CA2246620A1 - Signal mast assembly - Google Patents
Signal mast assembly Download PDFInfo
- Publication number
- CA2246620A1 CA2246620A1 CA 2246620 CA2246620A CA2246620A1 CA 2246620 A1 CA2246620 A1 CA 2246620A1 CA 2246620 CA2246620 CA 2246620 CA 2246620 A CA2246620 A CA 2246620A CA 2246620 A1 CA2246620 A1 CA 2246620A1
- Authority
- CA
- Canada
- Prior art keywords
- mast
- ladder
- signal
- platform
- assembly
- 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
- E06C9/00—Ladders characterised by being permanently attached to fixed structures, e.g. fire escapes
- E06C9/02—Ladders characterised by being permanently attached to fixed structures, e.g. fire escapes rigidly mounted
Abstract
The invention relates to a signal mast assembly. It is known in the art that winds, ice loads, and shifting ground lead to premature signal mast failure.
The present invention provides a stable signal mast assembly that prevents premature signal mast failure. The signal mast assembly comprises a unified base, which may include a foundation on which a base plate may be placed. A mast having a signal light positioned thereon, and a ladder are mounted on the unified base. A
platform and bracing are positioned between the mast and the ladder, and connecting rails surround the platform so that upon ascending the ladder, a worker may stand on the platform and grasp or lean on the connecting rails. By attachment of the mast and ladder to a unified base, and by joining the ladder and mast with the platform and the connecting rails, the invention provides a mast and ladder assembly having superior strength and low deflection.
The present invention provides a stable signal mast assembly that prevents premature signal mast failure. The signal mast assembly comprises a unified base, which may include a foundation on which a base plate may be placed. A mast having a signal light positioned thereon, and a ladder are mounted on the unified base. A
platform and bracing are positioned between the mast and the ladder, and connecting rails surround the platform so that upon ascending the ladder, a worker may stand on the platform and grasp or lean on the connecting rails. By attachment of the mast and ladder to a unified base, and by joining the ladder and mast with the platform and the connecting rails, the invention provides a mast and ladder assembly having superior strength and low deflection.
Description
SIGNAL MAST ASSEMBLY
The present invention relates to a signal mast assembly particularly for use with railroad signal lights.
BACKGROUND OF THE INVENTION
Railroad signal lights located on masts often require replacement or maintenance. A ladder is typically used to provide a worker to access the signal light. Such ladders have conventionally been permanent installations either attached to the mast with a cantilever mount, or positioned adjacent to the signal mast and having a pier system or foundation separate from that of the mast.
It is well known within the art that present signal mast assemblies are prone to premature failure, for example, as a result of wind storms and ice loads. Attachment of a ladder to a mast using a cantilever mount has the further disadvantage that extra stress is placed on the mast to support the weight of the ladder, which can lead to mast failure. If the mast and the ladder have separate foundations, the shifting of the ground which occurs over time may result in a change in the position of the ladder relative to the mast, necessitating replacement of either the ladder or the mast. When the mast and ladder are mounted on separate foundations, wind and ice loads can easily stress and thus damage the mast or the ladder.
In response to the problem of shifting ground, various foundations such as those disclosed in U.S. Patents Nos. 5,257,489 (Anglette; Nov. 2, 1993) and 5,533,845 (Anglette, July 9, 1996) have been proposed for securing railroad signal masts. However, support for an adjacent ladder is not addressed.
_2_ U.S. Patent No. 3,952,978 (Reinitz; April 27, 1976) teaches a cantilever arm signal assembly for use in suspending signal lights over a roadway.
Catwalk panels may be used along the cantilever arm, for a worker to access the signal lights when maintenance or repair is needed. Such an assembly causes stress on the mast to support the weight of the cantilever arm, and thus the mast must be formed of sturdy stress-resistant materials. A mast and ladder assembly providing access the catwalk is not addressed by Reinitz.
