US2059129A - Lock - Google Patents

Description

' 2 Sheets-Sheet 1 M. c. MAXWELL ET AL LOCK v Filed April 22, 1955 Oct 27 TORNE y Mrk/6M AT Y Oct. 27, `1936.

' M. C. MAXWELL ET AL LOCK4 Filed April 422, 1955 2 Sheets-Sheet 2 f ri 1. ,v

Patented Oct. 27, 1936 osano lLCK Maxwell C. Maxwell, Frank E. vlh'onipson, llharies lledin, and Charles B. lllowatamford, Goran.,

assignors to 'lheJale & 'Formen/iig. Co., Stamford, Conn., a corporation of Connecticut Application April 22, 1933, Serial No. 667,470

2i claims.

This invention relates to pin-tumbler cylinders adapted to resist picking and attack. It is the object of our invention to design a pin-tumbler lock which will have special features embodied 5 therein to resist attack as by drilling or forceful rotation, and which will resist thepicking of the tumblers by a special picking tool.

More particularly, our invention embodies a pin-tumbler lock having a portion 'of .relatively 0 weak cross section, and having mounted in that section an armor plate which ls exposed when the head of the plug covering the weak section is forcefully shorn therefrom as by forceful ro- 1 tation of the plug. Preferably, it is a further the armor plate that it will be impossible to remove it when the vfront head of lthe plughas been shorn, and to so position the'plate that it will cover that portion of the plug which must be attacked in order to reach the tumbler chambers.

A further feature of the invention embodies the design of a cylinder lock so that the first tumbler in all the locks of a particular series of cylinders will be ofexactly the same length,

the' length being so chosen as to prevent substantial movement of a picking tool in the lock. Preferably, it is a feature of the invention rto so arrange at least one of the rearward tumblers of the lock, that it will be rather short and will require such substantial movement of the picking tool as will be impossible of transmittal without movement of the long locking tumbler to plug locking position.

The drivers of our lock are necked or mushroomed so as to make them more pick resisting than regular types of drivers. As a further feature of our invention We design the front driver of such cross sectional strength as to prevent the shear of the relatively weaker necked or mushrooml tumblers, utilizing the length of the front driver to assure its assuming a locking position ahead of the mushroom drivers upon insertion of a tool into the plug keyway and attempted forceful rotation of the lock, whereby the long tumbler will relieve the necked or mushroomed tumblers from shearing torque.

It is still a further feature of our 'invention I 50 to design one of the drivers so that it has a tapered end portion adapted to align the plug of the cylinder lock with the cylinder itself, so as to prevent the application of torque to the remaining tumblers and to force the plug into initial locked position, if, during any picking opdetailed feature of the invention to so anchorl (ci. 'io-r1) eration, the application of torque-to the plug is momentarily stopped.

As a further feature of our invention we design the cylinder so that it may be manufactured of die cast metal with driver bores cast therein and 5 serving as guides for drills or punches to form corresponding holes in a brass sleeve which is used as a contact between the cylinder and the usual type of brass tumbler plug to prevent corrosion. '10

Further objects of our invention will appear from the description which follows.

In the drawings, Fig. l is. a4 cross section of a preferred embodiment of our invention. Figs.

2, 3 and 4 are sections taken along the lines 2, t, l5 and l of Fig. 1, with Fig. 3 showing a modicationof Fig. 1. Fig. 5 is a section taken along the lines iiof Fig. 1 showing the usual mushroom driver in plug releasing position. Fig. 6

is a view along the same section as Fig. 5 show- 2o ing the mushroom driver acting to lock the plug and cylinder together and in its pick resisting position. Fig. 'l is a view illustrating what normally happens when a usual type of tumbler lock is picked. Fig. 8 illustrates the manner in 25 whicnthe cast driver bores serve as guides for v a tool used to form the bore in the brass sleeve in which the usual brass plug of thricylinder lies.

Fig. 9 is a perspective View of the sleeve used in Fig. 8. 30

Referring now more particularly' to the drawings, reference numeral ill illustrates a die cast cylinder having formed therein a series of cast bores l l which serve as guides for a drill or other tool it (see Fig. 8) for forming aligned bores i3 35 in the brass sleeve lll. Preferably, but not necessarily, the brass sleeve it is formed with notches i5, so that when the cylinder lll is cast, With the sleeve il mounted in the mold, the cylindei` will be securely fastened to the sleeve by 40 metal flowing into the grooves l5. Of course, other methods may be utilized for securing the sleeve to the cylinder.

