US3073146A

US3073146A - Pin tumbler assembly

Info

Publication number: US3073146A
Application number: US67397A
Authority: US
Inventors: George P Patriquin
Original assignee: Independent Lock Co
Current assignee: Independent Lock Co
Priority date: 1960-11-04
Filing date: 1960-11-04
Publication date: 1963-01-15
Anticipated expiration: 1980-01-15
Also published as: GB926220A

Description

United States Patent @fificc Patented J....15,1%3

3,073,146 PIN TUMBLER ASSEMBLY George P. Patriquin, Gardener, Mass, assiguor to Independent Lock Company, Fitchburg, Mass., at corporation of Massachusetts Filed Nov. 4, 1960, Ser. No. 67,397 7 Claims. (Cl. 70-383) This invention relates to a method for providing, and the resultant improved lock assembly, and more particularly to a pin tumbler lock assembly.

Still more particularly, this invention relates to a tumbler lock assembly having a factory pin tumbler combination which renders the lock operable by a first key, said lock including novel means whereby operation by a specially designed second key will disable subsequent operation by the first mentioned key.

In the construction of new homes, apartment houses, office buildings, and the like, it is desirable to provide the workers with means for locking the individual units on which they are working in order to safeguard tools, construction materials and the like, which are necessarily left on the job. After construction work has been completed, however, it is necessary to assure the security of the tenant or owner that the combination of the locks previously employed be changed, so that holders of keys during the construction period are not able, after completion of the job, to reenter the premises through the use of these construction keys.

In the past, changing of the pin tumbler combination has required removal of the lock from the door, disassembly of the tumbler mechanism, and substitution of new driver and follower pins for the pins originally provided-in short, an operation requiring the skills of an experienced locksmith. Accordingly, it is an object of the present invention to provide a pin tumbler mechanism for use in door locks, and the like, the combination of said mechanism being adapted to be changed without disassembly of the door lock mechanism or the pin tumbler unit.

A further object of this invention is to provide a pin tumbler assembly, the combination of which assembly may be changed through the use of a specially prepared key.

A further object of this invention is to provide a pin tumbler assembly, the combination of which is changeable in the manner aforessaid by a special change key, the construction of the tumbler mechanism being such that one change key may be effective to change the combinations of a plurality of tumbler mechanism, all of which mechanisms may have different combinations after such change.

Still a further object of this invention is to provide a pin tumbler mechanism as aforesaid, wherein the change key may, if desired, be adapted for use as a master key.

A still further object of this invention is to provide a pin tumbler mechanism having a frangible follower pin in at least one tumbler thereof, said mechanism being operable by a key having one combination prior to fracture of said frangible pin, and being operative to that key after fracture of said follower pin.

The invention also has for its object a method of quickly and inexpensively converting a pin tumbler lock from one combination to another whereby only a predeterminedly bitted key will operate the key actuating mechanism and the removal of the pin'tumbler assembly to change the combination for key actuation is avoided.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, reference is made to the accompanying drawings, forming a part hereof in which:

FIGURE 1 is a vertical section through a pin tumbler assembly in accordance with the invention;

FIGURE 2 is a magnified fragmentary section illustrating the positions of the parts in the conversion or change tumbler with a construction or temporary key in position in the keyway;

'FIGURE 3 is a section simlar to the section of FIG- URE 2 with the conversion or change key positioned in the keyway;

FIGURE 4 is a view similar to the view of FIGURE 2 showing the changed combination; and

FIGURE 5 is a view similar to the view of FIGURE 2 showing the owners key in position within the keyway of the plug.

In accordance with the invention, a tumbler casing 10 is provided with a plug 11 rotatably mounted within main bore 12 of the casing. An annular flange 13 on the outer face of plug 11 is seated within annular shoulder 14 formed in the face plate 15 carried by the casing 10, thereby limiting the inward relative movement of the plug with respect to the casing 10. Movement of the plug 11 outwardly of the casing 10 is prevented by split spring washer 16 seated in annular groove 17 of the plug 11, said washer bearing against end wall 18 of the casing. The plug 11 is provided in the usual manner with a longitudinally extending keyway 19.

The casing 10 and plug 11 are provided in the usual manner with rows of parallel cross bores or holes 20, 21, respectively, for the driver springs, driver pins and follower pins. It will be understood that the cross bores 21 by rotation of the plug 11 will be brought into registry with the bores 21 in the casing. The bores 20 and 21 are charged with paired driver and

follower pins

22, 23, respectively, and with driver springs 24 bearing, at their upper ends 25, against the cap plate 30, and at their lower ends 26, against the upper or outer ends of driver pins 22. Springs 24 act in the usual manner normally to project the follower pins fully and the driver pins partly into the cross bores 21 of the plug, thereby causing the driver pins 22 to straddle the shear or parting line AA, thereby preventing the rotation of the plug 11 with respect to the casing 10 without the use of a suitable key.

The structure thus far described is conventional in nature, and the invention herein is concerned with the cross borings 20a, 21a, of the casing and plug, respectively, and the associated novel pins or tumblers charged therein, as well as the novel key mechanisms hereinafter described, it being understood that while one such assembly is shown, it may be embodied in as many of the borings as it may be desired to alter by the present invention.

In accordance with the illustrated embodiment, cross bore 20a is enlarged as compared with cross bores 20. The bore 20a is charged with a driver pin 22a and an auxiliary driver pin 23b, the pins being urged radially inwardly toward the axis of the main bore 12 by a driver pin spring 24a, having its upper end 2511 biased against the cap 30, and its lower end 26a biased against driver pin 22a. The bore 21a of the plug 11 is, in contrast to the bores 21, optionally but preferably drilled entirely through the plug 11. In addition, the bore 21a includes an enlarged counter-bored entering portion 21b, defining with the remainder of said bore an annular shoulder 210. A frangible follower pin 23a is seated within the bore 21a. The follower pin 23a includes an inner section 23b, an. outer section 23c, and a weakened or frangible neck connecting portion 23d.

In addition, the outer section 230 is provided with a mushroom like head portion 23c of a diameter substantially conforming with the enlarged portion 21b of the bore 21a.

The casing 11 is provided with an opening 31, opening into the main bore 12 and preferably positioned to register with the bore 21a in the locked position of the plug. The opening 31 is of a size which will permit the inner portion 23b of follower pin 23 to pass therethrough, the size of said opening31 being smaller than the head portion 23e, however. As seen in FIGURES 1 and 4, driver spring 24a in the locked position of the plug is effective to force the head portion 23c of the follower pin 23a against the shoulder 210 formed in the cross bore 21a.

As shown in FIGURE 2, a temporary key K1, having a bitted upper face B1, has been inserted into the keyway 19 of the plug 11. While the entire bitted face of key K1 has not been shown, it should be understood that said face is provided in the usual manner with a predetermined bitting suitable to raise the follower pins 23 to a point whereat their outermostends lie precisely on the shear line A--A, and thereby present no obstacle to theturning of the plug 11 within the cylinder 10.

The bitting B1 of the key K1 is likewise effective when engaged with the lower section 23!) of follower pin 23a to raise the outermost'end of the auxiliary driver pin 22b to the parting or shear line A A, thereby enabling the plug 11 to be turned within the .casing 10, bringing the eccentric actuator finger '32 carried by the plug 11 into tripping contact with any known suitable locking mechanism.

The combination of the pin tumbler assembly is changed by actuating said assembly with-a special change or master key K2 (see FIGURE 3). In the inserted position of key K2, the land or troughTZ of said ,key, whichis of a greater height than-the tropgh {T1 of key K1, serves to lift the follower pin ZSasufliQientlY toposition the weakened neck portion 2312 at the shear line A--A. The key K2 is then forcibly rotated in -the;plug 11, causing the lower portion 23b of follower pin 23a to become separated from the upper portion 23c thereof, by fracturing the follower pin at the nec k portion 2311. Under these circumstances, the lower portion 23a will be retained within the plug, and the upper portion 230 will be shifted to the bore 20a in the casing. ,As the plug 11 is turned by key K2, the widened portion 21b of bore 21 is brought into registry withopening 31in the casing 10, and the separated lowerpart 23b, at such registering position, may fall through the passage .31. If the lower or inner section 23a does not fall through open.- ing 31, as the plug is rotated to unlock the :door mechanism, this part will, as shown in FIGURE ,4, fall through said opening when the key K2 is withdrawn after the plug has been returned to the locked position thereof, since the opening 31 is optionally but preferably, positioned in the casing 10 to register with cross .bore 21a when the plug is in said locked position.

It will be readily recognized that opening *31 need not be aligned with the bore 21a in the locked position of the plug so long as said opening is positioned to register with the upper end 21b of said bore during some rotated position of the plug 11.

It will be further recognized that the opening 31 is desirably located at a point beneath the axis of the main bore 12 so that the inner section 23b will be induced to pass through said opening under the influence of gravity, At any rate, after the key K2 has been withdrawn, the combination of the tumbler assembly has been effectively changed by reason of the removal of the section 23b.

As shown in FIGURE 5, theowneris key K3 is bitted at its upper edge B3, and provided with a trough T3, which registers in the inserted position of the key K3 with the cross bore 21a. The trough T3 of key K3 is of a height calculated to raise the junction of follower pins 22a and 22b to the parting or shear line AA when the lower face of the outer follower pin section 23a is seated in said trough. Further, the comparison of FIG- URES 2 and will indicate that after the section 23b has been removed from the follower pin 23a, the construction or temporary key ,Kl will be ineffective to align the pins 4 in the bores 20a, 21a, with the shear line A-A, and thus will no longer be capable of operating the lock.

In the illustrated embodiment, the key K2 may serve as a master key to operate the lock even after the combination has been changed to deactivate the temporary or construction key K1. To permit the key K2 to serve the function of a master after a combination change has been effected, the weakened neck portion 23;! is located precisely at the center point of the follower pin 23a. Under these circumstances the trough T2 of the key K2 will be effective to lift the outer end of the outer section 230 of the follower pin precisely to the shear line AA, thus permitting the plug to be rotated in the casing. it will be readily recognized that'while the cross bores 20a, 21a are illustrated in the third position of a five pin tumbler unit, this positioning may be varied to provide additional security.

Likewise, while the cylinder plug device has been illustrated in connection with a pair of driver pins 22a, 22b in the change bore, it willbe readily recognized that if no mastering is desired, a single driver pin in the change bore may be employed. In such instance, the neck or fracture point of the follower pin should be positioned otherwise than at the center of such pin, and the change key K2, after effecting the removal of the inner follower pin section, willthereafterbe ineffective to operate-the lock mechanism since the remaining follower pin section will not be raised by the key K2 to the shear line AA. in such instance, the owners key will be bitted to raise the outer end of the outer follower pin section to the parting line. While the mastering through the use of following pins having a medially located fracture point has been suggested, it will be readily recognized that conventional mastering and the grand mastering methods utilizing a plurality of driver pins may be resorted to where desired.

The above described device will be found highly useful in the construction of hotels, office buildings, apartments, developments and the like, as providing a simplified system for changing the lock combination after construction is completed. The great advantage in the use of the invention herein described lies in the fact that the combination changing key will not be effective to operate the lock mechanism where the follower pin has not beenfractured'at a-central point. Thus, a maximum of security is assured.

By my invention .1 have provided a method of quickly and simply changing the pin length of one or more pins to change the pin tumbler combination of a lock in its mounting by the simple expedient of shearing the frangible neckof the mushroom like auxiliary pm at a predetermined frangible point and disposing of the sheared oif section without detection. Thus by aligning the boring 31 with theope-ning in a hollow door or within the shell of a door knob, whichever the pin tumbler assembly lock is mounted in, an inner tumbler section may beremoved, vpredeterminedly to change the key combination to provide the desired security from a temporary key to another key and without removing the lock from its mounting.

Having thus described the invention and illustrated its use, what is claimed as new and is desired to be secured by Letters Patent is:

1. in a pin tumbler mechanism, a casing having a main bore, a plug rotatably mounted in said bore, a radially extending cross bore in said casing communicating with said main bore, a radial passage formed through said plug in alignment with said cross bore, a keyway formed in said plug intersecting the longitudinal axis of said passage, a frangible follower pin reciprocablein said passage, said pin including inner and outer sections separated by a weakened neck portion, a driver pin reciprocable in said cross bore, spring means in said casing urging said driver pin against said outer section of said follower pin normally to project said driver pin partly into said passage, an opening in said casing angularly offset from said cross bore and positioned to register with said passage in at least one' rotated position of said plug, said opening being of a size to permit passage thereinto of said inner but not said outer section of said follower pin, first key means bitted to raise the outer end of said outer section to the periphery of said plug when engaged with the inner end of said inner section, second key means bitted to raise said neck to the periphery of said plug when engaged with the inner end of said inner section, and third key means bitted to raise the outer end of said outer section to the periphery of said plug when engaged with the inner end of said outer section.

2. In a pin tumbler mechanism, a casing having a main bore, a plug rotatably mounted in said bore, a radially extending cross bore in said casing communicating with said main bore, a radial passage formed through said plug in alignment with said cross bore, a keyway formed in said plug intersecting the longitudinal axis of said passage, a frangible follower pin reciprocable in said passage, said pin including inner and outer sections separated by a weakened neck portion, blocking means on said outer section of said follower pin engaging said plug to limit movement of said pin into said passage, a driver pin reciprocable in said cross bore, spring means in said casing urging said driver pin against said outer section of said follower pin normally to project said driver pin partly into said passage, an opening in said casing angularly offset from said cross bore and positioned to register with said passage in at least one rotated position of said plug, said opening being of a size to permit passage thereinto of said inner section but not said blocking means, first key means bitted to raise the outer end of said outer section to the periphery of said plug when engaged with the inner end of said inner section, second key means bitted to raise said neck to the periphery of said plug when engaged with the inner end of said inner section, and third key means bitted to raise the outer end of said outer section to the periphery of said plug when engaged with the inner end of said outer section.

3. In a pin tumbler mechanism, a casing having a main bore, a plug rotatably mounted in said bore, a radially extending cross bore in said casing communicating with said main bore, a radial passage formed through said plug in alignment with said cross bore, a keyway formed in said plug intersecting the longitudinal axis of said passage, a frangible follower pin reciprocable in said passage, said pin including inner and outer sections separated by a weakened neck portion, a head on said outer section of said follower pin, a driver pin reciprocable in said cross bore, spring means in said casing urging said driver pin against said outer section of said follower pin normally to project said driver pin partly into said passage, an opening in said casing positioned to register with said passage in at least one rotated position of said plug, said opening being of a size to permit passage thereinto of said inner section but not said head, first key means bitted to raise the outer end of said outer section to the periphery of said plug when engaged with the inner end of said inner section, second key means bitted to raise said neck to the periphery of said plug when engaged with the inner end of said outer section, and third key means bitted to raise the outer end of said outer section to the periphery of said plug when engaged with the inner end of said outer section.

4. In a pin tumbler mechanism, a casing having a main bore, a plug rotatably mounted in said bore, a radially extending cross bore in said casing communicating with said main bore, a radial passage formed in said plug rotatable into alignment with said cross bore, a keyway in said plug intersecting said passage, a frangible follower pin reciprocable in said passage, said pin including inner and outer sections separated by a weakened neck portion, a driver pin reciprocable in said cross bore, spring means in said casing urging said driver pin against said outer section of said follower pin normally to project said driver pin partly into said passage said outer section including means thereon limiting movement of said outer section into said passage, an opening in said casing communicating with said main bore at a point beneath the axis of said main bore positioned to register with said passage in at least one rotated position of said plug, said opening being of a size to receive said inner section of said follower pin.

5. In a pin tumbler mechanism, a casing having a main bore, a plug rotatably mounted in said bore, a radially extending cross bore in said casing communicating with said main bore, a driver pin reciprocable in said cross bore, a radial passage formed through said plug in alignment with said cross bore, a keyway formed in said plug intersecting the longitudinal axis of said passage, a frangible follower pin reciprocable in said passage, said pin including inner and outer sections separated by a weakened neck portion, an auxiliary driver pin interposed between said driver and follower pins, spring means in said casing urging said driver pin against said auxiliary driver pin normally to project said driver pin partly and said auxiliary driver and follower pins fully into said passage, an opening in said casing angularly offset from said cross bore and positioned to register with said passage in at least one rotated position of said plug, said opening being of a size to permit passage thereinto of said inner but not said outer section of said follower pin, first key means bitted to raise an end of said auxiliary driver pin to the periphery of said plug when engaged with the inner end of said inner section, second key means bitted to raise said neck to the periphery of said plug when engaged with the inner end of said inner section, and other key means bitted to raise an end of said auxiliary driver pin to the periphery of said plug when engaged with the inner end of said outer section.

6. A pin tumbler mechanism in accordance with claim 1 wherein said passage includes an enlarged portion adjacent the periphery of said plug and a constricted portion, and said driver pin is of a size to enter said enlarged portion but not said constricted portion.

7. A device in accordance with claim 5 wherein said inner and outer sections of said follower pin are of equal length.

References Cited in the file of this patent UNITED STATES PATENTS 1,650,564 Wolfi Nov. 22, 1927 1,650,568 Hurd Nov. 22, 1927 2,007,143 Keil July 2, 1935 2,059,129 Maxwell et a1. Oct. 27, 1936 2,591,652 Ziegliss Apr. 1, 1952 UNITED sTATEs PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,073,146 January 15, 1963 George P. Patriquin It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the sheet of drawings, in Figures 1 to 5, a reference numeral "20a" should identify the cross bores in casing 10 within which the pin 22a is disposed; that, in Figure 1, the lead line from reference numeral 20 should extend within the cross bore in the casing 10 within which the follower pin 22 is disposed; and that, in Figure 5, a legend "T3" should identify the trough on the upper edge B3 of key K3 directly beneath outer follower pin section 230; column 2, line 32, for "21", first occurrence, read 2O line 54, for "23h" read 22b same column 2, line 71, for "11" read 1O column 3, line 33, for "2310" read 23d line 37, for "23a" read 23d. line's 38 and 45, for "23a", each occurrence, read 23b same column 3, line 71, for "23a read 23c Signed and sealed this 19th day of November 1963,

(SEAL) Attest: EDWIN L, REYNOLDS ERNEST W. SWIDER Attesting Officer Ac ting Commissioner of Patents