1. Field of the Invention
The invention relates to an automatically-closing screen door, typically for enclosure with a conventional sliding glass door used for patio entry in residential and/or commercial dwellings. More particularly, the invention relates to an automatically-closing screen door in which a counterweight is employed to provide a controllable closing force to the door.
2. Description of the Related Art
Sliding glass door assemblies have become commonplace in both residential and commercial dwellings. A sliding door is mounted on a horizontal track in offset alignment with a fixed door. When an occupant of a dwelling desires to enter or leave the dwelling, the occupant slides the sliding door along the track to open and close the sliding door with respect to the fixed door.
In addition to having a sliding glass door, many sliding glass door assemblies have a sliding screen door as well mounted for sliding movement on a track that is generally parallel to the horizontal track for the sliding glass door. The sliding screen door allows the sliding glass door to be left in an opened position to allow airflow into the dwelling while preventing insects and other undesirable entities from entering the dwelling.
Sliding screen doors are typically moved between opened and closed positions by an occupant grasping a handle on the screen door and manually sliding the sliding screen door between the opened and closed positions. This is acceptable if the sliding screen door is maintained in the closed position.
However, if the sliding screen door is left in an open position, the sliding screen door does not return to the closed position on its own accord. This can be a problem if the occupant has young children who frequently forget to close the sliding screen door after entering or leaving the dwelling. In addition, if the occupant is entering or leaving the dwelling carrying an object or performing an activity that requires both of the occupant's hands (e.g., carrying trays of food), it may also be difficult to manually close the sliding screen door in an acceptable amount of time.
One solution to these problems has been to add a spring (e.g., a coil spring or a bungee cord) which is attached at one end to the sliding screen door and at an opposite end to a frame surrounding the sliding screen door. The spring thereby biases the sliding screen door to the closed position.
These spring-based automatic closure systems have some problems. First, the resistance on the screen door increases as you open the door since the return force of a spring-based system is proportional to the length it is extended (see Hooke's law where the spring force F=kx). Second, when a spring-based automatic closure system is released so that it travels from the opened position to the closed position, it can close very quickly as a result of the conversion of the potential energy stored in the extended spring into the kinetic energy as the sliding screen door moves toward the closed position. Third, repair of these so-called spring-based automatic closure systems can be difficult and costly. Fourth, the spring used in the so-called spring-based automatic closure system can lose elasticity over time and require replacement.
In one aspect, the invention relates to an automatically-closing screen door, typically for enclosure with a conventional sliding glass door used for patio entry in residential and/or commercial dwellings. More particularly, the invention relates to an automatically-closing screen door in which a counterweight is employed to provide a controllable closing force to the door. In one embodiment, the sliding screen door described herein according to the invention includes an adjuster which allows an occupant to adjust a closing velocity of the door.
Invention overcomes the limitations of the prior art by offering a simple manufacture, assembly and operation. It has a low profile relative to the door jamb, has a low cost to manufacture and has little resistance when opening the sliding screen door.
One aspect, the invention relates to a door slidable between a door open position permitting travel therethrough and a door closed position obstructing travel therethrough comprising a door frame defining a central opening therein through which ingress and egress can occur; and an automatic closure system comprising: a cable with a first end and a second end, wherein the first end is mounted to an upper portion of the sliding door; a counterweight connected at the second end of the cable and movable between a counterweight open position when the sliding door is in the door open position and a counterweight closed position when the sliding door is in the door closed position, wherein the counterweight open position is above the counterweight closed position; and a pulley mounted to the door frame for redirecting the cable from a generally horizontal orientation near the first end to a generally vertical orientation near the second end; wherein when a force is applied to the sliding door to cause the sliding door to slide to the door open position, the counterweight is elevated from the counterweight closed position to the counterweight open position by virtue of the attachment of the cable to the sliding door via the pulley, and when the force is released, the counterweight descends to the counterweight closed position thereby returning the sliding door to the door closed position.
Another aspect, the invention relates to a kit for adapting a sliding door mounted within a door frame to automatically move between a door open position permitting travel therethrough and a door closed position obstructing travel therethrough, the kit comprising: a cable with a first end and a second end, wherein the first end is adapted to be mounted to the sliding door; a counterweight adapted to be connected at the second end of the cable and movable between a counterweight open position when the sliding door is in the door open position and a counterweight closed position when the sliding door is in the door closed position; and a pulley adapted to be mounted to the door frame for redirecting the cable from a generally horizontal orientation near the first end to a generally vertical orientation near the second end; wherein, when the pulley is mounted to the door frame and when the first end of the cable is mounted to the sliding door, passed through the pulley and has its second end mounted to the counterweight, the sliding door will automatically move between the door open position and the door closed position after a force is applied to the sliding door to cause the sliding door to move to the door open position whereby when the force is released, the counterweight descends to the counterweight closed position thereby moving the sliding door to the door closed position.
Embodiments of the invention are also contemplated. The automatic closure system further can comprise a bracket mounted to the upper portion of the sliding door, wherein the cable is mounted to the bracket. The sliding door can be a screen door. The cable can be made from nylon. The pulley can be a wheel-type pulley. The pulley can be a complex pulley system.
The door frame can comprise a door jamb and the automatic closure system can further comprise a cover mounted on the door jamb to visually conceal the pulley, the second end of the cable, and the counterweight. The counterweight can have a thin profile so that the counterweight can easily be concealed under the cover. The counterweight can be at least one of a lead plate, a lead rod, a lead member, a lead-filled tube and a stainless steel member. The cover can have an opening to permit the cable to pass through the cover. The cover can have an elongated shape so that the cover can have an appearance similar to and blends in with the door jamb.
The automatic closure system can further comprise an adjuster to control movement of the counterweight between the counterweight open and counterweight closed positions. The adjuster can comprise a housing and a U-shaped member fastened to the housing, wherein the cable is received within the U-shaped member. The U-shaped member can be selectively moved toward the housing to constrict the cable between the U-shaped member and the housing, thereby restricting movement of the cable through the adjuster, retarding movement of the counterweight, and causing the sliding door to slide more slowly to the door closed position. The U-shaped member can be selectively moved away from the housing to loosen the cable, thereby causing the sliding door to slide at a faster rate to the door closed position. The adjuster can further comprise thumb screws to move the U-shaped member relative to the housing.
The door frame can comprise a door jamb, the automatic closure system can further comprise a cover mounted on the door jamb to visually conceal the pulley, the second end of the cable, and the counterweight, and the adjuster is mounted to one of the door jamb and the cover. The door frame can comprises a door jamb; the automatic closure system further comprises a cover mounted on the door jamb to visually conceal the pulley, the second end of the cable, the counterweight, and the adjuster; and wherein the adjuster comprises an arm having a first end mounted to the cover and a second end that extends towards the door jamb and abuts the counterweight as it moves between the counterweight open and counterweight closed positions, wherein the second end of the arm imparts a damping force onto the counterweight as it moves between the counterweight open and counterweight closed positions, thereby causing the sliding door to move more slowly between the door open position and the door closed position.
The adjuster can further comprise a bias adjuster to control the damping force imparted onto the counterweight by the arm. The bias adjuster can comprise a threaded fastener that is mounted through the cover and contacts the arm between the first and second ends of the arm so that movement of the threaded fastener towards the arm increases the amount of damping force exerted by the arm and movement of the threaded fastener away from the arm decreases the amount of damping force exerted by the arm. The arm can be comprised of a resilient material.
The adjuster can further comprise a spring mounted between the cover and the second end of the arm, wherein the spring biases the arm towards the counterweight. The automatic closure system can further comprise a cable brake to stop movement of the cable to retain the sliding door in the door open position or in the door closed position. The cover can have an opening to permit the cable to pass through the cover, and the cable brake can comprise a flange mounted to the cover near the opening and a tab slidably mounted to the flange, wherein the tab is movable between a released position where the tab does not obstruct the cable from moving through the opening and an engaged position where the tab blocks the opening to prevent the cable from moving through the opening and thereby retain the sliding door in the door open position or in the door closed position.
The damper can be provided, wherein the damper can selectively apply a drag force on at least one of the pulley, the cable, and the counterweight to control the travel of the sliding door during movement of the sliding door from the door open position to the door closed position. The damper can apply a compression force to the cable to control the movement of the sliding door. The damper can include a U-shaped member which surrounds the cable and pinches the cable between at least one of the damper, the cover, and the door frame.
Referring now to the drawings and to
With particular reference to
In accordance with the invention, a first embodiment of an automatic closure system 24 is mounted between the sliding glass door frame 18 and the screen door 16. The automatic closure system 24 comprises a bracket 26, a cable 28, a pulley 30, a counterweight 32 and a cover 34.
The bracket 26 is preferably mounted to an upper portion of the screen door 16. The pulley 30 is preferably mounted to the cover 34 in generally horizontal planar alignment with the bracket 26. A first end 36 of the cable 28 is mounted to the bracket 26 at the upper portion of the screen door 16. A second end 38 of the cable 28 is mounted to the counterweight 32. As can be seen in
The bracket 26 can be any suitable bracket or fastener for connecting the first end 36 of the cable 28 to the screen door.
The cable 28 can be made of any suitable material including, but not limited to, nylon.
The pulley 30 can be any conventional wheel-type pulley or other suitable member, such as an eyelet, looped fastener, sleeve, etc. which performs the function of redirecting the cable 28 from a generally horizontal orientation at the first end 26 to a generally vertical orientation at the second end 38 thereof.
The counterweight 32 is any suitable weight, although it has been found that an elongated, thin weight member (e.g., a thin lead plate or rod) works best because it has a thin profile and can be mounted within the cover 34 without interrupting the visual aesthetics or functional operation of any components of the door assembly 10.
The cover 34 is preferably a low-profile sheath that conceals the interior components of the automatic closure system 24. The cover 34 is also preferably elongated a sufficient extent to conceal the interior components of the automatic closure system 24 regardless of the length of travel of the counterweight 32 (e.g., at least three feet for a 36-inch screen door 16 plus the length of the counterweight 32). It will also be understood that complex pulley arrangements can be substituted for the pulley 30 without departing from the scope of this invention. For example, a complex pulley system (such as that found in compound bows) can be substituted for the pulley 30 whereby a shorter cover 34 can be employed because the length of travel of the cable 28 would be reduced as a result of the complex pulley arrangement.
The mounting of the cover 34 is also shown in
The use of the automatic closure system 24 associated with the screen door 16 is simple. When the screen door 16 is in the closed position (see
It will be understood that the particular poundage making up the counterweight 32 can be selected to return the screen door 16 from the open position to the closed position at a predetermined rate. In addition, the counterweight 32 can be preselected or optionally adjusted with additional or fewer weights depending upon the friction imparted by the screen door 16 on its associated track during slidable movement of the screen door 16 relative to the door frame 18. That is, the smoother or rougher the movement of the screen door 16 relative to its associated track, the less or more weight may be required for the counterweight 32 to close the door in a desirable rate and fashion.
In addition to varying the weight of the counterweight 32, the invention also contemplates the provision of an adjuster 42 which varies the drag encountered by the cable 28 as the screen door 16 moves between the opened and closed positions. The adjuster 42 is shown in
The adjuster 42 comprises a U-shaped member 44 which is fastened to a housing 46 which, in turn, is mounted to the door frame 18 or the cover 34. The U-shaped member 44 can be selectively moved toward or away from the housing 46. In assembly, the cable 28 is passed through the arms of the U-shaped member 44 so that the cable 28 is selectively intertwined with the U-shaped member 44. As the U-shaped member 44 is tightened onto the housing 46 (such as by thumb screws 48 shown in
As the U-shaped member 44 is further tightened against the housing 46, the U-shaped member 44 restricts the movement of the cable 28 therethrough, causing the screen door 16 to close more slowly (see
Of course, the U-shaped member 44 can also be positioned sufficiently far from the housing 46 so that the U-shaped member 44 and the housing 46 do not contact the cable 28 whatsoever, thus providing no additional drag to the cable 28.
Also in accordance with the invention, a second embodiment of an automatic closure system 24 is shown in
The second embodiment of the automatic closure system 24 also includes a counterweight 32 located within a suitable cover 34, however, in this embodiment, the adjuster 42 for controlling the closing speed of the screen door 16 comprises an arm 60 having a first end 62 mounted to an interior portion of the cover 34 and a second end 64 extending inwardly therefrom in register with an axial path of travel of the counterweight 32 between the open and closed positions of the door.
Preferably, the arm 60 is mounted so that the second end 64 thereof is positioned to abut the counterweight 32 as it moves toward the closed position of the screen door 16. The second end 64 of the arm 60 can be biased into the counterweight travel path by a spring 66, preferably mounted between the second end 64 of the arm 60 and the cover 34. Preferably, the arm 60 is mounted to the cover 34 at a desirable vertical height so that the counterweight 32 contacts the arm 60 during its travel as the screen door 16 moves between the open and closed positions.
It will be understood that the spring 66 is optional, and that the arm 60 can also be made from a material which has an inherent resiliency so that some resistance/damping is imparted to the counterweight 32 by the arm 60 when the screen door, and thus the counterweight 32, moves between the open and closed positions.
A bias adjuster 68 is provided with the arm 60 for adjusting the amount of bias, and thus the amount of damping force, applied against the movement of the counterweight 32 between the open and closed positions. An example of the bias adjuster 68 is shown in
The use of the second embodiment of the automatic closure system 24 for a screen door 16 will now be described. Initially, the door is typically in a closed position as shown in
During the travel of the screen door 16 from the open position (
In the example shown in
Another feature of the automatic closure system 24 according to the invention is shown in
The cable brake 50 can be used with either of the first embodiment of
The tab 52 can be maintained in the engaged position of
In use, if a user desires to prevent the automatic closure system 24 from operating, i.e., to prevent the counterweight 32 from drawing the screen door 16 from the open position to the closed position via the cable 28, the tab 52 is slid from the released position (
The invention overcomes the limitations of the prior art by offering simple manufacture, assembly and operation. It has a low profile relative to the door frame 18, has a low cost to manufacture and has little resistance when opening the sliding screen door unless the adjuster 42 or 68 and/or cable brake 50 is employed to provide additional resistance.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/319,397, filed Jul. 15, 2002, and U.S. Provisional Application Ser. No. 60/319,752, filed Dec. 4, 2002, both entitled “Automatically-Closing Screen Door and Closing Speed Adjuster for the Same.”
Number | Name | Date | Kind |
---|---|---|---|
4003102 | Hawks et al. | Jan 1977 | A |
4651469 | Ngian et al. | Mar 1987 | A |
4891911 | Yung | Jan 1990 | A |
6397530 | Terry et al. | Jun 2002 | B1 |
20010054260 | Plum et al. | Dec 2001 | A1 |
Number | Date | Country | |
---|---|---|---|
20040104001 A1 | Jun 2004 | US |
Number | Date | Country | |
---|---|---|---|
60319752 | Dec 2002 | US | |
60319397 | Jul 2002 | US |