5'di and thus,

with the remaining portions of the cylindrical groove Iiib but to the left of the slot |523 the latter being thereby exposed through the gap between the ends of the split ring 29. l

The key plug IS is thereupon rotated, with the aid to a key, of course, where necessary, to bring one end of the T-slot Ita in line with the slot |521, whereupon the connecting bar t8 may be slid upwardly, as viewed in Figure 4, out of the T-slot 8a and through the slot l 5e, and thus disengaged from the key-controlled mechanism. Thereupon,

the key plug i8 is givenfa 90 rotation, thus to bringv the T-slot i8b with one end thereof juxtaposed to the open slot Ia, whence the connecting bar ,28 is now inserted through the slot I52L and into the T-slot 28h, the shank of the connecting bar 28 being snugly received between the narrower portions ofthe T-slot mb and the laterally projecting lugs 28a and 28h projecting into the wider portions of the T-slct |811, assuming a relation such as is shown in Figure '7, the mechanical interrelation being lthe same as theretofore existed between the connecting bar 28 and the T-slot 25a) The split ring 28 is thereupon moved about the external groove 15b in clockwise direction, as viewed in Figure 4, whereupon the inwardly directed portion 28e thereof snaps into the slot |52, thus closing the latter and thus again coacting with the cylindrical housing portion and as a part of the latter to yprevent displacement vin a radial direction of the connecting bar 28 relative to the key plug.

In the course of these operations, it will be perceived that'the connecting bar 28 has been shifted through an angle of relative to the key plug I8 vand has thus been adapted to meet the changed requirements or conditions met with in practice and illustratively set forth above. This change in interrelation between the operating bar and the key plug will be seen to be possible of achievement without having to remove the key plug from the casing I3.

However, there may be and generally are conditions in practice under which it is necessary or desirable to remove the key plug I8 from the casing I3; for example, for purposes of repair, replacement, or change of parts, particularly of the tumblers, or even for purposes of fitting a new key. In such case, the casing I3 having been removed from the door the set screw 2'| (Figures 1, 3 and 4) is loosened up and the combined armor and locking plate 25 suciently Withdrawn relative to its slot 26 to disengage it from the annular groove 2| (Figure 1) in the key plug I8. To facilitate such withdrawal, I cut away, as at |411 (Figures 3 and 1) the rear wall of the slot 26, preferably in line with the tumbler-receiving housing portion I6, thus to expose an upper portion of the rear face of the plate 25. At such exposed portion of the plate 25 I provide in the latter a hole 25b (Figures 1 and 2) into which a suitable implement may be inserted to raise the plate 25 against the friction of its engagement with the slot 26.

It will be noted, however, that, Where it is necessary to attach or detach the connecting bar 28, or to shift or change its relation to the key plug or to the bolt mechanism IIJ, such operation or operations may be quickly and speedily performed without having to disturby the relation of the key plug, casing, tumbler, tumbler recesses, springs, and like parts, the plate member 25 dependably holding the latter against disarrangement or disassembly. Entire freedom of action or manipulation with respect to the connection of the connecting bar to the key plug is thus permitted.

A preferred construction, however, for achieving such results as are above pointed out and for achieving coaction with the armor plate member 25, some of which coactions are above indicated, I have shown in Figures 9-15 inclusive, in which, referring now to Figures 9, 10 and 11, the casing and key plug construction and tumbler arrangement, including the feature of the plate member 25, are substantially the same as described in detail above in connection with Figures 1, 2, 3, 4 and 8, and these parts, in Figures 9, 10 and 11, need not, therefore, be described in detail, excepting for certain features pointed out later herein. It will therefore be noted that the casing I3 (Figures 9, 10 and 11) again has the front disk-like plate slotted as above described to receive the armor plate member 25, the latter being capable of being locked in position by the screw 21, and coacting with the annular groove formed between the annular or ring-like shoulders Ill-20 in the front end of the key plug I8. 'Ihe casin'g I3 again has the lower cylindrical housing portion I5 which is bored out rotatably to receive the key plug I8 and extending upwardly therefrom is the tumbier-receiving housing portion I6, containing the tumblers for coaction with the key plug tumblers v and key, as above described. The rearward (to- Ward the left) extension of the cylindrical housshown in Figure 11, this rearward extension of 10y the housing portion I5 is upwardly extended .as at I5g and for greater compactness Vand convenience the lugs or ears |38 and |39 extend respectively to the left and right of this upward extension |51, as seenin Figure 11. l5I A With the added metal thus provided by the `portion I5?, I am enabled to provide therein a slot |511 (Figures 9 and 10) extending transversely of the bore I1 in which the key plug I8 is rotatably mounted, slot |511 having a width, 2()- as viewed in Figure 1l, substantially equal to the diameter of the bore all for a purpose about to be described.

The left or rear end of the key plug I8V is provided with two slots I8g and |811 (Figures 11 and 25 i I2), extending at right angles to each other and as will be later more apparent, these slots need not be undercut and thus lend themselves to less expensive manufacture, simplifying the casting, or milling operations. slot |811 extends in the plane of the key slot23 in the key plug I8, just as the slot |81L of the key plug of Figure 8 extends in the plane of the key slot 23, all as above described.

The connecting bar preferably takes the form 35..

better shown in Figures 13 and 14, the connecting bar 28 there shown being substantially T- shaped, having end lugs |2811 and |28b which, as is better shown in Figure 14, can be and preferably are in the plane of the connecting bar |28 40 itself; that need not be bent out of that plane as was the case with the illustrative form shown in Figures 5 and 6 and above described.

The right-hand end of the connecting bar |28,

as viewed in Figure 13, is receivable in either of 45 I the slots |88 or |811 in the rear end of the key plug |8, for reasons above already described in some detail, and in Figures 10 and 11 that end of connecting bar |28 is shown received within slot |811. 50

With the plate member 25 fixing the position of key plug 8, as above described, the plane of the bottoms of the end slots |81? and 811 in the key plug I8 (seenow Figure 10) is in line with the right-hand wall of a slot I5j (see also Figure 55 9) that is cut in the casing or extension portion I5g from the upper edge thereof right down into the bore I1, slot |51' connecting at its left-hand end (see Figures 9 and 10) with the transverse slot |511. Where slot I5j extends to the right or 60, forwardly of the transverse slot |511, I provide a slot |5k in the extension portion |511 to the left or rearwardly of transverse slot |511 (see Figures 9, 10 and 1.1), slot 511 extending from the top edge of the extension portion I5g right down into' 65 the bore and also connecting with the transverse slot |511 (Figure 9). Accordingly, with either slot |8lg or |811 extending vertically, a position achieved by rotating the key plug I8, as

viewed in Figure 11, that slot of the two which 70 is thus made to extend vertically, illustratively slot |811 (Figures 10 and 1l) is thus brought into alinement with the vertical slots I5k and |5j above described, these two slots being intersected by the transverse slot |511, and accordingly con- 5 One of the slots, such as 30 necting bar |28 may be slid in the direction of its own plane (vertically, as viewed in Figure 10) through the slots l5k and |51' and thus into the plug slot |811, much in the same manner as the connecting bar 28 of Figures 2 8 may be related to a transverse slot in the key plug when the cylindrical casing portion is opened up as at the slot I5a (Figure 3) therein upon moving the ring member 29 out oit slot-closing position.

The composite slot ihk-|51' of` Figures 9, 10 and 11, thus transversely opening up the cylindrical housing portion I5, I also provide to be closed or opened at will; for this purpose I employ a plate-like member |29 (see now Figure 15) shaped to be snugly fitted and received into the transverse slot I5h (Figures 9 and l1); the plate member |29 accordingly has parallel side edges adapted to mate with the parallel and vertically extending sides, as viewed in Figure 11, of the transverse slot |51, joined by a lower arcuate edge |2921 shaped or curved so as to snugly bottom in, or mate with the curvature of, the bore (see Figure 1l) and when thus bottoming in the bore i'i, the upper horizontal edge of the plate member |29 preferably mates with the upper horizontal edge of the extension portion I5g (Figure ll) of the housing. Now plate member |29 is virtually in the form o1" a ring, having an opening therein |29b of a diameter slightly in excess of the width of the connecting bar |28 (Figure 13) so that the latter may pass therethrough and be freely rotated relative thereto, but lugs I28e|2ilb (Figure 13) preventing the complete passage through the ring member |29 of the connecting bar |28.

Accordingly, when sliding the connecting bar |28 downwardly (Figure 10) through the composite slot ISL-iw, and the ring or plate member |29 having first been slipped onto the connecting bar |28, the member |29 moves downwardly into its slot I51fl as the connecting bar |28 passes downwardly through the slots I5k-I5g, emerges from the latter, and seats the head end, with lugs lifes-IEM, into plug slot Ih, resulting in a relation of the parts as is better shown in Figures 9, 19 and ll.

Withdrawal or the operating bar |28 in a direction toward the left, as seen in Figure 10, is precluded by the plate member |29, whose aperture |29b does not permit the passage therethrough of the lugs @9L-|291). With the plate member 25 preventing the key plug i8 from moving toward the right, as viewed in Figures 9 and 10, and with the member |29 preventing movement of the connecting bar |28 toward the left, as viewed in these figures, the telescopic connection between key plug I8 and connecting bar |28, the latter tting into the slot I8h (or I8g, as the case may be), is dependably and eectively maintained, and hence the rotation of the connecting bar |28 with consequent actuation of the bolt mechanism I9 (Figure 1) in response to rotation of the key plug i8 under the control of a, key must follow.

Referring again to Figure l5, the lower portion of member |29 is provided with a lug or tab |29c which, referring now to Figures lO and l1, is received within a slot I5m in the lower end of the cylindrical casing portion i5, slot l5m being, of course, in alineinent with the transverse slot l5h and thus dependably anchoring the lower end of the member |29.

Preferably the member |29 is relatively snugly or tightly fitted into its slot |51, or I5m, or both, so that it will be held within the slot by the frictional gripping action of the walls of the latter; it may be, for example, in the nature of a tapt as distinguished from a force-fit. And to facilitate withdrawal of the member |29 from its slot without having to subject the connecting bar 4 |28 to any strain or stress, I provide in the member |29 an aperture |29e positioned so that, when the member |29 is within its slots h-I 5m, aperture |29e is in alinement with the vertical slot I5k (see Figure 11) the aperture being thus accessible from the rear of the casing i3. Accordingly, any suitable instrument may be inserted through the slot |5k into the aperture |29e and member |29, and the latter withdrawn by such instrument against whatever forces hold the member in its slot.

Should such withdrawal of the holding member |29 be effected, plate member 25 (Figures 9 and 10) holds the key plug I8 against removal from the casing i3, and thus precludes spilling of the tumblers, springs, or like small parts. Replacement of the connecting bar which, it is to be noted, is disconnected from the key plug and casing at the same time that the member |29 is withdrawn as above described, is a simple operation, requiring only a reverse of what has just been described, and if it is necessary that the relation between connecting bar |28 and the key plug I8 be shifted the replacement of the connecting bar |28 is made after key plug I8 has been given a 90 turn, as with the key, to bring the other slot, illustratively slot I8g (Figure ll) in alinement with the composite vertical slot I5k|5j (Figure 19).

Once the connecting bar |28 is thus inserted into an end slot in the key plug and the member |29 returned to its slots I5h|5m so as again to form a p-art of or to restore the cylindrical housing portion I5, the latter, now having its composite transverse slot |5k--I5j closed, effectively prevents the connecting bar |28 from riding, in a transverse direction, out of whichever of the various slots in the plug I8 that it is seated in. Moreover, just as was the case with the construction above described in connection with Figures 1-8 inclusive, any side or transverse thrusts on or by the connecting bar, that is, in a radial direction relative to the key plug, are dependably and reliably resisted by the wall of the bore in which the key plug is rotatably mounted, and thus disconnection of the connecting bar from any plug by movement of the former along a radius (or slot) of the latter is reliably resisted by the wall of the bore to which such side or trans- Verse thrusts are transmitted.

As above indicated, the construction just described and shown in Figures 9-14 inclusive, is in all respects other than those just mentioned, the same as that set forth in connection with Figures l 1-8 inclusive.

The upper edge 25c (Figure 2 or l1) of the plate 25 has a curvature that matches the curved periphery of the front plater I4 so that when the plate 35 is in operative or downward position, the plate 25 does not project from the periphery of the front plate Ill. Moreover, the construction, when installed, as illustrated in Figure l, is such that the upper end of the slot 25, and hence also the upper edge 25c of the plate 25, are concealed and inaccessible inasmuch as the front plate I4 is snugly received within a suitably stepped or ilanged ring 39 (Figure 1) which covers over the periphery of the front plate i4, and, moreover, has portions that extend to the rear of the latter, such portions of ring 38 resting against the righthand face of the door Il, as shown in Figure 1,

and not being removable from the front or righthand side of the door II.

This because of the intertting relation between the ring 3E) and the front plate I4 and also the manner of securing the casing I3 in the hole I2 in the door II. In effect, the door II and the ring 39 are securely clamped between a back plate 36 (Figure l) that rests against the inner or lefthand face of the door II, extending underneath the casing of the lock mechanism I0, and the front plate I4 of the casing I3; this clamping is achieved by means of screws 37 that pass through the back plate 3B, excepting for their heads, and they are threaded into threaded openings in the ears 38 and 39 (Figure 3 and 4) integrally formed with the left or rear portion of the casing I3. A suitable hole in the back plate 36 permits the passage therethrough of the connecting bar 28 as it extends toward the left (Figure l) into the slot of the roll-back or other device by which the bolt mechanism Ii) is actuated.

Thus, it will be seen that there has been pro'- vided in this invention a lock construction in which the various objects hereinbefore set forth, together with many thoroughly practical advantages, are successfully achieved. It will be seen that the construction is of a thoroughly practical nature, is inexpensive, is timeand laborsaving in assembly or disassembly, and is of thoroughly dependable action in use. Moreover, also, dependable protection against drilling into vital parts of the key-controlled mechanism is afforded in a thoroughly reliable and simple manner and thus greater security achieved. Moreover, the construction is compact and neat and particularly as to the casing and key plug lends itself readily to casting, particularly die casting.

As many possible embodiments may be made of the above invention and as many changes might vbe made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is tol be interpreted as illustrative and not in a limiting sense.

l. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, tumbler means controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear end of said key plug and capable of disconnection only upon moving said connecting bar in the direction of a radius of said key plug, and means releasably holding said key plug against movement in an axial direction to maintain the key plug and tumbler means and casing in proper alinement and to cause a Wall of said bore to prevent movement in a radial direction of said operating bar and thus maintain interconnection thereof with said key plug.

2. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, tumbler means controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear end of said key plug and capable of disconnection upon moving sai-d connecting bar in the direction of a radius of said key plug, said key plug having a groove extending in the direction of its periphamigar vent axial displacement of said key plug and thereby to hold said connecting bar and said plug against disconnection.

3. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, tumblerV means controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear end of sai-d key plug and capable of disconnection upon moving said connecting bar in the direction of a radius of said key plug, said keyk plug having a peripheral groove adjacent its forward end and said casing having a slot in the front wall thereof, said slot extending in a direction transversely to the axis of the key plug and opening into said bore, and a plate-like member of relatively hard metal fitted into said last-mentioned slot and engaging into the peripheral groove in said key plug, thereby to hold the latter against axial displacement and in a position to cause a wall of said bore to prevent movement in a radial direction of said connecting bar relative to the plug.

4. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably tted into said bore, tumbler means controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear end of said key plug and capable of disconnection upon moving said connecting bar in the direction of a radius of said key plug, said key plug having a peripheral groove adjacent its forward end and said casing having a slot in the front wall thereof, said slot extending in a direotion transversely to the axis of the key plug and opening into said bore, and a plate-like member of relatively hard metal fitted into said lastmentioned slo-t and engaging into the peripheral groove in said key plug, thereby to hold the latter against axial displacement and in a position to cause a wall of said bore to prevent movement in a radial direction of said connecting bar relative tothe plug, said last-mentioned slot and hence the plate received therein having a width equal to or greater than the width of that portion of said casing with which said tumbler means coacts, thereby to prevent a tool like a drill from passage therethrough and into said portion of said casing.

5. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably tted into said bore, tumbler means controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear end of said key plug and capable of disconnection upon moving said connecting bar in the direction of a radius of said key plug, said key plug having a peripheral groove adjacent its forward end and said casing having a slot in the front wall thereof, said slot extending in a direction transversely to the axis of the key plug and opening into said bore, and a plate-like mem- CFI ber of relatively lhard metal tted into saidlastmentioned slot and engaging into the peripheral groove in said key plug, thereby to hold the latter against axial displacement and in a position to cause a wall of said bore to prevent movement in a radial direction of said connecting bar relative to the plug, and releasable means accessible from a face of said casing other than the front face thereof for locking said plate against withdrawing movement relative to its slot.

6. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, tumbler means controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear end of sai-d key plug and capable of disconnection upon moving said connecting bar in the direction of a radius of said key plug, said key plug having a peripheral groove adjacent its forward end and said casing having a slot in the front wall thereof, said slot extending in a direction transversely to the axis ci the key plug and opening into said bore, and a plate-like member of relatively hard metal fitted into said last-mentioned slot and engaging into the peripheral groove in said key plug, thereby to hold the latter against axial displacement and in a position to cause a wall of said bore to prevent movement in a radial direction of said connecting bar relative to the plug, and a screw threaded through a wall of said last-mentioned slot other than the front wall thereof for engagement with said plate and for locking the latter against withdrawing movement relative to its slot.

7. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably tted into said bore, tumbler means controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear endof said key plug and capable of disconnection upon moving said connecting bar in the direction of a radius of said key plug, said key plug having a peripheral groove adjacent its forward end and said casing having a slot in the front Wall thereof, said slot extending in a direction transversely to the axis of the key plug and opening into said bore, and a plate-like member of relatively hard metal iitted into said lastmentioned slot and engaging into the peripheral groove in said key plug, thereby to hold the latter against axial displacement and in a position to cause a wall of said bore to prevent movement in a radial direction of said connecting bar relative to the plug, and means for closing the open end of said second-mentioned slot.

8. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, tumbler means controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear end of said key plug and capable of disconnection upon moving said connecting bar in the direction of a radius of said key plug, said key lplug having a peripheral groove adjacent its forward end and said casing having a slot in the front wall thereof, said slot extending in a direction transversely to the axis of thekey plug and opening into said bore, and a plate-like member of relatively hard metal tted into said lastmentioned slot and engaging into the peripheral groove in said key plug, thereby to hold the latter against axial displacement and in a position to cause a wall of said bore to prevent movement in a radial direction of said connecting bar relative to the plug, and means interlocked With said front Wall when the mechanism is installed for closing the open end of said last-mentioned slot.

9. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, tumbler means controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear end of said key plug and capable of disconnection upon moving said connecting bar in the direction of a radius of said key plug, said key plug having a peripheral groove adjacent its forward end and said casing having a slot in the iront wall thereof, said slot extending in a direction transversely to the axis of the key plug and opening into said bore, and means mounted in said second-mentioned slot and engaging into the peripheral groove in said key plug for holding the latter against axial displacement and in a position to cause a wall of said bore to block movement of said operating bar in a radial direction relative to said key plug.

l0. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably tted into said bore, the rear end of said key plug having a transversely extending undercut slot open at a side of said key pluga connecting bar having an end portion shaped to move into said slot upon movement of said bar in the direction of the radius of said plug, thereby to interlock with said plug, and means for holding said plug against axial displacement relative to said casing and in such a position relative to the latter that a wall of said bore closes off the open end of said undercut slot.

il. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably iitted into said bore, the rear end of said key plug having a plurality of undercut slots therein extending at an angle to each other and each opening in the periphery of said plug, the wall of said bore having an axial extent suiiicient to encompass the portions of the plug in which said slots open, the wall oi said bore having a portion cut away thereby to expose, upon appropriate rotation of said plug, the open end of a slot, a connecting bar having an end portion shaped to pass 'through said cut away portion of said bore wall and to interlock with an undercut slot alined with said cut away portion, thereby to become interlocked with said key plug, and releasable means for closing off said cut away portion of said bore wall.

12. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, the rear end of said key plug having a plurality of undercut slots therein extending at an angle to each other and each opening in the periphery of said plug, the wall of said bore having an axial extent suicient to encompass the portions of 'the plug in which saidslots open, the wall of said bore having a portion cutaway thereby to expose, upon appropriate rotation of said plug, the open end of a slot, a connecting bar having an end portion shaped to pass through said cut away portion of said bore wall and to interlock with an undercut slot alined with said cut away portion, thereby to become interlocked with said key plug, and spring-mounted means yieldably movable into or out of the cut away portion of the wall of said bore.

13. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, the rear end of said key plug having a plurality of undercut slots therein extending at an angle to each other and each opening in the periphery of said plug, the wall of said bore having an axial extent sufficient to encompass the portions of the plug in which said slots open, the wall of said bore having a portion cut away thereby to expose, upon appropriate rotation of said plug, the open end of a slot, a connecting bar having an end portion shaped to pass through said cut away portion of said bore Wall and to interlock with an undercut slot alined with said cut away portion, thereby to become interlocked with said key plug, and a ring-like member rotatably engaged with the exterior of said bore wall having a portion that may be moved, upon rotation relative to said bore wall, into a position to close the cut away portion of the latter or into a position to expose said portion.

14. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably iitted into said bore, the rear end of said key plug having a plurality of undercut slots therein extending at an angle to each other and each opening in the periphery of said plug, the wall of said bore having an axial extent suiiicient to encompass the portions of the plug in which said slots open, the wall of said bore having a portion cut away, thereby to expose, upon appropriate rotation of said plug, the open end of a slot, a connecting bar having an end portion shaped to pass through said cut away portion of said bore wall and to interlock with an undercut slot alined with said cut away portion, thereby to become interlocked with said key plug, and a split spring ring gripping the exterior of the Wall of ysaid bore and movable relative to the latter to close or to expose the cut away portion therein.

15. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, the rear end of said Akey plug having a plurality of undercut slots therein extending at an angle to each other and each opening in the periphery of said plug, the wall of said bore having an axial extent sufficient to encompass the portions of the plug in which said slots open, the wall of said bore having a portion cutaway thereby to expose, upon appropriate rotation of said plug, the open end of a slot, a connecting bar having an end portion shaped to pass through said cut away portion of said bore wall and to interlock with an undercut slot alined with said cut away portion, thereby to become interlocked with said key plug, the exterior of the wall of said bore having a peripheral groove intersecting the cut away portion thereof, an-d a split spring ring rotatably mounted in said groove and having an inwardly directed portion normally seated in the out away portion of said wall.

16, In lock construction, in combination, a casing having an open-ended cylinder portion con# taining a bore, a key plug having .a key slot and rotatably fitted into said bore, the rear end of said key plug having a plurality of lundercut slots therein extending at an angle to each other and each opening in the periphery of said plug, the wall of said bore having an axial extent sulicient to encompass the portions of the plug in which said slots open, the wall of said bore having a portion cut away thereby to expose, upon appropriate rotation of said plug, the open end of a slot, a connecting bar having an end portion shaped to pass through said cut away portion of said bore wall and to interlock with an undercut slot alined with said cut away portion, thereby, to become interlocked with said key plug, the exterior of the wall of said bore having a peripheral groove intersecting the cut away portionthereof, and means having a gap therein and rotatably carried in said groove adapted upon rotary movement thereof to register said gap with said cut away portion or to move it out of registry therewith.

17. In lock construction, in combination, a. casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, the rear end of said key plug having a transversely extending slot open at a side of said key plug, a connecting bar having an end portion that may be moved into said transverse slot upon movement of said bar in the direction of a radius of said plug, and means for holding said plug against axial displacement relative to said casing and in such a. position relative to the latter that a wall of said bore closes ofi the open end of said transverse slot.

18. In lock construction, in combination, a oasing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably tted into said bore, the rear end of said key plughaving a transversely extending slot open at a side of said key plug, said cylinder `portion having a slot in the wall of the bore thereof with which the open end of said transverse slot may be made to register upon appropriate rotation of the key plug, a connecting bar having an end portion shaped to pass through said third-mentioned slot and into said transverse slot upon said two slots being brought into registry, thereby non-rotatably to interconnect said connecting bar and said key plug, and means mounted and carried by said casing for holding said connecting bar against movement out of the open end of said transverse slot if the latter sub- -sequently is brought into registry with said third-mentioned slot.

19. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably tted into said bore, the rear end of said key plug having a transversely extending slot open at a side of said key plug, said cylinder portion having a slot in the wall of the bore thereof with which the open end of said transverse slot may be made to register upon appropriate rotation of the key plug, a connecting bar having an end portion shaped to pass through said third-mentioned slot and into said transverse slot upon said two slots being brought into registry, thereby non-rotatably to interconnect said connecting bar and said key plug, and means carried by said casing for holding said connecting bar and said key plug against relative movement in an axial direction.

20. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, the rear end of saidv key plug having a transversely extending slot open at a side of said key plug, said cylinder` portion having a slot in the wall of the bore thereof with which the open end of said transverse slot may be made to register upon appropriate rotation of the key plug, a connecting bar having an end portion shaped to pass through said third-mentioned slot and into said transverse slot upon said two slots being brought into registry, thereby non-rotatably to interconnect said connecting bar and said key plug, and a member insertable into said third-mentioned slot for preventing movement of said connecting bar out of said transverse slot.

21. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, the rear end of said key plug having a plurality of slots therein extending at an angle to each other and each opening in the periphery of said plug, the wall of said bore having an axial extent sufficient to encompass the portions of the plug in which said slots open, the wall of said bore having a portion cut away thereby to expose, upon appropriate rotation or said plug, the open end of a slot, a connecting bar having an end portion shaped to pass through said cut away portion of said bore wall and to enter a slot exposed to said cut away portion, thereby to become non-rotatably connected with said key plug, and releasable means carried by said casing for holding said connecting bar against movement out of the slot in which it has been entered.

22. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably fitted into said bore, the rear end of said key plug having a plurality of slots therein extending at an angle to each other and each opening in the periphery of said plug, the Wall of said bore having an axial extent sullcient to encompass the portions of the plug in which said slots open, the wall of said bore having a portion cut away thereby to expose, upon appropriate rotation of said plug, the open end of a slot, a connecting bar having an end portion shaped to pass through said cut away portion of said bore wall and to enter a. slot exposed to said cut away portion, thereby to become] non-rotatably connected with said key plug, said end portion of the connecting bar having a greater transverse dimension than the remainder of -the connecting bar, said cylinder portion of the casing having a slot extending transversely of and to the rear of the rear end of said key plug, and a member having an aperture therein through which said remainder of the connecting bar extends but through which said end portion thereof cannot pass seated in said transverse slot and movable into or out of the latter in the same direction in which said connecting bar is movable into or out of a plug slot when the latter is exposed through said cut away portion of the wall of said bore.

23. In lock construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably iitted into said bore, the rear end of said key plug having a plurality of slots therein extending at angle to each other and each opening in the periphery of said plug, the wall of said bore said plug, the open end of a slot, a connecting bar 5 having an end portion shaped to pass through said cut away portion of said bore wall and to enter a slot exposed to said cut away portion, thereby to become non-rotatably connected with said key plug, said end portion of the connect- 10 l ing bar having a greater transverse dimension than the remainder of the connecting bar, and means coacting with said end portion for preventing movement in an axial direction of the connecting bar out of the slot in which it has 15 been entered.

24. In lo-ck construction, in combination, a casing having an open-ended cylinder portion containing a bore, a key plug having a key slot and rotatably tted into said bore, tumbler means-.20 controllable by a key inserted into said key slot for coaction with said key plug and casing, an operating bar, means forming a detachable interconnection between said operating bar and the rear end of said key plug and capable of discon- 25 nection upon moving said connecting bar in the direction of a radius ci said key plug, said detachable interconnection means including means for preventing movement of said connecting bar away from said key plug in the direction of the 30 axis of the latter and said key plug having a groove extending in the direction of its periphery and said plug normally having such a positio-n that a wall of said bore resists movement of said connecting bar along a radius of said key 35 plug, and means projecting from said casing into said groove to prevent axial displacement of said key plug.\

25. In lock construction, in combination, a casing having a bore for rotatably receiving therein 40 a key plug and having a iront end wall that is circular, there being a casing portion extending rearwardly of said front end wall for receiving tumbler means, said front end wall having a slot therein extending from the periphery thereof to 45 and into communication with said bore and being of suiiicient lateral expanse to extend in front of said tumbler portion of said casing, a key plug rotatably received in said bore and having a peripheral groove adjacent its forward end and 50 substantially alined with said slot, and a platelike member or" relatively hard metal tted into said slot and thereby extending across and in front of said tumbler portion of the casing and extending into the peripheral groove of said key 55 plug, thereby to hold the latter against axial displacement, and means inaccessible when said lock construction is installed for preventing withdrawing movement of said plate-like member relative to its slot. 60

26. A lock construction as claimed in claim 25 in which the means for preventing withdrawing movement of the plate-likey member comprises a screw threaded through a wall of said slot other than the front wall therefor for blocking with- 65 drawing movement of said plate-like member relative to its slot.

27. A lock construction as claimed in claim 25 in which the means forv preventing withdrawing movement of the plate-like member comprises a flanged ring-like member receivable over said circular front end wall and closing the outer end of said slot, a flange of said ring-like member engaging to the rear of said front end wall.

28. In lock construction, in combination, a

Vinder portion having a slot in the wall of the bore said cylinder portion having a slot in the wall of the bore thereof with which the open end of said transverse slot may be made to register upon appropriate rotation of the key plug, a connecting bar having an end portion shaped to pass .through said registered slots and to enter into the transverse slot in the key plug, thereby to become non-rotatably connected with said key plug, said end portion of the connecting bar having a greater transverse dimension than the remainder of the connecting bar, and means carried by ysaid casing and projectable radially into said bore and to the rear of said greater-dimensioned end portion of the connecting bar, thereby to prevent disengagement of said connecting bar in an axial direction from said key plug.

" 29. In lock construction, in combination, a casing having a cylinder portion containing a bore, a key plug rotatably fitted into said bore, the rear end of said key plug having a transversely extending slot open at a side of said key plug, said cylthereof with which the open end of said transverse slot may be made to register upon appropriate rotation of the key plug, a connecting bar having an end portion shaped to pass through said registered slots and to enter into the transverse slot in the key plug, thereby to become nonrotatably connected with said key plug, said end portion of the connecting bar having a greater .transverse dimension than the remainder of the connecting bar, said casing having a recess adjacent its rear end communicating with said bore, and a member encircling said connecting bar adjacent said end portion thereof and received into said recess as and when said connecting bar is inserted into said transverse plug slot upon registry of said two slots, for preventing disconnection of said connecting bar from said key plug in an axial direction.

30. In lock construction, in combination, acasing having a cylinder portion containing a bore, a key plug rotatably fitted into said bore, the rear end of said key plug having a transversely extending slot open at a side of said key plug, said cylinder portion having a slot in the wall of the bore thereof with which the open end of said transverse slot may be made to register upon appropriate rotation of the key plug, a connecting bar having an end portion shaped to pass through said registered slots and to enter into the transverse slot in the key plug, thereby to become nonrotatably connected with said key plug, said end portion of the connecting bar having a greater transverse dimension than the remainder of the connecting bar, said cylinder portion having a slot adjacent its rear end and intersecting said bore rearwardly of the rear end of said key plug, and a plate-like member having an aperture therein through which said remainder of the connecting bar extends but through which said end portion 'thereof` cannot pass received in said third-mentioned slot and movable into or out of the latter concurrently with movement of said connecting bar, when said first two-mentioned slots are in registry, into or out of said key plug slot.

31. In lock construction, in combination, a casing having an open ended cylinder portion containing a bore, a key plug rotatably fitted into said bore, therear end of said key plug having a transversely extending slot therein opening in the periphery of lsaid plug, the wall of said bore having an axial extent sufficient to encompass the portions of said plug in which said slot opens at the periphery and the wall of said bore having a portion cut away thereby to expose, upon appropriate rotation of said plug, the open end of said slot, said slot being undercut, a connecting bar having an end portion shaped to pass through said y cut away portion of said bore wall and to enter said slot when the latter is exposed to said cutv away portion and to interiit with said undercut slot, thereby to become non-rotatably connected with said key plug and said connecting bar and portion of the wall of said bore, thereby to pre- 2()A vent exposure of said slot and to prevent movement in radial direction of said connecting bar.

32. In lock construction, in combination, a casing having an open ended cylinder portion containing a bore, a key plug rotatably tted into said bore, the rearend of said key plug having a transversely extending slot therein opening in the periphery of said plug, the wall of said bore having an axial extent suflicient to encompass the portions of said plug in which said slot opens at the periphery and the wall of said bore having a portion cut away thereby to expose, upon appropriate rotation of said plug, the open end of said slot, said slot being undercut, `a connecting bar having an end portion shaped to pass through said cut away portion of said bore wall andto enter said slot when the latter is exposed to said cut away portion and to intert with said undercut slot, thereby to become non-rotatably connected with said key plug and said connecting bar and key plug being thereby incapable of disconnection, except through movement in radial direction of said connecting bar through said cut away portion, and spring-mounted means yieldably movable into or out of the cut away portion ofthe wall of said bore.

33. In lock construction, in combination, a casing having an open ended cylinder portion containing a bore, a key plug rotatably fitted into said bore, the rear end of said key plug having a transversely extending slot therein opening in the periphery of said plug, the wall of said bore having an axial extent suicient to encompass the portions of said plug in which said slot opens at the periphery and the wall of said bore having a portion cut away thereby to expose, upon appropriate rotation of said plug, the open end of said slot, and a connecting bar having a T-shapedend portion which is movable through said cut away portion and into said plug slot, thereby to become HENRY F. KEIL.