BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a door assembly, and more particularly, to such a door assembly that can be opened and closed with the application of a relatively small force. This type of door assembly is typically used for storm shelters that require its users to move relatively heavy doors in a short time.
2. Description of the Related Art
Several designs for door assemblies have been designed in the past. None of them, however, include the features claimed herein that overcome the need to apply a force of considerable magnitude to open and close a relatively heavy door, especially when this task needs to be accomplished in a relatively small period of time.
The present invention is particularly suited when used in storm shelters where a reliable door assembly is needed. Reliable door assemblies are typically heavy. With FEMA specifications, the door assemblies are heavy and difficult to open and close. This requires the application of relatively large forces.
In many instances, children, the elderly, or handicapped persons cannot operate the door assemblies. When a storm approaches a dwelling with a storm shelter, these individuals need to rapidly operate the door assembly by themselves. Thus, there is a need for this type of door assembly that can be readily operated.
SUMMARY OF THE INVENTION
It is one of the main objects of the present invention to provide a door assembly that can be easily opened and closed with the application of a relatively small force when compared to the weight of the activated door member.
It is another object of this invention to provide a door assembly that will reliably protect its users in an enclosure or storm shelter.
It is yet another object of this invention to provide such a door assembly that is inexpensive to manufacture and maintain while retaining its effectiveness.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings in which:
FIG. 1 represents an elevational cross-sectional side view of a storm shelter utilizing the door assembly incorporating an embodiment for the present invention with the door in the closed position.
FIG. 2 shows an isometric view of the door assembly represented in the previous figure, as seen from above at an angle. The outer and inner lever assemblies 40; 60 are horizontally disposed with door panel 32 in the closed position.
FIG. 2A is an isometric view of the door assembly shown in the previous figures seen from below at an angle and with slidable inner lever member 69 extended out and ready to be actuated.
FIG. 3 illustrates a side elevational view of the door assembly represented in the previous figures with the outer lever assembly 40 positioned at 90 degrees and inner lever assembly 60 at approximately 120 degrees. Door panel 32 is at approximately 60 degrees.
FIG. 3A is an enlarged elevational view of one end of curved connecting arm 66 pivotally mounted to angled plate 67, which in turn is rigidly mounted to inner lever member 69a. A portion of bearing member 64 has been removed to facilitate seeing angled plate 67.
FIG. 3B is a representation of lever assemblies 40 and 60 along with door panel 32 and the location of the pertinent vertical forces.
FIG. 4 is a side elevational view of door assembly 10 shown in the previous figures with the outer lever assembly 40 positioned at 180 degrees with door panel 32 at the extreme open position at approximately 120 degrees.
FIG. 4A is an enlarged elevational view of curved connecting arm 66 similar to FIG. 3A, but with inner lever assembly 60 at the zero degrees (horizontal) position (to the right).
FIG. 5 is an isometric representation of door panel assembly 30 shown in the previous figures with door panel 32 in the extreme open position with slidable inner lever member 69 in the distended position.
FIG. 6 represents an isometric view of the door assembly with door panel 32 at one extreme position (open) and the use of gas springs assemblies 80; 80a coupled to moving door panel 32.
FIG. 7 shows an alternate embodiment where a coil spring 90 is used to facilitate the opening and closing of door panel 32. In this position of inner lever assembly 60, coil spring 90 is in the compressed state exerting a force on assembly 60 at the end of member 69a, urging assembly 60 to move counterclockwise.
FIG. 8 is similar to the previous figure except that assembly 60 has traveled counterclockwise approximately 150 degrees, bringing door panel 32 to a substantially perpendicular position where it requires a minimum of force on assembly 60 to move it.
FIG. 9 is similar to the previous two figures wherein assembly 60 is shown rotated at 180 degrees with coil spring 90 at maximum expansion countering the moment of force of door panel 32 tending to move the latter counterclockwise.
FIG. 9A is an enlarged detail view of the portion of inner lever assembly 60 wherein coil spring 90 is mounted.
DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION
Referring now to the drawings, where the present invention is generally referred to with numeral 10, it can be observed that it basically includes a frame assembly 20 and a door panel assembly 30 hingedly mounted to the former. In FIG. 1, a cross-sectional view of a storm shelter is represented where door assembly 10 is shown in the closed position. A ladder L is internally disposed to facilitate the access and exit of users. This is one of two extreme positions for door panel 32. Telescopic outer lever assembly 40 is shown in the horizontal position, or the zero-degree position. Telescopic inner lever assembly 60 is also shown in the horizontal position that will be referred to as the 180-degree position. In this position for door panel 32, users may either be inside the protected area or outside.
FIG. 2 shows door panel 32, outer lever assembly 40, and inner lever assembly 60 in the horizontal position. Both outer and inner lever assemblies 40 and 60 are shown in the retracted position in FIG. 2. Slidable outer lever member 49 is selectively receivable inside outer lever member 49a of telescopic outer lever assembly 40. Slidable inner lever member 69 is selectively receivable inside inner lever member 69a of telescopic inner lever assembly 60. Hinge member 22 keeps door panel 32 pivotally mounted to frame assembly 20. Hinge member 22 defines a longitudinal pivoting axis for door panel 32. Lever assembly 40 is pivotally mounted to a fulcrum point defined by pivoting headed pin or shaft 42. Shaft 42 is journaled by bearing member 44 and one end of outer lever member 49a is pivotally mounted thereto through end plates 43 rigidly mounted to one end of member 49a. Connecting arm 46 is pivotally mounted to pivoting shaft 47 at one end 46a and to pivoting shaft 48 at the other end 46b. Shaft 47 is supported by bearing member 45. Slidable outer lever member 49 selectively and telescopically extends in and out of outer lever member 49a of assembly 40 in this embodiment.
Inner lever assembly 60 is pivotally mounted to headed pin or shaft 62, as best seen in FIG. 2. Curved connecting arm 66 is pivotally mounted at one end to door panel 32 and the other end to inner lever assembly 60, as best seen in FIG. 2A. FIG. 2A shows inner lever assembly 60 with inner lever member 69 in the extended position.
In the embodiment shown in FIG. 2, spacer assembly 50 is shown to include outer and inner plates 52 and 54, respectively, mounted at a parallel and spaced apart relationship to provide fixed reference supporting points for bearing members 44 and 64 (described below). The position of these fixed reference points can vary and different equivalent ways of providing them are contemplated. This unitary design provides a practical supporting mechanism for positioning the fulcrum points.
In FIG. 2A, locking pins 34 and 34a are shown disengaged in alignment with cooperating tubular members 35 and 35a, respectively. When door panel 32 is closed, pins 34 and 34a are moved outwardly to be received by tubular members 35 and 35a, respectively. Anchoring pins 36 are designed to be embedded in the surrounding structure where frame assembly 20 is mounted.
In FIG. 3, a user has moved (from inside the enclosure) inner lever assembly 60 to approximately the 120-degree position with door panel 32 reaching an approximately 60-degree position. Outer lever assembly 40 has moved from the horizontal position (0 degrees) to an approximately 90-degree position. Slidable inner lever member 69 is shown in the maximum distended position in FIG. 3 to achieve maximum leverage and torque to lift door panel 32.
In FIG. 4, a user has moved (from outside the enclosure) outer lever assembly 40 to approximately the 180-degree position, placing door panel 32 at approximately a 110-degree position. Slidable outer lever member 49 is slid completely out to achieve maximum leverage or torque. In FIG. 4A, this enlarged view facilitates the viewing of the different elements.
FIG. 5 shows door assembly 10 in the open position, ready to be closed by a user inside the protected enclosure. Slidable inner lever member 69 is completely extended out while member 49 is retracted. Locking pins 34; 34a have been moved inwardly. Door panel 32 is ready to be closed.
As it can be seen from FIG. 6, the moment of force created by a user will be a force he/she applies to lever assembly 40, and particularly at the distal end of member 49 when distended. This will maximize the moment of force applied. The pivot point for lever assembly 40 is at shaft 42.
Door assembly 30 pivots about its hinge member 22, which extends at a parallel and spaced apart relationship with respect to the pivot axis at shaft 42. As best seen in FIGS. 2 and 3, connecting arm 46 has end 46a pivotally mounted to pivoting shaft 47, which runs parallel and at a spaced apart relationship with respect to the axis of hinge member 22. The other end 46b of connecting arm 46 is pivotally connected to lever assembly 40 through pivoting shaft 48. As best seen in FIG. 3B, the moment F6·d1 created by the weight of door panel 32 needs to be overcome by the moment produced about shaft 48 by the vertical (perpendicular to lever assembly 40) component F2·d2. See FIG. 3. This moment of force is converted to F3·d3 and is transmitted through connecting arm 46 to door assembly 30, which is pivotally engaged at the pivoting point at shaft 47. The moment of force transmitted to door panel 32 will be the product of distance d4 (distance from hinge 22 to the pivoting point at shaft 47) and force F4 is applied at that point. Thus, the moment F4 times d4 needs to overcome the moment produced by the vertical component force F1, which corresponds to the weight of door panel 32 applied at its center of gravity, which is a distance d1 from the pivoting point at hinge 22.
Similarly, in FIG. 3B, the moments of force produced by lever assembly 60 are shown. Force F5 is applied by a user perpendicularly on lever member 69 at its distal end. The pivoting point for assembly 60 is at shaft 62 and the distance d5 multiplied by F5 provides the user's moment of force that is converted to moment F6 times the distance d6 from the pivoting point at shaft 62 to the projection of the pivoting point at shaft or pin 63 located at the distal end of angled plate 67. Distance d6 runs from the pivoting point of shaft 62 to the projection of the pivoting point at pin 63 on lever assembly 60. Distance d6 is considerably smaller than distance d5, thereby achieving a large multiplier for force F5. Force F6 is transmitted as force F7 to door panel 32 at shaft or pin 61, which is at a distance d7 from hinge 22. Force F7 multiplied by distance d7 provides a moment of force that overcomes F1, which is the perpendicular component of the weight W of door panel 32 multiplied by the distance d1 from hinge 22 to the center of gravity of door assembly 30.
Curved connecting arm 66 cooperates to clear bearing members 64; 64a. The location of the pivoting points at pins 61 and 63 for ends 66a; 66b of curved connecting arm 66 are also selected to clear bearings to cooperate with arm 66, as best seen in FIG. 2. Pin 61 is mounted to bearing member 68, keeping the former at a predetermined spaced apart relationship with respect to the plane of door panel 32.
The multiplier for force F5 is achieved by the ratio of the distance d5 over ds. The maximum length of extended lever assembly 60 is limited, in the case if a storm enclosure, by the height of the enclosure. Lever assembly 40 may have fewer limitations, depending on the physical surroundings.
As seen in FIG. 6, gas spring assemblies 80; 80a are mounted to reduce the moment of force required by a user as door panel 32 moves away from its perpendicular position. When door panel 32 is in the horizontal position, gas spring assemblies 80 urge the former to move counterclockwise. When door panel 32 is to the left of the perpendicular position, gas spring assemblies 80; 80a urge door panel 32 to move clockwise. When door panel 32 is perpendicular, very little force is needed to move it since the weight is vertically transmitted to hinge member 22.
In FIGS. 7 through 9, another alternate embodiment using coil spring 90 is shown. Coil spring 90 is mounted to a fixed point at inner plate 54 on one end 92 and the other end 94 of coil spring 90 is mounted to inner lever assembly 60 to member 69a, as best seen in FIG. 9A. Coil spring 90 is mounted in such a manner that it is at rest when door panel 32 is at a substantially perpendicular position. Coil spring 90 is at compression, in this embodiment, when assembly 60 is at the zero degree position, as seen in FIG. 7. Coil spring 90 is at rest, when door panel 32 is at a substantially perpendicular position, as seen in FIG. 8. Coil spring 90 is at the distended stage when the door panel 32 is as shown in FIG. 9.
The foregoing description conveys the best understanding of the objectives and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense.
Patent Grant
8397432
