US 3103375 A
Abstract available in
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Description (OCR text may contain errors)
Sept. 1o, 1963 E, 1 MCMULLIN 3,103,375
TELESCOPING POLE Filed April 7, 1961 INVENTOR.
.ma j ,w M/L/A/ United States Patent lO 3,103,375 l TELESCOPING POLE Earl L. McMullin, Rutland Townshi 'Mich. (RR. 2, Hastings, Mich.) Filed Apr. 7, 1961, Ser. No. 101,434 2 Claims. (Cl. 287-58) y This invention relates to ak sectional, telescopic pole and,
more particularly, relates to a pole which is constructed -which are telescopically interlitted. lEach section has an internal shoulder close to, but spaced from, one end thereof and has a radial opening therethrough between said shoulder and said one end. A plug closes the other end of cach of the sections and said plug has a springurged pin mounted therein in alignment with a further opening adjacent said other end of the section. The opening at the other end of each section is alignable with the opening adjacentvthe one end of the adjacent outer section and, when such alignment occurs, the pin moves outwardly to lock the two sections in their extended position with respect to each other. The structure disclosed inthe afore-mentioned application is such that each -springmrged pin can serve to lock only two .sections to eachother.
While this structure is effective and reliable, in a continuing effort to improve this structure it has been discovered that the utility thereof can be substantially increased by constru'cting same so that selected ones or all of the spring-urged pins can be used to lock more thantwo of the sections together. This providesa more effective and reliable `lock and also permits Va greater range of adjustment of the length of the pole. The
present invention is directed particularly to the discovery of certain critical relationships which make i-t possible to provide this novel locking arrangement.
Accordingly, it is an object of this inventionto provide an improved, sectional, telescoping pole. i
It is a further object of his invention to pro .'de. an improved, telescoping pole, as aforesaid, utilizing springurged pins to lock the sections with respect to each other wherein at least selected ones of said pins `are arranged so that they can simultaneously lock three or more sections of the pole together. l
It is a further object of this invention to provide an Barry County, j
. 2 lIn the drawings: FIGURE :l is a central sectional, broken view of the y telescoping pole to which the invention relates.
FIGUR-E Z isa viewl of a fragment of FIGURE l on an enlarged scale. f
The pole 101 to which the invention relates comprises a plurality of elongated, round, ktubular sections and, in the preferred embodiment of the invention illustrated in Athe drawings, said pole consists of six sections 11, 12,
13, 14, l15 and 16'of progressively smaller size. The pole may include a greater or lesser nurnber of sections, if desired, the minimum number of sections being three. The smallest section 1,6 may carry a tool T- at its outer end. Preferably, each of the sections is of such internal andl external diameter that it may slide for a limited distance within the adjacent larger section and, further, may receive the adjacent smaller section -for limited sliding movement therewithin.
The tubular sections are rigid and electrically non-con-y ductive and are preferably formed of a resin, such as a polyester-type resin or urea-formaldehyde-type resin, impregnated with glass fibers. Alternatively, the sections may be formed of a plurality of fiberglass fabric laminates impregnated with resin and bonded together to form a unitary structure. However, the sections may be yformed of other electrically non-conductive materials without tieparting from the scope of the invention.
mensional relationships of the sections are selected so that a spring-urged pin in one section can simultaneously extend through aligned openings in at least two more sections to simultaneously lock all of said sectionsin position with respectto each other'.
It is a further object of this invention to provide an improved, telescoping pole, as aforesaid, in which the structure of the pole sections which enables one pin to simultaneously lock three or more sections together can be provided without increasing manufacturing costs and while retaining all of the advantages of the pole described lin my afore-mentioned application.
Other objects and advantages of the invention will become apparent to persons acquainted with equipment of this type upon reading the following disclosure and inspecting the accompanying drawings.
Adjacent one end, hereinafter referred to as the upper end, of each section, except the smallest section 16, the wall thickness of the section is increased by decreasing the internal diameter thereof to provide an internal shoulder 211 spaced a predetermined distance from the upper end of the section and a relatively thick-walled, end vportion 22. extending between said shoulder and the upperend of the section. The end portion 22 of the sectionhas a radially extending opening 23 therethrough located between'the shoulder 21 and the upper end of the section. l
A plug A24 is removably disposed in the lower end of each section, except the largest section 11. The plug 24 has a shank Z5 which closely slidably tits within the lower end of the section and extends to a point located above the opening 23 of the adjacent outer section, when the two sections are in their extended positions. The plug 24' has an `enlarged ilange 26 located outside of Athe section in which it is mounted` and said 'enlarged 4flange is of suiicient size that it may slide within the end of passagez isaligned with an opening 29 through' lthe wall of the inner section adjacent the lower end thereof. The openings 23 and 29 in the inner and outer sections are alignable when the flange 26 on the plug .24 inthe inner section abuts against the shoulder Q1 on the outer section.
`A-pin 31 having an enlarged iiange 32 at the inner vend thereof is disposed in the passage 528 and said enlarged ange 32 is adapted to abut against the shoulder 30 of said passage to limit youtward movement of said pin. The pin 31 is of such size that it :may slidably extend through openings 23 and l29 when same are aligned. A coil spring 33 is disposed between the plug 37 and the enlarged ilange 32 of the pin 31 and urges said pin outwardly until said enlarged ilange abu-ts against the shoulder 30 of the passage. In such posit-ion, the
pin extends through the openings 29 and 23 in the inner and outer sections and provides a positive mechanical look therebetween.
An inner section is free to slide within the adjacent outer section until the Aiiange 26 on the plug 24 therein abuts against the internal shoulder 211 of the adjacent outer section. Desirably, the internal diameter of the thickened end portion 22 ofthe out-er section and the external diameter of the lower end of the inner section are such that when the sections are rin `their extended position, as shown in FIGURE 2 with respect to sec tions 11 and 12 and sections 13 and 14, a 'close dit exists betwen the overlapping portions of the two sec-V tions. This close fit, which enhances therigidity of the pole, is not suiicient as to prevent rotation of the sections with respect to each other. In the preferred embodiment of the invention illustrated in the drawings the internal wall of the thickened end portion 22 in the outer section and the external wall at the lower end of the inner `section are parallel ywith the axisV of the pole. However, if desired, these walls can be tapered. v
As shown in FIGURE 2 with respect to` sections 12, 13 `and 14, selected ones or all of the sections are arranged so that the pin 31 on one of the sections can simultaneously extend through two or more of the adjacent outer sections. Thus, the pin 31 in the lower end of section 14 extends through the aligned openings 23` in the sections 12 and 13. To accomplish this, the distance A between the shoulder 21 andthe center line of the opening 23 must be the same in each of the sections. However, this does not apply to the section 16 which carries tool T. Further, the distance B from the center line of opening 23 to the lower edge of each section, e.g., section 13', must be equal to the corresponding distance in the adjacent outer section, eg., section 14, minus the distance C. The distance C is equal to the distance between the center lines of the openings 29 in the two adjacent sections 13 and 12 when the lower end of the plug 24 of the inner section 13 isengaging the upper endof the plug in the adjacent outersection 12. In the preferred embodiment of the invention, the
plugs 24 in all ofthe sections are `of equal,axial length and the openings 29 are located the same distance from the upper and lower edges thereof and, thus, the distance C is equal to the axial length of the plug 24.
By following these dimensional relationships it will be possible to position the sections so that a pin 31 will lock at least two of the adjacent outer sections to the section in which said pin is mounted. By making the pin 31 of suitable length, the same can be used to lock even more sectionsv together because the openings 23 in any number of sections, constructed in accordance with the above stated dimensional relationships, may be brought into alignment with each other and with pin 31 in the innermost section.
In use, the sections may be placed in their extended position by moving `same longitudinally with respect to each other until the flange 26 on the plug 24 on the v inner section abuts against the internal shoulder 21 on the outer section. If the openings 29 and 23 in the inner and outer sections are not aligned, ysame may be readily accomplished'by rotating one section with respect .to the other until such openings are in alignment. kAt that time, the
. 4 Retraction of the sections may be accomplished by rst depressing the pin 31. The two sections may then be collapsed by moving same axially with respect to each other. When it is desired to lock an inner section, such as section 14, to two or more outer sections, such as sections 12 and 13, the same is done ordinarily by extending the y innermost section 14 and rotating it so that it locks to the adjacent outer section 13. Then the -two locked sections f 14 and 13 are moved inwardly into the next Aouter section 12 until plug 24 on section 13l abuts against plug 24 in section 12. The two locked sections `are rotated with respect -to section 12 until the pin 31 on the innermost lsection 14 is aligned with the opening in the outermost sec-v l. In a sectional, telescopic pole comprising a pluralityv of tubular, elongated sections of progressively smaller size which are telescopically intertted, each section having an internal shoulder spaced from one end thereof and having a rst radial yopening therethrough between said shoulder and said one end, a plug closing the other end of each section, said plug carrying a spring-urged pin which is extended through a secondradial opening adjacent the other end of each section, the plug having means movable against the shoulder of the adjacent outer section -at which time the second radial'opening lon the inner section is aligned with the lirst radial opening in the adjacent outer section so that the pin can extend therethrough to lock said sections together, the improvement which comprises: lsaid sections being of such length that the distance between said first radial opening and the other end of each section is equal -to the corresponding distance in the adjacent larger section less the distance between the center lines v of the two second radial openings in said sections when said plugs are abuttinglagainst each other and the distance between the shoulder and the irst radial opening in said sectionsbeing identical whereby a plurality of said sections can be disposed Within each other with their first radial openings in alignment, and the pin on the innermost of the thus telescoped sections can simultaneously extend into all of said aligned tirst openings.
2. A structure as defined in claim 1 wherein all of the plugs are of the same axial length and the distance between the shoulder and the other end of each section is less than the corresponding dimension of the adjacent larger section by an amount equal to the axial length of the plug.
References Citedin the file of this patent Y* UNITED STATES PATENTS Dunn Dec. 7, 1909 1,896,469 Soll Feb. 7, 1933 j 2,722,970
Stechmann Nov. 8, 1955