An increase the standard size of existing masts for railroad signals from the standard 5.5 inch outer diameter to an 8 to 10 inch outer diameter would contribute mast stability and strength. However, there is reluctance in the industry to change from 5.5 inch outer diameter, since signal light fixtures and accessories are sized for the current standard, and considerable expense would be incurred if this standard were to be changed. It is therefore desirable to achieve increased mast stability without increasing mast diameter.
It is an object of the present invention to provide a mast and ladder assembly which substantially obviates the above-noted deficiencies of the prior art.
SUMMARY OF THE INVENTION
According to the invention, there is provided a signal mast assembly comprising a unified base, a mast mounted to the unified base, a ladder mounted to the unified base, and a joining means for joining the mast and the ladder at a location above the unified base.
The mast and ladder are coupled by the joining means, which acts as a truss, thereby providing superior load carrying capability and deflection resistance when compared to a mast alone.
The unified base may comprise a foundation for placement on the ground and a base plate attached to an upper portion of the foundation, wherein the mast and the ladder are mounted on the base plate. A fixture, such as a signal light may be attached at an upper portion of the mast. The joining means may comprises a platform positioned between the mast and the ladder, and connecting rails may be positioned between the mast and the ladder. The joining means may also include at least one support bracket or gusset.
The signal mast assembly of the present invention has the advantage that the mast and the ladder share the unified base. Thus, shifting in the ground below the assembly does not change the arrangement of the mast and ladder relative to each other. Structurally joining the ladder to the mast also has the advantage of providing enhanced load carrying capability, and much lower deflection than a mast not joined to a ladder structure. Thus, the assembly of the present invention has an enhanced capacity to withstand wind and ice loads.
A further advantage of the invention is that the weight of the ladder is not supported by the mast since both the ladder and the mast attach to the unified base, reducing the likelihood of mast failure due to weight stresses induced by a cantilever mounted ladder.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
FIGURE la is a perspective view of an aspect of an embodiment of the invention, having one signal light;
FIGURE lb is a front view of the embodiment of FIGURE 1 a;
FIGURE lc is a side view of the embodiment of FIGURE 1 a;
FIGURE ld is a top view of the embodiment of FIGURE la;
FIGURE 2a is a perspective view of another aspect of an embodiment of the invention, having two signal lights facing the same direction;
FIGURE 2b is a partial side view of the embodiment of FIGURE 2a;
FIGURE 3a is a perspective view of another aspect of an embodiment of the invention, having two signal lights facing opposite directions;
FIGURE 3b is a front view of the embodiment of FIGURE 3a;
FIGURE 3c is a side view of the embodiment of FIGURE 3a;
FIGURE 4a is a perspective view of another aspect of an embodiment of the invention, having two signal lights facing opposite directions and gussets;
FIGURE 4b is a front view of the embodiment of FIGURE 4a; and FIGURE 4c is a side view of the embodiment of FIGURE 4a.
DESCRIPTION OF PREFERRED EMBODIMENTS
Having regard to FIGURES 1 to 4, the invention is described for use with masts which support railroad signal lights. However, it is to be understood that the invention is not limited thereto. The invention may be used for any mast requiring an adjacent ladder.
The invention provides a unified base for connection of the ladder and mast to a generally horizontal and fixed surface. According to embodiments of the invention relating to masts for support of railroad signals, the unified base may be any which is known in the art and which is adapted to have the mast and the ladder attached thereto. Preferably, the unified base consists of a foundation and optionally a base plate affixed to the foundation. The foundation may be made of any appropriate rigid material such as cement or metal. A pier type foundation may be used, having a plurality of vertical pier supports for placement above or below the ground surface, such as depicted in FIGS. 1 to 3, having 6 pier supports, and FIG. 4, having 4 pier supports.
The base plate located on the foundation is a rigid horizontal surface capable of having the lower portion of both the mast and the ladder affixed thereto. For example, but not intending to limit the present invention in any manner, according to the embodiments depicted in FIGS. 1 to 4, the foundations comprise reinforced concrete legs to which a base plate, such as a metal plate, is bolted. The mast and the ladder are bolted to the upper surface of the base plate. However, it is to be understood that other variations of the unified base are within the scope of the present invention. For example, the mast and ladder may be set into the foundation directly or attached to the foundation in an appropriate manner without the use of a base plate, provided that the foundation to which the mast and ladder are attached is unified in some manner.
The mast may be any rigid pole or pillar extending upwardly from the unified base. The mast may be affixed to the unified base through a permanent or semi-permanent connection such as bolts, mechanical fasteners, welding, etc.
Preferably, the mast is capable of supporting a fixture at the upper end thereof.
When referring to the embodiment wherein the mast is used to support a railroad signal, the mast may be of from 5 inches in outer diameter to over 10 inches in outer diameter, depending on the standards and requirements.
The ladder may be of any type which allows a worker to climb up and access upper regions of the mast. The lower end of the ladder is affixed to the unified base through any appropriate means and may be set directly in the foundation, or attached to the foundation or a platform using any suitable means such as bolts, mechanical fasteners, welding, etc. As shown in FIGS 1 to 4, the ladder has a plurality of horizontal rungs.
In order to further provide strength and rigidity to the signal mast of the present invention, the mast and associated ladder may be interconnected together by any suitable joining means which structurally joins the mast and the ladder at a position above the unified base, ensuring the formation of a truss-like structure. According to one embodiment, the joining means may comprise a platform, which may be a solid horizontal surface appropriate for a worker to stand on when manipulating a fixture positioned on the mast. The platform may be a planar rectangular surface, and one of the edges of the rectangle may be aligned with the mast and a side of the ladder.
A connecting rail may be positioned between the mast and the ladder at a location above the unified base, to stabilize the position of ladder relative to the mast. The connecting rail may be any rigid and generally horizontal attachment. In an embodiment of the invention wherein the joining means comprises both a platform and a connecting rail, the connecting rail may be positioned above the platform, so that a worker standing on the platform may be able to grasp or lean on a connecting rail for stability. According to a preferred embodiment, a plurality of connecting rails are located around all four sides of the platform, so as to surround a worker standing on the stage. In this embodiment, the connecting rails are supported by posts extending upwardly from the four respective corners of the platform.
A support bracket such as that shown in FIGS. 3a and 3b may also be provided to connect the ladder to the mast. The support bracket may be positioned below the platform in a configuration which is not perpendicular to the mast, to thereby further stabilize and support the assembly.
Further, a series of gussets, such as those shown in FIGS. 4a and 4b may be used as trusses to structurally join the ladder or the mast to the platform and _7_ thereby increase strength and reduce deflection as herein before described.
Such gussets may also be placed between the ladder and the base plate (as shown in FIGS. 4a) and 4b), or between the mast and the base plate.
The joining means may be a full assembly unit comprising a planar rectangular platform, connecting rails supported on posts extending upwardly from the four corners of the platform, and a gusset or support bracket. A
plurality of such full assembly units may be used in vertical alignment.
FIGURE 2 illustrates an embodiment of the invention having two full assembly units mounted in vertical alignment on the mast.
The fixture may be any structure capable of being supported by the mast.
Any fixture which requires regular maintenance, replacement or access could be incorporated with the assembly of the invention. The fixture is preferably located at the upper end of the mast, but may be located anywhere along the mast in a region accessible to a person standing on the ladder or on the platform. The signal light may be of any type, for example, but not wishing to limit the invention in any manner, the signal light may be of the type used along the railroad to wam local traffic before or during the passage of a train, as depicted in FIG. 1. A plurality of fixtures may be located on the mast, such as two signal lights vertically aligned both facing the same direction (see FIG.
The present invention relates to a signal mast assembly particularly for use with railroad signal lights.
BACKGROUND OF THE INVENTION
Railroad signal lights located on masts often require replacement or maintenance. A ladder is typically used to provide a worker to access the signal light. Such ladders have conventionally been permanent installations either attached to the mast with a cantilever mount, or positioned adjacent to the signal mast and having a pier system or foundation separate from that of the mast.
It is well known within the art that present signal mast assemblies are prone to premature failure, for example, as a result of wind storms and ice loads. Attachment of a ladder to a mast using a cantilever mount has the further disadvantage that extra stress is placed on the mast to support the weight of the ladder, which can lead to mast failure. If the mast and the ladder have separate foundations, the shifting of the ground which occurs over time may result in a change in the position of the ladder relative to the mast, necessitating replacement of either the ladder or the mast. When the mast and ladder are mounted on separate foundations, wind and ice loads can easily stress and thus damage the mast or the ladder.
In response to the problem of shifting ground, various foundations such as those disclosed in U.S. Patents Nos. 5,257,489 (Anglette; Nov. 2, 1993) and 5,533,845 (Anglette, July 9, 1996) have been proposed for securing railroad signal masts. However, support for an adjacent ladder is not addressed.
_2_ U.S. Patent No. 3,952,978 (Reinitz; April 27, 1976) teaches a cantilever arm signal assembly for use in suspending signal lights over a roadway.
Catwalk panels may be used along the cantilever arm, for a worker to access the signal lights when maintenance or repair is needed. Such an assembly causes stress on the mast to support the weight of the cantilever arm, and thus the mast must be formed of sturdy stress-resistant materials. A mast and ladder assembly providing access the catwalk is not addressed by Reinitz.
An increase the standard size of existing masts for railroad signals from the standard 5.5 inch outer diameter to an 8 to 10 inch outer diameter would contribute mast stability and strength. However, there is reluctance in the industry to change from 5.5 inch outer diameter, since signal light fixtures and accessories are sized for the current standard, and considerable expense would be incurred if this standard were to be changed. It is therefore desirable to achieve increased mast stability without increasing mast diameter.
It is an object of the present invention to provide a mast and ladder assembly which substantially obviates the above-noted deficiencies of the prior art.
SUMMARY OF THE INVENTION
According to the invention, there is provided a signal mast assembly comprising a unified base, a mast mounted to the unified base, a ladder mounted to the unified base, and a joining means for joining the mast and the ladder at a location above the unified base.
The mast and ladder are coupled by the joining means, which acts as a truss, thereby providing superior load carrying capability and deflection resistance when compared to a mast alone.
The unified base may comprise a foundation for placement on the ground and a base plate attached to an upper portion of the foundation, wherein the mast and the ladder are mounted on the base plate. A fixture, such as a signal light may be attached at an upper portion of the mast. The joining means may comprises a platform positioned between the mast and the ladder, and connecting rails may be positioned between the mast and the ladder. The joining means may also include at least one support bracket or gusset.
The signal mast assembly of the present invention has the advantage that the mast and the ladder share the unified base. Thus, shifting in the ground below the assembly does not change the arrangement of the mast and ladder relative to each other. Structurally joining the ladder to the mast also has the advantage of providing enhanced load carrying capability, and much lower deflection than a mast not joined to a ladder structure. Thus, the assembly of the present invention has an enhanced capacity to withstand wind and ice loads.
A further advantage of the invention is that the weight of the ladder is not supported by the mast since both the ladder and the mast attach to the unified base, reducing the likelihood of mast failure due to weight stresses induced by a cantilever mounted ladder.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
FIGURE la is a perspective view of an aspect of an embodiment of the invention, having one signal light;
FIGURE lb is a front view of the embodiment of FIGURE 1 a;
FIGURE lc is a side view of the embodiment of FIGURE 1 a;
FIGURE ld is a top view of the embodiment of FIGURE la;
FIGURE 2a is a perspective view of another aspect of an embodiment of the invention, having two signal lights facing the same direction;
FIGURE 2b is a partial side view of the embodiment of FIGURE 2a;
FIGURE 3a is a perspective view of another aspect of an embodiment of the invention, having two signal lights facing opposite directions;
FIGURE 3b is a front view of the embodiment of FIGURE 3a;
FIGURE 3c is a side view of the embodiment of FIGURE 3a;
FIGURE 4a is a perspective view of another aspect of an embodiment of the invention, having two signal lights facing opposite directions and gussets;
FIGURE 4b is a front view of the embodiment of FIGURE 4a; and FIGURE 4c is a side view of the embodiment of FIGURE 4a.
DESCRIPTION OF PREFERRED EMBODIMENTS
Having regard to FIGURES 1 to 4, the invention is described for use with masts which support railroad signal lights. However, it is to be understood that the invention is not limited thereto. The invention may be used for any mast requiring an adjacent ladder.
The invention provides a unified base for connection of the ladder and mast to a generally horizontal and fixed surface. According to embodiments of the invention relating to masts for support of railroad signals, the unified base may be any which is known in the art and which is adapted to have the mast and the ladder attached thereto. Preferably, the unified base consists of a foundation and optionally a base plate affixed to the foundation. The foundation may be made of any appropriate rigid material such as cement or metal. A pier type foundation may be used, having a plurality of vertical pier supports for placement above or below the ground surface, such as depicted in FIGS. 1 to 3, having 6 pier supports, and FIG. 4, having 4 pier supports.
The base plate located on the foundation is a rigid horizontal surface capable of having the lower portion of both the mast and the ladder affixed thereto. For example, but not intending to limit the present invention in any manner, according to the embodiments depicted in FIGS. 1 to 4, the foundations comprise reinforced concrete legs to which a base plate, such as a metal plate, is bolted. The mast and the ladder are bolted to the upper surface of the base plate. However, it is to be understood that other variations of the unified base are within the scope of the present invention. For example, the mast and ladder may be set into the foundation directly or attached to the foundation in an appropriate manner without the use of a base plate, provided that the foundation to which the mast and ladder are attached is unified in some manner.
The mast may be any rigid pole or pillar extending upwardly from the unified base. The mast may be affixed to the unified base through a permanent or semi-permanent connection such as bolts, mechanical fasteners, welding, etc.
Preferably, the mast is capable of supporting a fixture at the upper end thereof.
When referring to the embodiment wherein the mast is used to support a railroad signal, the mast may be of from 5 inches in outer diameter to over 10 inches in outer diameter, depending on the standards and requirements.
The ladder may be of any type which allows a worker to climb up and access upper regions of the mast. The lower end of the ladder is affixed to the unified base through any appropriate means and may be set directly in the foundation, or attached to the foundation or a platform using any suitable means such as bolts, mechanical fasteners, welding, etc. As shown in FIGS 1 to 4, the ladder has a plurality of horizontal rungs.
In order to further provide strength and rigidity to the signal mast of the present invention, the mast and associated ladder may be interconnected together by any suitable joining means which structurally joins the mast and the ladder at a position above the unified base, ensuring the formation of a truss-like structure. According to one embodiment, the joining means may comprise a platform, which may be a solid horizontal surface appropriate for a worker to stand on when manipulating a fixture positioned on the mast. The platform may be a planar rectangular surface, and one of the edges of the rectangle may be aligned with the mast and a side of the ladder.
A connecting rail may be positioned between the mast and the ladder at a location above the unified base, to stabilize the position of ladder relative to the mast. The connecting rail may be any rigid and generally horizontal attachment. In an embodiment of the invention wherein the joining means comprises both a platform and a connecting rail, the connecting rail may be positioned above the platform, so that a worker standing on the platform may be able to grasp or lean on a connecting rail for stability. According to a preferred embodiment, a plurality of connecting rails are located around all four sides of the platform, so as to surround a worker standing on the stage. In this embodiment, the connecting rails are supported by posts extending upwardly from the four respective corners of the platform.
A support bracket such as that shown in FIGS. 3a and 3b may also be provided to connect the ladder to the mast. The support bracket may be positioned below the platform in a configuration which is not perpendicular to the mast, to thereby further stabilize and support the assembly.
Further, a series of gussets, such as those shown in FIGS. 4a and 4b may be used as trusses to structurally join the ladder or the mast to the platform and _7_ thereby increase strength and reduce deflection as herein before described.
Such gussets may also be placed between the ladder and the base plate (as shown in FIGS. 4a) and 4b), or between the mast and the base plate.
The joining means may be a full assembly unit comprising a planar rectangular platform, connecting rails supported on posts extending upwardly from the four corners of the platform, and a gusset or support bracket. A
plurality of such full assembly units may be used in vertical alignment.
FIGURE 2 illustrates an embodiment of the invention having two full assembly units mounted in vertical alignment on the mast.
The fixture may be any structure capable of being supported by the mast.
Any fixture which requires regular maintenance, replacement or access could be incorporated with the assembly of the invention. The fixture is preferably located at the upper end of the mast, but may be located anywhere along the mast in a region accessible to a person standing on the ladder or on the platform. The signal light may be of any type, for example, but not wishing to limit the invention in any manner, the signal light may be of the type used along the railroad to wam local traffic before or during the passage of a train, as depicted in FIG. 1. A plurality of fixtures may be located on the mast, such as two signal lights vertically aligned both facing the same direction (see FIG.
2) or two signal lights facing opposite directions (see FIG. 3). The mast assembly of the invention may also be used with those masts supporting cantilever mounted signal lights, such as described in U.S. Patent No. 3,952,978.
The foregoing embodiments illustrate the invention, but should not be considered as limiting. Modifications and equivalents which readily occur to those skilled in the art also fall within the scope of the invention.
The foregoing embodiments illustrate the invention, but should not be considered as limiting. Modifications and equivalents which readily occur to those skilled in the art also fall within the scope of the invention.
Claims (8)
1. A signal mast assembly comprising: a unified base; a mast mounted to the unified base; a ladder mounted to the unified base; and joining means for joining the mast and the ladder at a location above the unified base.
2. The signal mast assembly according to claim 1, wherein the unified base comprises: a foundation; and a base plate attached to an upper portion of the foundation, wherein the mast and the ladder are mounted to the base plate.
3. The signal mast assembly according to claim 1, wherein the joining means comprises a platform positioned between the mast and the ladder.
4. The signal mast assembly according to claims 1, wherein the joining means comprises connecting rails positioned between the mast and the ladder.
5. The signal mast assembly according to claim 3, wherein the joining means additionally comprises a support bracket positioned between the mast and the ladder.
6. The signal mast assembly according to claim 3, wherein the joining means additionally comprises a gusset attached between the platform and one of the mast or the ladder.
7. The signal mast assembly according to claim 1, additionally comprising a fixture attached to an upper portion of the mast.
8. The mast and ladder assembly according to claim 7, wherein the fixture is a signal light.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2246620 CA2246620A1 (en) | 1998-09-04 | 1998-09-04 | Signal mast assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2246620 CA2246620A1 (en) | 1998-09-04 | 1998-09-04 | Signal mast assembly |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2246620A1 true CA2246620A1 (en) | 2000-03-04 |
Family
ID=29409849
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2246620 Abandoned CA2246620A1 (en) | 1998-09-04 | 1998-09-04 | Signal mast assembly |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2246620A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8397868B1 (en) * | 2010-03-30 | 2013-03-19 | J & A Industries, Inc. | Signal mast with folding stand |
| US10151143B2 (en) | 2016-08-25 | 2018-12-11 | Lindsay Transportation Solutions, Inc. | Signal light assembly |
-
1998
- 1998-09-04 CA CA 2246620 patent/CA2246620A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8397868B1 (en) * | 2010-03-30 | 2013-03-19 | J & A Industries, Inc. | Signal mast with folding stand |
| US10151143B2 (en) | 2016-08-25 | 2018-12-11 | Lindsay Transportation Solutions, Inc. | Signal light assembly |
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| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |