US2192371A - Lock construction - Google Patents

Description

March 5, 1940- S..BRANTINGSON 2,192,371

LOCK CONSTRUCTION Filed lay 5, 1939 29 INQENTOR s/suea dewvrm/aso/v its Patented Mar. 5, i940 UNITED STATES ook 'oons'rnno'rlon igurd Brantingson, Palisades Park, N. J., assigner to Francis Keil & Son, line, a corpora-- ticn of New York Application May 5, 1939, Serial No. 271,818

8 Claims. (Cl. iii-378) This invention relatesto lock construction, more particularly of the pin tumbler type.

One of the objects of this invention isto provide a pin tumbler type of lock that has a certain '5 type of structural characteristics for. resisting picking, with means to facilitate key insertion and removal. Another object is to provide a lock construction of the above-mentioned character that is difficult, if not impossible, to pick, and that Will reliably interfere with and make more complicated and difficult certain of the usual or normal steps employed in attempting to pick the lock. Another object is to provide alock construction of the above-mentioned type that will be inexpensive to manufacture, both as to its individual parts and as to assembly thereof. Another object is to provide a dependable pick-resisting lock construction free from such complications as make manufacture, assembly, repair, replacement, and the like, cumbersome or expensive. Another object is in general to improve the construction and operation of pin tumbler types of locks. Other Objects will be in part obvious or in part pointed out hereinafter.

tures of construction, combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafterdescribed and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing in which is shown by way of illustration one of the various possible mechanical embodiments of the various features of my invention,

35 Figure l is a central vertical longitudinal sectional view through the lock construction;

Figure 2 is a detached view on an enlarged scale and partly in central vertical section, of a preferred form of tumbler pin construction, and

Figure'3 is a duplication of a portion of the construction shown in Figure 1 but on a larger scale.

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

Referring first to Figure 1, I have there shown a lock casing generally indicated by the reference character. 5 ,ofany suitable shape to receive and .coact with a-suitably shapedzkey plug generally indicated by the referencecharacter .6. Preferably the casing 5 has va lower casing portion 1 I jgenerally cylindrical in shape and boredout, preferably:alsocylindrically, as-at 8, to movably, ;preferably rotatably, .receive :the key plug 6 which .raccordingly is preferably cylindrical in The invention accordingly consistsin the feashape to fit suitably into the bore 8 for movement relative thereto.

' In the illustrative construction, the key, plug 6 is to partake of rotary movement relative to the bore 8 of the casing 5 and hence any suitable means may be employed to restrict or limit relative movement in an axial direction; such means may comprise a flange 9 at the front end of the key plug 8, received in a suitable counterbore so, while at the other end of the key plug 6 the latter preferably extends beyond the end of thecasing or bore to receive any suitable means, such as a iember H to limit or restrict movement of the key plug toward the right, as viewed in Figure l. 1

The member I i may take any suitable form, such as a ring-like member suitably secured to the key plug and coacting with or engaging theflend portion of the casing.

The key plugand casing are provided with suitable bores or recesses, preferably cylindrical, for

'thereception of tumbler pins, and for that purpose the casing 5 may have an upward extension I2 in which are formed, by drilling, a suitable number of cylindrical bores or recesses whose axes, intersect the axis of the bore t and hence of the key plug 6 and, illustratively, I may provide fivesuch recesses, as at i3, is, iiniii and ii. The key plug-ii is provided with similar bores l8, l9, 2G, 2! and 22; the latter, in one position of the key plug 6 relative to the bore 8, are respectively 23 and cross-sectioned in any suitable way as by longitudinally extending ribs 24, if desired, it being noted that the tumbler recesses in the key plug intersect and extend downwardly into the key slot 23 so that the tumbler pins received in the former are exposed to the appropriately shaped edge of the proper key inserted into the key slot.

