CA2228083A1 - Plastic ladder - Google Patents
Plastic ladder Download PDFInfo
- Publication number
- CA2228083A1 CA2228083A1 CA 2228083 CA2228083A CA2228083A1 CA 2228083 A1 CA2228083 A1 CA 2228083A1 CA 2228083 CA2228083 CA 2228083 CA 2228083 A CA2228083 A CA 2228083A CA 2228083 A1 CA2228083 A1 CA 2228083A1
- Authority
- CA
- Canada
- Prior art keywords
- plastic
- side rails
- front side
- ladder
- rear side
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
- E06C—LADDERS
- E06C1/00—Ladders in general
- E06C1/02—Ladders in general with rigid longitudinal member or members
- E06C1/38—Special constructions of ladders, e.g. ladders with more or less than two longitudinal members, ladders with movable rungs or other treads, longitudinally-foldable ladders
- E06C1/39—Ladders having platforms; Ladders changeable into platforms
- E06C1/393—Ladders having platforms foldable with the ladder
-
- E—FIXED CONSTRUCTIONS
- E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
- E06C—LADDERS
- E06C7/00—Component parts, supporting parts, or accessories
- E06C7/08—Special construction of longitudinal members, or rungs or other treads
-
- E—FIXED CONSTRUCTIONS
- E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
- E06C—LADDERS
- E06C7/00—Component parts, supporting parts, or accessories
- E06C7/14—Holders for pails or other equipment on or for ladders
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Ladders (AREA)
Abstract
A ladder entirely made of plastic material comprises three components pivotally connected to one another; it includes an inverted U-shaped front rail body, a rear support body and an intermediate step plate connected to both bodies. The step plate is so configured that, when the rear support body is moved to bear against the front rail body, it is pivoted so as to lodge in a plane which is included within both bodies.
Description
TITLE OF THE INVENTION
Plastic ladder FIELD OF THE INVENTION
The present invention pertains to ladders and, more specifically, to a ladder entirely made of plastic material.
BACKGROUND OF THE INVENTION
Plastic ladders are known, such as the hollow plastic ladder described in U.S. patent 5,131,495 issued July 21, 1992 to Bartnicki et al.
The front and rear sections of the ladder described in this patent are folded towards and away each other through a linkage arrangement that consists of legs pivotally connected to one another by means of hinges. However, in order to be structurally reliable, such linkage component must be made of metallic material.
STATE=MENT OF THE INVENTION
It is an object of the present invention to provide a ladder which is entirely made of plastic material and which has a particular construction so as to give to the ladder the required stability, rigidity and strength when it is in a free standing position with a user mounted on one of its steps as well as neat compactness when it is in a folded position.
Plastic ladder FIELD OF THE INVENTION
The present invention pertains to ladders and, more specifically, to a ladder entirely made of plastic material.
BACKGROUND OF THE INVENTION
Plastic ladders are known, such as the hollow plastic ladder described in U.S. patent 5,131,495 issued July 21, 1992 to Bartnicki et al.
The front and rear sections of the ladder described in this patent are folded towards and away each other through a linkage arrangement that consists of legs pivotally connected to one another by means of hinges. However, in order to be structurally reliable, such linkage component must be made of metallic material.
STATE=MENT OF THE INVENTION
It is an object of the present invention to provide a ladder which is entirely made of plastic material and which has a particular construction so as to give to the ladder the required stability, rigidity and strength when it is in a free standing position with a user mounted on one of its steps as well as neat compactness when it is in a folded position.
Essentially, the ladder comprises three plastic components which are pivotally connected to one another to move between closed and opened standing positions.
The present invention therefore relates to a plastic ladder which comprises:
a first plastic component defining an inverted U-shaped body having opposite first and second front side rails integral with a top part;
a second plastic component having opposite first and second rear side rails extending coplanar with the first and second front side rails respectively; the upper end of each rear side rail being hingedly mounted to a respE~ctive front side rail; and a third plastic component connected to the first and second plastic components; the third plastic component defining an intermediate step plate having a top wall and opposite side walls;
the first, second and third components having inter-engaging means allowing pivotal movement of the second component to contact the first component whereby the rear side rails bear in coplanar arrangement against the front side rails and whereby the intermediate step plate lies substantially vertically in an area included within the first and second front and rear side rails bearing against each other.
In one form of the invention, the top part of the body defines a tray.
The present invention therefore relates to a plastic ladder which comprises:
a first plastic component defining an inverted U-shaped body having opposite first and second front side rails integral with a top part;
a second plastic component having opposite first and second rear side rails extending coplanar with the first and second front side rails respectively; the upper end of each rear side rail being hingedly mounted to a respE~ctive front side rail; and a third plastic component connected to the first and second plastic components; the third plastic component defining an intermediate step plate having a top wall and opposite side walls;
the first, second and third components having inter-engaging means allowing pivotal movement of the second component to contact the first component whereby the rear side rails bear in coplanar arrangement against the front side rails and whereby the intermediate step plate lies substantially vertically in an area included within the first and second front and rear side rails bearing against each other.
In one form of the invention, the top part of the body defines a tray.
In a further embodiment of the invention, a plastic tray is mountf:d to the top part of the body and is pivotable between a horizontal plane and a plane coincident with the parallel plane of the first and second front side rails.
Yet, in a further embodiment, a plastic tray is pivotally mounted to the first and second front side rails and is pivotable between a horizontal plane and a plane coincident with the parallel plane of a first and second front side rails.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that this detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a first embodiment of a plastic ladder made in accordance with the present invention;
Figure 2 is a side elevation thereof;
Figure 3 is a perspective view of the intermediate step plate;
Yet, in a further embodiment, a plastic tray is pivotally mounted to the first and second front side rails and is pivotable between a horizontal plane and a plane coincident with the parallel plane of a first and second front side rails.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that this detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a first embodiment of a plastic ladder made in accordance with the present invention;
Figure 2 is a side elevation thereof;
Figure 3 is a perspective view of the intermediate step plate;
Figure 4 is a perspective view of the second plastic component of the ladder;
Figure 5 is a front elevation view of the ladder shown in figure 1;
Figure 6 is a cross sectional view taken along lines 6-6 of figure 5;
Figure 7 is a cross sectional view, similar to that of figure 6, showing the ladder in the folded position;
Figure 8 is a perspective view of a second embodiment of the present invention; and Figure 9 is a perspective view of a third embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the drawings wherein like reference numerals refer to similar or identical parts throughout the several views, there is shown, in figures 1-7, a first embodiment 10 of a ladder which is made entirely of plastic material. It comprises a first plastic component, generally denoted 11, defining an inverted U-shaped body consisting of a plastic front side rail 12, havirng a bottom end 16, of a second plastic front side rail 18 having a bottom end 22 and of an integral top part 23. A plastic step 24 is integrally formed to thE~ inner walls of the side rails 12 and 18; additional steps may be provided, if required.
The ladder also comprises a second plastic component, generally denoted 25, consisting of a first rear side rail 26 having its upper end 28 hingedly connected to the side rail 12 and of a second rear side rail 30 which has its upper end 32 hingedly connected to the side rail 18. A
plastic X-shaped brace structure 34 extends between and is integral with the two rE~ar side rails 26 and 30 to provide reinforcement.
The ladder comprises a third plastic component, generally denoi:ed 36, defining an intermediate step plate which is connected to the front pair of side rails and to the rear pair of side rails. Referring more particularly to figure 3, the step plate 36 comprises a flat top face 38, having anti-skid means 39, and opposite side walls 40 and 42, each displaying a projecaion 41, 43 for pivotal connection to respective side rails 12 and 18.
The projections 41 and 43 are C-shaped to enable a snap engagement with corre:>ponding pins (one of which is shown as 44 in figures 6 and 7) integrally formed with the side rails 12 and 18. On each side wall of the step plate an elongated curved recess 45, 45' is provided to receive a pin 46, 47 (see figure 4) integral formed with an associated rear side rail 26, 30.
Referring to figures 6 and 7, the particular construction of the plate 36 is such that, from the standing open position of figure 6, pivotal movement of rear rails 26 and 30 about hinges 28 and 32 causes also the pivotal movement of plate 36 about pivots 44 whereby pins 46 and 47 slidably follow the curved path of recesses 45, 45' in the opposite side walls of the plate until they reach the position shown in figure 7 where the rear side rails c'.6 and 30 come to lie in a substantially coplanar arrangement with and to beer against their associated front side rails 12 and 18. As can be seen also in figure 7, the cross plate 36 reaches an almost vertical position in an area included between the pair of front and rear side rails to form a neat compact folded condition.
In the embodiment illustrated in figures 1 to 7, the top part 23 of the first plastic component is shaped to define an integral tray 64. This upper part of the ladder described above with respect to a first embodiment of the invention may have various arrangements. For example, in figure 8, the inverted U-shaped body 11' has a top portion 23' with a pivotal tray 66.
This bray may be moved from a horizontal position (for use) to a substantially vertical position (for storing) in a plane coincident with the plane of the front side rails 12' and 18'. No structural changes are required for components 25 and 36 of the ladder.
Figure 9 shows an inverted U-shaped structure 11 " with a tray 68 pivotally mounted to the inner walls of two side rails 12" and 18". Tray 68 is mounted so that it may be moved from a horizontal position (for use) to a plane (for storing) which is coincident with the plane of side rails 12"
and 18", changes are required for the components 25 and 36 to provide a compact storing arrangement.
Although the invention has been described above with respect to three specific forms, it will be evident to a person skilled in the art that it may be modified and refined in various ways. For example, the inter-engaging means between the three plastic components may be varied. It is therefore wished to have it understood that the present invention should not be limited in scope, except by the terms of the following claims.
Figure 5 is a front elevation view of the ladder shown in figure 1;
Figure 6 is a cross sectional view taken along lines 6-6 of figure 5;
Figure 7 is a cross sectional view, similar to that of figure 6, showing the ladder in the folded position;
Figure 8 is a perspective view of a second embodiment of the present invention; and Figure 9 is a perspective view of a third embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the drawings wherein like reference numerals refer to similar or identical parts throughout the several views, there is shown, in figures 1-7, a first embodiment 10 of a ladder which is made entirely of plastic material. It comprises a first plastic component, generally denoted 11, defining an inverted U-shaped body consisting of a plastic front side rail 12, havirng a bottom end 16, of a second plastic front side rail 18 having a bottom end 22 and of an integral top part 23. A plastic step 24 is integrally formed to thE~ inner walls of the side rails 12 and 18; additional steps may be provided, if required.
The ladder also comprises a second plastic component, generally denoted 25, consisting of a first rear side rail 26 having its upper end 28 hingedly connected to the side rail 12 and of a second rear side rail 30 which has its upper end 32 hingedly connected to the side rail 18. A
plastic X-shaped brace structure 34 extends between and is integral with the two rE~ar side rails 26 and 30 to provide reinforcement.
The ladder comprises a third plastic component, generally denoi:ed 36, defining an intermediate step plate which is connected to the front pair of side rails and to the rear pair of side rails. Referring more particularly to figure 3, the step plate 36 comprises a flat top face 38, having anti-skid means 39, and opposite side walls 40 and 42, each displaying a projecaion 41, 43 for pivotal connection to respective side rails 12 and 18.
The projections 41 and 43 are C-shaped to enable a snap engagement with corre:>ponding pins (one of which is shown as 44 in figures 6 and 7) integrally formed with the side rails 12 and 18. On each side wall of the step plate an elongated curved recess 45, 45' is provided to receive a pin 46, 47 (see figure 4) integral formed with an associated rear side rail 26, 30.
Referring to figures 6 and 7, the particular construction of the plate 36 is such that, from the standing open position of figure 6, pivotal movement of rear rails 26 and 30 about hinges 28 and 32 causes also the pivotal movement of plate 36 about pivots 44 whereby pins 46 and 47 slidably follow the curved path of recesses 45, 45' in the opposite side walls of the plate until they reach the position shown in figure 7 where the rear side rails c'.6 and 30 come to lie in a substantially coplanar arrangement with and to beer against their associated front side rails 12 and 18. As can be seen also in figure 7, the cross plate 36 reaches an almost vertical position in an area included between the pair of front and rear side rails to form a neat compact folded condition.
In the embodiment illustrated in figures 1 to 7, the top part 23 of the first plastic component is shaped to define an integral tray 64. This upper part of the ladder described above with respect to a first embodiment of the invention may have various arrangements. For example, in figure 8, the inverted U-shaped body 11' has a top portion 23' with a pivotal tray 66.
This bray may be moved from a horizontal position (for use) to a substantially vertical position (for storing) in a plane coincident with the plane of the front side rails 12' and 18'. No structural changes are required for components 25 and 36 of the ladder.
Figure 9 shows an inverted U-shaped structure 11 " with a tray 68 pivotally mounted to the inner walls of two side rails 12" and 18". Tray 68 is mounted so that it may be moved from a horizontal position (for use) to a plane (for storing) which is coincident with the plane of side rails 12"
and 18", changes are required for the components 25 and 36 to provide a compact storing arrangement.
Although the invention has been described above with respect to three specific forms, it will be evident to a person skilled in the art that it may be modified and refined in various ways. For example, the inter-engaging means between the three plastic components may be varied. It is therefore wished to have it understood that the present invention should not be limited in scope, except by the terms of the following claims.
Claims (10)
1. A plastic ladder comprising:
a first plastic component defining an inverted U-shaped body having opposite first and second front side rails integral with a top part;
a second plastic component having opposite first and second rear side rails extending coplanar with said first and second front side rails respectively; the upper end of each said rear side rail being hingedly mounted to a respective front side rail; and a third plastic component connected to said first and second plastic components; said third plastic component defining an intermediate step plate having a top wall and opposite side walls;
said first, second and third components having inter-engaging means allowing pivotal movement of said second component to contact said first component whereby said rear side rails bear in coplanar arrangement against said front side rails and whereby said intermediate step plate lies substantially vertically in an area included within said first and second front and rear side rails bearing against each other.
a first plastic component defining an inverted U-shaped body having opposite first and second front side rails integral with a top part;
a second plastic component having opposite first and second rear side rails extending coplanar with said first and second front side rails respectively; the upper end of each said rear side rail being hingedly mounted to a respective front side rail; and a third plastic component connected to said first and second plastic components; said third plastic component defining an intermediate step plate having a top wall and opposite side walls;
said first, second and third components having inter-engaging means allowing pivotal movement of said second component to contact said first component whereby said rear side rails bear in coplanar arrangement against said front side rails and whereby said intermediate step plate lies substantially vertically in an area included within said first and second front and rear side rails bearing against each other.
2. A plastic ladder as defined in claim 1, wherein said inter-engaging means include a curved recess on each opposite wall of said step plate.
3. A plastic ladder as defined in claim 2, wherein said inter-engaging means include first pin means on said rear side rails engaged in said curved recess and second pin means on said front side rails.
4. A plastic ladder as defined in claim 3, wherein said inter-engaging means include C-shaped projections on said opposite walls of said step plate, adapted for snap engagement with said second pin means on said first and second front side rails.
5. A plastic ladder as defined in claim 1, wherein said upper ends of said first and second rear side rails define C-shaped projections adapted for snap engagement with pin means on said first and second front side rails.
6. A plastic ladder as defined in claim 1, wherein said top part of said first component defines a tray.
7. A plastic ladder as defined in claim 1, further comprising a plastic tray pivotally mounted to said U-shaped body; said tray being movable between a plane coincident with said parallel plane of said first and second front side rails and a horizontal plane.
8. A plastic ladder as defined in claim 1, further comprising a plastic tray pivotally mounted to said top part of said U-shaped body; the tray being pivotable between a horizontal plane and a plane coincident with said parallel plane of said first and second front side rails.
9. A plastic ladder as defined in claim 1, comprising one or more steps integrally formed to said first and second front side rails.
10. A plastic ladder as defined in claim 1, comprising an X-shaped cross-member arrangement extending between and integral with said rear first and second rear side rails.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2228083 CA2228083A1 (en) | 1998-01-28 | 1998-01-28 | Plastic ladder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2228083 CA2228083A1 (en) | 1998-01-28 | 1998-01-28 | Plastic ladder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2228083A1 true CA2228083A1 (en) | 1999-07-28 |
Family
ID=29409167
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2228083 Abandoned CA2228083A1 (en) | 1998-01-28 | 1998-01-28 | Plastic ladder |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2228083A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110593748A (en) * | 2019-10-30 | 2019-12-20 | 南通创鸿新材料科技有限公司 | Stable aluminum alloy herringbone ladder |
-
1998
- 1998-01-28 CA CA 2228083 patent/CA2228083A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110593748A (en) * | 2019-10-30 | 2019-12-20 | 南通创鸿新材料科技有限公司 | Stable aluminum alloy herringbone ladder |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |