US2028525A - Lock - Google Patents

Description

Jan. 2l, 1936. F. E. sHMlD'r 2,028,525

LOCK

Fileduan. 25, 1935 F/G. 4 26 254/ 38 .2l 34 35 28 l l v (C) 36 4527 Z3 1-4246 58 2l [2 24 ,3 44 Q gl 0) /4 33 47 /5 F/G. 5 262 usas/34 35 28 ATTORNEY Patented Jan. 21, 1936 PATENT OFFICE I LOCK Frederic E. Schmidt, Crestwood, N. Y., assigner tc American Telephone andTeiegraph Company, a corporation of New York Application January 23, 1935, Serial No. 3,156

14 Claims.

This invention relates to locks and particularly to locks of the key operated type.

An object of the invention is to trap keys, by

means of which unauthorized persons may be attempting to operate the lock, and to prevent the removal of the key from the lock by such unauthorized persons.

Another object of the invention is to permit the removal of the trapped keys by authorized persons without necessitating dismantling the lock or in any way damaging the lock itself or the enclosure.

It is, of course, well known that unscrupulous persons often attempt to gain access to locked enclosures for fraudulent purposes by picking the lock. In order to defeat such attempts improvements in the lock mechanisms, in order to render them as nearly as possible pick-proof have been made from time to time. It quite often happens,- however, that unscrupulous persons come into possession of the proper key for unlocking a certain lock and pick-proofing arrangements are, ofcourse, no protection against such persons.

According to a feature of the invention, should an unauthorized person, who has come into possession of a key as above. mentioned, attempt to utilize such key to operate the associated lock, not only is the lock held ina locked condition but the key itself istrapped in the lock and its removal by the unauthorized holder is prevented. Means are included, however, whereby an authorized person may collect the key, that is, remove it from the lock, without damaging the lock or the enclosure in any way. The collected key is then, of course, returned to the proper authorities.

Locks of the nature contemplated by the invention may be used, to mention one specific application, on telephone coin collectors of the general type disclosed in Forsberg U. S. Patent No. 1,043,219 of November 5, 1912.

in accordance with a preferred arrangement of the look contemplated by the invention, means are provided whereby, upon an attempt to rotate Vthe key to unlock the lock, the key-barrel, after it has been rotated a comparatively slight distance by the key, is arrested in its movement and further rotation in either direction is prevented. Rotation in a clockwise direction is prevented by contact of the barrel with a shoulder provided on the bolt, the bolt in turn being prevented from moving by a lever member contacting a second shoulder of the bolt, while. counter-clockwise rotation of the barrel is prevented by a dog (Cl. 'I0-73) contacting a notch in the barrel. The unauthorized holder of the key is therefore prevented both from rotating the barrel in one direction to unlock the lock and from rotating the barrel in the other direction to its normal position at which removal of the key would be possible.

In order that authorized persons may be able to remove the trapped key without damaging the lock, the lever member is provided with a projection extending through an opening in the case of the lock. An authorized person may, by inserting and manipulating a tool in a manner to be described subsequently, move the lever which results in freeing the bolt from the arresting action of the lever member and also in freeing the barrel from the arresting action of the dog, whereupon rotation in a clockwise and also in a counter-clockwise direction may take place. The barrel may now be rotated in a direction to unlock the lock or in the other direction to remove the key.

In order that the barrel may be manipulated by the authorized person after it has been freed as above described, a latching arrangement is provided which, upon the lever having been moved by the tool as above mentioned, holds the dog free of the barrel and the lever 'free of the bolt. As the barrel is rotated in a counter-clockwise direction, however, the latching arrangement is tripped before the point at which the key may be removed has been reached and the trapping means is again made effective to trap a key subsequently inserted.

A thorough understanding of the operation of the arrangement contemplated by the invention and an appreciation of its various features may be gained from consideration of the following detailed description in connection with the attached drawing in which:

Figure 1 is a top view of a lock provided with key trapping means in accordance with the invention, the cover of the lock being' removed to show the internal mechanism;

Fig. 2 is a similar view of the lock showing the key-barrel partially rotated;

Fig. 3 is a similar View showing the key-barrel in trapped position;

Fig. 4 is a similar view showing the trapping mechanism operated to free the key-barrel, the tumblers being omitted;

Fig. 5 is a similar View of the lock showing the key-barrel just short of the position where the key can be removed, the tumblers being omitted in this view also;

Fig, 6 is a view of a portion of the cover of the lock showing particularly the key slot arrangement;

Fig. 7 is a detail View of a part of the latching mechanism, and

Fig. 8 is a rear view of a portion of a coin collector housing showing the lock in use and showing also a tool in position to free a trapped key.

Referring now to the drawing, a lock I I is shown which may be, so far as the bolt, key operated tumblers, key-barrel, etc. are concerned, of ordinary construction, for example, of the type fully described in Sharm U. S. Patent No. 1,793,254 of February 17, 1931.

While it is not believed necessary to describe these parts of the lock or their operation in detail, it might be pointed out in order to aid in the understanding of the key trapping means with which the present invention is concerned, that key-barrel I2 is provided with a projection I3 which, when the barrel is rotated, strikes shoulder I4 provided on bolt I5 and causes retraction thereof. A plurality of similarly shaped key operated tumblers or levers are arranged adjacent A the key-barrel having faces of different lengths to correspond to notches in the operating key (only one tumbler is shown in' order to avoid unnecessary complication of the drawing). The lower portions of the tumblers have projections which extend into the path of lug I'I provided on bolt I5 and prevent retraction thereof unless the projections are aligned and withdrawn from the path of the lug by rotation of a properly designed key in the key-barrel.

As usual in locks of this general construction and as shown in Fig. 6, a portion I8 of the cover is extended and encloses key-barrel I2, the edge of the extended portion overlapping the end of key slot 2| in such a manner that a key designed to operate the lock can be inserted into the key slot, or withdrawn therefrom, only if the barrel is rotated to the point at which the end of the key slot registers with recess 22 provided in the extended portion of the cover. This point of rotation of the key-barrel corresponds to the fully extended position of the bolt. The key cannot, therefore, be removed when the bolt is partially or fully retracted but only when the bolt is fully projected.

In addition to the parts referred to above of more or less standard construction, the lock is provided with a release lever 23 which is rotatably mounted on pivot 24, a link 25 one end of which is attached to lever 23 by pivot 26 and the other end of which is provided with a hookshaped extension 2, and a dog 28 which is rotatably mounted on pivot 3|.

A portion 32 of lever 23 (Fig. 8) is bent at right angles to the major length of the lever and projects through slot 33 provided in the case of the lock. A slot 34 is provided in link 25 which cooperates with pivot 3l to guide link 25 when movement thereof is caused by movement of lever 23. A coiled spring 35 is associated with dog 28 and tends to cause clockwise rotation of the dog about its pivot, one end of the spring being attached to the case of the lock and the other end being positioned in notch 36 provided in the dog. This rotation of the dog is retarded, however, due to the camming contact between edge 31 of tumbler IB and edge 38 of the dog so that rotation of the dog in a clockwise direction about the pivot can take place only as the tumber is rotated by means of a key above its pivot 4 I. At certain points in the rotation of key-barrel I2, the

'extension 42 thereof also retards the motion of the dog. A pin 43 is carried by dog 28 and cooperates with the hook-shaped extension of link 25 in a manner to be subsequently described, to latch the trapping mechanism in neutral position.

Let us now assume, for purposes of description, that a key 44, shown in cross-section in the drawing, be inserted in key slot 2I preparatory to unlocking the lock. The mechanism is in the position shown in Fig. 1.

Assuming that the key be rotated in a clockwise direction and referring particularly to Figs. 2 and 3, the tumblers will be moved by the action of the key, in the manner described in the Shann patent referred to above until the point of maximum deection, shown in Fig. 3, is reached. As the tumblers rotate about their pivot 4I, dog 28 is caused to rotate in a clockwise direction about its pivot 3|, this motion caused by the action of spring 35 being, as pointed out above, controlled by the motion of tumbler I6. Dog 28 rotates therefore until it reaches the position shown in Fig. 3 (an intermediate point in the motion of tumbler I6 and dog 28 being shown in Fig. 2) wherein projection 45 is, as shown, in contact with notch 46 of barrel projection 42.

Now while the tumblers are, as pointed out above, in their position of maximum deflection, that is, the projections on their faces have been moved out of the path of lug I'I of bolt I5 to permit retraction of the bolt, this retraction is nevertheless prevented as extension 32 of lever 23 is positioned in contact with shoulder 41 of bolt I5. This fact, that the bolt cannot be retracted, means of course, that further rotation of the key-barrel in a clockwise direction is prevented due to the contact of barrel extension I3 and shoulder I4 of the bolt. Counterclockwise rotation of the key-barrel is likewise prevented due to the contact of extension 45 and notch 46. The user of the key is therefore not only prevented from unlocking the lock but also from removing the key as the position in which the key-barrel is held (see Fig. 6) is such that the end of the key slot is not in registry with recess 22.

Let us assume now that an authorized person visits the station and, finding the trapped key, wishes to remove it. Referring to Fig. 8 a part of a telephone coin collector, which may be of the general type described in Forsberg U. S. Patent No. 1,043,219, is shown. The view is taken from the rear of the collector, the usual back plate being omitted to facilitate illustration of the invention. It will be understood, however, that this back plate is provided as usual and that it acts to close the rear openings of lower housing 5I and upper housing 52 and also cooperates with portions of these housings to prevent the removal of the upper housing from the lower housing unless bolt I5 of lock II is fully retracted. It will be understood that wall 53 is rigidly attached, for example by welding, to lower housing 5I.

The authorized person in order to free the trapped key rst gains access to the interior of the lower housing 5I by unlocking and removing the door of the cash receptacle housing which comprises the greater portion of the lower housing. He next inserts the end of the tool 54 through the cash receptacle housing and up through hole 55 provided in the upper wall thereof and then manipulates the tool to push end 32 of lever 23 sideways.

vIt will be remembered that before the above operation of tool 54, that is, when the key was trapped, the trapping mechanism was in the @gozaban position shown in Fig. '3. As leverfend l:32' is moved sideways by toolf54, however, the mechanism --assumes the position shown in Fig. '4. That is, -movement'ofleverf'end 32 to the leftplooking at `thefront ofthe-lock as infFigs. n1 to` 5, causes a movement of link 25 to the right due'itothe `piv- -otedconnection at 26. This'brings the camedge `ci-'hookshaped extension '21of -link 25 into con- `tact'vvithpini of dog 28, and, 'as themovement of thef link continues, dogf28 is raisedagainst'the action of spring Sithecam-surface passesunder fpin=`43 i' and `the pin .thereupon (drops into thefrecessedportion of extension`2l. 'Asimore'clearly shown in '7, a. shculderi'is providedV on pin f 43 andthe frictional contact between this shoulicler and the inner surface of .the hook-shaped --extensionxof link 25 results (spring `35,'of course, :tending to rotate dog 23 `in a" clockwisedirection While'the pressure of tumbler spring 15'! on .pin

"58 tendsto move the link 25 .to 'the left) `in the mechanism being heldor'latched-inlthe neutral position of Fig. 4.

'As shoWninFigra point li5'ofdog28`has now :been-raised out of contact withnotch 46 thereby permitting counter-clockwise rotation of `key- -barrel 1&2 .While end'32 of lever-'23 has been moved `out of contact with shoulder '4l thereby permitting clockwise rotation of thekey-barrel and conseque-nt 'retraction of bolt `I5. The `authorized person is now able, therefore, to unlock lthe lock `(if `he wishes to) Aand to vrotate the key-barrel -back tothe point at which the trapped key may be removediwhich point, as described above,correfsponds tothe fullyprojected-position'of the bolt. "ApproXimately'half-Way between theposition ilflustrated inFig. 3 and the position at Whichthe :key canbe `removed (the position of Fig. 1), the ilatched trapping mechanism is tripped to bring itintoposition to trap anotherl'key subsequently =inserted, this actionfbeing'shownin Fig. 5. As shown "in Fig. 5, the `:edge of projection `42 is lbrought `into contact iviththe-"adiacent edge of dog ias the key-barrel-is'rotated'in a'counterclockwise direction 'from the position of Fig. 4 `and 'as rotation of the barrel ucontinues,dog 28 `is -fo-rced 'upward fby this contact, fraising pin 43 `out or" engagement Withextension 21 of link 25 'whereupon dog 28, link :'andrlever 23allmove backto their normalpositionsas'shown infFig. 1. t -Will be understood, of course, that tumbler spring 51 `is effective in @returninglever 23 "to 'its normal position and that lever 23, in turn, is ef- `fective in `returning link 25 vto its'normal position. This spring also causes tumbler I6 to returnto its normal position When'released from lkeypressure and the contact of'edge 31'of the tumbler and `edge 33 of `the'dog forces the dog Ybaokto its normal position, kthe edge of `exten- 4sioni42 also being effective,throughrcontact with the'edge of dog 28'to return the dogto its normal position.

`It-rnay sometimes happenthat an unauthorized holder of "a key, `upon having it trapped in the `lock, Vwill lin his `efforts to release the key,

Abreak offthe exposed part leaving thebody portioniin the'key slot. The authorized person is `enabled in `such an instance to use 'a tooll as shown-by dotted lines (Fig. 8) `to'push back bolt 15er thelock after lever 23'has been moved as above-described for, as'pointedout, the tumblers are atthe pointV of maximumdeflection'when the key istrapped, that is, theprojections on their faces have been moved out ofthe path of lug l1 Yon bolt i5. Upon pushing-back bolt I5,`theupper' housing` 52 Vmaybe removed. fromrlower housing 5I thereby Vexposing `the lock which may then be dismantled for removal of the key.

While certain lembodiments of the invention `have been selected for detailed description the invention is'not, of course, limited in its application to the embodiments described. These embodiments should be considered as'illustrative` of the invention'rather than restrictive thereof.

Whatis claimed'is:

l. A lock comprising aicasing, a bolt, a barrel having `a slot for the reception of a key, a key operated tumbler for controlling the retraction of the bolt, means acting'directly on the barrel and eiective upon partial rotation of said barrel in one direction for preventing rotationof the barrel inthe oppositevdirection, and means projecting outside the casing and operable from-the exterior of said casing for controlling said preventing means.

`2. A lock comprising a casing, a bolt, a'barrel having a slot for the receptionof akey, a key operated tumbler for controlling the retraction of thebolt, means acting directly on the barrel and eective upon'partial rotation of the barrel in one direction for preventing rotation of said barrel in the opposite direction and additional means for preventing further rotation ori-the barrel in the first mentioned direction.

3.,A lock comprising a casing, a bolt, abarrel having a slot for the reception of a key, a key `operated tumbler for controlling the retraction of the bolt, means eiective upon partial rotation of the barrel in one direction orpreventing rotation of the barrel in the opposite direction, ad-

ditional means for preventing further rotation of the barrelin the first mentioned direction, and a single means projecting outside the casing and operablefrom'the exterior of said casing for controllingboth of said preventing means.

4. A lock comprising a casing, a bolt, a barrel `-h'avinga'slot for the reception of akey and having a portion for engaging the bolt and causing its retraction as the barrel is rotated, a=key operated tumbler for controlling the `retractionoi the bolt, a `pivoted member, and means eiective after partial rotation of the barrel for preventing further rotation thereof in either direction, said means preventing'rotation of the barrel in one direction by preventing retractionof thebolt and preventing rotation in the other direction by causing engagement ot'said pivoted member with `the barrel.

5.1In a lock of the type comprising a casing,

abolt, a barrel having a slot for the reception of a key, aportion of the casing being so -arranged with respect to the barrel that a key can be inserted therein or removed therefrom only When the slot registers with a certain definite pointin said portionof the casing, a key oper- `ated turnblerfor controlling the retraction of the bolt, a pivoted member andmeans for Vlocking the barrel after partial rotation thereof against -further rotation Iiii-either directiomsaid means :preventing rotation in one directionby causing Aengagement of said pivoted member with the bar- "relyA the pointat which the barrel is locked being v'so chosen that the slotin the barrel is out of reg- Iistry With the pointin the portion of thecasing at which a key'may Abe removed.

6.1111 a lock of the type comprising a casing.

a bolt, a barrel having a slot .for the reception of a key, a portion of the casing being so arranged with respect to the barrel theta key can be inserted therein or removed .therefrom only when theslot registers witha certain definite .point in said portion of the casing, a key operated tumbler for controlling the retraction of the bolt, a pivoted member and means for locking the barrel after partial rotation thereof against further rotation in either direction, said means preventing rotation in one direction by preventing retraction of the bolt and preventing rotation in the other direction by causing engagement of said pivoted member With the barrel, the point at Which the barrel is locked being so chosen that the slot in the barrel is out of registry with the point in the portion of the casing at which a key may be removed.

'7. A lock comprising a casing, a bolt, a barrel having a slot for the reception of a key, a key operated tumbler for controlling the retraction of the bolt, means effective upon partial rotation of the barrel in one direction for preventing rotation of the barrel in the opposite direction, additional means for preventing further rotation of the barrel in the first mentioned direction, a 'single means for controlling both of said preventing means projecting outside the casing and operable from the exterior of said casing to release the barrel and permit further rotation thereof and means effective upon the release of the barrel for holding said preventing means in neutral position.

8. A lock comprising a bolt, a barrel having a slot for the reception of a key, a key operated tumbler for controlling retraction of the belt, and means elective after rotation of a key in said barrel suicient to move said tumbler to nonrestrictive position with respect -tc said bolt for preventing further rotation of the key.

9. A lock comprising a casing, a bolt, a barrel having a slot for the reception of a key, a key operated tumbler for controlling retraction of the bolt, a shoulder on said bolt, a movable member normally positioned in contact with said shoulder, a shoulder on said barrel, a second movable member, and means for controlling the movement of said second movable member whereby rotation of said barrel causes contact of said second member and the shoulder on the barrel, said two movable members being so linked that movement of the first member out of Contact with the shoulder on the bolt results in movement of the second member out of contact with the shoulder on the barrel.

A lock comprising a casing, a bolt, a barrel having a slot for the reception of a key and having an extension arm, a key operated tumbler for controlling retraction of the bolt, a shoulder on said extension arm and a movable member acting in conjunction With said shoulder upon partial rotation of said barrel in one direction to prevent rotation of the barrel in the opposite direction, the movement of said member being controlled partially by said tumbler and partially by said extension arm.

11. A lock comprising a casing, a bolt, a barrel having a slot for reception of a key, a key operated tumbler for controlling the retraction of the bolt, a shoulder on the bolt, a lever pivotally mounted Within the casing, one end of said lever being normally in contact with said shoulder, a dog pivotally mounted Within the casing and a link member pivotally connected at one end to said lever and slidably connected at the other end to said dog, said key-barrel being provided with an extension arm, a shoulder on said extension arm, movement of said dog in one direction being so controlled by said key operated tumbler and said key-barrel that rotation of said barrel in one direction by means of a key and the resulting movement of the key operated tumbler results in movement of said dog into engagement with the shoulder on said extension arm thereby preventing movement of the key-barrel in the opposite direction.

12. A lock comprising a casing, a bolt, a barrel having a slot for reception of a key, a key operated tumbler for controlling the retraction of the bolt, a shoulder on the bolt, a lever pivotally mounted within the easing, one end of said lever being normally in contact with said shoulder, a dog pivotally mounted within the casing and a link member pivotally connected at one end to said lever and slidably connected at the other end to said dog, said key-barrel being provided with an extension arm, a shoulder on said extension arm, movement of said .dog in one direction being so controlled by said key operated tumbler and said key-barrel that rotation of said barrel in one direction by means of a key and the resulting movement of the key operated tumbler results in movement of said dog into engagement with the shoulder on said extension arm thereby preventing movement of the key-barrel in the opposite direction, movement of the first mentioned lever out of engagement with the shoulder on the bolt being effective to move the dog out cf engagement with the shoulder on the exten'- sion arm.

13. A lock comprising a casing, a bolt, a barrel having a slot for reception of a key, a keyoperated tumbler for controlling the retraction of the bolt, a shoulder on the bolt, a lever pivotally mounted Within the casing, one end of said lever being normally in Contact with said shoulder, a dog pivotally mounted Within the casing, a link member pivotally connected at one end to said lever and slidably connected at the other end to said dog, a hook-shaped extension on said link member and a pin provided with a shoulder on said dog, said key-barrel being provided with an extension arm, a shoulder on said extension arm, movement of said dog in one direction being so controlled by said key operated tumbler and said key-barrel that rotation of said barrel inone direction by means of a key and the resulting movement of the key operated tumbler results in movement of said dog into engagement with the shoulder on said extension arm, thereby preventing movement of the key-barrel in the opposite direction, movement of the rst mentioned lever out of engagement with the shoulder on the bolt being effective to move the dog out of engagement with the shoulder on the extension arm and to position said pin in said hook-shaped extension whereby said lever and said dog are held out of contact with the respective shoulders.

14. A lock comprising a casing, a bolt, a barrel having a slot for reception of a key, a key operated tumbler for controlling the retraction of the bolt, a shoulder on the bolt, a lever pivotally mounted Within the casing, one end of said lever being normally in contact with said shoulder, a dog pivotally mounted within the casing, a link member pivotally connected at one end with said lever and slidably connected at the other end to said dog, a hook-shaped extension on said link member and a pin provided with a shoulder on said dog, said key-barrel being provided with an extension arm, a shoulder on said extension arm, movement of said dog in one direction being so controlled by said key operated tumbler and said key-barrel that rotation of said barrel in one direction by means of a key and the resulting 'ing movement of the key-barrel in the opposite direction, movement of the first mentioned lever out of engagement with the shoulder on the bolt being effective to move the dog out of engagement with the shoulder on the extension arm and Yto position said pin in said hook-shaped extension whereby said lever and said dog are held out of contact with the respective shoulders, contact between said extension arm and said dog resulting from rotation of the key-barrel to normal position being effective to disengage said pin from said hook-shaped extension.

FREDERIC E. SCHMIDT.

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