In so far as certain features of my invention are concerned, it might be noted that it has heretofore been proposed to employ, for the tumbler pins to bereceived in the tumbler recesses of the casing portion [2, a construction like that shown in Figure 2, according to which each tumbler pin is made up of a shank 26 on which are strung a suitablenumber of washers or apertured disks2l,

suitable enddisks 28, 29 holding them assembled suitable way; thus, member 29 might be integral with the shank 26, while the other end member 28 may be heldin place as by suitably heading over'the end of the shank 26, as at 30.

Prior proposals to employ tumbler pins of thisc-haracter do not result in satisfactory operation of the lock; when all of the casing tumbler pins are of this construction, the normal locked position of the key plug relative to the casing finds all of the upper tumbler pins of this type bridged across the junction between key plug and casing bore and it is possible in such a construction, made according to prior proposals, to effect such a jamming of the parts that it is impossible to insert even the intended key to effect authorized actuation of the lock. For example, some lateral play between the washer-like members .21 (Figure '2) -must be present if resistance to picking is to .be retained but with all of the tumbler pins bridging the above-mentioned junction, that same lateral play is present so that it is possible, unintentionally, to bring about or leave the construction in a locked position but with the tumbler recesses in the key plug displaced from or not alined with the tumbler recesses in the casing, due to such permissible side or lateral play. If, then, the proper key is inserted, a jamming occurs just as it is intended to take place'when attempt is made to pick the lock; the misalinement of the upper and lower tumbler recesses thus insures the presence of a ledge against which the washer-like parts 27 can catch to resist upward movement of. the tumbler pins, and only one disk member of one tumbler pin need catch to block the insertion of even the proper key. In so far as certain features of this invention are concerned, a dominant aim is to overcome such deficiencies and to make it possible in a dependable and inexpensive way to utilize the advantages of the just-described type of construction without incurring the liability of facing its disadvantages. r

In Figure l is shown a preferred or illustrative construction whereby I am enabled to overcomev the above-mentioned deficiencies. Thus, in plug tumbler recesses I9, 20, 2| and 22,'I provide tumbler pins 32- Which may be straight cylindrical pins and of varyinglengths, according to the coding of the key, to bring their upper ends,

when their lower ends bottom in the tumbler recesses, below the junction between key plug and easing bore. In the casing tumbler recesses I4,

15, l6, I1, I provide tumbler pins 33 of the type preferably have the same fit relative to their bores or recesses; this fit is preferably somewhat loose and might be typified by giving the tumbler pins 32, 33 an outside diameter of say 0.3.15 inch where "the bores or recesses in which they operate are a diameter ,of 0.123 inch. 1Such-a difference in an axial direction of the key plug 6 relative to the casing bore 8.

In plug tumbler recess I8 I positiona tumbler" pin .37 which is of a length such that when it bottoms in its recess 18 or is otherwise in its lowermost or normal position, its upper end is a flush with the junction between key plugand case ing bore, as is better shown in the enlarged view in its bore !8, being illustratively of a diameter '10 of Figure 3, and it preferably fits relatively snugly l -of 0.118 inch, the difference taking into account the above-mentioned end play, I v

Coasting with tumblerpin 3i and inserted into the casing tumbler recess it! is a tumbler pin 38 which, like the tumbler pin 31, is cylindrical and preferably has the same relatively snug fit with 20'.

its bore or recess l3, being hence of a diameter of 0.118 inch, the tumbler. recesses l8 and [3 being of a diameter of 0.l23 inch and hence, as earlier noted, of the same diameter as the rest of the tumbler pin recesses.

The adjacent ends, however, of the tumbler pins 31 and38I, preferably shape so that the two pins coact to tend to maintain themselves in coaxial alinement, aspringtll of suflicient stiffness in the casing tumbler recess 13 acting upon the upper tumbler to'press it toward and in engagernent with the lower tumbler.

30 In Figure 3 is shown an illustrative and pre-j ferred form of shaping of the adjacent end portions of pins 31 and 38. Thus, the upper end of pin 3'! has a recess 40, formed as by drillingor counterboring, and it provides, exposed upwardly a surface which is shaped substantially like that of an inverted cone whose axis is coincident with the axis of. the pin 31. The lower end oflthe upper pin,38 is rounded off as at 4|, the surface being a surface of revolution whose axis is coin'- cident with the axis of pin 38 and is of such curvature that it enters to 'a substantial extent into the conicalv recess i0, thecurvature of its upper side portions, as seen in Figure 3, being preferably relatively slight and approximating,

l3 and i8 into coaxial alinement, the coaction' between the spring 39 and the surfaces of the. parts 4| and Ml normally maintaining these relationships, thus also maintaining the respective upper and lower tumbler recesses of thetumbler pins 3332 likewise in coaxial alinement.

In achieving these relationships,- the coacting surfaces of the parts 4| and 40 act as cam-like force-multiplying parts to translate the comparatively small force of the spring 39 into a relatively v :45 .for example, the surface of a frustrum of a cone."

large side thrust to impose upon the movable :key plug 6 thethrust or force necessary to shift it; in

the illustrative embodiment by a rotary movement, s'uiiiciently to bring the key plug tumbler; recesses into alinement with the casing' turnbler recesses;

The key for operating the lock, whereth'e pin 31 is dimensionedas to length, asin the illustrative embodiment, so that its upper end "is that when the key is completely insertedpin 3! again bottoms in its recess. l8. During insertion of the ;key, the other portions of the keyraise.

-70 flush with the junction between key plugand casing bore, has a notch, for pin 31, of such depth, f

the pin 31 to bring its upper end into the 'tumbler recess l3 and thus pin 31, in bridging the junction of tumbler recesses l8 and I3, holds the key plug in proper position to maintain registry of the other upper and lower recesses so that the other portions of the key may freely position the other tumbler pins 32-33 without the washer-like parts of the latter becoming jammed at the junction.

The key may now be freely turned to move the key plug 6, as in a looking or unlocking movement. At the beginning of this movement, ro-

tary in the illustration, the surface of the recess All in coaction with the surface of the portion 4| of the upper pin 38, simply cams the latter upwardly, part 4| being cammed over the upper peripheral edge of the recess 4|] of the lower pin, 31.

At the, conclusion of the movement necessary to thereafter efiect withdrawal of the key, the rounded end portion 4| of the upper pin 38 slides over the peripheral end or edge portion of the lower pin 31 and under the action of spring 39 is cammed or forced downwardly into the recess 49, in effect snapping the two pins 31 and 38 and hence the key plug and casing tumbler re- I cesses into axial alinement, also taking up any end play, and holding that alinement of parts, whence the key may be promptly withdrawn, again without danger of having any of the displaceable washer-like parts 21 of the tumbler pins 33 jam or catch at the junction between the now alinedv plug tumbler recesses and casing tumbler recesses. After removal of the key, the continued coaction between tumbler pins 31 and 38 continues to maintain the desired alinement of the parts so that subsequent insertion of the key takes place easily and smoothly.

Butby reason of such coactions,I also achieve greater security against picking of the lock whether or not the tumbler pins 33 are of the type above described and shown in Figure 2. With the tumbler pin 31 dimensioned as above described in the illustrative embodiment, it has to bottom in its recess l8 if relative movement between key plug and casing is to take place, for any upward movement projects it across the junction between key plug and easing bore and blocks such relative movement; that action could take place if pin 31 is raised as by a picking implement inserted into the key slot and usually accompanies any attempt to lift one of the pins 32 to the rear of pin 31, since in such case attempt has to be made to by-pass the pin 31 without raising it.

Assuming that such attempt is successful, the succeeding attempts to raise the rear pins to catch the upper pins on a ledge caused by displacing the key plug relative to the casing, must be accompanied by exerting a delicate force upon the key plug 6, usually a torsional force, to bring about a displacement sufficient to create such a ledge; this is usually done by cut and try methods in which sensitiveness of control of the displacing or torsional force exerted upon the key plug is practically vital. But any such attempts to displace the key plug, according to my invention, are met by the greatly multiplied force of the spring 39 acting, through the wedge-like or cam faces of the parts 40, 4|, in opposition to such displacing or torsional force. This force of opposition is, due to the relative shaping of the parts 4!! and 4|, greatly in excess of the comparatively small force exerted by the spring 33 and, again by appropriately shaping the parts Ml, 4|, may have a variable, as distinguished from straight-line, effect or relationship to the amount of misalinement between the axes'of the pins 31 and 38.

Thus, the individual who attempts to pick the lock meets with a substantial force of opposition to his control of the displacement of the key plug, thus upsetting the necessary sensitiveness of control ofv the manually applied displacing force, and where, as in the preferred case, the cam or wedge effect in multiplying the force of the spring 39 is variable and is hence a noniinear function of the displacement of the axes of the pins 31 and 38, this opposing force partakes of such variation or change that the sensitiveness of displacement or torsional control, manually, of the key plug relative to the casing, in the effort to catch the rear tumbler pins at the right elevation, is completely upset and picking of the lock made so time-consuming or so difficult or impossible that, for practical purposes, frustration of picking attempts results.

As earlier above indicated, the tumbler pin. 31 is preferably of such a length that, when it assumes its normal or lowermost position, its upper I peripheral edge portions are substantially at or in the junction betweenthe key plug 6 and the bore In the illustrative embodiment, that preferred relationship is achieved by letting the tumbler pin 31 bottom in its bore it; the bore !8 may be given any suitable depth or axial length and, for example, it may be of the same length as the bores 53, 20, 2!, 22, though, as in Figure 1, it may be desirable to give the bore it a greater depth, somewhat as indicated, particularly where it may be desired to relate the lower end of the tumbler pin 31 to one of the longitudinally extending ribs 24 in the key slot 23.

Thus, it will be seen that there has been provided in this invention a lock construction in which the various objects above noted, together with many thoroughly practical advantages, are successfully achieved. It will be seen that the construction is of a thoroughly practical nature, is capable of inexpensive manufacture; and is well adapted to meet the conditions of hard practical use. 7

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

I claim:

1. A lock construction comprising a casing hava bore, a k y plug movably mounted in said said key plug having a key slot and a plutumbler bores intersecting said key slot, g having a p urality of tumbler bores alineahle with said first-mentioned :r :ores, tumbler pins in said key plug ,oler bores, spring pressed tumbler pins in said ,ssing tumbler bores, at least one of said tumblers in said casing bores comprising a member having strung thereon a plurality of Washerlike parts capable of relative lateral displacement to present one or more projecting edges capable of catching upon the ledge formed" between said key plug casing upon. inappropriate alinement of the key plug bore and casing bore in which said tumbler pin is slidable, at least one of the remaining tumbler pins in a casing bore and its coacting key plug tumbler pin having a relatively close fit with their bores and having their adjacent ends-provided with interfitting means capable, in response to the spring pressure exerted on the casing tumbler pin, of bringing said two pins into coaxial alinement and thereby forcing such displacement of the key plug relative to the casing that therespective tumbler bores of the latter are brought into coaxial alinement, thereby preventing'a laterally displaced part of said first-mentioned tumbler pin from catching and jamming the insertion or removal of the key relative to said key slot.

2. A lock construction as claimed in claim 1 in which the interfitting means of said two tumbler pins comprises a recess in the end of one of said pins and a projecting extension on the other of said pins and enterable into said recess under said spring pressure.

34A lock construction as claimed in claim 1 in which the interfitting' means of said two tumbler pins comprises a recess in the end of one of'said tumbler pins and an extension, substantially wedge-shaped, of the other of said tumbler pins, said wedge-shaped extension being enterable under spring pressure into said recess.

4. A construction as claimed in claim 1 in which the key plug tumbler pin of said two tum bler pins that have said interfitting means is of such a length that the effective junctionbetween said two pins, when said key plug tumbler pin bottoms in its bore, substantially mates with th junction between the key plug and casing, said interfitting means having coacting faces to efiect disengagement therebetween upon movement of thekey plug by the proper key inserted into said key slot.

5. A look construction comprising a casing having a bore, a key plug movably mounted in said bore, said key plug having a key slot and a plurality of tumbler bores intersecting said key slot, said casing'having a plurality of tumbler bores respectively alineable with said first-mentioned tumbler bores, tumbler pins in said key plug tumbler bores, spring pressed tumbler pins in said casingtumbler bores, and means for upsetting sensitiveness of control of manual application to the key plug of a force for displacing the key plug relative to the casing such as is necessary in the attempt to pick the lock con- "struction, said last-mentioned means comprising cam means at the adjacent ends of at least one pair of casing and key plug pins for translating the spring pressure on the casing tumbler pin into a force acting in a direction in opposition to such manually applied force of displacement. l

6. A look construction comprising a casing having a bore, a key plug movably mounted insaid bore, said key plug having a key slot and a plurality of tumbler bores intersecting said key slot, said casing having a plurality of tumbler bores respectively alineable with said first-mentioned tumbler bores, tumbler pins in said key plug tumbler bores, spring pressed tumbler pins in said casing tumbler bores, "and'me'ans for up setting sensitiveness of control of manual application to the key plug of a force for displacing the key plug relative to the casing such as is necessary in the attempt to pick the lock construction, :said last-:fnen'tioned means comprising means acting upon said tumbler pin in respouse to the pressure exerted thereon by its; companion casing tumbler pin for exerting a displacing force upon the key plug, through the" key plug'tumbler pin,.: and thereby to interfere with the said force of displacement manually applied asaforesaid. a

'7. A lock construction. comprising a casing having a bore, a key plug movably mounted said bore, said key plug'having a key SIOt'dhd! 1 a plurality of tumbler bores intersecting "said key slot, said casing having a plurality of 'tum bler bores respectively alineable with said firstmentioned tumbler bores, tumbler pins in said key plug tumbler bores, spring pressed tumbler? pins in said casing tumbler bores, and means for upsetting sensitiveness of control of manual application to the key plug of'a force for displac- I ing the key plug relative to the casing, such as is necessary in the attempt to pick the lock construction and comprising a pair of said casing tumbler pins and key plug tumbler pins, the adjacent ends of said pair of pins having coact'-' ing parts acting in response to a displacement between said key plug and casing to transform the spring pressure exerted upon the casing tumbler pin of said pair into a yieldable resistance} to displacement. i

8. A look construction comprising a casing having a bore, a key plug movably mounted in said bore, said key plug having a key; slot and l a plurality of tumbler bores intersecting said key slot, said casing having a plurality of tumbler bores respectively alineable with said first-mentioned tumbler bores, tumbler pins in said key plug tumbler bores, spring pressed tumbler pins in said casing tumbler bores," at least one of the key plug tumbler'pins being of a length such that in normal position of the lock parts its up per end is substantially coincident tion between key plug and casing it operates such' that, when it is bridged across said junction, substantially no displacement, or only a slight displacement; between the adjacent ends of casing and key plug bores can take place, and means acting upon said one plugtumbler pin in response to the pressure exerted thereon by its companion casing tumbler pin for exerting a displacing force upon the key plug through said key plug tumbler pin and thereby upset sensitiveness of control of manual application to the key plug the key plug relative to the casing such'as is necessary in the attempt to tion. I Y SIGURD BRAN'I'INGSON.

of a force for displacing pick the lock construcwith the junc-f V and having a diameter relative to the alineable bores in which-

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