Miscellaneous hardware (e.g. – bushing – carpet fastener – caster – Closers – Spring
Reexamination Certificate
1999-08-13
2001-11-20
Browne, Lynne H. (Department: 3626)
Miscellaneous hardware (e.g., bushing, carpet fastener, caster,
Closers
Spring
C016S082000, C016S049000, C016S069000, C016S058000, C016S057000, C016S071000
Reexamination Certificate
active
06317922
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a door closer, and more particularly to a door closer with advanced manual locking to hold a door open.
2. Prior Art
A door closer is an apparatus to return an opened door to a closed position. Common door closers typically utilize a pneumatic or hydraulic cylinder with an end attachable to a door or door frame. The cylinder contains a piston with a rod extending from the free end of the cylinder. A compression coil spring is enclosed in the cylinder and pushes on the piston which transmits the force to the rod's extending end which is attachable to a door or door frame. The spring urges the piston to return to a maximum retracted position in the cylinder. With typical prior art devices, the speed at which the door closer returns the opened door to its closed position is adjusted by a bolt or screw attached to an end of the cylinder.
Usually a manually operated lock such as a cantable washer is mounted on the portion of the rod extending beyond the cylinder, to allow a user to arrest the door temporarily in an open position. Such a lock is cumbersome to the user and often results in the user pinching their fingers in between the washer and the cylinder. Its operation normally requires two hands, one being used to open and hold the door while the other is used to slide the washer on the rod until it contacts a stop provided on the cylinder. Upon release of the door, the stop cants the washer so that it grasps and arrests the rod and the door is held open. To unlock the door, the user must open the door further to relieve the force on the washer applied by the stop and then slide the washer along the rod to a location where it will not contact the stop for the entire retracting movement of the rod into the cylinder as the door closes.
Door closers with more conventional locks have been proposed in the prior art, but have not gained commercial acceptance. These devices incorporate automatic and semi-automatic locking techniques and are considerably more expensive and intricate than closers with manual locking as described and each have particular drawbacks peculiar to the mechanisms employed. These devices also fail to indicate to the user whether the mechanism is in a locking or unlocking mode, and if an uninformed user were to actuate the device, the door might close on the user unintentionally. Moreover, adjustment of existing door closers are cumbersome. These devices incorporate low profile adjustable screws which are obstructed from accesses by mounting brackets used to attach the cylinder to the door.
It can be seen then that a door closer is needed which is inexpensive, reliable, durable and more convenient to lock and unlock than existing door closers with conventional manually operated locks. The present invention address these problems, as well as others, associated with door closers.
SUMMARY OF THE INVENTION
The present invention is directed to a door closer that employs a cylinder having a free end and an end attachable to a door or door frame, such as may be used with storm doors. Slidably retained within the cylinder is a piston biased by a spring to a maximum retracted position in the cylinder. The piston is attached to a first end of a rod having a second end that extends from the cylinder and is attachable to a door frame or door. Confined to a location proximal the free end of the cylinder and riding on the rod, is a cantable washer. Structural members at the proximal end of the cylinder maintain the washer in a perpendicular orientation on the rod so that the rod may slide through the washer freely as the door is opened or closed when the structural elements are rotated to a first position. To initiate locking, the structural elements are rotated to a second position which causes the washer to cant, arrest the piston rod, and hold the door open. Thus, unlike conventional door closers employing a cantable washer, the user does not have to slide the washer on the rod to a desired latching position or continuously engage an automatic or semi-automatic locking mechanism. In the present invention, the washer is intrinsically canted to contact the rod by the door closer itself when locking is activated.
In a more particular example of the invention, the door closer has an end cap coupled to the cylinder proximate the free of the cylinder and rotatable between a first and second position. A support cap member having angled surfaces is coupled to the cylinder and longitudinally spaced from the end cap and intermediate the end cap and the spring. An L-shaped washer is mounted on the rod within the cylinder between the end cap and the support cap member. The end cap and support cap members both have passages formed through them for receiving the piston rod. The end cap further includes an inner cavity and first and second retainer tabs coupled to the end cap within the inner cavity and extending parallel to the piston rod. The first retainer tab is positioned parallel and apart from the second retainer tab such that the angled washer is assembled within the end cap, disposed and held between the first and second retainer tabs. The L-shaped washer is retained between the first and second retainer tabs and maintained by the angled contact surfaces of the support cap in a position which is substantially perpendicular to the piston rod, allowing the rod to freely retract and extend within the cylinder when locking is not desired and the end cap is rotated to the first, unlocked position. When locking is desired, the end cap is rotated to the second, locked position whereat the extended leg of the retained washer engages the contact surface perpendicular to the piston rod and the washer is maintained in a position where the washer eccentrically contracts and arrests the piston from further retraction into the cylinder. Once the end cap is rotated to its locking position, the door can be opened further and again held to a new opening position. The door will only close when the end cap is rotated to its unlocked position.
A knob-type adjusting screw is coupled to the attachable end of the cylinder. A bracket, which attaches the cylinder to the door or door frame, is arranged to provide non-intrusive access to the adjusting screw. A jamb bracket, which couples the attachable end of the piston rod to the door or door frame, accommodates two piston rod connection holes, allowing adjustment of the piston rod retraction within the cylinder and enabling the piston to trigger an air release valve within the cylinder to provide the door closer with an additional “kick” as the piston arrests to its retracted position. In addition, a cover bracket can be added to the jamb bracket to provide aesthetic appeal.
The present invention provides a door closer which is more user friendly and safe to operate. The closer provides easy reliable adjustment and actuation for closing and locking that is not possible with prior art closer devices.
These features of novelty and various other advantages which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
REFERENCES:
patent: 4286412 (1981-09-01), Stevens
patent: 4382311 (1983-05-01), Watts
patent: 4545322 (1985-10-01), Yang
patent: 4815163 (1989-03-01), Simmons
patent: 5630248 (1997-05-01), Luca
patent: 5842255 (1998-12-01), Luca
Browne Lynne H.
Merchant & Gould P,C,
Rodgers Matthew E.
Truth Hardware Corporation
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