Hatch assembly with modular installation construction and hatch cover lift assembly

Information

  • Patent Grant
  • 6560931
  • Patent Number
    6,560,931
  • Date Filed
    Monday, April 2, 2001
    23 years ago
  • Date Issued
    Tuesday, May 13, 2003
    21 years ago
  • Inventors
  • Examiners
    • Redman; Jerry
    Agents
    • Alix, Yale & Ristas, LLP
Abstract
A universal hatch assembly for accessing an enclosure includes a door. The frame has an opening defined therein that is dimensioned and configured for mounting the door. A hinge apparatus allows pivotal movement of the door about a first axis between a first position in which the door covers the opening and a second open position. The interior side of the door has an elongated channel extending in substantially perpendicular relationship to the first axis. An operating lever for positioning the door, has first and second axial extremities. A first axial part of the operating lever is spaced apart from the second axial extremity which is pivotally connected to the frame. The second axial extremity is dimensioned and configured for sliding meshing engagement with the elongated channel. The hatch assembly includes a lift assembly to provide a favorable counterbalance for the door. The frame may include a peripheral groove extending around substantially the entire frame. At least one module selected from several different modules according to a given application has a mounting surface dimensioned and configured for engaging the peripheral groove.
Description




BACKGROUND OF THE INVENTION




This invention relates to building construction and particularly to hatch assemblies. Such hatch assemblies typically include a hatch having a hinged cover. This invention has application to various types of hatches including, but not limited to:




(1) exterior sidewalk hatches also known as vault or pit access hatches or horizontal doors;




(2) interior floor hatches also known as horizontal floor doors;




(3) roof hatches also known as roof scuttles or roof access doors; and




(4) automatic fire vents also known as heat and smoke vents.




Historically, the construction industry has utilized hatches designed and constructed for specific installations. For example, a roof hatch conventionally is typically manufactured and constructed in a manner that does not facilitate adaptation of that hatch for use as an exterior sidewalk hatch. Known hatch constructions utilize a variety of means to assist the user in opening the door of the hatch assembly. These means include compression springs having either a vertical or a horizontal axis, torsion bars, torsion coil springs, gas struts, and telescoping compression springs.




SUMMARY OF THE INVENTION




An object of the present invention is to provide a hatch assembly having interchangeable installation modules to facilitate installation of the hatch assembly in a variety of different types of physical locations without the necessity of welding structural elements for a given application.




Thus, an object of the invention is to provide a hatch assembly that includes interchangeable modular elements that may be configured for use as an exterior sidewalk hatch, an interior floor hatch, or a roof hatch.




Another object of the invention is to provide a spring mechanism which imparts favorable counterbalancing characteristics to facilitate opening of the hatch in a reliable consistent manner.




Still another object of the invention is to provide a spring mechanism that is compact and disposed and constructed to minimize interference both with the passageway provided in the hatch assembly and with the hinged cover.




Yet another object of the invention is to provide apparatus having a more standardized and more uniform characteristic which is also adaptable to a wide range of applications and environments to thereby realize production efficiencies and reduce inventory requirements throughout manufacturing and product distribution channels.




A further object of the invention is to provide structure that incorporates a lifting mechanism that is compact and does not extend vertically and which thereby expands possible installation sites by minimizing potential interference between the lifting mechanism and the support structure and the hatch assembly structure.




It now has been found that these and other objects of the invention may be attained in a universal hatch assembly for accessing an enclosure which includes a door having a first side and a second side. The frame has an opening defined therein that is dimensioned and configured for engaging the door and the assembly also includes hinge apparatus mounting the door to the frame. The hinge apparatus allows pivotal movement of the door about a first axis between a first position in which the door covers the opening and a second position in which the door does not cover the opening. The first side of the door is disposed in facing relationship to the enclosed chamber when the door covers the opening. The first side of the door has an elongated channel extending in substantially perpendicular relationship to the first axis. The assembly also includes an operating lever for positioning the door. The operating lever has first and second axial extremities. A first axial part of the operating lever spaced apart from the second axial extremity is pivotally connected to the frame. The second axial extremity is dimensioned and configured for sliding meshing engagement with the elongated channel. The lift assembly also includes structure for biasing the pivotal position of the operating lever with respect to the frame including a coil extension spring. The lift assembly further includes a cable extending from the coil extension spring to a second axial part of the operating lever that is spaced apart from the first axial part of the operating lever.




In some forms of the lift assembly in accordance with the invention, the coil extension spring has a second axis. The second axis may be disposed in generally parallel relationship to the first axis, although in other forms of the invention the second axis may be perpendicular to the first axis or disposed at an oblique angle with respect to the first axis. The opening may have a first side and the first axis and the second axis may be disposed proximate to the first side. In some forms of the invention, the door has a depending flange and an elongated channel is formed in the depending flange.




A generally cylindrical member may be dimensioned and configured for sliding meshing engagement with the elongated channel. The assembly may further include a sheave cooperating with the cable.




Some forms of the hatch assembly in accordance with the invention may include the features described above in addition to the structural features described below. Other forms of the invention may include only the structural features described below.




The structure of the frame may include a first peripheral groove extending around substantially the entire frame. At least one module has a mounting surface dimensioned and configured for engaging the first peripheral groove. Several types of modules each specifically adapted for a given application are provided.




The hinge apparatus may include first and second plates, coupled by a hinge pin. The frame is dimensioned and configured for receiving the first plate. The second plate engages the door. The first plate has a second groove. The second groove is disposed in registered aligned relationship with the first peripheral groove to define a continuous uniform groove about the entire periphery of the frame. The frame includes a second peripheral groove extending around substantially the entire frame in some forms of the invention. The second peripheral groove may include a plurality of longitudinally extending ridges, dimensioned and configured for engaging a threaded fastener for securing modules to the frame. The first peripheral groove and the second peripheral groove may be parallel and proximate to each other. The module may take the form of a skirt, a clamp, an integral carpet/tile stop, or a flange for supporting and/or positioning the hatch assembly with respect to an opening.











BRIEF DESCRIPTION OF THE DRAWING




The invention will be better understood by reference to the accompanying drawing in which:





FIG. 1

is a plan view, partly in phantom, of a hatch assembly in accordance with one form of the present invention.





FIG. 2

is a perspective view of the hatch assembly of

FIG. 1

, with the door disposed in the open position.





FIG. 3

is a partially sectional view taken along the line


3





3


of

FIG. 1

, illustrating the position of some of the components when the door is in the open position.





FIG. 4

is a fragmentary elevational view, illustrating some of the elements when the door is in the closed position.





FIG. 5

is a perspective view of the door control lever and the cable that connects to a coil extension spring to provide counterbalancing forces when the door is opened.





FIG. 6

is a plan view, partially in phantom, of the door control lever and the cable that connects to a coil extension spring to provide counterbalancing forces when the door is opened.





FIG. 7

is an end elevational view similar to

FIGS. 5 and 6

.





FIG. 8

is a side elevational view, partially in phantom and partially broken away, similar to

FIGS. 5

,


6


and


7


.





FIG. 9

is a perspective view of an alternate embodiment having a separate cable connecting to each of two-door control levers.





FIG. 10

is a perspective view of another alternate embodiment, having a cable connecting to a door control lever that has a pivot point intermediate to the lever connection to the door, and the lever connection to the cable.





FIG. 11

is a perspective view of still another embodiment in which spring bias cables connect to opposing sides of a door control lever.





FIGS. 12

,


13


and


14


are respectively plan, end elevational and perspective views of the hinge that supports the door, and which also provides part of a continuous circumferential groove about the housing for engagement with a mounting skirt module,

FIGS. 12 and 13

being partially in phantom.





FIGS. 15

,


16


and


17


are sectional views of respective skirt modules and installed in various environments as further illustrated by broken lines.





FIGS. 18 and 19

are sectional views of respective flange modules installed in various environments as further illustrated by broken lines.





FIGS. 20

,


21


and


22


are respective end views of alternate extruded mounting surfaces that cooperate with flange and skirt modules.





FIGS. 23 and 24

are respectively to side elevation and perspective views of another member configured for cooperation with respective flange and skirt modules.





FIG. 25

is a diagrammatic view of an extension spring actuating mechanism.





FIG. 26

is a diagrammatic view of an alternate extension spring actuating mechanism.





FIG. 27

is a diagrammatic view of a frame section in accordance with a preferred form of the invention.





FIGS. 28

,


29


,


30


, and


31


are diagrammatic views of elements that may engage the frame section illustrated in FIG.


27


.





FIG. 32

is a diagrammatic view of the frame section illustrated in

FIG. 27

showing a forward in place installation, the most common installation method, for exterior sidewalk hatches in new construction.





FIG. 33

is a diagrammatic exploded view of the frame section illustrated in

FIG. 27

, together with a mating element and screw fastener for a drop in installation, the most common installation method, for interior floor hatches or exterior sidewalk hatches where an opening already exists prior to installation.





FIG. 34

is a diagrammatic view of the apparatus illustrated in

FIG. 33

fully assembled and dropped into an existing opening.





FIG. 35

is a diagrammatic exploded view of the frame section of

FIG. 27

in combination with associated elements for a common roof installation.





FIG. 36

is a diagrammatic view of the elements shown in

FIG. 35

, fully assembled and installed on an associated roof.





FIG. 37

is a diagrammatic view of the frame section shown in

FIG. 27

, supported by a support angle fixed to a concrete slab.





FIG. 38

is a diagrammatic view of a surface mount installation of the frame section illustrated in

FIG. 27

in combination with a generally planar associated structure and which illustrates the clearance between the lifting mechanism and the support structure.





FIG. 39

is a diagrammatic view, illustrating a retrofit installation of an existing industry standard hatch assembly with a frame section, and a lifting mechanism in accordance with the present invention.





FIG. 40

is a diagrammatic view of a roof hatch installation with a full exterior skirt.





FIG. 41

is a diagrammatic view of a drainage channel frame profile in accordance with one form of the present invention.





FIGS. 42 and 43

are diagrammatic views of angle frame profiles used on drainage frames commonly used for interior floor hatches.





FIG. 44

is a diagrammatic view of a roof hatch curb having a capped flashing for waterproofing.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




A universal hatch assembly in accordance with present invention may assume a wide number of configurations. Each hatch assembly has a frame that includes mounting surfaces to enable easy attachment of various load-bearing flanges, weather-sealing gaskets and cap-flashing modules without the need for welding or other specialized manufacturing steps. In a preferred embodiment, the hatch assembly includes a compact, horizontally mounted, extension coil spring, lifting mechanism suitable for retrofits and replacement applications as well as original installations. Advantageously, the appropriate modules may be assembled at the job site without the cost and long fabrication times associated with factory custom-made constructions.




Referring now to

FIGS. 1-8

, there is shown a hatch assembly


10


in accordance with one form of the present invention that employs the same lift assembly


11


as that shown diagrammatically in FIG.


25


. This hatch assembly


10


includes a cover or door


12


having a stiffener


14


fixed to the interior face thereof. The stiffener is provided with an elongated slot


16


that is rectilinear except for an L-shaped axial extremity


17


(shown in

FIG. 3

) for locking the door


12


in the open position. Hinges


18


mount the door


12


to the frame


20


. An operating lever or hold open arm


22


is pivotally connected by a bolt


29


at a first axial extremity to the frame


20


. A second axial extremity of the lever


22


is provided with a cylindrical follower


26


dimensioned and configured for meshing sliding engagement with the slot


16


. A coil extension spring assembly


24


is connected by a cable


27


to an axial point


28


on the operating lever


22


intermediate the first and second axial extremities. A sheave


25


guides the cable


27


around the right angle intersection of the sides of the frame


20


.




The embodiments illustrated in

FIGS. 1-8

,


10


,


25


and


26


each utilizes a single cable


27


connected to a single lever


22


or


40


.

FIGS. 9 and 11

illustrate alternative embodiments that each incorporates two discrete coaxial coil springs. In the embodiment of

FIG. 9

, each of two coil springs (not shown) is anchored at a bolt


120


disposed in between two operating levers


22


. The operating levers


22


are disposed on opposed sides of the hatch assembly. Ordinarily, the use of two operating levers


22


, instead of one operating lever, is reserved for particularly heavy doors


12


.

FIG. 11

illustrates another embodiment where two coaxial springs (not shown) are respectively fixed to two discrete cables


22


. The three ends of the cables


22


are fixed to a common bolt


124


that extends through a single lever


22


. This physical arrangement is also most useful when the weight of the door


12


is particularly heavy.




Referring now to

FIG. 25

, there is shown diagrammatically a coil extension spring actuating mechanism lift assembly


11


in which the axis of the coil spring


32


is aligned with the lever


40


. This structure more fully illustrated in

FIG. 10

is functionally equivalent to the structure diagrammed in FIG.


25


. This coil extension spring actuating mechanism


30


includes a coil extension spring


32


. In the embodiment of

FIG. 25

the geometric axis of the spring


32


is parallel to the direction of elongation of the lever


40


. The left (as viewed) axial extremity of the coil extension spring


32


engages a pin


34


. A housing


36


, having a generally square cross-section, encloses the spring


32


. A plurality of vertically extending holes


38


in the upper and lower surfaces of the housing


36


are dimensioned and configured for retaining the pin


34


, at any of a plurality of axial positions. Since the force produced by the spring


32


is proportional to the linear extension of the spring


32


, it is possible to adjust the operating characteristics of the coil extension spring actuating mechanism


30


by movement of the pin


34


to a different pair of holes


38


.




An operating lever


40


is provided with a pivot


42


that is intermediate the axial extremities of the operating lever


40


(unlike the operating lever


22


that is pivotally connected to the frame


20


at an axial extremity thereof). A cable


26


(preferably a multi strand steel cable, although some embodiments may use nylon or other materials) is attached to the second axial extremity of the spring


32


. The cable


26


passes over a guide member


44


and is fixed to the lower (as viewed) axial extremity of the lever


40


. The upper axial extremity (not shown) of the lever


40


is provided with a cylindrical follower


26


, that engages a slot as in the embodiment illustrated in

FIGS. 1

,


2


and


3


.




Accordingly, if the cover or door


12


is heavy and is otherwise restrained in the closed or horizontal position, the lever


40


is rotated fully around the pivot point


42


, in the maximum counterclockwise direction (the direction indicated by the arrow A). The spring


32


is extended to a length corresponding to a spring force necessary to counteract the weight of the cover


12


to provide an efficient and effective counterbalance for the cover


12


. Thus, when the cover


12


is opened, the spring


32


, exerts a force on the cable


27


that exerts a force on the lever


40


, thereby exerting a force on the underside of the cover


12


to lift the cover to the full opening or vertical position. Thus, the mechanism converts a horizontal motion of the extension spring


32


to an upward force.




Referring now to

FIG. 26

, there is shown a lift assembly


13


in which the geometric axis of the spring


32


is perpendicular to the direction of elongation of the lever


22


. (Reference numeral


22


is used herein to identify a lever that is pivotally mounted at an axial extremity of the lever as in the embodiment illustrated

FIGS. 1

,


2


,


3


,


4


and


26


. Reference numeral


40


is used herein to identify a similar lever that is pivotally mounted at a point intermediate the axial extremities of the lever.) The embodiment shown in

FIG. 26

enables the spring housing


36


to be disposed in a position that is not in line with the lever


22


. Those skilled in the art will recognize that although the geometric relationship in

FIG. 26

is a perpendicular relationship other included angles such as 30, 60, or 120 degrees could be constructed with substantially the same physical structure.




The hatch assemblies employ cover lift assemblies


11


or


13


which efficiently redirect the force of a horizontally mounted coil extension spring into a reliable, predictable, upward-lifting force, without imposing unnecessary torque or other stress on the frame, hinges or the cover. Thus, the lift assemblies


11


and


13


offer significant advantages over existing lifting mechanisms in terms of safety, durability, adjustability, and ease of installation. The use of a coil springs is desirable because of the greater precision associated with such coil extension springs as compared to alternative biasing.




Referring now to

FIG. 27

, there is shown a cross-section of the frame


20


that is also shown in

FIGS. 1

,


2


and


3


. The cross-section illustrated in

FIG. 27

is identical throughout the circumferential extent of the frame


20


(except as the parts thereof where the hinges


18


are disposed). Alternative frame cross-sections are shown in

FIGS. 20-22

. The upper face of the members that form the frame


20


is provided with a plurality of parallel grooves


45


. The grooves


45


will function to prevent slipping if the hatch assembly is installed where people walk. Alternatively, the grooves are decorative. Alternative flange constructions are shown in

FIGS. 18 and 19

.

FIG. 18

illustrates a standard flange


134


for “drop in” installation of interior or exterior floor hatches.

FIG. 19

illustrates a flange


136


with an integral carpet/tile stop that is primarily for interior floor hatches.

FIGS. 15

,


16


and


17


, respectively, illustrate a full exterior skirt


140


, a fixed cap flashing


142


, and a roof material clamp


144


.




The four extrusions which constitute the principal support structure of the generally rectangular frame


20


are provided with first and second peripheral grooves


46


,


48


intended to receive and mount various auxiliary structures. More particularly, the groove


46


has a generally square cross-section in the preferred embodiment. The groove


48


has a generally rectangular cross-section wherein the upper and lower surfaces thereof are provided with longitudinally extending ridges or serrations, as best seen in

FIGS. 20-23

and


24


, that are dimensioned and configured for receiving threaded fasteners as best seen in

FIGS. 15-19

.




The various auxiliary structures or modules are intended to convert the basic frame


20


from a standard “pour in place” or “surface mount” floor/sidewalk hatch configuration to a “drop in place” floor/sidewalk hatch configuration, a roof hatch configuration or other possible configurations. The frame components and the modules may be extruded structures. For example, the adapter


56


illustrated in

FIG. 29

is intended to convert a standard frame from a standard “pour in place” or “surface mount” floor/sidewalk hatch configuration to a “drop in place” floor/sidewalk hatch configuration.




The adapter


54


illustrated in

FIG. 28

is intended to convert a standard frame from a standard “pour in place” or “surface mount” floor/sidewalk hatch configuration to a roof hatch configuration. Similarly, the inner face of the frame


20


includes a groove


50


that is also intended to receive and mount various additional structures intended to convert the basic frame


20


for various applications. For example, a weather seal gasket


52


illustrated in

FIG. 31

is dimensioned and configured for engagement with the groove


50


. The ease with which alternate configurations are achieved with minimal effort and without special tools, glue or welding either at the factory or in the field is a significant advantage of the apparatus of the present invention.





FIG. 30

illustrates a cross-section of the hinge


18


that is also shown in

FIGS. 1

,


2


and


3


. The left (as viewed in

FIG. 30

) portion of the hinge


18


is provided with a peripheral groove


60


that is dimensioned and configured for alignment and registration with the groove


46


so that one continuous groove extends completely around the circumferential extent of the frame


20


.

FIGS. 12-14

illustrated the hinge


18


in still greater detail.




Referring now to

FIG. 32

, there is shown the cross-section of the frame


20


with poured concrete


66


disposed around the outer and bottom portions of the frame


20


. This is a “poured in place” installation.

FIGS. 33 and 34

show respectively the adapter


56


, illustrated in

FIG. 29

, together with a fastener


68


in exploded relationship with a frame


20


, as well as assembled to the frame


20


in a “drop in” installation. In other words, in a concrete surface


66


defines an opening, such as a sidewalk opening, and the hatch assembly is dropped into the opening.




As shown in

FIGS. 35 and 36

, the frame


20


is bolted with bolts


70


to a roof


72


. Optional insulation


74


may be installed in the recess


76


and a skirt


78


may be secured with a bolt


80


. The system preferably includes various other caps flashing, flashing clamps and full skirts for various types of waterproof roof constructions.

FIG. 37

illustrates still another “drop in” construction, utilizing a support angle


84


that is secured to the side of a concrete wall


82


. The frame


20


is dropped in and rests on the support angle


84


with the top of the frame


20


disposed in substantially flush relationship to the top surface of concrete


82


. The side of the frame


20


is disposed in side abutting relationship to the concrete


82


.





FIG. 38

illustrates still another surface mount installation in which the frame


20


is secured by a bolt


86


to a concrete support


82


. A coil extension spring actuating assembly


30


is disposed on the side of the frame. Advantageously, the horizontal mounting of the coil extension spring actuating assembly


30


provides ample clearance for the surrounding structure without compromising access through the hatch assembly. This is notably superior to other mechanisms that assist the user to lift the door


12


. More particularly, such conventional structures often have portions that extend downward and thus, in the case of the specific environment shown, interfere with the concrete


82


, as illustrated in FIG.


38


.




Referring now to

FIG. 39

, there is shown a retrofit installation of one form of the apparatus in accordance with the present invention. In a typical hatch installed outside of a building, the existing structure will include a drain channel


98


that extends around the entire circumferential extent of the hatch assembly. A base


100


and opposed first and second walls


90


and


102


define the drain channel


98


. As seen in

FIG. 39

, a frame member


96


particularly designed for the retrofit market has a generally L-shaped contour. The frame member


96


is secured by a bolt


97


to the inboard (nearer the center of the hatch assembly) side


102


of the drain channel


98


. More specifically, the frame member


96


is nested within the drain channel


98


. A coil spring actuating mechanism


104


, similar to the coil spring actuating mechanism


30


illustrated in

FIG. 25

, is secured by fasteners


106


to the outboard wall


90


of the drain channel


98


. Thus, it will be seen that the frame member


96


allows attachments via the circumferential groove


108


and specifically the attachment of a variety of devices in the manner described with respect to the embodiments intended for original equipment hatch assemblies.




A roof hatch installation


110


is shown in FIG.


40


. This installation utilizes the same frame member


20


used in other


10


installations. Bolts


112


secure the frame member


20


to the roof


114


. A coil extension spring actuating assembly


30


is fixed to the inboard face of frame member


20


. A full exterior skirt


116


(also referred to as a fully enclosed curb) is secured by a bolt


114


to the frame member


20


.




With reference to

FIG. 41

, some embodiments of the present invention incorporate a drain channel


118


(also known as a gutter or trough frame) having a drain coupling


20


welded to the underside of the drain channel


118


for connection to a drain pipe. This structure has particular application is for exterior sidewalk hatches. Other embodiments of the present invention will incorporate angle frame members such as members


122


,


124


shown respectively in

FIGS. 42 and 43

. Such members are commonly used for interior floor hatches. A preferred form of a roof hatch curb


126


is shown in FIG.


44


.




As used herein, the term “cable” refers to a multistrand steel cable as well as equivalent means for transferring a tension force, including other metallic, plastic and fiber cables. In the preferred embodiments the cover


12


is provided with a stiffener


14


having an elongated slot


16


formed therein. Those skilled in the art will recognize that various other structures may be utilized including, but not limited to, T-shaped slots to achieve the sliding meshing engagement that is required.




While the present invention has been described with reference to the preferred embodiments illustrated in the drawing, the detailed description thereof is not intended to limit the scope of the invention as claimed in the appended claims.



Claims
  • 1. A universal hatch assembly for accessing an enclosure which comprises:a door having a first side and a second side; a frame defining an opening; hinge means mounting said door to said frame, said hinge means allowing pivotal movement of said door about a first axis between a first position in which said door covers said opening and a second position in which said door does not cover said opening; said first side of said door being disposed interiorly when said door covers said opening, said first side of said door having an elongated channel extending in substantially orthogonal relationship to said first axis; an operating lever for positioning said door, being pivotally connected to said frame at a first lever location and being dimensioned and configured for sliding meshing engagement with said elongated channel at a second lever location axially spaced from said first location; and counterbalance means for biasing the pivotal position of said operating lever with respect to said frame comprising a coil extension spring, said counterbalance means further including a cable extending from said coil extension spring and connecting to said operating lever at a third location spaced from said first and second locations.
  • 2. A universal hatch assembly in accordance with claim 1, wherein said coil extension spring has a second axis and said second axis is disposed in generally parallel relationship to said first axis.
  • 3. A universal hatch assembly in accordance with claim 2, wherein said opening is defined by a first side and said first axis and said second axis are disposed proximate to said first side.
  • 4. A universal hatch assembly in accordance with claim 3, wherein said door has a depending flange, said elongated channel being formed in said depending flange.
  • 5. A universal hatch assembly in accordance with claim 4, wherein a said generally cylindrical member is dimensioned and configured for sliding meshing engagement with said elongated channel.
  • 6. A universal hatch assembly in accordance with claim 1, further including a sheave cooperating with said cable.
  • 7. A universal hatch assembly in accordance with claim 6, wherein said frame includes a first peripheral groove extending around substantially all of said frame.
  • 8. A universal hatch assembly in accordance with claim 7 further including at least one module having a mounting surface dimensioned and configured for engaging said first peripheral groove.
  • 9. A universal hatch assembly in accordance with claim 8, wherein said hinge means comprises first and second plates coupled by a hinge pin, said frame being dimensioned and configured for receiving said first plate, said second plate mounting said door, said first plate having a second groove, said second groove being disposed in aligned relationship with said first peripheral groove to define a substantially continuous uniform groove about the entire periphery of said frame.
  • 10. A universal hatch assembly in accordance with claim 8, wherein said module is a skirt.
  • 11. A universal hatch assembly in accordance with claim 8, wherein said module is a clamp.
  • 12. A universal hatch assembly in accordance with claim 8, wherein said module is a flange with an integral carpet/tile stop.
  • 13. A universal hatch assembly in accordance with claim 8, wherein said module is a flange for positioning said hatch assembly with respect to said opening.
  • 14. A universal hatch assembly in accordance with claim 7, wherein said frame includes a second peripheral groove extending around substantially all of said frame.
  • 15. A universal hatch assembly in accordance with claim 14, wherein said second peripheral groove includes a plurality of longitudinally extending ridges dimensioned and configured for threadably engaging a threaded fastener.
  • 16. A universal hatch assembly in accordance with claim 14, wherein said first peripheral groove and said second peripheral groove are parallel.
  • 17. A universal hatch assembly in accordance with claim 1, wherein said frame is a substantially rectangular structure having four interior sides and said spring is disposed in generally parallel relationship to one said frame.
  • 18. A universal hatch assembly in accordance with claim 1 further comprising adjustment means for adjusting the biasing force of said counterbalance means.
US Referenced Citations (5)
Number Name Date Kind
4951323 Shalom Aug 1990 A
5134805 Frantzen et al. Aug 1992 A
5335451 Druzynski Aug 1994 A
6000071 Fettes Dec 1999 A
6446307 Wilkins Sep 2002 B2