Patent Application
20120104771
The present invention relates to locks for protective barriers, and in particular to a hook latch receiver to mate with an enclosure for a hook latch to protect the workings of the mortise and latch against contaminants and tampering.
It is often desirable to section off portions of the workplace that may contain dangerous equipment, expensive equipment, or sensitive equipment that is easily damaged. Protective barriers and enclosures are also used to section off portions of a work space that may expose the individual to unusual or unexpected dangers, such as high electrical voltage, liquefied gasses, and radiation. It is desirable that the partitions for sectioning off protected areas be attractive in appearance, easy to assemble, rigid, and difficult to compromise.
An important part of such partitions is the provision of a gate allowing access to and from the protected area, and a lock for locking the gate. The lock must have sufficient strength such that it will not fail when subjected to tampering or brute force. The lock assembly must also have a sufficiently long life expectancy to survive for many years.
Locksets are generally either a hook latch, in which a hook is extended from the mortise as the latch is operated with the hook engaging a bar on a receiver. Such hook latches are particularly desirable for sliding doors and gates where the hook retains the sliding member from being withdrawn from the receiver. Alternately, a lockset may include a slam latch, such as a deadbolt in which an elongate member extends from the mortise and is received in a transverse opening in the receiver. Such slam latches are particularly desirable for swinging doors and gates in which the transverse opening retains the slam latch, or deadbolt, to prevent the gate or door from swinging.
Hook lock mortises having the physical strength to retain such gates are readily available in the art; however, such locks must be mounted in an enclosure that mates with a suitable latch plate so that the lock will withstand outside contaminants, tampering, and brute force to which such locks are inevitably subjected. Accordingly, there is a need for an enclosure a suitable latch plate for use with a hook lock.
Briefly, the present invention is embodied in a latch receiver for receiving the hook of a hook latch that is enclosed in a metal container having parallel spaced apart sides and a planar forward surface from which the hook of the latch extends.
In accordance with the invention, the latch receiver includes a metal C-shaped outer guard cover including parallel spaced apart side panels defining an open end that is a little wider than the width of the spaced apart sides of the latch enclosure. The C-shaped guard cover further has a planar back surface from which the side panels extend.
Positioned within the C-shaped guard cover is a receiver plate including a central body portion and upper and lower end portions, the central portion extending parallel to and spaced a short distance forward from the back surface of the C-shaped guard cover. The upper and lower end portions contact the back surface of the C-shaped guard cover and are welded thereto.
Between the central body portion and the end portions are shield plates that support the central body and obstruct access to the central body by a tampering tool. The shield plates also space the central body of the latch plate from the latch enclosure.
A better understanding of the invention will be had after a reading of the following detailed description taken in conjunction with the drawings wherein:
Referring to
Referring to
A latch receiver 26 in accordance with the present invention includes a U-shaped guard covers 28 having generally parallel side panels 30, 32 and joining parallel spaced ends on each of the side panels 30, 32 a planar back panel 33 that extends generally perpendicular to the side panels 30, 32. In the preferred embodiment, the guard cover further includes upper and lower end panels 35, 36 which enhance the appearance of the latch receiver and obstruct a tampering tool from reaching the hook 27. To retain the shell 28 to a support member 14 on the barrier 10, the receiver 26 further includes a mounting panel 34 that joins a forward end of one of the side panels 30.
As shown in
Referring to FIGS. 3,5, and 7, fitted within the guard cover 28 is a latch plate 45 that includes a central panel 46 having a rectangular an aperture 48 therein with dimensions that are larger than the cross-sectional dimensions of the hook latch 27 adapted to be received therein. The aperture 48 includes an edge plate 78 suitable for receiving the hook 27. The central panel 46 is retained a short distance 54 forward of the back panel 33 by upper and lower end panels 50, 51, each of which includes a projection that extends forward of the central panel 46 a second short distance 56 to form upper and lower forward contact edges 52, 53 respectively. The contact edges 52, 53 formed by upper and lower end panels 50, 51 extend a third distance 60 forward of the surface of the back panel 33. Finally, the latch plate 45 includes upper and lower mounting panels 62, 63 oriented parallel to the central panel 46 and adapted to fit against the surface of the back panel 33. To provide a solid receiver for receiving the hook 27 of a hook latch, the upper and lower mounting plates 62, 63 are securely welded to the back panel 33.
Referring to
An important feature of the present invention is that the upper and lower contact edges 52, 53 are adapted to make contact with the outer end of the lock enclosure 24 while the hook latch 27 is engaged over an edge 78 of the aperture 48 so as to leave a minimum of horizontal movement, or “play” between the latch enclosure 24 and the latch receiver 26. Keeping horizontal movement to a minimum inhibits the space accessible to a tampering tool and therefore protects the integrity of the lock. Also, the upper and lower end panels 50, 51 space the contact edges 52, 53 from the back panel 33 a distance 60 that is greater than the distance that the outer end of the hook 27 extends outward of the locking enclosure 24 thereby preventing the distal end of the hook 27 from contacting the rear panel 33 of the latch receiver 26. Where the distal end of the latch 27 is able to contact an inner surface of a latch receiver, the contact may interfere with the operation of the latch and result in the hook 27 failing to engage the edge 78 of the aperture 48. Such failures generally occur when the gate 20 is slammed hard against the latch receiver 26 allowing only a fraction of a second for the latch to engage the receiver. Any interruption with the movement of the hook 27 will prevent the hook from engaging the edge 78 and cause the gate 20 to bounce away from the receiver 26 without having become engaged thereto.
Another feature of the invention is that the length 75 of the upper mounting panel 62 and the length 77 of the lower mounting panel 63 are chosen so that the outer ends 64, 65 thereof will fit snuggly between the upper and lower end panels 35, 36 of the guard cover 28 thereby positioning the central panel 46 and the aperture 48 to receive the hook 27 of the latch.
Referring to
As can be seen, a lock receiver 26 in accordance with the present invention, will obstruct tampering with the hook 27 that engages the central panel 46 thereof to securely retain a gate 20 against the lock receiver 26.
While the present invention has been described with respect to a single embodiment, it will be appreciated that many modifications and variations can be made without departing from the spirit and scope of the invention. It is therefore the intent of the appended claims to cover all such modifications and variations that fall within the spirit and scope of the invention.
