The present invention relates to mechanisms for closure of movable objects such as doors or gates; more particularly, to strike mounts for such closures; and most particularly, to a system for absorbing the shock of strike closure, especially in swinging or sliding closure of heavy doors or gates.
Industrial yards, construction sites, apartment complexes, office complexes and other such secured areas commonly control entry and egress. In some cases, security is accomplished by use of a security gate which may be either a sliding gate or a swinging gate which is held in the closed position by a lock which may be controlled either remotely or locally by a key, keypad, magnetic access device, RFID device, or other such control.
One particular problem with generally large and heavy gates is that when the gate is closed with application of substantial force, such as a result of wind, manual force, or an impact such as that caused by a vehicle, the resulting closing forces may cause damage to the gate installation, particularly to the lock mechanism itself. The resulting damage can inhibit proper operation of the gate and result in substantial maintenance and repair costs to correct the damage. An additional problem is that the momentum of a heavy closing gate often causes the automatic lock to fail to stay secured under the rebounding forces of the gate.
What is needed in the art is a resilient strike assembly to reduce the impact of lock engagement and to absorb some of the closing forces of a heavy door or gate.
It is a principal object of the present invention to reduce the risk of damage to a lock during locking engagement.
It is a further object of the invention to improve the reliability of a secured closure during a closing event.
Briefly described, an impact-absorbing strike assembly for a lock on a closure such as a gate and post has a strike plate mounted in spaced relationship from a mounting plate. A connecting element, preferably a bolt having a head, extends slidably through a bore in the mounting plate and is attached to the strike plate. A primary compression spring is disposed between the mounting plate and the strike plate, preferably surrounding the bolt. A secondary compression spring is positioned on the bolt between the head and the rear of the mounting plate. Upon closure, the strike plate engages and is held by the latch or lock mounted on a fixed structure such as a gate post. Alternatively, the strike assembly may be mounted on the gate post, with the latch mounted on the gate. The momentum of the gate causes the spring between the strike plate and the mounting plate to be compressed, absorbing the energy of the impact as the bolt slides in the mounting plate. Resilient movement of the strike plate may be further guided by pins pressed into the strike plate that extend through grommets located in bores in the mounting plate. Once the primary, shock-absorbing spring has been compressed and has absorbed the impact or load, the primary spring expands from a compressed state, causing the secondary spring to be compressed between the head of the bolt and the rear of the mounting plate. After progressively decreasing oscillations, the strike assembly returns to a steady state condition with the gate in a closed position.
In another embodiment, the impact-absorbing strike assembly includes a latch component such as a clevis-style strike for use with a mechanical locking device that may be electromechanical.
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrates one preferred embodiment of the invention in one form, and such an exemplification is not to be construed as limiting the scope of the invention in any manner.
Referring to
Strike assembly 10 may be adapted for use with closures of various configurations but is especially useful on closures involving heavy duty gates. As described above, heavy duty gates for industrial or commercial use have substantial mass and can have substantial kinetic energy. Excessive loads imposed on a strike by a heavy gate closing or by other forces, such as by impact of a vehicle striking the gate, can cause the gate to close with excessive force, damaging the gate, gate posts, and/or lock components. Strike assembly 10 operates to absorb much of the closing impact, reducing damage and wear to a gate and preventing misalignment as may occur from the damage due to high impact conditions.
Strike assembly 10 is intended specifically for gates having electromagnetic locks or latches L as shown in
Strike assembly 10 includes a mounting plate 12, shown as being generally rectangular but which may be of any configuration and size. Preferably, mounting plate 12 is formed of a durable material, for example, a hardened stainless steel, and may be secured to the moveable portion of gate G at an L-shaped flange 14 which is secured to gate G by welding or fasteners; welding is preferred to minimize tampering and to deter intrusions. Gate G is shown as a swinging gate in
Alternatively, bore 44 is omitted, and connecting element 18 threads into a threaded bore (not shown) formed in the rear surface of strike plate 40, or connecting element 18 may be welded to strike plate 40 with head 22 attachable to the connecting element for securing mounting plate 12 in place.
A primary compression spring 50, stronger than secondary compression spring 25, is disposed on connecting element 18 interposed between mounting plate 12 and strike plate 40. A washer 52 may be disposed between one end of compression spring 50 and strike plate 40.
One or more guide bores 30,32 are provided in mounting plate 12 disposed adjacent bore 16. Bushings 68, 70 are disposed in guide bores 30,32, respectively. A pair of blind bores 60,62 on the inner face of strike plate 40 are positioned to align with guide bores 30,32 in mounting plate 12. Guide pins 64,66, formed preferably of stainless steel or a similar material, are pressed into blind bores 60,62 and are slidingly received in bushings 68,70 so that as primary compression spring 50 is compressed, the reciprocal movement of strike plate 40 relative to mounting plate 12 is guided by guide pins 64,66. Bushings 68,70 may be secured to mounting plate 12 by a suitable fastener such as, for example, a thread locker.
Referring now to
In
Secondary spring 25, with a properly selected spring rate, may be useful in resisting attempts to force gate G open by an unwanted application of a sharp, impact force against the gate in direction 69 in
Referring now to
A strike plate 140 is spaced from mounting plate 112 and is secured to connecting element 118 as by a fastener or other means. A primary compression spring 150 stronger than secondary spring 125 is disposed on connecting element 118 interposed between mounting plate 112 and strike plate 140. One or more pins 164 may be used to guide the reciprocal movement of strike plate 140.
Embodiment 100 is intended for use with non-electromagnetic locks. Accordingly, strike subassembly 170 preferably comprises an outer clevis 172 which pivotally supports an inner clevis 175. Clevis 175 is secured to outer clevis 172 and strike plate 140 by fasteners 176 and has a sleeve 180 that is captured within a cooperating mechanical latch component (not shown) when the closure components are engaged. The installation and shock absorbing operations are as described above with respect to
While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.
The present application claims priority from U.S. Provisional Patent Application Ser. No. 61/008,852, filed Dec. 20, 2007.
Number | Date | Country | |
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61008852 | Dec 2007 | US |