c. THORPE TELESCOPIC MAST July 23, 1957 Filed April 7, 1953 FIG. I
INVENTOR. CHARLES L. THORPE TELESCOPIC MAST Charles L. Thorpe, Eatontown, N. J., assignor to the United States of America as represented by the Secretary of the Army Application April 7, 1953, Serial No. 347,420
Claims. (Cl. 18926) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described in the following specification and claims may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.
The present invention relates to a portable mast.
The invention is concerned particularly with that type of mast made up of a plurality of telescoping tubes, each of approximately the same length. In such masts, the first tube of the mast is secured or fixed and all other tubes are movable. When collapsed or unextended, each of the sections are telescopically engaged within each other. By a unique system of pulleys aflixed at the upper end of each section, and separate lengths of cables, the ends of which, with the exception of the first tube, terminate at the top and bottom of alternate sections of the mast, the mast can be raised to its full length. 'This is accomplished by pulling the cable, which is secured to the base of the second section, over the top of the first section, thereby shortening the distance of the cable confined within the telescoping sections, causing said section to be raised. As said section is being raised, the third section will of necessity be raised, inasmuch as there is a cable extending from the bottom of the third section to the top of the first section, and as the second section is raised the third section will move up simultaneously. In like fashion, all the remaining tubular sections of the mast will be elevated.
Heretofore, in masts of the type described above, the cable was either manually pulled or wound upon a winch, usually by a hand crank. Masts so constructed were usually installed upon a fixed base or foundation, such as the top of a building, cast into a firm cement foundation, or mounted upon a vehicle such as a truck body. Masts so constructed do not readily lend themselves to varied usage due to the limitations exacted by the manner in which the masts are mounted and supported as indicated above.
A typical use of such masts is for supporting an antenna of a radio receiver and/or transmitting set. It has been found, however, that when using masts of the type described above, the mobility or extent of use of a radio set would be limited by the travel of the truck body upon which such mast would be mounted. Also such masts once attached to a vehicle would become a semipermanent attachment to the body and could not be readily removed if needed elsewhere.
It is, therefore, a primary object of the present invention to overcome the aforesaid difficulties and disadvantages by the provision of a mast of the general type outlined above, that is portable and readily assembled for use at any desired site.
An important feature of the present invention resides in the provision of a portable telescopic type mast in combination with a cradle that will permit automatic erection of the mast at any desired location. By the incorporation of the cradle, there is no need of thewinch type erection means, thereby eliminating a relatively high cost item heretofore required for the operation of such masts.
Other objects and advantages will appear as the description proceeds to be read in conjunction with the drawings in which:
Fig.1 is a side elevation al view of the cradle and the mast, partially shown, in open or extended position;
Fig. 2 is a side elevational view of the cradle closed and with the mast in collapsed position;
Fig. 3 is a view in perspective showing the first tubular section of the mast and its associated travelling sleeve and fixed collar;
Fig. 4 is a diagrammatic view showing the cable and pulley arrangement of the first three sections of the mast in collapsed position, and
Fig. 5 is a sectional view of the cradle and mast in locked position taken on the line 5-5 of Fig. 2.
Referring to the drawing, the supporting carriage is shown generally as 11. The carriage comprises, in part, a pair of spaced substantially parallel aligned rails 13. Each of the rails 13 is channel shaped in cross-section, and of sufficient depth to accommodate a trolley as more fully described hereinafter. Positioned between the rails 13 is a casing or housing generally designated as 15. The housing 15 comprises two longitudinally aligned U-shaped sections, the upper section being designated as 17 and the lower section designated as 19 respectively. The space formed between the abutting sections 17, 19 serves as a storage area for the mast generally designated as 21 when the mast is in its collapsed position as shown in Fig. 2. The upper section 17 is provided with a cutout 18 to permit a trolley (hereinafter described) to ride freely to prevent any possible jamming. The same section 17 is further provided with an opening 16 which is utilized when locking the various components when the mast is raised as hereinafter set forth. For locking the sections 17, 19 there are provided a pair of latches, one on each side of the panels as shown at 23 so that when transported the sections will not separate. The lower section 19 is further provided with four angle irons 25, each having one of their respective sides secured, by Welding or the like, to the sides of the lower sections 19. The other side of each angle iron extends perpendicularly outwardly from the section and is provided with an opening 26, through which stakes can be driven into the ground to afford a supporting means for the cradle 11. The rails 13 are held in position by a pair of bolts 24 and 27, with bolt 24 extending through the lower section 19 while bolt 27 extends through a pair of cars 29 each of which is welded to the respective side walls of the section 19. The bolt 27 is not fixedly held in the openings of the ears 29, but can be readily removed so that the upper section 17 can be raised to its elevated position as shown in Fig. l as hereinafter described. A bolt 31 extends through the first section of the mast and both the upper and lower sections 17 and 19, about which pin the upper section 17 and the first section of the mast pivot.
In the description of the mast that follows, for convenience of description, various sections of the mast will be designated as first, second and third sections. Such designations, i. e. first, will indicate that portion of the mast that is the bottom or lowermost section of the mast when fully extended, the term second section will indicate the next succeeding section and so forth.
In addition, when in the specification, the terms top and bottom are used in describing parts of the sectional portions of the mast, the term top will be meant to indicate the upper portion of any one section of the mast when erected, and the term bottom will indicate the lower portion of the same section.
In the perspective view of Fig. 3, there is shown the first section at 33. All the sections of the mast are tubes,
3 wherein. each succeeding. section is of smaller diameter than. the tube preceding it, so that the. tubes. can be. tel scopically engaged as shown in Fig. 4. V
Rigidly secured to and encompassing the top end of the. section 33. is. a fixed-collar: 35-. The: colder-U315 is: made up. of a. pair of1semi-circular plates 36, prouided; with extending flanges 37, and secured together" by bolts 39. Within a cavity formed: between one; pair of flanges are a pair of non-linearly aligned reels 41,43, which are. carried on and rotate about shaft 45 which in turn are secured to the flanges 37'. Circumferentially spaced. about the outer periphery of the. plates 36., and extending therethrough, are apljurality of roller bearings 47 to permit ease of movement between the first and-second sections of the mast. While. not shown in; the-drawings. each; of the'tubular sections of, the mast are; likewise provid with bearings similar to those shown at 47 designated as 4.7.
Also, encompassing the. first. section 3.3 iS. a freely slidable tubular sleeve 49; which, is spaced: from first. section 33 by a plurality of roller bearings 51- which serve to ease the movement of the sleeve; 49 in its travel as hereinafter described. Attached to the surface of the sleeve 49 is a pulley 53 supported by a. shaft 55. Alsosecured to the surface of the sleeve 49 are. a pair of trolleys. 56 spaced 180 apart. The wheels of each trolley are of a diameter slightly smaller than that of the widthof, the rails 13 and are carried on shafts 57- which terminate. in the base 58. In turn, the base 58. is supported by a shaft 6%) which is pivotably secured to the slidable sleeve 49. By means of the pivotable shaft, the trolleys 56 can freely ride within the rails 13.
In Fig. 4 there are shown, in; section, partial views of the first, second and third tubular: sections of the mast. The first section is shown at. 3.3, and, the, details of the fixed collar 35 and the slidable sleeve 49'- have been; de-
end of second section 59 is secured a fixed collar 73 having a single pulley 77 positioned, therein and; rotatable on a shaft 79 which is secured to the side walls of the flange. Also shown in Fig. 4 is a partial VlQW; of the third tubular section. at 3.1 which is spaced; fromfsecond section 59 by means of roller bearings 4.7 which also assist in case of movement of the. second. and third tubular sections relative to each other. Section 81 is. similarly provided with a pulley at its top end (not. shown) and a bolt 85 secured to its lower end.
For coupling the various tubular sections of the. mast so that they can be raised to their extended. position, utilizing the supporting cradle heretofore. described, the following cable looping. system is utilized. For linking the first and second sections av single length of cable 87 is initially secured to the bolt 39 of the fixed collar 37.. The cable then is brought over the pulley -3. of the movable sleeve 49 and then brought: over. the reel 41. From reel 41 the cable extends over the pulley 67 of the second section 59 and then back to and: over the pulley 43. From pulley 43 the cable 87 is then brought back to. the. lower end of second section 59 where; it isrsecured to the bolt 71. The cable linkage between the first section 33 and the third tubular section 81 is a single length of cable 89 which is tied to the bottom of section 81 at bolt 85 and then looped over pulley 77 in the flange of the fixed collar 73 of the second section and to one of the bolts 39 in a flange of the fixed collar 35. of the first section where it is securely tied.
The succeeding sections of the mast. are linked in a manner identical to the way in which the first and third sections are linked as described immediately above. Accordingly, there is shown a partial section of cable 91 which is tied to the fixed collar of second section 59 and which extends over a pulley (not shown) on the top of the third section 81 and is secured to the bottom of the fourth section (not shown). in the same manner that the cable 89 is secured to the bottom of section 81. All succeeding sections are linked in similar manner.
When it is desired to raise the mast to the extended position as shown in Fig. 1, the device heretofore described is operated in the following manner., T heentire assembly is transported to the site where the mast is to be erected and staked to the ground by driving stakes through the openings. 26 of supports 25. The latch 23 is then opened allowing the upper sections 17 of the casing tobe raised. The locking bolt; 27 is. then temporarily removed from its openings through the rails 13 and the ears 29. The upper section 17 of the. casing is then raised. to the position. shown in Fig. 1. In this position the. opening 16 of the upper portion 17 of the casing will be in register with theopenings in the rails 13 and the opening in the car 29. The bolt 27 is then reinserted through all of the openings indicated above. The bolt 27 is preferably threaded so that a nut may be screwed onto it thereby assuring that the components will be securely locked. Such locking action will insure that the; raised section 17 willv remain rigid at all times. To elevate the mast to its extended position the first tubular section 33 is grasped at its upper end and lifted upwardly. In such movement, the sliding sleeve 49 carried by trolleys 55 will travel in the rails 13 of the carriage support. As section 33 of the mast is being raised, the slidable sleeve will move in a direction away from the fixed collar 35. In such movement the cable 87 within the first and second sections will be shortened, thereby urging the second section upwardly.
At the same time as the second tubular section 81 is being raised and extended along with its fixed collar. 73, the length of cable 89 between the second and third sections, and linking first section 33 and third section 81, will be shortened thereby urging third tubular section 81 upward. All other sections of the mast will be simultaneously extended. A conventional form of locking stop (not shown) is provided to lock each section of the mast once itreaches its fully extended position.
T o prevent the mast. from falling or tilting, there are secured to the upper section 17 of the casing, two arcuate shaped. bands 92 each of which are hinged to each. side of the section, and provided, with a clasp 93. After the mast is erected, the bands are brought together and joined by the clasp 93. thereby securing the mast.
For supporting the mast within the casing, there are provided a plurality of supporting brackets 95 and 97 respectively, with bracket 95 being secured to the side walls of lower section 19 or the casing, and bracket 97 being secured to the side walls of upper section 17'.
Although there has been shown herein a detailed prefer-red form of the invention, it is obvious that certain parts may be modified without departing from the invention. It is therefore intended that this disclosure .cover all such modifications as come within the scope of the appended claims.
What is claimed is: 1. In a mast comprising a plurality of telescoping tubu- .lar sections emanating from a first tubular section wherein housing along which guide. said. slidable sleeve is directed,
the spacing between the fixed ends of said guide being substantially equal to the length of said first tubular section, whereby upon movement of said slidable sleeve on said first section and along said guide as said first section is pivotally elevated at a point proximal to one of the terminal ends of said guide, said second section will be raised and all succeeding sections of said mast Will be urged upwardly.
2. In a mast comprising a plurality of telescoping tubular sections emanating from a first tubular section wherein each succeeding section of said mast is urged upwardly by movement of the section preceding it, a housing, a first pivotable tubular section having a sleeve traversable thereon, said sleeve including a pulley and a trolley extending from the outer surface of said sleeve, a second tubular section slidable in said first section, and discrete successive sections slidable in the section preceding it, a cable extending from said first section over said pulley to said second section and discrete cables linking alternate sections of said mast thereafter, a guide supported by and afiixed to said housing along which said trolley can be directed, the spacing between the fixed ends of said guide being substantially equal to the length of said first tubular section whereby as said first tubular section is pivotably elevated at a point proximal to one of the terminal ends of said guide, said sleeve will be longitudinally displaced causing second section to be raised and all succeeding sections of said mast to be urged upwardly.
3. A mast of the type set forth in claim 2 wherein the guide supported by said housing comprises a substantially channel-shaped rail.
4. In a mast comprising a plurality of telescoping tubular sections emanating from a first tubular section wherein each succeeding section of said mast is urged upwardly by movement of the section preceding it, a first pivotable tubular section having a slidable sleeve thereon, said sleeve having a pulley mounted thereon, a second tubular section telescopically slidable in said first section, a third tubular section telescopically slidable in said secend section and successive sections telescopically slidable in the section preceding it, separate cable means linking said first and second sections over the pulley of said slidable sleeve, said first and third sections and alternate sections thereafter, and guide means for directing said slidable sleeve, the spacing between the ends of said guide means being substantially equal to the length of said first tubular section whereby upon movement of said slidable sleeve on said first section and along said guide means said first section is pivotably elevated at a point proximal to one of the ends of said guide means and all the succeeding sections of said mast will be urged upwardly.
5. In a mast comprising a plurality of telescoping sections emanating from a first tubular section wherein each succeeding section of said mast is urged upwardly by movement of the section preceding it, a housing, a first pivotable tubular section having a sleeve traversable thereon, said sleeve including a first pulley and a trolley extending from the outer surface of said sleeve, a pair of reels secured to said first section, a second tubular section slidable in said first section and having a second pulley at one end thereof, and discrete successive tubular sections slidable in the section preceding it, a cable ex-' tending from said first section over said first pulley to one of said reels and over said second pulley then to said second of said reels and then to said second section, and discrete cables linking alternate sections of said mast thereafter, a guide supported by and aflixed at its ends to said housing along which said trolley can be directed, the spacing between the fixed ends of said guide being substantially equal to the length of said first tubular section, whereby as said first tubular section is pivotably elevated at a point proximal to one of the ends of said guide said sleeve will be longitudinally displaced causing said section to be raised and all succeeding sections of said mast to be urged upwardly.
References Cited in the file of this patent UNITED STATES PATENTS 110,434 Clarke Dec. 27, 1870 1,132,303 Carr Mar. 16, 1915 2,369,534 Cohen Feb. 13, 1945 2,384,279 Calhoun Sept. 4, 1945 2,459,280 Lange et a1. Ian. 18, 1949 2,675,211 Regoord Apr. 13, 1954 FOREIGN PATENTS 625,345 France Apr. 23, 1927