Title:
SIGNAL MASTARM BRACKET
United States Patent 3764099
Abstract:
A universal mastarm bracket for mounting traffic signal lights or the like on mastarms, the bracket including an elongated member threaded at its opposite ends, a pair of fixture retaining end pieces threadedly engaged at opposite ends of the member, a mastarm clamp means, including variable length chains for extending around and frictionally engaging a mastarm, and means for adjustably securing said mastarm clamp means in a selected location along the length of said elongated member.
US Patent References:
SIGNAL MASTARM BRACKET
Parduhn - June 1971 - 3586280
Traffic light holder
Pfaff - March 1960 - 2928641
Holding device
Derbyshire - November 1929 - 1737151
Universal lamp mounting and attaching means therefor
Anderson - April 1924 - 1491893
SIGNAL MASTARM BRACKET
Parduhn - June 1971 - 3586280
Traffic light holder
Pfaff - March 1960 - 2928641
Holding device
Derbyshire - November 1929 - 1737151
Universal lamp mounting and attaching means therefor
Anderson - April 1924 - 1491893
Application Number:
05/231131
Publication Date:
10/09/1973
Filing Date:
03/02/1972
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
248/230.500, 248/230.900
International Classes:
G08G1/095; G09F7/18; F16M13/02
Field of Search:
248/230,214,316A,221 52/40 116/63
Primary Examiner:
Foss, Franklin J.
Claims:
What is claimed is
1. A universal mastarm bracket for mounting traffic signal lights and the like comprising:
2. A universal mastarm bracket as defined in claim 1 wherein said clamp means comprises:
3. A universal mastarm bracket as defined in claim 1 wherein said clamp means comprises:
4. A universal mastarm bracket as defined in claim 3 wherein said first fitting threadedly engages said elongated member, and is characterized in having an apertured free end spaced from said elongated member and terminating at one side of said fitting in a triple lobed opening.
5. A universal mastarm bracket for mounting traffic signal lights in various selected positions on mastarms of various sizes comprising:
6. A pole-supported traffic control device comprising:
1. A universal mastarm bracket for mounting traffic signal lights and the like comprising:
2. A universal mastarm bracket as defined in claim 1 wherein said clamp means comprises:
3. A universal mastarm bracket as defined in claim 1 wherein said clamp means comprises:
4. A universal mastarm bracket as defined in claim 3 wherein said first fitting threadedly engages said elongated member, and is characterized in having an apertured free end spaced from said elongated member and terminating at one side of said fitting in a triple lobed opening.
5. A universal mastarm bracket for mounting traffic signal lights in various selected positions on mastarms of various sizes comprising:
6. A pole-supported traffic control device comprising:
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a universal bracket suitable for mounting and supporting traffic lights and other fixtures on horizontally or vertically extending supporting structures, such as mastarms or vertical masts, with said brackets permitting adjustability of the angular and vertical positions of the supported fixture or light.
2. Brief Description of the Prior Art
In my U.S. Pat. No. 3,586,280, I disclose a mastarm bracket by which traffic signal lights and other fixtures may be mounted on a mastarm so that the fixtures may be adjusted in their angular position (angulation about a vertical axis), and in their angular position with respect to the mastarm. Although th mastarm brackets disclosed in my patent have gained wide commercial acceptance and are in widespread use, I have found that several significant improvements in the structure disclosed in my patent can be effected, and afford important advantages over the mastarm bracket which is there depicted and described.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
Broadly described, the present invention comprises a simple, minimum part universal mastarm bracket which includes an elongated member having a first fitting connected to one end thereof and projecting substantially normal to the longitudinal axis of the elongated member, with the first fitting being adapted to engage one end of a fixture. A second fitting is adjustably secured to the elongated member for selective spacing from the first fitting along the length of the member, and projecting substantially normal to the longitudinal axis of the member. The second fitting is adapted to engage a second end of the fixture engaged by the first fitting. Clamp means is adjustably secured to the elongated member between the first and second fittings, and is selectively positionable along the length of the member. The clamp means includes at least one pair of variable length chains, and further includes means for connecting the ends of each of the two chains in each of said pairs around a supporting mast or the like so as to tension the chains.
In a preferred embodiment of the invention, the elongated member is threaded over a portion of its length adjacent its end opposite that end thereof which is connected to the first fitting, and the second fitting threadedly engages this threaded portion of the elongated member so that it can be threaded along the elongated member for adjustment of its position thereon. The preferred embodiment of the invention further includes in the clamp means, a clamp plate assembly which is slidably mounted on the elongated member, and includes a tensioning means for clamping opposed parts of the clamp plate assembly tightly on the elongated member to resist sliding movement therealong. The clamp plate assembly further includes a threaded protuberance projecting substantially normal to the longitudinal axis of the member. A threaded collar threadedly engages the threaded protuberance and has one end of each of the chains in said chain pair connected thereto. Finally, means is provided for securing the threaded collar against rotation on the threaded protuberance so as to fix the relation of these elements to each other in a selected position.
The mastarm bracket of the invention contains relatively few parts, is very easily assembled and is completely universal in its ability to receive traffic signal lights or other fixtures of varying sizes. Moreover, the construction of the clamp means included in the bracket permits it to be quickly and tightly secured about mastarms and masts of varying cross sectional configuration.
It is a broad object of the present invention to provide a completely universal bracket by which traffic signal heads of varying geometry may be quickly and securely fastened on a supporting mastarm or mast.
Another object of the invention is to provide a mastarm bracket by which heavy fixtures such as traffic signal lights or the like may be secured to a mastarm of substantially any geometric cross sectional configuration or any diameter.
A further object of the invention is to provide a mastarm bracket which can be quickly and easily assembled by relatively unskilled personnel, and which is rugged in construction and has a long and trouble free service life.
Additional objects and advantages of the invention will become apparent as the following detailed description of the invention is read in conjunction with the accompanying drawings which illustrate the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a vertical column, mastarm, mastarm bracket of the present invention, and traffic signal lights supported thereby.
FIG. 2 is an enlarged cross sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is an enlarged, exploded perspective view of the signal lamp and the mastarm bracket by which the signal lamp is supported.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Referring initially to FIG. 1 of the drawing, a traffic signal pole 10 is representative of any shaft, pillar, post, stanchion, column or mast vertically arranged and utilized to support and house wires, connections, control devices, lamps, traffic signal lights or similar fixtures. The traffic signal pole 10 may comprise a hollow tapered steel shaft 11 having a base 12 and a top or capital 13. A tapered hollow mastarm 14 is suitably secured to the top of the shaft 11 by means of an adjustable split bracket 15 of adequate strength, shape and size to support the mastarm 14. Traffic signal heads 16 are fastened to the mastarm at spaced intervals therealong and support a plurality of stacked traffic signal lamps 18 in a manner well understood in the art.
The present invention is, as previously described, a bracket for supporting traffic signal heads and other similar fixtures in a desired position on a mastarm or other supporting member. The mastarm bracket 19 of the invention is best illustrated in FIGS. 2 and 3 and includes the vertically extending tubular member 20 which is threaded at its opposite ends as shown by the threads 22 and 24. The threads 24 at the upper end of the tubular member 20 extend over a substantial portion of its length to permit adjustability and universality in usage of the bracket of the invention in a manner hereinafter described.
Threadedly connected to the bottom of the tubular member 20 by means of the threads 22 is a fitting 26. The fitting 26, when connected to the tubular member 20, extends substantially normal thereto and carries at its outer end an aperture which terminates at the top side in a three lobed opening 28. The outer end of the fitting 26 is adapted to be connected to the lower end of, and support, the signal head 16 or other fixture. The three lobed opening 28 is provided particularly for use with a signal head for the reason that a bundle or harness of electrical leads may be easily extended through this opening and flared to make connections to various terminals in the lower end of the signal head housing.
At the opposite end of the elongated tubular member 20 from the end which carries the fitting 26, a second fitting 30 which includes an internally threaded collar 30a at one end thereof is threadedly engaged with the threads 24 carried at the upper end of the tubular member 20. It will be perceived that by rotation of the fitting 30 around the longitudinal axis of the tubular member 20, this fitting may be threaded down along the length of the tubular member 20 to a selected position so that its spacing from the fitting 26 is selectively adjustable. Thus, by adjustment of the spacing between the fittings 26 and 30, signal heads of varying height, or including varying numbers of signal lamps in the stack, may be accommodated between these fittings and supported by the bracket of the invention. When the fitting 30 has been screwed down on the tubular member 20 to the position desired, a set screw 32 is screwed inwardly to engage the tubular member 20 and fix the position of the fitting 30 thereon. At its outer end, the fitting 30 carries a downwardly facing socket 34 which is adapted for engagement with the upper end of the signal head 16. It will be understood, of course, that the length of the fittings 26 and 30 are sufficient to permit signal heads of varying transverse dimensions to be accommodated without interference by the tubular member 20.
Intermediate the length of the tubular member 20, a clamp means designated generally by reference numeral 36 is frictionally engaged with the tubular member, and is provided for the purpose of mounting the universal bracket of the invention on a mastarm or mast in a manner hereinafter described. The clamp means 36 includes a clamp plate assembly which engages the tubular member 20 and includes a first plate 38 having a concavo-convex central portion with aligned monoplanar flanges extending from the opposite side edges thereof. A pair of relatively small, complimentary shaped clamp plates 40 and 42 are positioned on the opposite side of the tubular member 20 from the plate 38.
Aligned bolt holes are provided in the plates 40, 42 and 38 so that bolts may be extended through these holes to interconnect the two plates 42 and 40 on one side of the tubular member 20 with the plate 38 on the oppostie side thereof. The bolts 44 are placed in tension by the tightening of suitable nuts 46 so that the plate 38 is drawn against the tubular member 20 toward the plates 40 and 42. In this manner, frictional engagement of sufficient tenacity is provided to prevent the tubular member 20 from sliding relative to the clamp plate assembly constituted by the several plates 38, 40 and 42 and by the bolts 44 and nuts 46.
On the convexly protuberant side of the plate 38 opposite the tubular member 20, the plate 38 carries an externally threaded tubular protuberance 50. The threaded protuberance 50 projects into and threadedly engages an internally threaded collar 52 which is secured to an anchor plate 54 which has its opposite side edges rolled into pin receiving sleeves 54a. Projecting through these sleeves are anchor pins 56 to which are secured one end of each of plurality of chains. The chains secured to the anchor pins 56 may be said to be grouped in two pairs, with one pair of chains 58 and 60 being secured to the top side of the anchor plate 54, and the other pair of chains 62 and 64 being secured to the lower side of the anchor plate 54. The chains 58, 60, 62 and 64 are variable length chains from which the terminal links may be quickly removed by unsnapping to shorten the chains, or, alternatively, additional links may be quickly added to increase the length of each chain. A pair of terminal links are provided on the chains in each chain pair with the links having apertures formed therethrough to accommodate elongated bolts. Thus, a bolt 66 is extended between the terminal links of the chains 58 and 62, and a nut 67 is threaded on the end of this bolt and is used for tensioning the chains after they have been extended about a mastarm, such as the mastarm 14 shown in FIG. 1. The same type of connection is formed using the chains 60 and 64, a bolt 68 and associated nut 69.
In the use of the universal mastarm bracket of the invention, it is usually preferably to assemble the bracket on the ground and to fit the particular signal head or other fixture between the fittings 26 and 30 before elevating the bracket and the fixtures supported thereby to the mastarm for securement to the mastarm. It may be pointed out, however, that this is not entirely essential to the use of the bracket of the invention, since it may be first secured to the mastarm, and the fixture then positioned between the fittings 26 and 30 if desired. In some instances, where it is desired to increase the stack height of the signal head by the addition of one or more additional lamps in the stack, it may be expedient to leave the bracket secured to the mastarm, remove the original traffic head from between the fittings 26 and 30, then adjust the upper fitting 30 by rotating it around the threaded portion of the tubular member 20 until it has been spaced fom the fitting 26 by the distance necessary to accommodate the new fixture. It is then locked in position by means of the set screw 32.
In any event the universality of the bracket of the invention with respect to various sizes of traffic light fixtures or other fixtures is assured by the ability to selectively position the upper fitting 30 along the length of the tubular member 20. In most instances, it will then be desirable to remove the protruding upper portion of the tubular member 20 by means of a hack saw. Of course this proecedure will not be followed where it is anticipated that from time to time adjustment of the position of the fitting 30 may be required.
Another adjustable aspect of the bracket of the invention resides in the adjustability of the tubular member 20 in its position relative to the clamp means 36. By loosening the bolts 44, the tubular member 20, fittings 26 and 30 and the traffic head or other fixture carried between these fittings may be moved upwardly or downwardly relative to the mastarm to which the clamp means is secured.
Another feature of adjustability of the bracket of the invention resides in the ability of angle the longitudinal axis of the tubular member 20 with respect to the mastarm by rotating the threaded protuberance 50 within the internally threaded collar 52 until the desired angulation is attained. The set screw 53 is then set to lock the members in this position relative to each other.
Another adjustable aspect of the bracket of the present invention is the ability of the bracket to be securely mounted on mastarms of varying sizes and cross sectional geometric configurations. This adjustability is derived from the adjustable lengths of the several chains 58, 60, 62 and 64 and from the flexibility of these chains. They can, as a result of such flexibility, be conformed to elliptically cross sectioned mastarms, as well as to circularly cross sectioned mastarms. When the chains have been adjusted to the appropriate length, they can be tightened to bite into the mastarm and grip it frictionally so as to retain the tubular member 20 in a vertically extending orientation. It will be apparent, of course, that if a situation should exist where it were desired to cant the longitudinal axis of the mastarm 20 with respect to the vertical, and in a direction toward the plane containing the mastarm, this can be accomplished by simply loosening the chains 58, 60, 62 and 64 slightly and rotating the entire bracket around the mastarm until the desired angulation is achieved. The chains are then re-tensioned by tightening the nuts on the bolts 66 and 68.
In the provision of the tubular member 20 which is threaded over a substantial portion of its length adjacent its upper end, it becomes necessary to manufacture and stock only one length of this tubular member in order to accommodate the various sizes of traffic light fixtures which may be encountered in varying situations. Moreover, the inclusion of the variable length chains in the clamp means which is provided, and the flexibility of these chains, permit the bracket of the invention to be mounted on any type of existing mastarm.
Although a preferred embodiment of the invention has been herein described, it will be understood that various changes and modifications in the described and depicted structure can be effected without departure from the basic principles which underlie the invention. Changes and innovations of this type are therefore deemed to be circumscribed by the spirit and scope of the invention except as the same may be necessarily limited by the appended claims or reasonable equivalents thereof.
1. Field of the Invention
This invention relates to a universal bracket suitable for mounting and supporting traffic lights and other fixtures on horizontally or vertically extending supporting structures, such as mastarms or vertical masts, with said brackets permitting adjustability of the angular and vertical positions of the supported fixture or light.
2. Brief Description of the Prior Art
In my U.S. Pat. No. 3,586,280, I disclose a mastarm bracket by which traffic signal lights and other fixtures may be mounted on a mastarm so that the fixtures may be adjusted in their angular position (angulation about a vertical axis), and in their angular position with respect to the mastarm. Although th mastarm brackets disclosed in my patent have gained wide commercial acceptance and are in widespread use, I have found that several significant improvements in the structure disclosed in my patent can be effected, and afford important advantages over the mastarm bracket which is there depicted and described.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
Broadly described, the present invention comprises a simple, minimum part universal mastarm bracket which includes an elongated member having a first fitting connected to one end thereof and projecting substantially normal to the longitudinal axis of the elongated member, with the first fitting being adapted to engage one end of a fixture. A second fitting is adjustably secured to the elongated member for selective spacing from the first fitting along the length of the member, and projecting substantially normal to the longitudinal axis of the member. The second fitting is adapted to engage a second end of the fixture engaged by the first fitting. Clamp means is adjustably secured to the elongated member between the first and second fittings, and is selectively positionable along the length of the member. The clamp means includes at least one pair of variable length chains, and further includes means for connecting the ends of each of the two chains in each of said pairs around a supporting mast or the like so as to tension the chains.
In a preferred embodiment of the invention, the elongated member is threaded over a portion of its length adjacent its end opposite that end thereof which is connected to the first fitting, and the second fitting threadedly engages this threaded portion of the elongated member so that it can be threaded along the elongated member for adjustment of its position thereon. The preferred embodiment of the invention further includes in the clamp means, a clamp plate assembly which is slidably mounted on the elongated member, and includes a tensioning means for clamping opposed parts of the clamp plate assembly tightly on the elongated member to resist sliding movement therealong. The clamp plate assembly further includes a threaded protuberance projecting substantially normal to the longitudinal axis of the member. A threaded collar threadedly engages the threaded protuberance and has one end of each of the chains in said chain pair connected thereto. Finally, means is provided for securing the threaded collar against rotation on the threaded protuberance so as to fix the relation of these elements to each other in a selected position.
The mastarm bracket of the invention contains relatively few parts, is very easily assembled and is completely universal in its ability to receive traffic signal lights or other fixtures of varying sizes. Moreover, the construction of the clamp means included in the bracket permits it to be quickly and tightly secured about mastarms and masts of varying cross sectional configuration.
It is a broad object of the present invention to provide a completely universal bracket by which traffic signal heads of varying geometry may be quickly and securely fastened on a supporting mastarm or mast.
Another object of the invention is to provide a mastarm bracket by which heavy fixtures such as traffic signal lights or the like may be secured to a mastarm of substantially any geometric cross sectional configuration or any diameter.
A further object of the invention is to provide a mastarm bracket which can be quickly and easily assembled by relatively unskilled personnel, and which is rugged in construction and has a long and trouble free service life.
Additional objects and advantages of the invention will become apparent as the following detailed description of the invention is read in conjunction with the accompanying drawings which illustrate the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a vertical column, mastarm, mastarm bracket of the present invention, and traffic signal lights supported thereby.
FIG. 2 is an enlarged cross sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is an enlarged, exploded perspective view of the signal lamp and the mastarm bracket by which the signal lamp is supported.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Referring initially to FIG. 1 of the drawing, a traffic signal pole 10 is representative of any shaft, pillar, post, stanchion, column or mast vertically arranged and utilized to support and house wires, connections, control devices, lamps, traffic signal lights or similar fixtures. The traffic signal pole 10 may comprise a hollow tapered steel shaft 11 having a base 12 and a top or capital 13. A tapered hollow mastarm 14 is suitably secured to the top of the shaft 11 by means of an adjustable split bracket 15 of adequate strength, shape and size to support the mastarm 14. Traffic signal heads 16 are fastened to the mastarm at spaced intervals therealong and support a plurality of stacked traffic signal lamps 18 in a manner well understood in the art.
The present invention is, as previously described, a bracket for supporting traffic signal heads and other similar fixtures in a desired position on a mastarm or other supporting member. The mastarm bracket 19 of the invention is best illustrated in FIGS. 2 and 3 and includes the vertically extending tubular member 20 which is threaded at its opposite ends as shown by the threads 22 and 24. The threads 24 at the upper end of the tubular member 20 extend over a substantial portion of its length to permit adjustability and universality in usage of the bracket of the invention in a manner hereinafter described.
Threadedly connected to the bottom of the tubular member 20 by means of the threads 22 is a fitting 26. The fitting 26, when connected to the tubular member 20, extends substantially normal thereto and carries at its outer end an aperture which terminates at the top side in a three lobed opening 28. The outer end of the fitting 26 is adapted to be connected to the lower end of, and support, the signal head 16 or other fixture. The three lobed opening 28 is provided particularly for use with a signal head for the reason that a bundle or harness of electrical leads may be easily extended through this opening and flared to make connections to various terminals in the lower end of the signal head housing.
At the opposite end of the elongated tubular member 20 from the end which carries the fitting 26, a second fitting 30 which includes an internally threaded collar 30a at one end thereof is threadedly engaged with the threads 24 carried at the upper end of the tubular member 20. It will be perceived that by rotation of the fitting 30 around the longitudinal axis of the tubular member 20, this fitting may be threaded down along the length of the tubular member 20 to a selected position so that its spacing from the fitting 26 is selectively adjustable. Thus, by adjustment of the spacing between the fittings 26 and 30, signal heads of varying height, or including varying numbers of signal lamps in the stack, may be accommodated between these fittings and supported by the bracket of the invention. When the fitting 30 has been screwed down on the tubular member 20 to the position desired, a set screw 32 is screwed inwardly to engage the tubular member 20 and fix the position of the fitting 30 thereon. At its outer end, the fitting 30 carries a downwardly facing socket 34 which is adapted for engagement with the upper end of the signal head 16. It will be understood, of course, that the length of the fittings 26 and 30 are sufficient to permit signal heads of varying transverse dimensions to be accommodated without interference by the tubular member 20.
Intermediate the length of the tubular member 20, a clamp means designated generally by reference numeral 36 is frictionally engaged with the tubular member, and is provided for the purpose of mounting the universal bracket of the invention on a mastarm or mast in a manner hereinafter described. The clamp means 36 includes a clamp plate assembly which engages the tubular member 20 and includes a first plate 38 having a concavo-convex central portion with aligned monoplanar flanges extending from the opposite side edges thereof. A pair of relatively small, complimentary shaped clamp plates 40 and 42 are positioned on the opposite side of the tubular member 20 from the plate 38.
Aligned bolt holes are provided in the plates 40, 42 and 38 so that bolts may be extended through these holes to interconnect the two plates 42 and 40 on one side of the tubular member 20 with the plate 38 on the oppostie side thereof. The bolts 44 are placed in tension by the tightening of suitable nuts 46 so that the plate 38 is drawn against the tubular member 20 toward the plates 40 and 42. In this manner, frictional engagement of sufficient tenacity is provided to prevent the tubular member 20 from sliding relative to the clamp plate assembly constituted by the several plates 38, 40 and 42 and by the bolts 44 and nuts 46.
On the convexly protuberant side of the plate 38 opposite the tubular member 20, the plate 38 carries an externally threaded tubular protuberance 50. The threaded protuberance 50 projects into and threadedly engages an internally threaded collar 52 which is secured to an anchor plate 54 which has its opposite side edges rolled into pin receiving sleeves 54a. Projecting through these sleeves are anchor pins 56 to which are secured one end of each of plurality of chains. The chains secured to the anchor pins 56 may be said to be grouped in two pairs, with one pair of chains 58 and 60 being secured to the top side of the anchor plate 54, and the other pair of chains 62 and 64 being secured to the lower side of the anchor plate 54. The chains 58, 60, 62 and 64 are variable length chains from which the terminal links may be quickly removed by unsnapping to shorten the chains, or, alternatively, additional links may be quickly added to increase the length of each chain. A pair of terminal links are provided on the chains in each chain pair with the links having apertures formed therethrough to accommodate elongated bolts. Thus, a bolt 66 is extended between the terminal links of the chains 58 and 62, and a nut 67 is threaded on the end of this bolt and is used for tensioning the chains after they have been extended about a mastarm, such as the mastarm 14 shown in FIG. 1. The same type of connection is formed using the chains 60 and 64, a bolt 68 and associated nut 69.
In the use of the universal mastarm bracket of the invention, it is usually preferably to assemble the bracket on the ground and to fit the particular signal head or other fixture between the fittings 26 and 30 before elevating the bracket and the fixtures supported thereby to the mastarm for securement to the mastarm. It may be pointed out, however, that this is not entirely essential to the use of the bracket of the invention, since it may be first secured to the mastarm, and the fixture then positioned between the fittings 26 and 30 if desired. In some instances, where it is desired to increase the stack height of the signal head by the addition of one or more additional lamps in the stack, it may be expedient to leave the bracket secured to the mastarm, remove the original traffic head from between the fittings 26 and 30, then adjust the upper fitting 30 by rotating it around the threaded portion of the tubular member 20 until it has been spaced fom the fitting 26 by the distance necessary to accommodate the new fixture. It is then locked in position by means of the set screw 32.
In any event the universality of the bracket of the invention with respect to various sizes of traffic light fixtures or other fixtures is assured by the ability to selectively position the upper fitting 30 along the length of the tubular member 20. In most instances, it will then be desirable to remove the protruding upper portion of the tubular member 20 by means of a hack saw. Of course this proecedure will not be followed where it is anticipated that from time to time adjustment of the position of the fitting 30 may be required.
Another adjustable aspect of the bracket of the invention resides in the adjustability of the tubular member 20 in its position relative to the clamp means 36. By loosening the bolts 44, the tubular member 20, fittings 26 and 30 and the traffic head or other fixture carried between these fittings may be moved upwardly or downwardly relative to the mastarm to which the clamp means is secured.
Another feature of adjustability of the bracket of the invention resides in the ability of angle the longitudinal axis of the tubular member 20 with respect to the mastarm by rotating the threaded protuberance 50 within the internally threaded collar 52 until the desired angulation is attained. The set screw 53 is then set to lock the members in this position relative to each other.
Another adjustable aspect of the bracket of the present invention is the ability of the bracket to be securely mounted on mastarms of varying sizes and cross sectional geometric configurations. This adjustability is derived from the adjustable lengths of the several chains 58, 60, 62 and 64 and from the flexibility of these chains. They can, as a result of such flexibility, be conformed to elliptically cross sectioned mastarms, as well as to circularly cross sectioned mastarms. When the chains have been adjusted to the appropriate length, they can be tightened to bite into the mastarm and grip it frictionally so as to retain the tubular member 20 in a vertically extending orientation. It will be apparent, of course, that if a situation should exist where it were desired to cant the longitudinal axis of the mastarm 20 with respect to the vertical, and in a direction toward the plane containing the mastarm, this can be accomplished by simply loosening the chains 58, 60, 62 and 64 slightly and rotating the entire bracket around the mastarm until the desired angulation is achieved. The chains are then re-tensioned by tightening the nuts on the bolts 66 and 68.
In the provision of the tubular member 20 which is threaded over a substantial portion of its length adjacent its upper end, it becomes necessary to manufacture and stock only one length of this tubular member in order to accommodate the various sizes of traffic light fixtures which may be encountered in varying situations. Moreover, the inclusion of the variable length chains in the clamp means which is provided, and the flexibility of these chains, permit the bracket of the invention to be mounted on any type of existing mastarm.
Although a preferred embodiment of the invention has been herein described, it will be understood that various changes and modifications in the described and depicted structure can be effected without departure from the basic principles which underlie the invention. Changes and innovations of this type are therefore deemed to be circumscribed by the spirit and scope of the invention except as the same may be necessarily limited by the appended claims or reasonable equivalents thereof.