At the front end of the cylinder, there is mounted a hardened steel plate it which serves as an armor to prevent access to the drivers by a drill. Cooperating with the armor plate it is a further armor plate il resting in a grooved portion i8 of thetumbler plug I9. The member il also rides in a groove 20 in the cylinder so 50 as to be retained in the cylinder independently of the plug body.l The purpose of this construc-v tion is to prevent the application of shearing stress to the cylinder plug I9 as by a screw driver driven into the front portion of the keyway 2i of 55 the plug I9. For instance, should a screw driver or other tool be driven into the keyway 2l, force-` ful rotation will simply shear the head of the plug from the remainder of the plug, due to the weakened section in which Ithe armor plate I1 rests, leaving an exposure as shown in Fig. 2 with the armor plate I1 preventing further access into the plug. It will be impossible to remove the armor plate I1 because of the groove 20.

In order to prevent the picking of the lock, We utilize a series of mushroom drivers 22 best illustrated in Figs. 5 and 6. The heads of these drivers cooperate with the grooves 23 in the lsleeve I4,-as shown in Fig. 6, whenever sufficient torque is applied to the plug to rotate it the amount permitted by the peculiar shape of the drivers. Movement of the -drivers into release position of Fig. 5, from the locked position of Fig. 6, is then practically impossible. It will be readily understood that these mushroom drivers 22 are rather weak because of the cutting away of a portion of their body, and in order to prevent their shearing by the application of shearing torque to the plug, the first pin tumbler of the lock, pin 24, is made of slightly larger section than the remaining tumblers, and of hardened stainless steel. In addition, this tumbler 24 and its driver are made to fit very closely within the bore to allow for but little play. Also, first tumbler 24, in addition tot its stronger section, is made considerably longer than the remaining tumblers so that the insertion of a picking tool in the keyway 2I will immediately move the first tumbler into a locking position. Since this tumbler is designed to permit but very slight rotation of the plug and less than is permitted by the drivers 22 in Fig. 6, it will prevent application of torque to the mushroom drivers and will prevent shearing of the drivers.

By this association of elements, it is readily seen that We utilize the mushroom drivers 22 to prevent picking of the lock, and that to prevent the shearing of these drivers, due to their inherent weak construction, we utilize the front long pin. This pin is immediately forced into locking position by the insertion of a torque applying tool, and will absorb the torque due to the fact that it will be immediately placed in torque resisting position while the grooved or mushroom tumblers are designed to allow considerable movement of the plug from the position of Fig. 5 to the position of Fig. 6 before they perform their locking function.

Fig. '1 illustrates the manner in'which an ordinary plug may be operated by a picking tool, by simply applying torque various drivers 25 have been forced entirely into the cylinder chamber II while the pins 26 have gradually, one by one, been allowed to move over until they are over-hung by the body 21b immediately adjacent the driver bore II, and the part 21a of the plug will effectively prevent downward locking movement of the driver 25. Those skilled in the art will appreciate that the position of Fig. 7 is attained by each pin-tumbler and driver in undetermined sequence by skillful use of apicking tool. Any slight counter clockwise movement from Fig. '7 will immediately realign the driver and tumbler bores to interlock the plug and cylinder.

Preferably, to aid in forcing the plug body I9 back into a position wherein the pin 26 will be aligned with the driver 25 upon the alleviation of torque to the plug I9, we utilize a locking driver 21 best illustrated in Figs. 1 and 4. I'his lockto the plug until the ing driver has a bevelled surface 28 which will cooperate with a bevelled surface 29 of the plug I9 so as to rotate the plug back into bore aligning position immediately when picking torque on the plug I9 is decreased to a deiinite point. For instance, should picking torque be taken from the plug I9 in the position of Fig. '1, the locking driver 21 would immediately act as in Fig. 4 to force the plug in a counter clockwise direction to align the pin 26 with the driver 25 whereupon the driver would be forced down into the pin chamber to lock the plug to the cylinder. Preferably, the spring 30 used with the locking driver is of relatively greater strength than the other springs used in the plug so as to exert considerable pressure.

We prefer to utilize astill further means of forcing the plug I9 back into aligned position to prevent picking such as shown in Fig. '7, by bevelling the upper portion 3II of the front long pin 24 as shown in Fig. 3. Thus, should the pin 24 be forced into an upward position by the picking tool, it will act through its bevelled head 3|, to force an alignment of the plug and cylinder bores whereupon, in-a case such as Fig. 7, the plug I9 would be placed once more in locking condition by the driver 25. Preferably, at least one of the tumblers is of such slight length that a picking tool capable of operating it into a release position would necessarily actuate the long pin 24 into its locking and aligning position.

While we have shown a particular embodiment of our invention, it should be understood that variations of the same Will readily occur to those skilled in the art, and that we do not wish to be limited in our patent monopoly except as may be required by the state of the prior art.

We claim:

1. In a lock, a cylinder, a key plug, a series of tumblers in said key plug cooperating with drivers in said cylinder, the first of said tumblers being of relatively great length to prevent substantial `movement of a picking tool in the plug keyway,

Without moving said tumbler into a locked position, and having a tapered end adapted to enter the cylinder driver bore opposite it even when the plug has been rotated suiiiciently to disalign slightly the tumbler and driver bores.

2. In a lock, a cylinder and a key plug having aligned driver and tumbler bores, drivers and tumblers in said bores, the first of said tumblers being of relatively great length to prevent substantial movement of a picking tool in the plug keyway, without moving said tumbler into a vlocked position, and having a tapered upper end adapted to enter the particular driver bore associated therewith even when the plug has been rotated somewhat to disalign the tumbler and driver bores, whereby slight actuation of said pin by a picking tool will act to rotate the plug relatively to the cylinder and into driver and tumbler bore alignment.

3. In a cylindei` lock, a cylinder, a key plug, an armor plate covering a cross sectional part of the key plug and adapted to rotate with said key plug, and a retaining groove in said cylinder in which said armor plate is adapted to rest whereby to be maintained against removal even when that part of the plug in front of said plate is destroyed.

4. In a cylinder lock, a cylinder, a key plug having a cutaway portion leaving a relatively weak section, an armor plate adapted to rest in said cutaway portion and covering a vital cross sectional part of said plug and adapted to rotate with said key plug, and a retaining groove in 2,059,129 Asaid cylinder in which said armor plate is adapted to rest whereby to be maintained against removal even when the plug in front of said plate is destroyed.

5. In a cylinder lock, a cylinder, a key plug having a cutaway portion leaving a relatively weak section, an armor plate adapted to rest in said cutaway portion, said cylinder having a groove, a portion of said armor plate arranged to extend into said groove, said armor plate being of such configuration and size that if the front of the plug and said weak section be broken away, said armor plate will not be movable out of its groove in the cylinder and will remain in` protecting relation to the remainder of 4the plug.

. 6. In a cylinder lock, a cylinder, a key plug having a cutaway portion leaving a relatively Weak section, an armor and retaining plate adapted to rest in said cutaway portion 'and to rotate with said plug, said cylinder having a groove, a portion of said armor plate arranged to extend into said groove, said armor plate being of such coniiguration and size that if the front of the plug and said weak section be broken away, said armor plate will not be movable out of its groove in the cylinder and will remain in protecting and retaining relation to the remainder oi the plug.

7. In a cylinder lock, a cylinder, a key plug having a cutaway portion leaving a relatively weak section, an armor. and retaining plate adapted to rest in said cutaway portion and to be supported by said weak section, said cylinder having a groove, a portion of said armor plate arranged to extend into said groove, said armor plate being of such conguration and size that if the iront of the plug and said weak section are broken away, said armor plate will not be movable out of its groove in the cylinder and will remain in protecting and retaining relation to the remainder of the plug.

8. In a cylinder lock, a cylinder, a key plug mounted to rotate in the usual plug bore in said cylinder, said plug having a weakened section, said cylinder having a groove in its plug bore in the vertical plane occupied by said weakened plug section and an opening leading from said groove to the outside of said cylinder, and an armor plate insertible through said opening and into the weakened section of said plug.

9. In a cylinder lock, a cylinder, a key plug mounted to rotate in the usual plug bore in said cylinder, said plug having a weakened section, said cylinder having a groove in its plug bore in the vertical plane occupied by said weakened plug section and an opening leading from said groove to the outside of said cylinder, and an armor plate insertible through said opening and into the weakened section of said plug, said armor plate having also a portion adapted to ride in the cylinder groove.

iii. In a cylinder lock, a cylinder, a key plug mounted to rotate in the usual plug bore in said cylinder., said plug having a weakened section, said cylinder having 'a groove in its plug bore in the vertical plane occupied by said weakened plug section and an opening leading from said groove into the outside of said cylinder, an armor plate insertible through said opening and into the weakened section of said plug, said armor plate being rotatable with said plug and having a portion adapted to extend into the cylinder groove.

11. In a cylinder lock, a cylinder, a key plug mounted to rotate the usual plug bore in said cylinder, said plug having a weakened section, said cylinder having a groove in its plug bore in the vertical plane occupied said weakened plug section and an` opening leading from said groove to the outside of said cylinder, an armor plate insertible through said opening and into the weakened section of said plug, said armor plate'being rotatable with said plug and having a portion adapted to extend into the cylinder groove wherebyto rotate in 'said groove, said plate being of such conguration relatively to the plug bore and groove that should the front of the plug and said weakened section be cut away, said armor plate will not be movable out yof its groove in the cylinder and will remain in retaining and protecting relation to the remaining portion oi' the plug. y i

12. A cylinder lock comprising a cylinder of cast material. a key plug for said cylinder operating in a cast bore therein, a relatively non-corrosive sleeve lining for said cylinder bore in which said plug is adapted to rotate, aligned tumbler chambers in said plug, sleeve, and'cylinder, said cylinder bores being cast therein, said sleeve bores being punched or drilled therein in alignment with said cast bores.

13. A cylinder lock comprising a cylinder of cast material, a key plug of cast material for said cylinder and operating in a cast bore therein; a relatively non-corrosive lining for said cylinder bore in which said plug rotates, aligned tumbler chambers in said plug, sleeve, and cylinder, said sleeve being secured against rotation relatively to said cylinder by fastening means formed during the casting of said cylinder.

14. A cylinder lock comprising a cylinder, a key plug for said cylinder operating in said plug bore in said cylinder, and a relatively non-corrosive sleeve of an internal diameter substantially the diameter of the plug and an external diameter substantially the diameterof the cylinder plug bore, arranged between the plug and cylinder.

15. A cylinder lock comprising a cylinder having a plug bore, a key plug for said cylinder operating in said plug borein said cylinder, and a relatively non-corrosive sleeve of an internal diameter substantially the diameter of the plug and an external diameter substantially the diameter of the cylinder plug bore arranged between the plug and cylinder, and means whereby said sleeve is secured against rotation relatively to one of the said elements between which itis mounted. I

16. In a cylinder lock, a cylinder, a key plug having a cut-away portion leaving a relatively weak section, an armor plate adapted to be inserted in said cut-away portion and to cover a vital cross sectional part of said plug, said armor plate being retained against endwise or rotary movement relatively to the plug so as to rotate with the plug when said plug is released for rotation, a retaining groove in said cylinder in vwhich a porti/on of said armor plate is adapted to rotate'as it moves with said plug, said retaining groove being adapted to maintain said armor plate against removal even when the plug in front of said plate is destroyed.

17. A cylinder lock comprising a cylinder of castA material, a key plug oi cast material for said cylinder and operating in a cast bore therein, a relatively non-corrosive lining `for said cylinder bore Ain which said plug rotates, aligned tumbler chambers in said plug, sleeve and cylinder, said sleeve functioning as a spacer element between said plug and cylinder to prevent corrosive attraction of the two.

18. A cylinder lock comprising a cylinder of cast material having a plug bore, a key plug for said cylinder operating in said plug bore in said cylinder, and a relatively non-corrosive sleeve lining for said plug bore arranged to separate the key plug from contact with the walls of said bore.

19. A cylinder lock comprising a cylinder of cast material having a plug bore, a key plug for said cylinder operating in said plug bore in said cylinder,'and a relatively non-corrosive sleeve arranged to separate the key plug from contact with the walls of said bore.

20. A cylinder lock comprising a cylinder of cast material havinga plug bore, a key plug for said cylinder operating in a plug bore in said cylinder, a relatively non-corrosive sleeve arranged to separate the key plug from contact with the walls of said bore, and aligned tumbler chambers in said plug, sleeve, and cylinder.

21. A cylinder lock comprising a cylinder of cast material having a plug bore, a key plug for said cylinder operating in a plug bore in said cylinder, a relatively non-corrosive sleeve arranged to separate the key plug from contact with the walls of said bore, aligned tumbler chambers in said plug, sleeve, and cylinder, and means for securing said `sleeve in position to maintain its chambers always in proper alignment relatively to said plug and cylinder chambers.

22. In acylinder lock, acylinder having a driver containing portion terminating in an upper surface, a. key plug mounted to rotate in the usual plug bore in said cylinder, said plug having a cutaway section, said cylinder having an opening in the plane of said cutaway section leading from the upper surface of the driver containing por- -tion downwardly into the plug bore, and an armor plate insertible through said opening and into said cutaway portion of the plug.

23. In a cylinder lock, a cylinder having a driver containing portion terminating in an upper surface, a key plug mounted to rotate in the usual plug bore in said cylinder, said plug having a cutaway section, said cylinder having an opening in the plane of said cutaway section leading from the upper surface of the driver containing portion downwardly into the plug bore, an armor plate insertible through said opening and into said cutaway portion of the plug, and a portion of said armor plate being adapted to remain in the cyl,- inder.

24. In a cylinder lock, a cylinder, a key plug mounted to rotate in the usual plug bore in said cylinder, said plug having a cutaway section, said cylinder having an opening in the plane of said cutaway section leading from the outside thereof to the plug bore, an armor plate insertible into the cylinder through said opening and having portions thereof lying in the cutaway section of the plug and in the cylinder, and a further armor plate inserted through said opening and adapted to prevent outward movement of said rst armor plate while serving also to protect the cylinder.

MAXWELL C. MAXWELL. FRANK E. THOMPSON.- CHARLES LEDIN. CHARLES B. LOWE.

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