The present invention relates to locking devices and more particularly to a latch for use with multiple padlocks.
Multiple lock systems are used to allow access to an area by multiple users while preventing access to unauthorized persons. Such systems may be used, for example, on property with oil and gas leases, hunting leases, or wireless communications towers. One advantage of multiple lock systems over a single lock system is that a user authorized to access multiple areas may use locks with the same key for each area, eliminating the need for that user to carry multiple keys and reducing confusion over which key provides access to which area. Another advantage is that when a user is no longer authorized to access the area, the user's lock can be replaced or eliminated, and the distribution of new keys to all of the other users is not required.
One simple prior known multiple lock system uses a chain around a gatepost and gate secured by multiple padlocks linked in series with each user having their own padlock and key. One disadvantage of this system is that a user may bypass one or more locks when resecuring the chain, thereby preventing access to the users of the bypassed locks. The padlocks are also vulnerable to being forced or cut open. Detection of an unauthorized lock, added by cutting the chain and inserting the lock, is very difficult with this system.
U.S. Pat. No. 2,707,125 to Ritter discloses a tubular multiple padlock system that mounts on a gatepost. U.S. Pat. No. 3,889,497 to Tuttle discloses a plate type multiple padlock -device where-padlocks must be used in multiples of four. U.S. Pat. No. 3,988,031 to Meyer and U.S. Pat. No. 4,997,219 to Carter disclose vertical wheel type multiple padlock devices where removal of a peripheral padlock provides access to a hole that allows retraction of a locking bar. U.S. Pat. No. 4,697,443 to Hillin discloses a horizontal wheel type multiple padlock device having radial access-channels with a fastening gate for each padlock. Each of the above patented devices has a predetermined number of positions for padlocks and none can be reconfigured as the number of users changes.
U.S. Pat. No. 5,868,015 to Eaker discloses a multiple padlock system with a locking bar and a plurality of coupling segments. Segments can be added or removed if the number of users changes. The number of segments cannot be controlled by a master user since any authorized user could add a segment. When a user is no longer authorized, that user's padlock and at least one segment must be removed to reconfigure the system. Such a reconfiguration requires coordination with one of the users adjacent to the user that is being removed, in order to remove the segment. In each of the above listed devices the padlocks are vulnerable to boltcutters or a sledgehammer.
Accordingly, there is a need for a multiple padlock system that can be readily reconfigured, without the coordination of several current users, as the number of users changes. A master user should be able to control the reconfiguration. The multiple lock system should also protect the padlocks from boltcutters and sledgehammers.
A multiple padlock latch includes a housing, a sliding bar extending through the housing, a swinging plate pivotally mounted in the housing, and a plurality of push bolts. The sliding bar is movable between a latched position and an unlatched position. The swinging plate is biased by a spring toward a first position and movable away from the first position to a second position. When the sliding bar is in the latched position and the swinging plate is in the first position, the swinging plate engages the sliding bar and prevents the sliding bar from moving. When the swinging plate is moved to the second position, the sliding bar is released. The push bolts are slidably mounted in apertures in the housing. Pushing a push bolt into the housing moves the swinging plate to the second position. Each push bolt has a padlock aperture and cannot be pushed into the housing when a padlock is in the padlock aperture. The push bolts include one master bolt and slave bolts. The user of the master bolt can activate or deactivate the slave bolts, so the number of users of the latch can be controlled and readily configured. Guard plates between the push bolts protect the padlocks from boltcutters and sledgehammers.
Details of this invention are described in connection with the accompanying drawings that bear similar reference numerals in which:
Referring to
Describing the specific embodiments herein chosen for illustrating the invention, certain terminology is used which will be recognized as being employed for convenience and having no limiting significance. For example, the terms “front”, “back”, “top”, “bottom”, “vertical” and “horizontal” refer to the illustrated embodiments in the normal position of use. Further, all of the terminology above-defined includes derivatives of the word specifically mentioned and words of similar import.
The housing 11 shown is in the form of a vertically oriented, elongated square tube, having a front wall 17, a spaced back wall 18, spaced first and second side walls 19 and 20 each extending between the front and back walls 17 and 18, a closed bottom end 21, and an open top end 22, forming an interior cavity 23. A removable top cap 25 mounts in and closes the top end 22. Two spaced hook portions 27 are rigidly mounted on the housing 11 intermediate the bottom and top ends 21 and 22. The hook portions 27 extend in parallel from the first side wall 19 first outwardly, forwardly, then outwardly and then outwardly, rearwardly to form an open, rearwardly facing hook eye 28.
As shown in
The stop ring 33 fits around and is rigidly mounted on the cylindrical portion 32, inside the interior cavity 23 of the housing 11. The stop ring 33 is positioned on the cylindrical portion 32 such that when the stop ring 33 is against the first side wall 19, the sliding bar 12 is in the latched position and the cylindrical portion 32 extends completely across hook eye 28 and into the end sleeve 31, and when stop ring 33 is against the second side wall 20, the sliding bar 12 is in the unlatched position, shown in dashed lines, and the cylindrical portion 32 does not extend across hook eye 28.
Referring to
The engaging portion 38 of the swinging plate 14 is aligned vertically with the sliding bar 12. When the sliding bar 12 is in the latched position, the springs 40 bias the swinging plate 14 rearwardly to a first position with the engaging portion 38 contacting the cylindrical portion 32 inward from the stop ring 33, blocking movement of the sliding bar 12 toward the unlatched position. When the swinging plate 14 is pivoted forwardly to a second position, shown in dashed lines in
As shown in
The push bolts 15 shown have an elongated cylindrical shape and include a master push bolt 48 and a plurality of slave push bolts 49. Referring to
The distance from the inner end 52 to the pin aperture 54 of the master push bolt 48 is selected such that when the swinging plate 14 is in the first position and the inner end 52 of the master push bolt 48 contacts the push portion 39 of the swinging plate 14, the master push bolt pin 55 is at or near the outer extent of the master push bolt sleeve slots 43. The distance from the inner end 52 to the padlock aperture 53 of the master push bolt 48 is selected such that when the swinging plate 14 is in the first position and the inner end 52 of the master push bolt 48 contacts the push portion 39 of the swinging plate 14, the padlock aperture 53 is just outside the outer extent of the master push bolt sleeve 42, so that when a padlock 57 is in the padlock aperture 53, the master push bolt 48 cannot move the swinging plate 14 toward the second position. The distance from the inner end 51 to the outer end 52 of the master push bolt 48, and the length of the master push bolt sleeve slots 43 are each selected such that the master push bolt 4B pushes the swinging plate 14 to the second position before the outer end 52 of the master push bolt 48 reaches the outer extent of the master push bolt sleeve 42 and before the master push bolt pin 55 reaches the inner extent of the master push bolt sleeve slots 43.
Referring to
The distance from the inner end 59 to the padlock aperture 60 and the distance from the inner end 59 to the outer end 58 of the slave push bolt 49 are selected in the same manner as the respective distances are selected for the master push bolt 48. A pin aperture 63, sized to receive the slave push bolt pin 62, extends through each slave push bolt 49 at the inner extent of the pin slot 61, perpendicular to the padlock aperture 60. When the slave push bolt pin 62 is assembled through the pin slot 61, the slave push bolt 49 is activated and can be pushed to release the sliding bar 12, if there is no padlock 57 in the padlock aperture 60. If the slave push bolt pin 62 is removed, the slave push bolt 62 rotated 90 degrees and the slave push bolt pin 62 assembled through the pin aperture 63, the slave push bolt 49 is deactivated and will not move if pushed inwardly.
Referring to
Each guard plate 66 includes an inward opening access plate channel 67 extending across the access opening 65. An access plate 68 slides downwardly through the access plate channels 67 to cover the access opening 65. An access plate stop 69, rigidly mounted on the outside of the back wall 18 below the lowest guard plate 66, limits downward travel of the access plate 68. The top cap 25, as shown in
The back portion 83, as shown in
A top wall 98, inwardly spaced from the top edge 86, extends horizontally from the top end 95 of the second side wall 93 to the first side wall 91, and projects forwardly even with the front edge 94 of the second side wall 93. A bottom wall 99,inwardly spaced from the bottom edge 87, extends horizontally from the bottom end 96 of the second side wall 93 to the first side wall 91, and projects forwardly even with the front edge 94 of the second side wall 93. A vertical, rectangular housing attachment bar 101 projects inwardly from the first side wall 91, forward from the top and bottom walls 98 and 99. An upper housing attachment aperture 102 extends through the second side wall 93, adjacent to the top wall 98, and a lower housing attachment aperture 103 extends through the second side wall 93, adjacent to the bottom wall 99.
Aligned first and second sliding bar apertures 105 and 106, sized to receive the sliding bar 79, extend through the first and second side walls 91 and 93, respectively, between the upper and lower housing attachment apertures 102 and 103. Spaced inner and outer limit screws 108 and 109 are mounted on the sliding bar 79, inside and outside respectively of the second side wall 93, to limit movement of the sliding bar 79 between a latched position and an unlatched position. The unlatched position is shown in dashed lines in
Referring to
A plate stop 118, spaced inward from the first side wall 91, projects upward from the bottom wall 99, to stop the swinging plate 80 at a first position with the push portion 116 substantially horizontal. The plate stop 118 has a vertical first edge 119 that faces the first side wall 91, and a spaced second edge that faces and slopes upwardly away from the second side wall 93. A spring 122 connects from the bottom wall 99 to the push portion 116 to bias the push portion 116 downward against plate stop 118.
The swinging plate 80 includes a flat, substantially rectangular engaging portion 123 that projects outward from the pivot 115, adjacent to the first side wall 91, generally upwardly and substantially perpendicular to the push portion 116. The engaging portion 123 is sized and positioned to fit into the stop groove 111 of the sliding bar 79 when the sliding bar 79 is in the latched position and the swinging plate 80 is in the first position, thereby preventing the sliding bar 79 from moving. When the push portion 116 is pushed upward, the swinging plate 80 pivots to a second position, shown in dashed lines in
Referring to
The front and back walls 125 and 126 of the front portion 84 fit against the first side wall 91 of the back portion 83, with the housing attachment bar 101 being received between the front and back walls 125 and 126 of the front portion 84. The side wall 129 of the front portion 84 includes inwardly projecting upper and lower housing attachment stubs 131 and 132, sized and positioned to fit into the upper and lower housing attachment apertures 102 and 103 in the second side wall 93 of the back portion 83. The side wall 129 of the front portion 84 includes a rearwardly opening sliding bar notch 133, around the sliding bar 79 and between the upper and lower housing attachment stubs 131 and 132. The front portion 84 is removed from the back portion 83 by sliding the front portion 84 sideways away from the first side wall 91 of the back portion 83 until the housing attachment bar 101 clears the front portion 84 and the upper and lower housing attachment stubs 131 and 132 clear the back portion 83.
The push bolts 81 have an elongated rectangular shape and are sized to slidably fit between the front and back walls 125 and 126 of the front portion 84. A plurality of spaced push bolt apertures 135, sized to receive push bolts 81, extend through the bottom wall 128, between the front and back walls 125 and 126, of the front portion 84. For each push bolt aperture 135, a corresponding, vertically extending push bolt slot 136 extends though the back wall 126, above the bottom wall 128, of the front portion 84. Each push bolt 81 includes a padlock aperture 137 near the lower end.
The push bolts 81 include a master push bolt 139 and a plurality of slave push bolts 140. The master push bolt 139 is assembled in the push bolt aperture 135 nearest to the first side wall 91 of the back portion 83. The master push bolt 139 includes an engagement stub 142, spaced above the padlock aperture 137, that extends rearwardly through the push bolt slot 136. The distance from the engagement stub 142 to padlock aperture 137 is selected such that when the engagement stub 142 is at the bottom of the push bolt slot 136, the padlock aperture 137 is below the bottom wall 128 of the front portion 84.
When the engagement stub 142 is at the bottom of the push bolt slot 136, the engagement stub 142 extends rearwardly under the push potion 116 of the swinging plate 80 so that when the master push bolt 139 is pushed up; the engagement stub 142 moves the swinging plate 80 to the second position. When the engagement stub 142 is at the bottom of the push bolt slot 136, the engagement stub 142 engages the first edge 119 of the plate stop 118, preventing disassembly of the front portion 84 from the back portion 83 of the housing 76. When the master push bolt 139 pused up, the engagement stub 142 moves above the plate stop 118, allowing disassembly of the front portion 84 from the back portion 83 of the housing 76.
A push bolt hole 144 extends though the back wall 126, below the top wall 127 of the front portion 84, above each push bolt slot 136, except the push bolt slot 136 for the master push bolt 139. Each slave push bolt 140, as shown in
The distance from the lower aperture 145 to padlock aperture 137 of a slave push bolt 140 is selected in the same manner as the distance from the engagement stub 142 to padlock aperture 137 of the master push bolt 139 is selected. The upper aperture 146 is located near the upper end of the slave push bolt 140. When the cap screw 147 is in the lower aperture 145 with the head 148 of the cap screw 147 in the push bolt slot 136, the slave push bolt 140 is activated. When the head 148 of the cap screw 147 is at the bottom of the push bolt slot 136, the head 148 extends rearwardly under the push portion 116 of the swinging plate 80 so that when the slave push bolt 140 is pushed up, the head 148 moves the swinging plate 80 to the second position. A slave push bolt 140 is deactivated by removing the cap screw 147 from the lower aperture 145, pushing the slave push bolt 140 upward until the upper aperture 146 is visible in the push bolt hole 144 in the back wall 126 of the front portion 84, and then assembling the cap screw 147 through the push bolt hole 144 into the upper aperture 146.
Solid, rigid guard plates 150 extend vertically downward from the bottom wall 128 of the front portion 84, between each pair of push bolts 81, with one additional guard plate 150 outside each of the outer push bolts 81, and protect the padlocks 57 from boltcutters and sledgehammers. Padlocks 57 in the padlock apertures 137 of the push bolts 81 prevent the push bolts 81 from being pushed up. When a padlock 57 is removed from a padlock aperture 137 of any push bolt 81, that push bolt can be pushed upward to release the sliding bar 79. The user of the master push bolt 139 can readily configure the latch 77 to the desired number of users by activating or deactivating slave push bolts 140.
The two embodiment are described to illustrate the variety of structure that can be used to implement the invention. Both embodiments include a housing, a sliding bar that moves between a latched and an unlatched position, a swinging plate biased toward a first position and movable to a second position, a master push bolt, a plurality of slave push bolts that can be activated or deactivated, and a means for accessing the slave push bolts, by the master push bolt user, for reconfiguring the slave push bolts. In the first embodiment the pivot 36 of the swing plate 14 is perpendicular to the sliding bar 12 while the pivot 115 of the swinging plate 80 in the second embodiment is parallel to the sliding bar 79. Push bolts 15 in the first embodiment are shown as cylindrical while push bolts 81 in the second embodiment are shown with a rectangular cross-section. A slave push bolt pin 62 is used to reconfigure the slave push bolts 49 in the first embodiment while a cap screw 147 is used to reconfigure the slave push bolts 140 in the second
The slave push bolts 49 in the first embodiment are accessed for reconfiguration by removing the accessed plate 68 while the slave push bolts 140 in the second embodiment are accessed for reconfiguration by separating the front portion 84 from the back portion 83 of the housing 76.
The first embodiment preferably mounts vertically while the second embodiment preferably mounts horizontally, when used on a horizontally moving gate or door.
Although the shown sliding bars 12 and 79 are substantially straight, other configurations can be used. The plate, shown as swinging plates 14 and 80 that pivot, may alternatively be designed to move linearly. The latches 10 and 77 can readily be reconfigured for a different number of users by activating or deactivating slave push bolts 49 or 140. When a slave push bolt user is no longer authorized, the master push bolt user can deny that slave push bolt user access by removing that slave push bolt user's slave push bolt with the padlock 57, and inserting another slave push bolt, either activated for a new user or deactivated. The master push bolt user can reconfigure the number of users without cooperation or coordination of the slave push bolt users.
Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.
This application claims the benefit under 35 U.S.C. 119(e) of the U.S. provisional patent application No. 60/396,190 filed on Jul. 16, 2002.
Number | Name | Date | Kind |
---|---|---|---|
1213863 | Goins | Jan 1917 | A |
2707125 | Ritter, Sr. | Apr 1955 | A |
3656789 | Ray | Apr 1972 | A |
3889497 | Tuttle | Jun 1975 | A |
3988031 | Meyer | Oct 1976 | A |
4085599 | Fischer et al. | Apr 1978 | A |
4697443 | Hillin | Oct 1987 | A |
4997219 | Carter | Mar 1991 | A |
5020342 | Doan et al. | Jun 1991 | A |
5284036 | Rosenbaum | Feb 1994 | A |
5868015 | Eaker | Feb 1999 | A |
6557384 | Cuesta | May 2003 | B1 |
Number | Date | Country | |
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20040226322 A1 | Nov 2004 | US |
Number | Date | Country | |
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60396190 | Jul 2002 | US |