Safety roof hatch system

Abstract

A system is provided for safe access to a roof through an opening in a roof of a structure having a fixed ladder leading upward to the opening. The system includes a mechanism to drive a set of pushrods to raise a hatch covering the opening. The system may include a section of ladder secured to the underside of the hatch. The system may have an extendable ladder driven by the drive mechanism to slide along the fixed ladder and extend through the opening in the roof when the hatch is raised. The system may include a safety pole driven by the drive mechanism to extend through the opening in the roof when the hatch is raised. The system allows someone who needs to access the roof for inspection or maintenance to safely open the hatch, climb up through the opening in the roof, and safely step onto the roof.

Claims

1. A safety system for a hinged roof hatch closing over an opening in a roof, the system comprising: a lower pushrod; a pole connected to the lower pushrod and slidable along a fixed ladder extending upward to the roof hatch; an upper pushrod connected at a lower end with a first hinge to a top end of the lower pushrod and connected at an upper end with a second hinge to an underside of the roof hatch; and a drive mechanism connected to the lower pushrod which, through movement of the lower and upper pushrods when activated, raises the hatch and extends the pole through the opening in the roof.

2. The safety system of claim 1, wherein the drive mechanism is hand operated.

3. The safety system of claim 2, wherein the hand operated drive mechanism is operated from the bottom of the fixed ladder.

4. The safety system of claim 2, wherein the hand operated drive mechanism is operated from the top of the fixed ladder.

5. The safety system of claim 1, wherein the drive mechanism is motorized.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A illustrates a conventional ladder/hatch configuration;

(2) FIG. 1B illustrates another conventional ladder/hatch configuration;

(3) FIG. 2A illustrates a prior art ladder extension device;

(4) FIG. 2B illustrates a prior art telescoping support pole;

(5) FIG. 3A is a side view of an embodiment of a roof hatch safety system of the present invention in the hatch closed position;

(6) FIG. 3B is a front view of the system of FIG. 3A;

(7) FIG. 3C is a side view of the system of FIG. 3A in the hatch open position;

(8) FIG. 4A is a side view of another embodiment of a roof hatch safety system of the present invention in the hatch closed position;

(9) FIG. 4B is a side view of the system of FIG. 4A in the hatch open position;

(10) FIG. 5A is a front view of a third embodiment of a roof hatch safety system of the present invention in the hatch closed position;

(11) FIG. 5B is a side view of the system of FIG. 5A in the hatch closed position;

(12) FIG. 5C is a side view of the system of FIG. 5A in the hatch open position;

(13) FIG. 6A is a front view of a fourth embodiment of a roof hatch safety system of the present invention in the hatch closed position;

(14) FIG. 6B is a side view of the system of FIG. 6A in the hatch closed position; and

(15) FIG. 6C is a side view of the system of FIG. 6A in the hatch open position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(16) The described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

(17) FIGS. 3A and 3B are side and front views, respectively, of an embodiment of the roof hatch safety system 100 of the present invention with the hatch lid in its closed position. FIG. 3C is a side view of the system 100 with the hatch lid 16 in its open position. The hatch lid 16 is connected to the hatch curb 12 with one or more hinges 18. An existing ladder 10 and hatch lid 16 may be retrofitted with the system 100 or the system 100 may be used as part of a new installation.

(18) The system 100 includes a section of ladder 102 mounted on the underside of the hatch lid 16 with one end (hereinafter “the lower end”) close to the hinge side of the hatch lid 16; the opposite (“upper”) end of the lid-mounted ladder section 102 extends towards the opposite side of the hatch lid 16. Thus, the ladder section 102 is in a plane substantially parallel to the underside of the lid 10. The system 100 also includes a pair of upper and lower pushrods 104A, 104B, a connecting ladder section 106, and a drive mechanism 120, which is secured with a bracket 122 to the fixed ladder 10 or the inside wall behind or next to the fixed ladder 10.

(19) One end (the “upper end”) of each upper pushrod 104A is secured to the underside of the hatch lid 16 and the opposite end (the “lower end”) of each is connected through a hinge 104C to one end (the “upper end”) of a corresponding lower pushrod 104B. As shown in the front view of FIG. 3B, the opposite end (the “lower end”) of each lower pushrod 104B is coupled to the drive mechanism 120 through a drive shaft 124. One end (the “upper end”) of each side of the frame of the connecting ladder section 106 is connected through a hinge to the corresponding sides of the frame of the lower end of the lid-mounted ladder section 102. The opposite end (the “lower end”) of each side of the frame of the connecting ladder section 106 is shaped like a hook facing the inside wall. When the system 100 and hatch lid 16 are in the closed position, the lower ends of the sides of the connecting ladder section 106 remain free and rest against the outside (relative to the wall) of the drive shaft 124.

(20) When the drive mechanism 120 is operated, the drive shaft 124 rotates and causes the upper and lower pushrods 104A, 104B to rise. The pushrods 104A, 104B in turn push the hatch lid 16 upward. As the hatch lid 16 rises, the hatch-mounted ladder section 102 rises with it, pulling the upper end of the connecting ladder section 106 with it. When the hatch lid 16 is fully in the open position, the pushrods 104A, 104B firmly hold the hatch lid 16 upright and prevent it from closing. In addition, the hooked lower ends of the sides of the connecting ladder section 106 mate with the drive shaft 124 or the upper end of the fixed ladder 10, thereby connecting the fixed ladder 10 with the hatch-mounted ladder section 102 and forming a continuous ladder from the bottom of the fixed ladder 10 onto the hatch lid 16. In this way, someone who needs to access the roof for inspection or maintenance, is able to open the hatch lid 16 from a safe position and climb up the fixed ladder 10, through the opening in the roof 14 onto the connecting ladder section 106 and the hatch-mounted ladder section 102, and then safely step over the hatch curb 12 onto the roof 14.

(21) FIGS. 4A and 4B illustrate side views of another embodiment of a roof hatch safety system 200 of the present invention in the hatch closed and open positions, respectively. The system 200 includes a ladder section 202 that is connected at its upper end to the hatch lid 16 with hinges. A pushrod 204 is coupled at its lower end to the drive mechanism 120 and the opposite end is coupled to the hatch-mounted ladder section 202 below the upper end of the hatch-mounted ladder section 202. When the drive mechanism 120 is activated, the upper end of the pushrod 204 rises, lifting the hatch lid 16 and with it the hatch-mounted ladder section 202. When the hatch lid 16 is fully open, as in FIG. 4B, the hatch-mounted ladder section 202 is contiguous with the fixed ladder 10, forming a continuous ladder from the bottom of the fixed ladder 10 onto the hatch lid 16. As with the system 100 illustrated in FIGS. 3A-3C, someone who needs to access the roof for inspection or maintenance, is able to open the hatch lid 16 from a safe position and climb up the fixed ladder 10, through the opening in the roof 14 onto the hatch-mounted ladder section 202, and then safely step over the hatch curb 12 onto the roof 14.

(22) FIGS. 5A, 5B, and 5C illustrate a third embodiment of a roof hatch safety system 300 of the present invention. In the system 300, the drive mechanism 120 raises and lowers a pushrod 304, the top section 304A of which is attached with a hinge or pivot to both the lower section 304B and the underside of the hatch lid 16 and is also attached to a sliding ladder extension 306. When the drive mechanism 120 is operated in one direction, the pushrod 304 is raised to open the lid 16. The ladder extension 306 also rises and extends upward through the opening in the roof (FIG. 5C), allowing a user to safely climb up the ladder through the hatch and step onto the roof 14. When the drive mechanism 120 is operated in the opposite direction, the pushrod 304 retracts the ladder extension 306 and closes the lid 16.

(23) FIGS. 6A, 6B, and 6C illustrate a fourth embodiment of a roof hatch safety system 400, similar to the third embodiment 300 but with a safety pole 408 instead of a ladder extension. The drive mechanism 120 raises and lowers a pushrod 404, to which the safety pole 408 is attached. A top section 404A of the pushrod 404 is attached with a hinge or pivot to both a lower section 404B and the underside of the hatch lid 16. When the drive mechanism 120 is operated in one direction, the pushrod 304 is raised to open the lid 16 (FIG. 6C). The connected safety pole 408 also rises and extends through the opening in the roof 14, allowing a user to safely climb up the ladder through the hatch and step onto the roof 14 while holding onto the pole 408. When the drive mechanism 120 is operated in the opposite direction, the pushrod 404 retreacts the pole 408 and closes the lid 16.

(24) The systems 300 and 400 may be included as part of a new installation or may be retrofitted to an existing installation.

(25) In the various embodiments, the drive mechanism 120 may be hand operated, such as with a hand crank. Alternatively, the drive mechanism 120 may include an electric motor. Although the drive mechanism 120 may be operated at the top of the fixed ladder, for safety and convenience it is preferable that it be operated from the bottom of the ladder 10. When the drive mechanism 120 is operated from the bottom of the fixed ladder 10, the hand crank or motor may be coupled to the drive mechanism 120 through any appropriate device, such as a drive rod, gear and chain, or the like. Whether located at the hatch lid 16 or the bottom of the ladder 10 and whether hand operated or electrically driven, the drive mechanism 120 is preferably lockable to prevent unauthorized use.

(26) The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.