CA2590676A1 - Tumbler lock mechanism improvement to prevent break-in by "bumber key" - Google Patents
Tumbler lock mechanism improvement to prevent break-in by "bumber key" Download PDFInfo
- Publication number
- CA2590676A1 CA2590676A1 CA 2590676 CA2590676A CA2590676A1 CA 2590676 A1 CA2590676 A1 CA 2590676A1 CA 2590676 CA2590676 CA 2590676 CA 2590676 A CA2590676 A CA 2590676A CA 2590676 A1 CA2590676 A1 CA 2590676A1
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- CA
- Canada
- Prior art keywords
- key
- lock
- plug
- pins
- bumper
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05B—LOCKS; ACCESSORIES THEREFOR; HANDCUFFS
- E05B27/00—Cylinder locks or other locks with tumbler pins or balls that are set by pushing the key in
- E05B27/0057—Cylinder locks or other locks with tumbler pins or balls that are set by pushing the key in with increased picking resistance
- E05B27/006—Cylinder locks or other locks with tumbler pins or balls that are set by pushing the key in with increased picking resistance whereby a small rotation without the correct key blocks further rotation of the rotor
- E05B27/0064—Cylinder locks or other locks with tumbler pins or balls that are set by pushing the key in with increased picking resistance whereby a small rotation without the correct key blocks further rotation of the rotor whereby the rotor is irreversibly blocked or can only be moved back with an authorized tool or key
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- Lock And Its Accessories (AREA)
Abstract
The invention provides a cost effective way to improve the presently used Tumbler Lock design to prevent break-ins by the use of a "Bumber Key", which involves hitting with modest force an inserted preformed key to cause all the top pins (Tumblers) to fly up for a moment and allowing the inner cylinder to turn, thus opening the lock. The invention consists of adding 2 rows of radially directed additional holes in the rotating cylinder (Plug) of the lock, at a 30° angle from the centre line in both directions, and adding one additional, specially shaped pin, above the two regular pins in each chamber. When a "Bumper Key" is used to attempt an illegal entry, the added pins, being the last in the column, fly up, permitting the Plug to turn 30° in either direction, when these pins fall into the added holes and lock up the cylinder in that 30° position. The lock becomes inoperable and the "Bumper Key" is captured and cannot be extracted, leaving evidence of an attempted break-in.
Description
Tumbler Lock Mechanism Improvement to prevent break-in by "Bumper Key"
2. Background of the invention The technique of opening a locked tumbler lock with a "Bumper Key" has long been known to locksmiths. In recent years the method has become known to many, due to the popularization of the technique on the Internet.
The technique is based on the principle discovered by Newton that when a force is applied to a line of hard objects in close contact with each other, the force will be transmitted down the line to the object at the end of the line and that object will then act on the force received and fly off. The principle is demonstrated by the popular toy where 5 steel balls hang on threads and are touching each other. When one end ball is pulled away and allowed to hit the line of balls, the other end ball flies away, leaving the other 4 balls motionless in place.
A Pin Tumbler Lock has in each chamber 2 pin tumblers pressed together by a spring. There are 4, or 5, or 6 chambers in line, each one holding 2 pins and a spring. See Drawing #1.
When no key is inserted, the 2 pins in each chamber are aligned so that the top pin crosses the Shear Line (between the cylinder and the housing) and prevents the Plug (The inner cylinder which holds the key) from turning. When the correct key is inserted, it lifts the lower pin up to the shear line, pushing the upper pin above the shear line. This position of the pins permits the plug to turn. All the first pins are cut to a different length, depending on the depth of the cut in the key at that point. When all cuts in a key match the height of the lower pins, it allows all lower pins to reach the Shear Line, the plug turns and the lock opens.
See drawings #1, #2 & #3.
The 'Bumper Key" is a key that fits the keyhole profile of the plug, but has all its cuts filed down to the lowest point. When this key is inserted into the lock, the plug would not turn, since all top pins are crossing the shear line. Then the key is held a fraction out of the lock and is hit with a hard object. The sloping angles of the cuts in the key bump all lower pins upward. However, the force exerted on the lower pins is immediately transmitted to the upper pins and they fly up, pushing the springs above them, leaving the lower pins in place.
This action moves the upper pins out of the shear line for a moment, and that is the moment the operator turns the key and opens the lock. See drawing #4.
Clubs have sprung up around the world, where amateur locksmiths compete with each other to open various makes of locks by this method, for sport. Once learned, it takes 5 seconds to open a lock with a "Bumper Key".
The key has to fit the Keyway of the lock and the Bitting (the actual cuts in the key) are filed down to the lowest possible level, known in the trade as Position 9. Hence the other name for this technique is known as the 999 Method. See drawing #4.
This method of opening a lock works with almost all makes of common Tumbler Locks, as used in homes and post boxes and padlocks, and is now common knowledge. It is to be expected that not only sport enthusiasts would use this method. Not only is the home and office vulnerable to a break-in - there will be no evidence that forced entry was used.
Insurance companies may refuse to pay when it is possible that the owner had left the door open and thus has contributed to the resulting loss.
2. Background of the invention The technique of opening a locked tumbler lock with a "Bumper Key" has long been known to locksmiths. In recent years the method has become known to many, due to the popularization of the technique on the Internet.
The technique is based on the principle discovered by Newton that when a force is applied to a line of hard objects in close contact with each other, the force will be transmitted down the line to the object at the end of the line and that object will then act on the force received and fly off. The principle is demonstrated by the popular toy where 5 steel balls hang on threads and are touching each other. When one end ball is pulled away and allowed to hit the line of balls, the other end ball flies away, leaving the other 4 balls motionless in place.
A Pin Tumbler Lock has in each chamber 2 pin tumblers pressed together by a spring. There are 4, or 5, or 6 chambers in line, each one holding 2 pins and a spring. See Drawing #1.
When no key is inserted, the 2 pins in each chamber are aligned so that the top pin crosses the Shear Line (between the cylinder and the housing) and prevents the Plug (The inner cylinder which holds the key) from turning. When the correct key is inserted, it lifts the lower pin up to the shear line, pushing the upper pin above the shear line. This position of the pins permits the plug to turn. All the first pins are cut to a different length, depending on the depth of the cut in the key at that point. When all cuts in a key match the height of the lower pins, it allows all lower pins to reach the Shear Line, the plug turns and the lock opens.
See drawings #1, #2 & #3.
The 'Bumper Key" is a key that fits the keyhole profile of the plug, but has all its cuts filed down to the lowest point. When this key is inserted into the lock, the plug would not turn, since all top pins are crossing the shear line. Then the key is held a fraction out of the lock and is hit with a hard object. The sloping angles of the cuts in the key bump all lower pins upward. However, the force exerted on the lower pins is immediately transmitted to the upper pins and they fly up, pushing the springs above them, leaving the lower pins in place.
This action moves the upper pins out of the shear line for a moment, and that is the moment the operator turns the key and opens the lock. See drawing #4.
Clubs have sprung up around the world, where amateur locksmiths compete with each other to open various makes of locks by this method, for sport. Once learned, it takes 5 seconds to open a lock with a "Bumper Key".
The key has to fit the Keyway of the lock and the Bitting (the actual cuts in the key) are filed down to the lowest possible level, known in the trade as Position 9. Hence the other name for this technique is known as the 999 Method. See drawing #4.
This method of opening a lock works with almost all makes of common Tumbler Locks, as used in homes and post boxes and padlocks, and is now common knowledge. It is to be expected that not only sport enthusiasts would use this method. Not only is the home and office vulnerable to a break-in - there will be no evidence that forced entry was used.
Insurance companies may refuse to pay when it is possible that the owner had left the door open and thus has contributed to the resulting loss.
Tumbler Lock Mechanism Improvement to prevent break-in by "Bumper Key"
There are locks produced by industry that are not vulnerable to this technique, but they are much more expensive and their numbers used are modest when compared to the "Standard"
lock used everywhere.
Not only would it be desirable to change the present locking devices so they would not be vulnerable to this method of illegal entry, but it would be desirable to leave evidence that an attempt has been made to open the lock with a "Bumper Key".
Totally redesigning locks to prevent 'Bumping" would be very costly to the industry.
The invention here requires only a modest change to the tooling to achieve both objectives:
1. Prevent 'Key Bumping" as a method to open the lock 2. Prevent removal of the "Bumper Key" when an attempt to use it is made, thus leaving evidence of attempted break-in.
There are locks produced by industry that are not vulnerable to this technique, but they are much more expensive and their numbers used are modest when compared to the "Standard"
lock used everywhere.
Not only would it be desirable to change the present locking devices so they would not be vulnerable to this method of illegal entry, but it would be desirable to leave evidence that an attempt has been made to open the lock with a "Bumper Key".
Totally redesigning locks to prevent 'Bumping" would be very costly to the industry.
The invention here requires only a modest change to the tooling to achieve both objectives:
1. Prevent 'Key Bumping" as a method to open the lock 2. Prevent removal of the "Bumper Key" when an attempt to use it is made, thus leaving evidence of attempted break-in.
Tumbler Lock Mechanism Improvement to prevent break-in by "Bumper Key"
3. Description of prior art See drawing #1.
A Pin Tumbler lock has in each chamber 2 pin tumblers pressed together by a spring. There are 4, or 5, or 6 chambers in line, each one holding 2 pins and a spring. See Drawing #1.
When no key is inserted, the 2 pins in each chamber are aligned so that the top pin crosses the Shear Line (between the cylinder and the housing) and prevents the Plug (The inner cylinder which holds the key) from turning. When a key is inserted, it lifts the lower pin up to the shear line, pushing the top pin above the shear line. See drawing #2. This position of the pins in all chambers permits the plug to turn (drawing #3). All first pins are cut to a different length, depending on the depth of the cut in the key at that point. When all cuts in a key match the height of the lower pins, all lower pins reach the shear line, the plug turns and the lock opens (drawing #3).
The above described principle has been the basis of tumbler lock design for over 150 years.
Some refinements are made to this design by allowing for Master Keys and Individual Keys in the same lock. A Master Key will open many locks, each of which has a different Individual key. This is achieved by replacing the top pin with a pair of pins, allowing for 2 positions of the key cut to reach the shear line - one position with the lower pin itself reaching the shear line, the other, Master Key cut position, allowing the lower plus the middle pins to remain in the plug and reach the shear line. Thus 2 keys of different cut are able to open the same lock, and the Master Key shares its setting with many locks, while the Individual Key opens only its own designated lock.
Tumbler Lock Mechanism Improvement to prevent break-in by "Bumper Key"
4. Summary and description of the invention The invention consists of adding 2 rows of radially directed additional holes in the Plug (The rotating cylinder of the lock), at a 30 angle from the center line in both directions, and of a diameter smaller than the regular chambers. See drawing #5. The regular top pin in each chamber is replaced by 2 pins: the top one has the lower end of its diameter reduced to fit into the added holes drilled at 30 from the centre line in the plug, and a second pin with standard diameter below that. The length of both upper pins together is equal to the total length of the single top pin it replaced. The angle of 30 is a suggested position, but is not a critical factor and may wary by up to 100 up or down.
When a regular key is inserted in the lock, the 2 upper pins are lifted above the shear line (See drawing #6) and the lock opens. Note that the middle pins slide over the additional holes in the plug as it turns, since their diameter is larger than the diameter of these additional holes.
When a "Bumper Key" is inserted to attempt an illegal entry and is hit sharply with a hard object, all lower pins feel the sudden upward force exerted on them. The force is transmitted up the column of 3 pins and the top pins, being the last in the column, fly up against the springs (See drawing #7), permitting the Plug (cylinder) to turn 30 in either direction, at which point these top pins fall into the added holes and lock up the cylinder in that 30 position (See drawing #8). The lock becomes inoperable and the "Bumper Key"
cannot be extracted, leaving evidence of an attempted break-in.
The middle pin, when the correct key is used, would normally stay above the shear line and permit opening of the lock. When the "Bumper Key" is used, that middle pin remains below the shear line, in the plug. The upper pin, with its narrower end, fits into the extra narrower holes and locks up the plug at 30 .
The 'Bumper key" remains trapped in the plug and cannot be extracted, as it is held in place by the two lower pins in the plug.
The description above deals only with one set of pins, but all 4, 5, or 6, chambers and sets of pins act in the same fashion. The number of chambers in locks varies between 4 and 6.
3. Description of prior art See drawing #1.
A Pin Tumbler lock has in each chamber 2 pin tumblers pressed together by a spring. There are 4, or 5, or 6 chambers in line, each one holding 2 pins and a spring. See Drawing #1.
When no key is inserted, the 2 pins in each chamber are aligned so that the top pin crosses the Shear Line (between the cylinder and the housing) and prevents the Plug (The inner cylinder which holds the key) from turning. When a key is inserted, it lifts the lower pin up to the shear line, pushing the top pin above the shear line. See drawing #2. This position of the pins in all chambers permits the plug to turn (drawing #3). All first pins are cut to a different length, depending on the depth of the cut in the key at that point. When all cuts in a key match the height of the lower pins, all lower pins reach the shear line, the plug turns and the lock opens (drawing #3).
The above described principle has been the basis of tumbler lock design for over 150 years.
Some refinements are made to this design by allowing for Master Keys and Individual Keys in the same lock. A Master Key will open many locks, each of which has a different Individual key. This is achieved by replacing the top pin with a pair of pins, allowing for 2 positions of the key cut to reach the shear line - one position with the lower pin itself reaching the shear line, the other, Master Key cut position, allowing the lower plus the middle pins to remain in the plug and reach the shear line. Thus 2 keys of different cut are able to open the same lock, and the Master Key shares its setting with many locks, while the Individual Key opens only its own designated lock.
Tumbler Lock Mechanism Improvement to prevent break-in by "Bumper Key"
4. Summary and description of the invention The invention consists of adding 2 rows of radially directed additional holes in the Plug (The rotating cylinder of the lock), at a 30 angle from the center line in both directions, and of a diameter smaller than the regular chambers. See drawing #5. The regular top pin in each chamber is replaced by 2 pins: the top one has the lower end of its diameter reduced to fit into the added holes drilled at 30 from the centre line in the plug, and a second pin with standard diameter below that. The length of both upper pins together is equal to the total length of the single top pin it replaced. The angle of 30 is a suggested position, but is not a critical factor and may wary by up to 100 up or down.
When a regular key is inserted in the lock, the 2 upper pins are lifted above the shear line (See drawing #6) and the lock opens. Note that the middle pins slide over the additional holes in the plug as it turns, since their diameter is larger than the diameter of these additional holes.
When a "Bumper Key" is inserted to attempt an illegal entry and is hit sharply with a hard object, all lower pins feel the sudden upward force exerted on them. The force is transmitted up the column of 3 pins and the top pins, being the last in the column, fly up against the springs (See drawing #7), permitting the Plug (cylinder) to turn 30 in either direction, at which point these top pins fall into the added holes and lock up the cylinder in that 30 position (See drawing #8). The lock becomes inoperable and the "Bumper Key"
cannot be extracted, leaving evidence of an attempted break-in.
The middle pin, when the correct key is used, would normally stay above the shear line and permit opening of the lock. When the "Bumper Key" is used, that middle pin remains below the shear line, in the plug. The upper pin, with its narrower end, fits into the extra narrower holes and locks up the plug at 30 .
The 'Bumper key" remains trapped in the plug and cannot be extracted, as it is held in place by the two lower pins in the plug.
The description above deals only with one set of pins, but all 4, 5, or 6, chambers and sets of pins act in the same fashion. The number of chambers in locks varies between 4 and 6.
Tumbler Lock Mechanism Improvement to prevent break-in by "Bumper Key"
5. Detailed Description of the Invention This invention permits the manufacturer of the locks to retain all the tooling and assembly devices for the production of the locks.
The only addition in the usual tooling for the production of the plug is the drilling of the 2 rows of radially directed holes at 300 in both directions from the centerline.
These holes are 100 Th. Diameter and 200 Th. Deep. (Th. = 1/1000 of an Inch).
The top pin normally placed in each chamber is replaced by 2 pins, whose total length is equal to the single pin being replaced.
The upper pin has dimensions as shown in drawings #5 to #8.
The new replacement pins are manufactured from the same materials as the pin being replaced - usually brass.
The normal operation of the lock with the aforementioned additions remains the same as before the additions suggested by this invention.
When an attempt at illegal entry by means of a "Bumper Key" is made, the added upper pins fly up into the chamber, the lock turns up to 30 either side, but then the springs in the chambers push these upper pins to drop into the holes in the side of the plug and prevent further turning of the plug. The lock does not open and the "Bumper Key"
remains captured inside the plug as evidence that tampering took place.
5. Detailed Description of the Invention This invention permits the manufacturer of the locks to retain all the tooling and assembly devices for the production of the locks.
The only addition in the usual tooling for the production of the plug is the drilling of the 2 rows of radially directed holes at 300 in both directions from the centerline.
These holes are 100 Th. Diameter and 200 Th. Deep. (Th. = 1/1000 of an Inch).
The top pin normally placed in each chamber is replaced by 2 pins, whose total length is equal to the single pin being replaced.
The upper pin has dimensions as shown in drawings #5 to #8.
The new replacement pins are manufactured from the same materials as the pin being replaced - usually brass.
The normal operation of the lock with the aforementioned additions remains the same as before the additions suggested by this invention.
When an attempt at illegal entry by means of a "Bumper Key" is made, the added upper pins fly up into the chamber, the lock turns up to 30 either side, but then the springs in the chambers push these upper pins to drop into the holes in the side of the plug and prevent further turning of the plug. The lock does not open and the "Bumper Key"
remains captured inside the plug as evidence that tampering took place.
Claims (8)
1. The invention changes the construction of a Tumbler Lock and thereby prevents the opening of a Tumbler Lock by means of a "Bumper Key", which is a key with all its cuts filed down to their lowest point and can be used to open a tumbler lock without a proper key.
2. The proposed change in design of the lock thwarts any attempt to use a "Bumper Key"
for unauthorized entry.
for unauthorized entry.
3. The proposed new design captures the "Bumper Key" inside the Plug and prevents its removal, leaving evidence of an illegal attempt at entry, while also preventing opening of the lock.
4. Two rows of holes drilled along the sides of the Plug, with a diameter smaller than the regular chambers of the Plug and body of the locking device, used to capture the special upper pins (tumblers) inserted for that purpose in each chamber of the lock, to stop the Plug from turning further and opening the lock.
5. The replacement of the single top pin in each chamber with 2 pins, the top pin being of a special shape, with its lower end diameter reduced to fit into the additional holes along the Plug.
6. The advantage of simplicity in adapting present manufacturing processes to produce the new locks embodying the invention described herein.
7 7. Drawings #1 to #8 - following pages
8
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2590676 CA2590676A1 (en) | 2007-05-17 | 2007-05-17 | Tumbler lock mechanism improvement to prevent break-in by "bumber key" |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2590676 CA2590676A1 (en) | 2007-05-17 | 2007-05-17 | Tumbler lock mechanism improvement to prevent break-in by "bumber key" |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2590676A1 true CA2590676A1 (en) | 2008-11-17 |
Family
ID=40030423
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2590676 Abandoned CA2590676A1 (en) | 2007-05-17 | 2007-05-17 | Tumbler lock mechanism improvement to prevent break-in by "bumber key" |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2590676A1 (en) |
-
2007
- 2007-05-17 CA CA 2590676 patent/CA2590676A1/en not_active Abandoned
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |