US 3255618 A
Description (OCR text may contain errors)
June 14, 1966 T. HERMANN 3,255,618
DOOR LOCK Filed April 22, 1964 4 Sheets-Sheet 1 :2 I INVENTOR.
TOBIAS HERMANN ATTORNEYS.
June 14, 1966 1'. HERMANN 3,255,618
DOOR LOCK Filed April 22, 1964 4 Sheets-Sheet 2 INVENTOR. TOBIAS HERMANN A T TOR NE Y1 June 14, 1966 T. HERMANN 3,255,618
DOOR LOCK Filed April 22, 1964 4 Sheets-Sheet 3 FIG. 5 fg gz A TTOR NE Y5:
T. HERMANN June 14, 1966 DOOR LOCK 4 Sheets-Sheet 4 Filed April 22, 1964 FIG] ATTORNEYS.
United States Patent 3,255,618 DOOR LOCK Tobias Hermann, Burlington, Iowa, assignor of fifty percent to Gerard B. McDermott, Burlington, Iowa Filed Apr. 22, 1964, Ser. No. 361,848 14 Claims. (Cl. 70-114) This invention relates to a lock particularly suited for doors and other closure members and other closure memhers and more particularly to a so-called security lock for reducing the possibility of unauthorized entry and which is less susceptible to tampering, especially from the outside of the door.
While no door lock is completely burglar proof, certain types of locks are more resistant to tampering and make unauthorized entry more difficult. Locks especially designed for this purpose are often referred to as security locks in that they provide maximum security from unauthorized entry to a room or container which they protect.
A wide variety of security locks have been proposed in the past offering various degrees of protection from different types of burglarization, depending upon the particular use and application of the closure device to which they are affixed. However, many of these locks are difficult to operate in that they have a tendency to bind, in some instances are subject to excessive wear, and very often do not provide the tamper resistance to unauthorized entry or burglarization intended.
The present invention provides a novel security type door lock overcoming many of the above disadvantages. It is intended to provide maximum security from outside entry and limited security from inside attack. At the same time the lock is readily adaptable to a wide variety of door types and constructions and is useable with double doors, wood or metal, inswing or outswing, single doors of this nature and even overhead or lift doors with the lock and bolts mounted in a horizontal direction. Likewise, a wide variety of locking arrangements may be used in conjunction with the lock of this invention including single and double custody arrangements, used in conjunction with various key and handle combinations.
Most locks using vertical locking bars of the type under consideration can be fairly easily burglarized by breaking off the outside handle and driving the conventional handle shaft through the door. Such action will vary often release the locking bars, or if not, will expose an actuating tube having a central aperture of rectangular cross-section to which an iron bar or other strong instrument may be applied to force the lock. Tampering of this type will not open or seriously damage the lock of the present invention since provision is made for the support of a bolt cam plate by a central .circular tube with the plate held in position by a spacer welded to the tube. The bolt bars are held in position on cam plate studs by cotter keys so they can not be jarred off. Actuation of the bolt bars is by way of an apertured lever slidable over a pair of pins rotatably received by the locking bars. Thus, breaking oif the handle and driving out the handle shaft through the door removes all direct coupling to. the locking bars without at the same time releasing the bolts so that nothing is accessible from the exterior of the door by means of which the locking bars or bolts may be forced.
Locks and cam plate are mounted on a single piece of metal in the form of a lock mounting plate .so that one may not be moved out of alignment with the other. The lock mounting plate is fastened to the inside of the door by a plurality of screws several of which are located behind the cam plate so they cannot be easily removed when the camplate is in the locked position. One or more Patented June 14, 1966 cylinder locks are fastened to the lock mounting plate by socket head screws which cannot be removed with a screwdriver.
The entire assembly is constructed of heavy gauge metal to resist wear and abuse, all joints are welded, and the supporting tube for the cam plate extends through the door so that pulling on the inside handle when closing the door does not crush the door material which is possible when the lock is used on wood or hollow core metal doors. Heavy locking bars are provided and are in vertie cal alignment when the device is in the locked posit-ion to provide a complete deadlock and ready visual indication of the locked condition. Bolt brackets are provided preferably having a shield holding the bars away from the door and thus limiting wear on the door by movement of the locking bars.
If the outside handle is broken off or dismantled in a burglary attempt the cam plate and bars are held in locked position. The outside rim of each cylinder lock is screwed directly -to the mounting plate eliminating the possibility of turning the cylinder in the door to unlock it. In the preferred embodiment the bar bolts are provided with approximately l /z inches of throw to completely eliminate prying.
It is therefore one object of the present invention to provide a novel door lock.
Another object of the present invention is to provide a security type door lock.
Another object of the present invention is to provide a lock giving maximum security from outside entry and limited security from inside attack.
Another object of the present invention is to provide a door lock for a wide variety of doors of relatively simple construction, easy to operate, and one which is not seriously affected by excessive wear.
Another object of the present invention is to provide a novel security lock embodying a complete deadlock, with the position of the lock bars giving an instantaneous visual indication ofwhether the bolts are in the locked position, that is they are straight when locked, and staggered when unlocked.
Another object of the present invention is to provide a door lock wherein the handle mechanism is so constructed as to be completely removable from the cam plate without affecting locking operation of the device. If enough turning pressure is applied to the outside handle, or the inside handle, while .the device is in locked position, the handle will break free from the cam control bar or lever (which bar is welded to the handle and engages the cam bolt stud pins) or twist off before the cam plate can be forced into unlocked position. In other words, the device is designed to withstand the twisting off and complete removal of the handle without causing a successful entry by force. In addition, the outside rim cylinder is held in position by retaining screws which pass completely through the mounting plate. The lock cylinder is therefore fastened directly to the lock mounting plate thus minimizing the danger of twisting the cylinder FIGURE 4 is an inside elevational view of a single custody lock similar to that of FIGURE 1;
"FIGURE 5 is a view similar :to that of FIGURE 4 showing the device in the unlocked position;
FIGURE 6 is a horizontal section through the lock and door of FIGURES 4 and 5;
FIGURE 7 is a vertical section through the lock; and
FIGURE 8 is a partial vertical section similar to that of FIGURE 7 showing the device in the locked position with the handle assembly remove-d.
As previously pointed out, most locks using sliding locking bars can be easily burglarized by breaking off the outside handle and driving the handle shaft through the door. This results either in release of the bars or makes accessible the operating mechanism of the lock so that it may be forced with an appropriate tool. This forced entry is avoided by the novel lock of this invention by the provision of a circular support tube upon which the bolt actuating cam plate is rotatably mounted. A circular handle shaft is rotatably received through the support tube and carries at its inner end a lever slidably receiving a pair of pins mounted on the cam plate.
' Hence, inward movement of the handle shaft during a forced entry attempt simply causes the ends of the lever to slide off the pins thus completely breaking the coupling or mechanical link-age from the exterior of the door to the cam plate.
Referring to the drawings, there is illustrated in FIG- URE 1 the novel lock device of the present invention generally indicated at 10. The lock 10 is mounted on a single door 11 swingable inwardly in the direction of the arrow 12 and supported from a wall 14 between a floor 16 and a ceiling 18. Lock 10 is provided with a handle 20 rotatable from the locked vertical position illustrated in the direction of the arrow 22 in FIGURE 2. Movement of the handle 20 reciprocates a pair of lock bars 24 and 26 in the vertical direction as indicated by the arrows 23in FIGURE 1. The outer ends of the lock bars are slidably received through locking bar guides 28 and 30 mounted on the door and the extreme outer ends of the locking bars 24 and 26 are received in suitable cavities provided in the ceiling and floor as indicated by the dashed lines at 32 and 34.
FIGURE 2 is an enlarged view of the lock of FIGURE 1 and similarly shows what hereinafter will be referred to as the inside of the lock mechanism. That is the lock and door are viewed in FIGURES 1 and 2 from that side of the door or from the room to which access is to be prevented. In FIGURES 1 and 2, the lock is of the double custody type and is shown provided with a pair of more or less conventional cylinder locks 36 and 38 which by way of example only may be Yale locks. Each of the locks is provided with a conventional locking tongue or bolt 40 and 42 respectively, the bolt 40 in FIGURE 2 being illustrated as retracted While bolt 42 is shown as extended into locking position in a cooperating notch 44 formed on one side of a flat cam plate 46. Bolt 40 of cylinder lock 36 is adapted to be received in a similar notch 48 formed on the other side of the cam plate 46. In FIGURE 2, the locks 36 and 38 are indicated as operable by keys from the inside as well as the outside, normally each lock being actuated by a different key in the custody of a different person, hence the lock is referred to as a double custody lock.
FIGURE 4 illustrates a single custody embodiment incorporating the single cylinder lock 38. In this embodiment the cam plate 46' is provided with only the single notch 44 receiving the single bolt 42. In all other respects the embodiment of FIGURE 4 is similar to that of FIGURE 2.
FIGURE 3 is an exploded view showing the lock handle structure which is the same for both single and double custody embodiments. As illustrated in the drawings and as seen in FIGURES 3-5, U-shaped inner handle 20 is provided with a longer leg or handle shaft 49 I threaded at its outer end 50. Welded to this leg as at 52 is a cam control bar or lever 54. This lever is provided with apertures 56 and 58 at each end slidingly re ceiving pins 60 and 62 rigidly connected to the opposite sides of the cam plate 46 or 46 as the case may be. Each of the pins 60 and 62 is provided with a transverse aperture receiving a cotter pin 64 and 66. The cotter pins hold washers 68 and 70 on the pins which washers retain the ends of the pressure bars 24 and 26 rotatably mounted on the pins.
Threadedly received over the end 50 of handle shaft 49 is an outer handle 68 retained in position between a threaded inner spacer nut 70 and an outer threaded bushing nut 72.
As best seen in FIGURES 6 and 7, shaft 49 of the handle is rotatably received through a hollow circular tube 74 which is secured to the door on the outside by a retaining plate 76 and a lock nut 78. The lock nut is threadedly received over the end of the tube as illustrated at 80 in FIGURE 6. Rotatably mounted on the tube 74 is a spacer bearing 82 and welded to the tube 74 is a retainer 84 and a mounting plate 86. Bearing 82 and cam plate 46 are thus rotatably retained on the tube by the spaced plates 84 and 86, both rigidly welded to the tube. As best seen in FIGURE 2, each of the cylinder locks 36 and 38 is connected to the mounting plate and to the door by four socket head screws so that they cannot be operated from the inside with a screwdriver. The penetration of these screws through the plate 86 and into the door 11 is illustrated in dashed lines in FIGURE 6. The cylinder lock 38 is mounted approximately flush with the outer surface 92 of the door, as indicated generally at 94, and is preferably bolted to the mounting plate 86 by means of a pair of bolts 96 and 98 illustrated in FIG- URE 6. The mounting plate itself is secured to the door 11 by means of six screws 100 and as best seen in FIG- URES 4 and 5 three of these screws are positioned beneath or behind the cam plate 46 or 46' when the device is in the locked position so as to make access to them quite difiicult.
Referring to FIGURES 4 and 5, the former shows the unit from the inside in the locked position with the bolt 42 received in the notch 44. The edges of the notch are turned over to form flanges 102, 104 and 106 so as to provide a larger surface against which the bolt 42 may act. Also a stop pin 108 is provided on mounting plate 86 to be engaged by the cam plate 46' so as to limit the rotation of this plate. When the bolt 42 is moved to the retracted position by the insertion of a key into the cylinder lock 38 and rotation of the key therein, the cam plate 46' is free to rotate so as to withdraw the locking bars 24 and 26 from locking brackets such as bracket 110 illustrated in FIGURE 4. These locking bars preferably move longitudinally a distance about an inch and a half so as to completely clear the locking brackets and permit the door :to open. Rotation of the cam plate 46' from the locked position illustrated in FIGURE 4 to the open or unlocked position illustrated in FIGURE 5 may be effected by rotation of either the handles 20 or 68. In either case, the shaft 49 is rotated by the handle, thus rotating the lever 54. Rotation of the lever is transmitted through pins 60 and 62 to the locking bars 24 and 26 and to the cam plate 46'. Rotation of either of the handles in the opposite direction will return the elements from the open position of FIGURE 5 to the closed position of FIGURE 4. The device may then again be locked by actuation of the conventional cylinder lock 38.
FIGURES 7 and' 8 illustrate the increased tamper resistance of the lock of this invention particularly to forced entry by the method of driving the handle actuator rod or shaft 49 through the door. FIGURE 7 is a cross-section showing the entire assembly while FIGURE 8 illustrates what is left after the handle has been removed and the shaft 49 driven inwardly through the tube 74. Inward movement of the shaft 49 through the tube simply causes the lever 54 to slide off the ends of pins 60 and 62 and to fall to the floor. Thus, all that remains for access at the outer surface 92 of the door is the threaded end 80 of the hollow tube 74. Since the central aperture of the tube indicated by the dashed lines at 112 in FIGURE 8 is circular no tool may be inserted and rotated so as to force the lock. Likewise, the nails 100 cannot be driven backwardly from the outside of the door since at least three of them lie underneath the cam plate 46' and can only be backed off until their heads engage this cam plate.
In addition to the fact that the door provides maximum security from the outside and limited security from the inside, it is also quite easy to operate and will not tend to bind, become misaligned or fail to operate with excessive wear. Rotation of either of the handles provides for direct actuation of the retainer bars 24 and 26 by way of the pins 60 and 62. The bars are retained rotatably on the pins by means of the cooperating washers and cotter keys 64 and 66. Positive locking is provided and the device is locked with the locking bars in vertical alignment to provide a positive deadlocked arrangement. The cylinder lock 38 is retained by screws 96 and 98 thus fastening the lock cylinder directly to the lock mounting plate 86 so as to minimize the danger of twisting the cylinder in the door to unlock the inside bolt.
The lock may be used with a wide variety of doors and with a wide variety of locking arrangements. These locking arrangements include:
(a) Key control from inside and outside With handle control from the inside only.
(b) Key control from the outside with a turn knob (on the lock bolt) and handle inside.
(c) Key and handle control from inside only.
The above locking arrangements can be accomplished with no additional accessories to the device but instead an elimination of components shown in the drawings. For example, the arrangement (b) given above, is accomplished by using a Yale lock of the same size and operation as shown but instead of using a key on the inside to activate the bolt a turn knob replaces the inside key. This arrangement finds use for example in store rooms where a single door is the only Way in.
Lock arrangement (e) above involves the same basic construction as that shown but the outside cylinder is eliminated as is the outside handle. The tubular cam plate support 74 is cut an flush with the back of the mounting plate 86. Handle shaft or leg 49 is cut off just long enough to extend one-quarter inch beyond the end of the shortened cam plate, support tube 74. This end of the handle spindle may be threaded and a nut attached to hold the handle within the cam plate support tube. A relief hole is in this case drilled part way into the door to accommodate the extending end of the handle shaft and nut. Lock mount plate 86 is screwed directly to the door as in any other type installation. In this arrangement no handle is available for actuation from the outside and none of the door lock assembly is visible from the outside of the door. This arrangement is ideally suited for super markets where back service doors are desired to be locked at all times. Obviously, if there are no handles on the outside of the door bolts they cannot be thrown to the unlocked position from the outside. Thus, if the door is closed and the bolts thrown, this door is in'elfect locked to anyone outside even if the key is not turned on the inside lock. This also allows personnel to open and close the doors for deliveries without having access to keys. In addition, it is considerably less vulnerable to outside attack since persons outside have no knowledge where the lock is located and have much more difficulty in centering an attack on the pertinent areas of thedoor. The inside handle can still be driven or twisted off without gaining access to the inside.
FIGURE 1 shows an arrangement involving a double custody lock. This is accomplished by extending the mounting plate 86 beyond the cam plate 46 as illustrated Y in FIGURE 2 far enough to accommodate a second lock 36 like the lock 38. Another slot 48 is cut in the cam plate to allow the bolt of the second lock to enter it at the opposing edge of the slot. The bolt operation, cam plate, tube and handle constructions are unchanged. This double custody arrangement of FIGURE 1 is a very special type arrangement having a limited demand where it is desirable to have two persons present when opening the lock and requiring two difierent keys. I
By way 'of example only in one embodiment constructed in accordance with the present invention the locking bars -24 and 26 were formed of 1" x fiat steel and had a 1 /8" throw. The guides 28 and 30 were made of 1" x Vs" x 4 /2" flat steel. The bars were held away from the door A" by a guide mounting strap welded to each of the guides. The cam plate was of fiat steel and carried two as" cold rolled steel pins and 62. The mounting plate was /s" x 4 /2" x 9 steel plate and the handle shaft and inside handle was a one-piece construction having a diameter of /2" formed of cold rolled steel and having an overall length of 4". In some instances where the door material is strong enough (not for light sheet metal or hollow core wooden doors) the support tube may be eliminated and the cam plate may be rotatably mounted directly on the handle shaft.
It is apparent from the above that the present invention provides a novel security lock that not only increases the security of the door upon which it is incorporated but one that is relatively simple and inexpensive, reliable in operation and one which will not bind or become inoperative with wear. All parts are positively connected, with the bolts and cam plates securely aligned by their mounting on a common mounting plate.
The invention may be embodied in other specific for-ms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
What is claimed-and. desired to be secured by States'Letters Patent is: 1
1. A door lock comprising a mounting plate for a-tt-achment to a door, a hollow cylindrical tube passing through said mounting plate and rigidly attached thereto, a handle shaft rotatable in said tube, a cam plate rotatably mounted on said tube, locking means coupled to and actuated by said cam plate, key actuated means for holding said cam plate against rotation, and means releasable upon longitudinal movement of said handle shaft in an inward direction away from said cam plate coupling said handle shaft to said cam plate.
2. A door lock according to claim '1 wherein said releasable means comprises at least one pin mounted on said cam plate, and .a lever rigidly mounted on said handle shaft, said lever having an aperture slidably received over said p-in.
United 3. A door lock comprising a mounting plate, means for attaching said mounting plate to a door, a hollow tube having a circular central aperture passing through said mounting plate and rigidly attached thereto, a handle shaft rotatable in said tube, a handle attached to at least one end of said handle shaft, a cam plate rotatably mounted on said tube, said cam plate carrying at least one pin, looking means rotatably received over said pin, key actuated means for holding said cam plate against rotation and a- 5. A door lock according to claim '4 wherein said bolt is part of a cylinder lock mounted on said mount-ing plate adjacent said cam plate.
6. A door lock comprising a mounting plate,.means for attaching said mounting plate to a door, a hollow tube having a circular central aperture passing through said mounting plate and rigidly attached thereto, a handle shaft .rotatable in said tube, a handle attached to at least one end of said handle shaft, a cam plate rotatably mounted on said tube, said cam plate carrying a pair of pins spaced upon diametrically opposite sides of said tube, a pair of locking bars each having an end rotatably received over one of said pins, key actuated means for holding said cam plate against rotation, and a lever rigidly mounted on said handle shaft, said lever having an aperture at each end slidably received over one of said pins.
7. A door lock according to claim 6 wherein said handle shaft is provided with a handle at each end.
8. A door lock according to claim 6 wherein said key actuated means comprises a pair of cylinder looks mounted on said mounting plate adjacent said cam plate, each of said cylinder locks having -a sliding bolt movable into and out of engagement with a corresponding notch in the edge of said cam plate.
9. A door lock comprising a mounting plate, means for attaching said mounting plate to a door, a hollow tube having a circular central aperture passing through said mounting plate and rigidly attached thereto, a handle shaft rotatable in said tube, a handle attached to at least one end of said handle shaft, a cam plate rotatably mounted on said tube, said cam plate carrying a pair of pins spaced upon diametrically opposite sides of said tube, a pair of elongated slidable locking bars extending away from said cam plate on opposite sides thereof, the adjacent ends of said locking bars being rotatably mounted over said pins, means for retaining said adjacent ends of said bars on said pins, a cylinder lock bolted to said mounting plate adjacent said cam plate, said cylinder lock having a bolt movable into and out of engagement with a corresponding notch in the edge of said cant plate to hold said cam plate against rotation, and a lever rigidly mounted on said handle shaft, said lever having an aperture at each end slidably received over one of said pins.
10. A door lock according to claim 9 wherein said cam plate overlies at least three mounting screw apertures in said mounting plate when said cam plate is in the locked position with said bol-t engaged in said notch.
11. A door lock according to claim 10 wherein said locking bar retaining means comprises a washer on each of said pins and a cotter key passing through each pin,
said washers and cotter keys spacing said locking bars from said lever.
12. A door lock assembly comprising a door and surrounding door frame structure, a mounting plate secured to the inside surface of said door, a hollow tube having a circular central aperture passing through said door and said mounting plate and rigidly attached to said mounting plate, a handle shaft having a handle at each end rotat ably received through said tube, a cam plate rotatably retained on said tube, said cam plate carrying a pair of pins spaced upon diametrically opposite sides of said tube, a pair of elongated slidable locking bars extending away 'from said cam plate on opposite sides thereof, the adjacent ends of said locking bars being rotatably mounted over said pins, means for retaining said adjacent ends of said bars on said pins, a receptacle in said door frame structure at each end of said door, the remote ends of said locking bars being slidab-le into and out of said receptacles with the rotation of said cam plate, a cylinder lock bolted to said mounting plate adjacent said cam plate, said cylinder lock having a bolt movable into and out of engagement with a corresponding notch in the edge of said cam plate to hold said cam plate against rotation, and a lever rigid- 'ly mounted on said handle shaft, said lever having an aperture at each end slidably received over one of said pins.
13. An assembly according to claim 12 including a second cylinder look on said mounting plate adjacent said cam plate, said second cylinder lock also having a bolt movable into and out of engagement with a corresponding notch in the edge of said cam plate.
14. An assembly according to claim 12 wherein said cylinder lock is mounted on said mounting plate by socket head screws, and wherein said mounting plate is secured to said door by a plurality of mounting screws, said cam plate overlying the heads of at least three of said mounting screws when said cam plate is in the locked position.
References Cited by the Examiner UNITED STATES PATENTS 201,146 3/1878 Adler 2926 1,240,981 9/1917 Kohl 1 14 1,567,811 12/1925 Murphy 70-414 1,922,062 8/1933 Sullivan 70'1 14 2,819,692 1/1958 Johnson et a1 70116 X 2,969,666 1/196'1 Muessel 70-116 3,173,572 3/1965 Beecher 2927 JOSEPH D. SEE-RS, Primary Examiner.
BOBBY R. GAY, Examiner.