Rung ladder in composite material

• US 20010017233A1
• Filed: 02/22/2001
• Published: 08/30/2001
• Est. Priority Date: 02/24/2000
• Status: Abandoned Application

• Current Assignee: Genex S.r.l. (CTE Group Srl)
• Original Assignee: Genex Sri
• Inventors: Panzeri, Luca
• Application Number:
  US09/790,835
• Publication Number:
  US 20010017233A1
• Time in Patent Office: Days
• US Class Current: 182/228.6
• CPC Class Codes: E06C 7/087 with a connecting piece installed around the rung

Abstract

A ladder made of composite material comprises a plurality of rungs having an elongated body (19) provided with at least one connecting portion (3) adapted to engage an upright (4) of a ladder. Engagement means (5) locks the rung (2) to the upright (4); this means comprises a coupling element (6) made by co-moulding on the connecting portion (3) of the elongated body (19) or, alternatively, on the connecting seating (20) of the upright (4), a mechanical fastener (9) operatively acting in an installation housing (8) of the coupling element (6) and a locking element (10) adapted to prevent disengagement of the mechanical fastener (9). The ladder (1) is made through the following steps: arranging the rungs (2), simultaneously arranging a pair of uprights (4), associating the coupling elements (6) either with the connecting portions (3) of the rungs or with the connecting housings (20) on the uprights and finally rigidly linking rungs (2) and uprights (4) together by screws (9) provided with locking screw anchors (10) fitted in the installation housings (8).

Claims

1. A ladder comprising:

a plurality of rungs (2) having each at least one respective connecting portion (3),

at least one upright (4) provided with a plurality of connecting seatings (20),

a plurality of coupling elements (6) interposed each between the connecting portion of a respective rung and the corresponding connecting seating on the upright for connection of said rungs (2) to the connecting seatings (20) of the upright (4), characterized in that said coupling element (6) is made by co-moulding on said portion or said connecting seating.

2. The ladder as claimed in

claim 1

, characterized in that the coupling element (6) is made by co-moulding on the connecting portion (6) of each rung (2), said coupling element being preferably made of plastic material.

3. The ladder as claimed in

claim 1

, characterized in that the coupling element is made by co-moulding on a predetermined number of connecting seatings (20) of the upright (4), said coupling element being preferably made of plastic material.

4. The ladder as claimed in

claim 1

, characterized in that it comprises at least one second upright (4), each rung (2) having the respective ends connected with said uprights (4), said uprights being parallel to or converging towards each other.

5. A rung (2) for ladders preferably of the type in accordance with

claim 1

, comprising:

an elongated body (19) having at least one connecting portion (3) adapted to engage an upright (4), said elongated body (19) being made of a plastic resin incorporating reinforcing fibres;

engagement means (5) associated with the elongated body (19), adapted to lock the connecting portion (3) to the upright (4), said engagement means (5) comprising a coupling element (6), characterized in that said coupling element (6) is made by co-moulding on the connecting portion (3) of the elongated body (19).

6. The rung as claimed in

claim 5

, characterized in that said connecting portion (3) is an end portion of the elongated body (19).

7. The rung as claimed in

claim 1

, characterized in that the coupling element (6) further comprises abutment extensions (7) operatively interacting with the connecting portion (3) of the elongated body (19).

8. The rung as claimed in

claim 5

, characterized in that the coupling element (6) has at least one installation housing (8), said engagement means (5) comprising a mechanical fastener (9) operatively active in said installation housing (8) between the coupling element (6) and the upright (4).

9. The rung as claimed in

claim 5

, characterized in that said engagement means (5) comprises at least one locking element (10) active on said mechanical fastener (9) to prevent disengagement of same from the installation seating.

10. The rung as claimed in

claim 9

, characterized in that said locking element (10) is embodied by a screw anchor.

11. The rung as claimed in

claim 5

, characterized in that the connecting portion (3) comprises a predetermined number of locating seats (22), said abutment extensions (7) being operatively engaged in said locating seats (11) of the connecting portion (3).

12. The rung as claimed in

claim 5

, characterized in that the coupling element (6) has a section conforming in shape to a connecting seating (20) formed in the upright (4).

13. The rung as claimed in

claim 6

, characterized in that the coupling element (6) has a perimetric abutment region (12) adapted to abut against the upright (4).

14. The rung as claimed in

claim 6

, characterized in that the coupling element (6) has a lead-in portion (13) close to the installation housing (8), said lead-in portion (13) being arranged to receive the mechanical fastener (9).

15. The rung as claimed in

claim 5

, characterized in that it has a substantially flat rest surface (14), said rest surface (14) being arranged in a substantially horizontal plane under use conditions of the ladder.

16. The rung as claimed in

claim 5

, characterized in that said rung (2) is a section member, preferably of tubular structure.

17. A process for making rungs for ladders preferably of the type in accordance with

claim 5

, characterized in that it comprises the steps of:

arranging an elongated body (19) made of plastic resin incorporating reinforcing fibres and having at least one connecting portion (3) adapted to engage an upright (4) of a ladder;

co-moulding to the connecting portion (3), a coupling element (6) for connection of the ladder rung (1) to the ladder upright (4).

18. The process for making rungs for ladders according to

claim 17

, characterized in that the step of co-moulding the coupling element (6) to the connecting portion (3) simultaneously forms the abutment extensions (7) having a shape conforming to the locating seats (11).

19. The process for making rungs for ladders according to

claim 17

, characterized in that in the co-moulding step the abutment extensions (7) are formed by forced introduction of the plastic material into the locating seats (11).

20. An upright for ladders preferably of the type in accordance with

claim 1

, comprising:

an axial body (21) having a plurality of connecting seatings (20) adapted to engage the rung (4), said axial body (21) being made of plastic resin incorporating reinforcing fibres;

engagement means (5) associated with the axial body (21), adapted to lock the connecting seating (20) to the rung (2), said engagement means (5) comprising a coupling element (6), characterized in that said coupling element (6) is obtained by co-moulding on the connecting seating (20) of the axial body (21).

21. The upright as claimed in

claim 20

, characterized in that the coupling element (6) has a shape conforming to the connecting seating (20) formed on the axial body (21).

22. The upright as claimed in

claim 20

, characterized in that the coupling element (6) has a connecting projection (22) adapted to house the connecting portion (3) of the rung (2).

23. The upright as claimed in

claim 20

, characterized in that the connecting projection (22) has a pre-established number of locking ridges (23) adapted to carry out engagement of the connecting portion (3) of the rung (2) with the connecting projection (22).

24. A process for making uprights for ladders preferably of the type in accordance with

claim 20

, characterized in that it comprises the steps of:

arranging an axial body (21) made of plastic resin incorporating reinforcing fibres and having a preestablished number of connecting seatings (20) adapted to engage a rung (2);

co-moulding the coupling element (6) to the connecting seating (20).

25. A process for making ladders of the type as claimed in

claim 5

or of the type as claimed in

claim 20

, comprising the following steps:

arranging a plurality of rungs (2);

arranging at least two uprights (4);

mechanically locking the rungs (2) to the assembling seatings provided on the uprights (4).

26. The process for making ladders as claimed in

claim 25

, characterized in that the step of arranging the rungs (2) comprises the following steps:

obtaining the elongated body (19) of composite material by forming;

transversely cutting the elongated body (19) to predetermined lengths;

making the locating seats (11) of the connecting portion (3) by drilling;

working the connecting portions (3) by milling so as to make them ready for assembling with the upright (4);

co-moulding the coupling element (6) on the connecting portions (3) or the connecting seatings (20).

27. The process for making ladders as claimed in

claim 25

, characterized in that the step of locking the rungs (2) to the uprights (4) comprises the following sub-steps:

handling a plurality of rungs (2) aligned along a first feed direction (15);

handling the uprights (4) along a second feed direction (16) transverse to said first feed direction (15) of the rungs (2);

associating the rungs (2) with the assembling seatings provided on the uprights (4);

installing the mechanical fasteners (9) between the rungs (2) and the uprights (4).