CA2097774C - Telescopic mast for a global positioning system antenna - Google Patents
Telescopic mast for a global positioning system antennaInfo
- Publication number
- CA2097774C CA2097774C CA 2097774 CA2097774A CA2097774C CA 2097774 C CA2097774 C CA 2097774C CA 2097774 CA2097774 CA 2097774 CA 2097774 A CA2097774 A CA 2097774A CA 2097774 C CA2097774 C CA 2097774C
- Authority
- CA
- Canada
- Prior art keywords
- mast
- section
- stays
- lowermost
- uppermost
- 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.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/12—Supports; Mounting means
- H01Q1/1235—Collapsible supports; Means for erecting a rigid antenna
Landscapes
- Support Of Aerials (AREA)
Abstract
The disclosure herein describes a telescopic mast for a global positioning system antenna, the mast being formed of a plurality of telescoping sections which are opened and retracted by means of a single cable operating through a pulley-and-winch arrangement. A
plurality of the stays extend through three levels of mast sections and are each connected, at the lowermost section, to a device that is used by an operator to adjust the verticality of the mast as a result of viewing, through an optical instrument mounted on the lowermost section, reference points located on the upper end of the uppermost section.
plurality of the stays extend through three levels of mast sections and are each connected, at the lowermost section, to a device that is used by an operator to adjust the verticality of the mast as a result of viewing, through an optical instrument mounted on the lowermost section, reference points located on the upper end of the uppermost section.
Description
FT~T n OF THE INVENTION
The present invention pertains to a telescopic mast for a global positioning system (GPS) antenna; more particularly, the invention pertains to a mast which may 5 be raised or lowered in order to adjust the height of a receiver antenna above obstructions present around the observing site, especially in wooden areas.
BA~ JvNv OF THE INVENTION
The global positioning system has been utilized 10 for quite sometime now in geodetic and topographic data gathering. One of the main advantages of GPS wlth respect to conventional systems is that an intervisibility between observation sites are not required. However, the visibility of satellites above 15 the horizon of each of the observation sites is necessary. In certain areas where it is required to establish geodetic reference points, obstruction problems caused by trees or buildings can occur. This means that the reception of GPS signals will not be possible in 20 certain portions of the sky. It is noted that GPS
carrying waves have a frequency of 1. 6 GHz and 1. 2 GHz .
The resultant is a degraded precision of the results of the positioning caused by an inadequate distribution of satellites in the sky of the observer.
~ 2097774 One of the important tasks in the planning of GPS work is to ensure that the sky of observation sites are exempt of all obstructions above an elevation angle usually, 15. In wooden areas, an alternative used to increase the reception of signals is to free an area E;uf f iciently large around the observation station .
However, such a practice, although efficient, results in an unuseful waste of ligneous matter. Indeed, trees which are cut are not always economically recuperable.
Similarly, such a practice is contrary to the spirit of conservation and recuperation which is now a concern of society .
Hence, the use of a telescopic mast to avoid obstructions, such as trees and buildings, is ~:xLL ly useful. One such basic mast may be found described in U.S. patent no. 5,052,645 issued October 1, l991 to Hixon .
OBJE~T~ ~Nn S~r~MTJ~Tll OF T~ .I ~V t.~ Qll It is therefore an object of the present invention to provide a telescopic mast which will overcome the reception difficulties of GPS signals in wooden areas.
It is also an object of the present invention to provide such a mast which will provide the required ~ 2097774 precision needed for the installation of an observation station, i.e. verticality, height and centering.
The present invention therefore relates to a telescopic mast for a global positioning system antenna 5 which comprises:
- a plurality of telescoping sections;
- means for opening and retracting the sections to vary the height of the antenna;
- anchor means for maintaining the mast in a 10 vertical upright position, the anchor means including a 6eries of stays under tension, each having a ground engaging end, an intermediate section slidably mounted to a corresponding telescoping section and an opposite end secured to the lowermost telescoping section;
- optical means for indicating the position of the mast relative to a vertical axis, including a f irst member mounted at the upper end of the uppermost section and bearing reference points thereon, and a second member mounted on the lowermost section and having means to view the reference points on the uppermost section; and - tension adjusting means secured to the opposite ends of the stays on the lowermost section for adjusting the tension of one or more of the stays to thereby achieve verticality of the mast.
In one preferred form of the invention, the int~ te sections of the stays are mounted at three separate levels of the mast.
`-- 2097774 In another form of the invention, the second member of the optical means consists of a reversed tribrach with optical plummet rotatably mounted to the lowermost section while the first member of the optical means consists of a disc mounted on the uppermost section with reference points at the periphery thereof.
Yet, in another form of the invention, the opening and retracting means consist of a winch mounted to the lowermost section and of a single cable having one end fixed to the winch and the opposite end fixed to the lower end of the uppermost section.
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 DESt`~TP~ION OF THE n~WTN~;8 For a better understanding of the present invention, reference is had to the following description taken in connection with the accompanying drawings in which:
`~ 20977~
Figure l is a perspective elevation of one embodiment of a telescoping mast made in accordance with the present invention;
Figure 2 is a partly cross-sectional elevation 5 of the mast;
Figure 3 is an elevation with parts broken away of the mast;
Figure 4 is a cross-sectional view taken along lines 4-4 of figure 3; and Figure 5 is a schematic plan view showing the operation of the optical instrument.
DESCRIPTION OF ~k ~ - F!MRnnTMlDNT~;
Referring to figure 1, there is illustrated a telescopic mast 10 which is held in an upright position by means of a series of stays 12. In the embodiment illustrated, there are nine stays (12a to 12i) distributed with three stays at each of three separate levels of the mast.
Referring to figure 2, the telescopic mast is formed of a series of tubular sections 14, 16, 18 and 20.
The uppermost section 14 carries a disc 24 on which is secured an antenna 25 while the lowermost section 20, in the present P)nhnr~;t-nt, is fixed to a base 26 by means of a series of legs 28. The lower end of the lowermost section may have other constructions, such as a rounded point .
~ 20~ 774 The opening and retracting of the telescopic mast is accomplished by means of a winch 30 and of a single cable 32 which has one end secured to the winch and its upper extremity secured to the uppermost section 5 14 at 34. The cable passes internally within the tubular sections and engages a series of pulley devices 36, 38, 40, 42, 44 and 46. When winch 30 is operated, the cable 32 will cause the simultaneous opening and retracting of all the tubular sections.
Referring to figure 3, the stays 12 each have one end secured to the ground, as shown in f igure 1, and have their opposite end secured to a tensioning device mounted to the lowermost section 20. In the embodiment illustrated, there are nine ground engaging devices; in 15 another embodiment, there may be three stays at each ground engaging device. The in~ -l;Ate section of each stay passes through a pulley 50 supported on a ring 52 secured to a corresponding tubular section. As can be seen, stays 12a, 12b and 12c are mounted through corresponding pulleys 50a, 50b, 50c to the ring 52', the stays 12d, 12e and 12f are mounted through corresponding pulleys 50d, 50e, 50f to the ring 52" and the stays 12g, 12h and 12i are mounted through corresponding pulleys 50g, 50h, 50i to the ring 52"'.
The lower end of each stay is secured to a corresponding tensioner 54 (of which only seven are shown ~ 2097t774 in figure 3). The tension of each stay is adjusted by manually rotating key 56 of each device. As illustrated in figure 4, the tensioners are mounted on a sleeve 58 ~ecured to the lowermost tubular section 2 o .
Referring to figures 3 and 5, the verticality of the mast is achieved by means of an optical arrangement that consists of a conventional tribrach instrument 60 with optical plummet which has, however, been invertedly mounted under a rotatable support 62 fixed to a sleeve 64 which is adapted to rotate relative to the lowermost tubular section 20. A spherical level 65 is mounted to the tribrach 60. Also, as shown in figure 5, a second spherical level 66 i8 fixedly mounted to the lowermost tubular section 2 0 in order to obtain the verticality of the lowermost section. The tribrach 60 has a viewing aperture 68 so that its intersecting lines 70 and 72 ma be viewed l t t f y re a lve o re erence points on the disc 24 on the uppermost section; in this case, the reference points are at the peripheral edge 74 of the disc.
In operation, verticality and height is achieved in the following matter. The verticality of the lowermost section of the mast is f irst obtained with the aid of the spherical level 66. By adjusting the tension on the stays 12g, 12h and 12i by manually operating the keys 56g, 56h and 56i, the bulb 80 of the spherical level _ _ _ _, _ _ _ , . . ..
~ Z097774 66 is brought within its circular reference 82. Then, the three tubular sections 14, 16 and 18 are simultaneously retracted from the lowermost section 20 by operating the winch 3 0 .
Although not shown in the drawings, it is well known that masts of this nature are usually provided with a measuring tape secured to the lowermost section with one end of the tape f ixed to the upper end of the uppermost section so that, as the tubular sections are retracted, the measuring tape indicates the height of the antenna 25. The opening of the mast is therefore stopped and f ixed at a desired height by locking the winch .
The next step consists in positioning the antenna situated on the uppermost section of the mast vertically above the base of the mast. The rotation of the carrying support 62 allows the verticality of the antenna to be noted along two perpendicular directions (see figure 5). The pivotal travel 75 of the cross point of the intersecting lines 70 and 72 corresponds to the periphery of the disc supporting the antenna. First, the tribrach 60 is levelled by utilizing the spherical level 65 and by correspondingly adjusting screws 77. Viewing through the aperture 68, the cross point of lines 70 and 72 must be seen to intersect periphery 74 of the disc.
If this is not the case, the tensioning devices 54a, 54b and 54c (and, if necessary, devices 54d, 54e and 54f) are ~ 209'777~
g manually operated in order to obtain the verticality of the uppermost section 14.
By being telescopically constructed, the entire mast may be dismounted and easily transported by two 5 persons or, for example, on the roof of an automobile.
Although the invention has been described above with respect with one specific form, it will be evident to a person skilled in the art that it may be modif ied and refined in various ways. For example, the antenna lo situated at the uppermost position of the mast may be replaced with a surveying target or by one or more prisms for distance meter. It is therefore wished to have it understood that the present invention should not be limited in interpretation, except by the terms of the 15 following claims.
The present invention pertains to a telescopic mast for a global positioning system (GPS) antenna; more particularly, the invention pertains to a mast which may 5 be raised or lowered in order to adjust the height of a receiver antenna above obstructions present around the observing site, especially in wooden areas.
BA~ JvNv OF THE INVENTION
The global positioning system has been utilized 10 for quite sometime now in geodetic and topographic data gathering. One of the main advantages of GPS wlth respect to conventional systems is that an intervisibility between observation sites are not required. However, the visibility of satellites above 15 the horizon of each of the observation sites is necessary. In certain areas where it is required to establish geodetic reference points, obstruction problems caused by trees or buildings can occur. This means that the reception of GPS signals will not be possible in 20 certain portions of the sky. It is noted that GPS
carrying waves have a frequency of 1. 6 GHz and 1. 2 GHz .
The resultant is a degraded precision of the results of the positioning caused by an inadequate distribution of satellites in the sky of the observer.
~ 2097774 One of the important tasks in the planning of GPS work is to ensure that the sky of observation sites are exempt of all obstructions above an elevation angle usually, 15. In wooden areas, an alternative used to increase the reception of signals is to free an area E;uf f iciently large around the observation station .
However, such a practice, although efficient, results in an unuseful waste of ligneous matter. Indeed, trees which are cut are not always economically recuperable.
Similarly, such a practice is contrary to the spirit of conservation and recuperation which is now a concern of society .
Hence, the use of a telescopic mast to avoid obstructions, such as trees and buildings, is ~:xLL ly useful. One such basic mast may be found described in U.S. patent no. 5,052,645 issued October 1, l991 to Hixon .
OBJE~T~ ~Nn S~r~MTJ~Tll OF T~ .I ~V t.~ Qll It is therefore an object of the present invention to provide a telescopic mast which will overcome the reception difficulties of GPS signals in wooden areas.
It is also an object of the present invention to provide such a mast which will provide the required ~ 2097774 precision needed for the installation of an observation station, i.e. verticality, height and centering.
The present invention therefore relates to a telescopic mast for a global positioning system antenna 5 which comprises:
- a plurality of telescoping sections;
- means for opening and retracting the sections to vary the height of the antenna;
- anchor means for maintaining the mast in a 10 vertical upright position, the anchor means including a 6eries of stays under tension, each having a ground engaging end, an intermediate section slidably mounted to a corresponding telescoping section and an opposite end secured to the lowermost telescoping section;
- optical means for indicating the position of the mast relative to a vertical axis, including a f irst member mounted at the upper end of the uppermost section and bearing reference points thereon, and a second member mounted on the lowermost section and having means to view the reference points on the uppermost section; and - tension adjusting means secured to the opposite ends of the stays on the lowermost section for adjusting the tension of one or more of the stays to thereby achieve verticality of the mast.
In one preferred form of the invention, the int~ te sections of the stays are mounted at three separate levels of the mast.
`-- 2097774 In another form of the invention, the second member of the optical means consists of a reversed tribrach with optical plummet rotatably mounted to the lowermost section while the first member of the optical means consists of a disc mounted on the uppermost section with reference points at the periphery thereof.
Yet, in another form of the invention, the opening and retracting means consist of a winch mounted to the lowermost section and of a single cable having one end fixed to the winch and the opposite end fixed to the lower end of the uppermost section.
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 DESt`~TP~ION OF THE n~WTN~;8 For a better understanding of the present invention, reference is had to the following description taken in connection with the accompanying drawings in which:
`~ 20977~
Figure l is a perspective elevation of one embodiment of a telescoping mast made in accordance with the present invention;
Figure 2 is a partly cross-sectional elevation 5 of the mast;
Figure 3 is an elevation with parts broken away of the mast;
Figure 4 is a cross-sectional view taken along lines 4-4 of figure 3; and Figure 5 is a schematic plan view showing the operation of the optical instrument.
DESCRIPTION OF ~k ~ - F!MRnnTMlDNT~;
Referring to figure 1, there is illustrated a telescopic mast 10 which is held in an upright position by means of a series of stays 12. In the embodiment illustrated, there are nine stays (12a to 12i) distributed with three stays at each of three separate levels of the mast.
Referring to figure 2, the telescopic mast is formed of a series of tubular sections 14, 16, 18 and 20.
The uppermost section 14 carries a disc 24 on which is secured an antenna 25 while the lowermost section 20, in the present P)nhnr~;t-nt, is fixed to a base 26 by means of a series of legs 28. The lower end of the lowermost section may have other constructions, such as a rounded point .
~ 20~ 774 The opening and retracting of the telescopic mast is accomplished by means of a winch 30 and of a single cable 32 which has one end secured to the winch and its upper extremity secured to the uppermost section 5 14 at 34. The cable passes internally within the tubular sections and engages a series of pulley devices 36, 38, 40, 42, 44 and 46. When winch 30 is operated, the cable 32 will cause the simultaneous opening and retracting of all the tubular sections.
Referring to figure 3, the stays 12 each have one end secured to the ground, as shown in f igure 1, and have their opposite end secured to a tensioning device mounted to the lowermost section 20. In the embodiment illustrated, there are nine ground engaging devices; in 15 another embodiment, there may be three stays at each ground engaging device. The in~ -l;Ate section of each stay passes through a pulley 50 supported on a ring 52 secured to a corresponding tubular section. As can be seen, stays 12a, 12b and 12c are mounted through corresponding pulleys 50a, 50b, 50c to the ring 52', the stays 12d, 12e and 12f are mounted through corresponding pulleys 50d, 50e, 50f to the ring 52" and the stays 12g, 12h and 12i are mounted through corresponding pulleys 50g, 50h, 50i to the ring 52"'.
The lower end of each stay is secured to a corresponding tensioner 54 (of which only seven are shown ~ 2097t774 in figure 3). The tension of each stay is adjusted by manually rotating key 56 of each device. As illustrated in figure 4, the tensioners are mounted on a sleeve 58 ~ecured to the lowermost tubular section 2 o .
Referring to figures 3 and 5, the verticality of the mast is achieved by means of an optical arrangement that consists of a conventional tribrach instrument 60 with optical plummet which has, however, been invertedly mounted under a rotatable support 62 fixed to a sleeve 64 which is adapted to rotate relative to the lowermost tubular section 20. A spherical level 65 is mounted to the tribrach 60. Also, as shown in figure 5, a second spherical level 66 i8 fixedly mounted to the lowermost tubular section 2 0 in order to obtain the verticality of the lowermost section. The tribrach 60 has a viewing aperture 68 so that its intersecting lines 70 and 72 ma be viewed l t t f y re a lve o re erence points on the disc 24 on the uppermost section; in this case, the reference points are at the peripheral edge 74 of the disc.
In operation, verticality and height is achieved in the following matter. The verticality of the lowermost section of the mast is f irst obtained with the aid of the spherical level 66. By adjusting the tension on the stays 12g, 12h and 12i by manually operating the keys 56g, 56h and 56i, the bulb 80 of the spherical level _ _ _ _, _ _ _ , . . ..
~ Z097774 66 is brought within its circular reference 82. Then, the three tubular sections 14, 16 and 18 are simultaneously retracted from the lowermost section 20 by operating the winch 3 0 .
Although not shown in the drawings, it is well known that masts of this nature are usually provided with a measuring tape secured to the lowermost section with one end of the tape f ixed to the upper end of the uppermost section so that, as the tubular sections are retracted, the measuring tape indicates the height of the antenna 25. The opening of the mast is therefore stopped and f ixed at a desired height by locking the winch .
The next step consists in positioning the antenna situated on the uppermost section of the mast vertically above the base of the mast. The rotation of the carrying support 62 allows the verticality of the antenna to be noted along two perpendicular directions (see figure 5). The pivotal travel 75 of the cross point of the intersecting lines 70 and 72 corresponds to the periphery of the disc supporting the antenna. First, the tribrach 60 is levelled by utilizing the spherical level 65 and by correspondingly adjusting screws 77. Viewing through the aperture 68, the cross point of lines 70 and 72 must be seen to intersect periphery 74 of the disc.
If this is not the case, the tensioning devices 54a, 54b and 54c (and, if necessary, devices 54d, 54e and 54f) are ~ 209'777~
g manually operated in order to obtain the verticality of the uppermost section 14.
By being telescopically constructed, the entire mast may be dismounted and easily transported by two 5 persons or, for example, on the roof of an automobile.
Although the invention has been described above with respect with one specific form, it will be evident to a person skilled in the art that it may be modif ied and refined in various ways. For example, the antenna lo situated at the uppermost position of the mast may be replaced with a surveying target or by one or more prisms for distance meter. It is therefore wished to have it understood that the present invention should not be limited in interpretation, except by the terms of the 15 following claims.
Claims (8)
1. A telescopic mast for a global positioning system antenna, comprising:
a) a plurality of telescoping sections, each having upper and lower ends; said telescoping sections including a lowermost section and an uppermost section;
b) means for opening and retracting said sections to vary the height of the antenna;
c) anchor means for maintaining the mast in a vertical upright position, said anchor means including a series of stays under tension each having a ground engaging end, an intermediate section slidably mounted to a corresponding telescoping section and an opposite end secured to said lowermost section;
d) optical means for indicating the position of the mast relative to a vertical axis, said optical means including a first member mounted at the upper end of said uppermost section and bearing reference points thereon, and a second member mounted on said lowermost section and having means to view said reference points on said uppermost section; and e) tension adjusting means secured to said opposite ends of said stays on said lowermost section for adjusting the tension of one or more of said stays to thereby achieve verticality of the mast.
a) a plurality of telescoping sections, each having upper and lower ends; said telescoping sections including a lowermost section and an uppermost section;
b) means for opening and retracting said sections to vary the height of the antenna;
c) anchor means for maintaining the mast in a vertical upright position, said anchor means including a series of stays under tension each having a ground engaging end, an intermediate section slidably mounted to a corresponding telescoping section and an opposite end secured to said lowermost section;
d) optical means for indicating the position of the mast relative to a vertical axis, said optical means including a first member mounted at the upper end of said uppermost section and bearing reference points thereon, and a second member mounted on said lowermost section and having means to view said reference points on said uppermost section; and e) tension adjusting means secured to said opposite ends of said stays on said lowermost section for adjusting the tension of one or more of said stays to thereby achieve verticality of the mast.
2. A mast as defined in claim 1, wherein the intermediate sections of said stays are mounted at three separate levels of the mast.
3. A mast as defined in claim 2, comprising nine stays with three stays per level.
4. A mast as defined in claim 1, 2 or 3, wherein said tension adjusting means consist of a series of tensioners corresponding in number to that of the stays; said opposite end of each stay being mounted to a corresponding tensioner.
5. A mast as defined in claim 4, further comprising level indicating means mounted on said lowermost section to assist in achieving verticality of said lowermost section.
6. A mast as defined in claim 1, wherein said second member of said optical means consists of a reversed tribrach rotatably mounted to said lowermost section and wherein said first member of said optical means consists of a disc on said uppermost section with said reference points being at the periphery thereof.
7. A mast as defined in claim 1, wherein said opening and retracting means consist of a winch mounted to said lowermost section and a single cable having one end fixed to said winch and the opposite end fixed to the lower end of said uppermost section.
8. A mast as defined in claim 7, wherein each said section, but said uppermost section, has, at the lower end thereof and internally thereof, a first set of pulley means and, at the upper end thereof and externally thereof, a second set of pulley means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2097774 CA2097774C (en) | 1993-06-04 | 1993-06-04 | Telescopic mast for a global positioning system antenna |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2097774 CA2097774C (en) | 1993-06-04 | 1993-06-04 | Telescopic mast for a global positioning system antenna |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2097774A1 CA2097774A1 (en) | 1994-12-05 |
| CA2097774C true CA2097774C (en) | 1996-12-31 |
Family
ID=4151748
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2097774 Expired - Fee Related CA2097774C (en) | 1993-06-04 | 1993-06-04 | Telescopic mast for a global positioning system antenna |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2097774C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11156326B2 (en) | 2018-07-05 | 2021-10-26 | Clark Construction Group, Llc | Device and method for use thereof for facilitating substantially leveled attachment of construction tool |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10108964A1 (en) * | 2001-02-16 | 2002-09-19 | Johann Banzhaf | Holding device, mast connection, mast with holding device and mast connection and method for building a mast |
| US8191322B2 (en) * | 2007-10-11 | 2012-06-05 | Frank Liestenfeltz | Payload mast |
-
1993
- 1993-06-04 CA CA 2097774 patent/CA2097774C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11156326B2 (en) | 2018-07-05 | 2021-10-26 | Clark Construction Group, Llc | Device and method for use thereof for facilitating substantially leveled attachment of construction tool |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2097774A1 (en) | 1994-12-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |