US20070095610A1

US20070095610A1 - Lift ladder

Info

Publication number: US20070095610A1
Application number: US11/266,696
Authority: US
Inventors: Derek Grundler
Original assignee: A1A Dock Products Inc
Current assignee: A1 A DOCK PRODUCTS Inc; A1A Dock Products Inc
Priority date: 2005-11-02
Filing date: 2005-11-02
Publication date: 2007-05-03

Abstract

A lift ladder has a support frame with two support bars each having a U-shaped portion and a vertical support portion. A transverse bar is disposed between the two supporting bars at the vertical support portion. The transverse bar has a catch member. A guide member is provided at an end of the vertical support portion of each of the support bars. The guide member is formed with a cutout. A ladder body to be supported by the support frame includes two vertical support members each to be slidably guided by a respective guide member. Rungs operatively engage with the catch member to fix the ladder in a position. A locking member is formed on each of the two vertical support members. The locking member is shaped to fit into the cutout of the guide member for minimizing movement of the ladder body with respect to the support frame.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The invention lies in the field of ladders, especially marine ladders used on swim floats, docks, seawalls, etc. The invention relates to a lift ladder that can be extended and retracted between a maximum extended position and a maximum retracted position and, thus, be adjusted to various heights. More specifically, the invention relates to a lift ladder that can be safely secured in any desired position.
Lift ladders for marine application exist in the prior art. Applicant's U.S. Pat. No. 6,422,340 B1 (Grundler), for example, shows such a lift ladder, which has a catch mechanism for supporting the rungs of the ladder and a stop member for defining the maximum height of the lift ladder.
However, the lift ladder as shown in U.S. Pat. No. 6,422,340 has a problem of swinging when the ladder is extended to the maximum extent, which may be caused by the wind or a wake created by a boat, for example. The swaying of the ladder can cause injury to a person swimming toward the ladder or to a person climbing the ladder. When mooring a boat, the swaying of the ladder can also cause damage to the boat.
Therefore, there is a need for an improved lift ladder that can be more safely secured in the maximum extended position to prevent injuries to persons or damage to boats.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide an improved lift ladder that can be more safely secured in the maximum extended position.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a lift ladder, comprising:

- a support frame having two support bars, each of the support bars having:
  - a U-shaped portion; and
  - a vertical support portion having an end;
- a transverse bar disposed between the two support bars at the vertical support portion, the transverse bar having a catch;
- guide members provided at the end of the vertical support portion of each of the support bars, at least one of the guide members defining a cutout; and
- a ladder body movably supported by the support frame, the ladder body having:
  - two vertical support members each slidably guided by a respective one of the guide members;
  - rungs each releasably engaged with the catch for setting a vertical position of the ladder body with respect to the support frame; and
  - a locking member formed on at least one of the two vertical support members, the locking member shaped to fit into the cutout for reducing movement of the ladder body with respect to the support frame.

In accordance with another feature of the invention, each of the guide members defines a cutout; and a locking member is formed on each of the two vertical support members, the locking members each shaped to fit into the cutout.
In accordance with a further feature of the invention, the locking member reduces lateral movement of the ladder body with respect to the support frame when disposed in the cutout.
In accordance with an added feature of the invention, the support frame has a longitudinal extent; and the locking member reduces movement of the ladder body in a direction orthogonal to the longitudinal extent when disposed in the cutout.
In accordance with an additional feature of the invention, the ladder body has an end; and the locking member is disposed on the vertical support member from a second uppermost one of the rungs to the end of the ladder body.
In accordance with yet another feature of the invention, the locking member is disposed on the vertical support member substantially at the second uppermost rung.
In accordance with yet a further feature of the invention, the ladder body has an end; and the locking members are disposed on a respective one of the vertical support members from a second uppermost one of the rungs to the end of the ladder body.
In accordance with yet an added feature of the invention, the locking members are disposed on a respective one of the vertical support members substantially at a location of the second uppermost rung.
In accordance with yet an additional feature of the invention, the catch has a L-shape; the rungs have a ceiling and two sides in an upside-down U-shape; and one of the sides operatively connects with the catch to releasably fix the ladder body in a position.
In accordance with another feature of the invention, there is provided a cable for connecting a respective one of the vertical support members of the ladder body to a respective one of the support bars.
With the foregoing and other objects in view, there is also provided, in accordance with the invention, a lift ladder, comprising:

- a ladder body having rungs and a locking member;
- a support frame slidably supporting the ladder body and having:
  - a guide member for guiding the ladder body between a stowed position and at least one extended position; and
  - a catch releasably engaging one of the rungs in at least one of the stowed position and the at least one extended position; and
- the locking member operatively connecting the guide member and locking the ladder body at the at least one extended position.

With the foregoing and other objects in view, there is also provided, in accordance with the invention, a lift ladder, comprising:

- a support frame having:
  - two substantially vertically oriented hand rails having a lower portion; and
  - a transverse bar fixedly connecting the two hand rails to one another, the transverse bar having a catch;
- at least one guide member provided at the lower portion of at least one of the hand rails, the at least one guide member defining a cutout; and
- a ladder body movably supported by the support frame, the ladder body having:
  - rungs each releasably engaged with the catch for setting a position of the ladder body with respect to the support frame; and
  - a locking member formed on at least one of the two vertical support members, the locking member shaped to fit into the cutout for reducing movement of the ladder body.

Other features that are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a lift ladder, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
Additional advantages of the invention will be set forth in part in the description which follows, and in part will be clear from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, perspective view of a lift ladder according to the invention secured to a dock;
FIG. 2 is a perspective view of the lift ladder of FIG. 1 in a retracted position;
FIG. 3 is a perspective view of the lift ladder of FIG. 1 in a maximum extended position;
FIG. 4 is fragmentary cross-sectional view along section line IV-IV in FIG. 3; and
FIG. 5 is fragmentary cross-sectional view along section line V-V in FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention may be understood more readily by reference to the following detailed description of preferred embodiments of the invention.
Before the invention is disclosed and described, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.
The invention will now be described in detail with reference to the accompanying drawings.
Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a lift ladder 100 according to the invention having a support frame 110 fixed to a dock 200 and a ladder body 120 that can be slidably supported by the support frame 110. The support frame 110 includes two support bars 111, each having a U-shaped portion 112 and a vertical support portion 113, and a transverse bar 115 with a L-shaped catch member 116 disposed between the two vertical support portions 113 of the support bars 111. The U-shaped portions 112 of the support bars 111 are each fixed to the dock 200 by a tie-down member 114 or by any other measures. A guide member 117 is provided at an end 113′ of a respective vertical support portion 113 of the support bar 111 for guiding the ladder body 120 during the extension and retraction movements. Each guide member 117 has a cutout 118 formed therein. The ladder body 120 has two vertical support members 121 and a plurality of U-shaped rungs 122 adapted to engage with the L-shaped catch member 116 to support the ladder body 120 with the support frame 110. Each of the vertical support members 121 has at least one locking member 123 projecting outwardly therefrom. In a preferred embodiment, a single locking member 123 is formed between the uppermost rung 122 and the second uppermost rung 122 of the ladder body 120. The locking member 123 is shaped to fit into the cutout 118 of the guide member 117. However, each vertical support members 121 may be provided with more than one locking members 123. For example, another locking member 123 may be provided on the vertical support members 121 at the lowermost rung 122.
FIG. 2 shows the lift ladder 100 in a retracted position. Cables 300 are provided to connect the ladder body 120 to the U-shaped portion 112 of the support bar 111. The cables 300 can facilitate the extending and retracting movements of the ladder body 120 and more particularly, prevent the ladder body 120 from being lost in the water if it is dropped or knocked loose. As shown in FIG. 2, the U-shaped rung 122 second from the bottom of the ladder body 120 is engaged with the L-shaped catch member 116 on the transverse bar 115 of the support frame 110.
In comparison to FIG. 2, FIG. 3 shows the lift ladder 100 in a maximum extended position, in which the uppermost rung 122 of the ladder body 120 is engaged with the catch member 116 on the transverse bar 115 of the support frame 110. Each locking member 123 on the ladder body 120 fits into the cutout 118 of the respective guide member 117 to provide the ladder body 120 with additional stability.
FIG. 4 even more clearly shows the connection between the catch member 116 and the rung 122. FIG. 4 illustrates how the upside-down U-shaped rung 122 of the ladder body 120 is engaged with the L-shaped catch member 116 formed on the transverse bar 115 of the support member 110. In this view, it can be seen that the transverse bar/support member 115/116 connection is a pivot, about which the ladder body 120 can rotate. It is this pivoting motion that the cutout/locking member 118/123 prevents.
FIG. 5 clearly shows how the locking member 123 fits into the cutout 118 of the guide member 117. Specifically, the cutout 118 has a diameter 118′ that is slightly greater than a diameter 123′ of the locking member 123. Because of this relatively tight fit, the two contact points (115/116 and 118/123) are stable and do not present a pivot for movement of the lowermost portion of the ladder body 120 when it is subjected to the moving force of water, or any other force. When a locking member 123 is provided on the vertical support members 121 at the lowermost rung 122, the two contact points (115/116 and 118/123) can also prevent the uppermost portion of the ladder body 120 from swiveling at a stowed position due to the wind.
As can be seen from FIG. 5, the distance between the two vertical support members 121 of the ladder body 120 is slightly smaller than the distance between the two vertical support portions 113 of the support bars 111 of the support frame 110 to accommodate the ladder body 120 within the guide members 117 on the vertical support portions 113.
It is apparent from the above description that the lift ladder 100 according to the invention has an advantage over the prior art—the ladder body 120 can be secured with additional stability to prevent the ladder body 120 from swaying, thus, preventing injury to a person or damage to a boat.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only.

Claims

1. A lift ladder, comprising:

a support frame having two support bars, each of said support bars having:

a U-shaped portion; and

a vertical support portion having an end;

a transverse bar disposed between said two support bars at said vertical support portion, said transverse bar having a catch;

guide members provided at said end of said vertical support portion of each of said support bars, at least one of said guide members defining a cutout; and

a ladder body movably supported by said support frame, said ladder body having:

two vertical support members each slidably guided by a respective one of said guide members;

rungs each releasably engaged with said catch for setting a vertical position of said ladder body with respect to said support frame; and

a locking member formed on at least one of said two vertical support members, said locking member shaped to fit into said cutout for reducing movement of said ladder body with respect to said support frame.

2. The lift ladder according to claim 1, wherein:

each of said guide members define a cutout; and

a locking member is formed on each of said two vertical support members, said locking members each shaped to fit into said cutout.

3. The lift ladder according to claim 1, wherein said locking member reduces lateral movement of said ladder body with respect to said support frame when disposed in said cutout.

4. The lift ladder according to claim 1, wherein:

said support frame has a longitudinal extent; and

said locking member reduces movement of said ladder body in a direction orthogonal to said longitudinal extent when disposed in said cutout.

5. The lift ladder according to claim 1, wherein:

said ladder body has an end; and

said locking member is disposed on said vertical support member from a second uppermost one of said rungs to said end of said ladder body.

6. The lift ladder according to claim 5, wherein said locking member is disposed on said vertical support member substantially at said second uppermost rung.

7. The lift ladder according to claim 2, wherein:

said ladder body has an end; and

said locking members are disposed on a respective one of said vertical support members from a second uppermost one of said rungs to said end of said ladder body.

8. The lift ladder according to claim 7, wherein said locking members are disposed on a respective one of said vertical support members substantially at a location of said second uppermost rung.

9. The lift ladder according to claim 1, wherein:

said catch has a L-shape;

said rungs have a ceiling and two sides in an upside-down U-shape; and

one of said sides operatively connects with said catch to releasably fix said ladder body in a position.

10. The lift ladder according to claim 1, further comprising a cable for connecting a respective one of said vertical support members of said ladder body to a respective one of said support bars.

11. A lift ladder, comprising:

a ladder body having rungs and a locking member;

a support frame slidably supporting said ladder body and having:

a guide member for guiding said ladder body between a stowed position and at least one extended position; and

a catch releasably engaging one of said rungs in at least one of said stowed position and said at least one extended position; and

said locking member operatively connecting said guide member and locking said ladder body said at least one extended position.

12. The lift ladder according to claim 11, wherein said support frame has a transverse bar and said catch is formed on said transverse bar.

13. The lift ladder according to claim 12, wherein:

said guide member defines a cutout; and

said locking member fits into said cutout for minimizing movement of said ladder body with respect to said support frame.

14. The lift ladder according to claim 11, wherein:

said guide member is two guide members each defining a cutout; and

said locking member is two locking members each shaped to fit into said cutout.

15. The lift ladder according to claim 11, wherein said locking member reduces lateral movement of said ladder body with respect to said support frame when disposed in said cutout.

16. The lift ladder according to claim 11, wherein:

said support frame has a longitudinal extent; and

17. The lift ladder according to claim 11, wherein:

said ladder body has an end; and

said locking member is disposed on said ladder body from a second uppermost one of said rungs to said end of said ladder body.

18. The lift ladder according to claim 11, wherein:

said catch is L-shaped;

said rungs have a ceiling and two sides in an upside-down U-shape; and

one of said sides operatively connects with said catch to releasably fix said ladder body in at least one of said stowed position and said at least one extended position.

19. A lift ladder, comprising:

a support frame having:

two substantially vertically oriented hand rails having a lower portion; and

a transverse bar fixedly connecting said two hand rails to one another, said transverse bar having a catch;

at least one guide member provided at said lower portion of at least one of said hand rails, said at least one guide member defining a cutout; and

a ladder body movably supported by said support frame, said ladder body having:

rungs each releasably engaged with said catch for setting a position of said ladder body with respect to said support frame; and

a locking member formed on at least one said two vertical support members, said locking member shaped to fit into said cutout for reducing movement of said ladder body.

20. The lift ladder according to claim 19, wherein:

said at least one guide member is two guide member each defining a cutout;

a locking member is two locking members formed on each of said two hand rails; and

said locking members are each shaped to fit into said cutout.

21. The lift ladder according to claim 19, wherein said locking member reduces lateral movement of said ladder body with respect to said support frame when disposed in said cutout.

22. The lift ladder according to claim 19, wherein:

said support frame has a longitudinal extent; and

23. The lift ladder according to claim 19, wherein:

said ladder body has an end; and

24. The lift ladder according to claim 23, wherein said locking member is disposed on said ladder body substantially at said second uppermost rung.

25. The lift ladder according to claim 19, wherein:

said catch has a L-shape;

said rungs have a ceiling and two sides in an upside-down U-shape; and

26. The lift ladder according to claim 19, further comprising a cable for connecting a respective one of said vertical support members of said ladder body to a respective one of said support bars.