US3333808A

US3333808A - Utility pole construction

Info

Publication number: US3333808A
Application number: US461907A
Authority: US
Inventors: Boff Philip L Du
Original assignee: Shelfmaker Products Corp
Current assignee: Shelfmaker Products Corp
Priority date: 1965-06-07
Filing date: 1965-06-07
Publication date: 1967-08-01
Anticipated expiration: 1984-08-01

Description

Aug. 1, 1967 P. L. DU BOFF UTILITY POLE CONSTRUCTION Filed June '7, 1965 FiG INVENTOR Piwfl' L. Duo??? ATTORN United States Patent Jersey Filed June 7, 1965, Ser. No. 461,907 4 Claims. (Cl. 248-354) This is a continuation-in-part of my copending application Ser. No. 370,878, filed May 28, 1964, now abandoned.

This invention relates to household utility poles, i.e., poles of the type which are commonly used for room dividers, planters, towel racks, shelf supports and the like.

In recent years, household utility poles have been put to wide-spread use by virtue of their adaptability to conveniently support various types of holding means. Yet, notwithstanding the wide use to which such poles have been put, it has been found that the poles previously suggested do not always yield the desired support characteristics.

Normally in the use of poles of the type in question, the user supports the same between two vertically spaced apart surfaces, such as the floor and ceiling of a room. With different types of construction, used both in residential and commercial applications, the pole constructions must not only be vertically positionable with relative ease, but they must also be adjustable to accommodate different vertical spacings, such as, for example, different floor to ceiling heights. Moreover, for many purposes, it is desirable to place such poles in raised position with respect to a floor or in a lower position with respect to a ceiling, i.e., in some instances, it is desirable to be able to install the poles between the top of a table or a cabinet and the ceiling, and/or between a depending upper surface and the floor. Thus, the poles should possess adjustability which will permit the same to be positioned between two surfaces, regardless of the distance at which they are spaced apart.

The adjustability aspects of the pole constructions can be comparatively easily understood, but the required functional characteristics are not readily susceptible to determination merely from an inspection of a pole construction. Instead, to determine the functional strength characteristics, it appears that, as least, four specific tests should be applied, namely, (1) resistance to sliding motion; (2) deflection under load; (3) resistance to rotary motion; and (4) resistance to flexure. These tests indicate the durability of the pole units, as well as the suitability thereof for use in given applications.

In determining the resistance to sliding motion consistent with the tests outlined above, a pole would be installed in a normal vertical position, and then a force would be applied at the base of the pole tending to move the same laterally-i.e., sideways. In other words, resistance to sliding motion of any pole construction is determined by the load required to laterally shift the pole with the load being applied sideways thereof, as by pulling sideways on the pole.

To ascertain the deflection under load, the pole assembly would again be installed in its vertical normal position, but the pole would then be loaded with weights at one or more positions therealong. The deflection at the center of the pole span would be measuredi.e., the deflection from vertical position Wuld be determined.

The resistance to rotary motion test involves the use of a moment arm installed on the pole construction as vertically positioned, but with no load applied thereto. The moment arm is subjected to measured torsion forces to determine the force required to rotate the pole assembly or construction as installed.

To determine the resistance to flexure of a pole construction the same is installed in its normal position, and then a given force is imparted at the center of the pole unt. More specfically,'the pole is subjected to a given impact at its center and a measurement is made of the deflection and recovery motion.

The prior pole constructions most commonly produced on the commercial market incorporate a plurality of pole sections, and at least one spring pressed plungertype mechanism engageable with one of the surfaces between which the pole is to be supported. These prior devices, when subjected to the test procedures outlined above, do not prove satisfactory. Their resistance to rotary motion and resistance to flexure and deflection under load are not particularly desirable. In another type of commercially produced pole construction wherein telescoping sections are locked together by a set screw, generally similar problems are encountered. There thus remains a need for a pole construction capable of being used as a support member and which favorably responds to the adjustability requirement as well as to the operational and/or functional tests discussed above.

Still another important consideration in pole units of this type is the need to compensate for any ceiling deviation subsequent to erecting of the unit. Pole units of the type described herein are often utilized in rooms having ceilings which are formed of soft acoustical tiles. In-itially, the pole may be erected to tightly; engage, at its upper end, against such tiles. However, in time, the tile against which the pole is bearing may give or settle somewhat, and thus pole will be only loosend engaged thereagainst. Similarly, the floor portion against which the lower end of the pole is engaged, may tend to sag or settle somewhat in time. Under conditions of this type, the pole unit does not have the desirable strength characteristics, and under conditions of load, the pole unit might topple over. It can thus be seen that a need exists for a pole unit which, under any circumstances, will remain firmly engaged against its supporting surfaces, and which will not become loosened, regardless of any subsequent give, settling, sag or other deviation of the supporting surfaces.

Furthermore, as aforementioned, resistance to rotary motion is a factor which must be considered in pole units of this type. In certain embodiments of the present invention, as described more fully hereinafter, it is specifically desired to permit one or more of the pole sections to rotate relatively to one another. Still, even in such embodiments, it will be appreciated that only the central sections are to be rotatable once the pole is erected. It is true that, during erect-ion of the pole unit, the lower section is intended to rotate to create the desired jacking action which telescopically expands the pole sections, but even during such an operation, the upper section should not rotate or else walking will occur. Walking is the undesirable result which occurs when the upper section twists or spins upon its supporting surface, thus moving the pole out of its desired vertical alignment.

With the foregoing matter in mind, it is, therefore, an object of the present invention to overcome the difficulties and shortcomings associated with the prior art, and to provide in their stead, an improved multi-section pole construction.

Another object of the present invention is to provide a means which enables a plurality of pole sections to be assembled to form a pole unit wherein selected sections can rotate and wherein all of the sections, can be vertically adjusted relatively to one another.

Another object of the present invention is to provide a utility pole suitable for use in room dividers, planters, towel racks, shelving, and the like, which utility pole incorporates a combination of features yielding greater resistance to sliding, greater resistance to deflection, greater resistance to rotary motion and greater resistance to flexure than any pole constructions previously'commercially available.

Another object of the present invention is to provide a pole unit incorporating a jack means at least at one end thereof wvhereby selective rotation of a .pole section operates the jack means to expand the pole unit until it is tightly engaged against its supporting surfaces.

Another object of the present invention is to provide a pole unit incorporating a compensated spring means which assures that the pole unit will always remain tightly against its supporting surfaces, even if such supporting surfaces should separate slightly after the pole unit is erected.

j Further objects of the present invention include the provision of a utility pole construction which: (a) is highly attractive in appearance; (b) is relatively inexpensive to produce; (c) is capable of satisfactory operation for extended durations of time; (d) will not walk during assembly; (e) can be easily assembled and disassembled with .a minimum of manipulation; (f) can be easily loosened and moved from one location to another without complete disassembly; and (g) is of high strength, when erected, and can support heavy loads, even if eccentrical'ly applied.

Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment thereof.

The foregoing objects are attained by: (-a) the provision of such a utility pole which incorporates at least one set of telescoping pole sections, a resilient gripping means at the upper end thereof, a jack device at the lower end thereof, including an adjustable jacking member, which permits the pole to be locked in position between two spaced apart surfaces, and an adjusting collar associated with one of the telescoping sections to support an overlying telescoping section in relation thereto; whereby to permit dual adjustment of pole extension initially by the collar and finally by the jack device; (b) the provision of such a utility pole wherein the adjusting collar vertically supports one of the telescoping sections with relation to the other and includes a bore through which one of the telescoping sections extends, and a socket at the other end thereof adapted to receive the overlying telescoping section in supporting engagement therewith; (c) the provision of such a utility pole wherein the socket of the supporting collar is so contoured and designed as to compensate for minor differences in size of respective overlying telescoping pole sections without interferring with the normal operation of the overall pole; (d) the provision of such a utility pole wherein as many sections as desired may be easily coupled together with at least two of the sections being telescopically disposed and with the remaining sections fitting in end-to-end engagement with successive sections having reduced end portions terminating in shoulders engageable with the upper edge of the next adjacent lower end portion of the next lower section; (e) the provision of such a utility pole wherein the jacking device terminates in a foot member, inclunding a base plate coated with a durable synthetic plastic material frictionally engageable with a lower supporting surface; (f) the provision of such a utility pole wherein the support collar and the jacking device are both formed from a durable and substantially friction-free material, preferably nylon; and (g) the provision of a utility pole having at its upper end, a cup disposed in the pole section, a compensated spring housed within the cup, and a cap overlying the spring and abutting the upper supporting surface, whereby when the pole is erected, the jacking action compresses the spring, but if subsequently the supporting surfaces should separate due to give or settling,

the spring will expand to keep the pole tightly engaged against both of its supporting surfaces.

Aside from the above considerations, it is important to understand that the utility pole assembly of the present invention, can easily be shipped in so-called knock-down form, which can readily be assembled by the ordinary housewife or home owner without requiring any mechanical proficiency or manual dexterity, and can be easily locked in its desired Vertical position by merely following two simple adjustment steps. In this latter regard, the utility pole assembly of the present invention can be installed by adjustably telescopically presetting the telescoping sections of the pole unit in approximate desired positions by locking the support collar in a given location and by thereafter locking the entire assembly in position under desired force by merely rotating the lower of the telescopic sections to cause the jacking device to expand and positively fix the pole between the supporting surfaces.

Referring to the drawings:

FIGURE 1 is a side sectional view of a pole unit in accordance with the principles of therpresent invention, showing a compensated spring means disposed within the upper end of the pole unit;

FIGURE 2 is a side sectional view, similar to FIG- URE l, but showing the compensated spring means compressed; and

- FIGURE 3 is an exploded perspective view of the compensated spring means and its mounting means.

As shown in, FIGURE 1, the pole assembly of the present invention includes three

pole sections

10, 12 and 14. The pole section 12 is telescopically engageable in overlying relation with the pole section 10, with both such poles being of substantially uniform diameter. In contrast, the pole section 14 includes a lower end portion 16 of reduced diameter and an enlarged diameter upper end portion 18, with such end portions being connected by a flared web 20 therebetween. The -web 20 rests upon the top edge 22 of the pole section 12. The upper end portion 18 preferably has an outer diameter corresponding to the outer diameter of the pole section 12 and the lower end portion 16 preferably has a diameter corresponding to both the outer diameter of the pole section 10 and the inner diameter of the pole section 12. Thus, the

pole sections

12 and 14 are coupled together by the end portion 16.

The pole means is preferably hollow throughout its length and various sections, but in any event, it has hollow opposed upper and lower end portions.

The lower end portion thereof receives a jack means generally designated 36. This jack means includes a plug member generally designated 38 having a base portion 40 engaged in the lower end'portion 26 of the pole means. The plug member 36 further includes an underlying enlarged head 42 which is integrally formed with the base portion 40 of the plug member 38 and which engages against the lower end of the pole section 10. The plug member 36 is centrally and cylindrically recessed as at 44, again to facilitate its insertion into the end portion 26, but also and more important, to receive therein the end of a threaded shaft 46 which forms part of an adjustment means. The adjustment means, in addition to the threaded shaft 46, includes .a foot piece 48 secured to the shaft and adapted to rest upon the floor F. The shaft 46 passes through a threaded aperture 49 extending coaxially through the plug member 38 and into the recess 44.

The plug member 38 is preferably formed of nylon and the foot piece 48 associated therewith preferably comprises a circular metal plate 50 embedded in and covered by a synthetic resin covering 52. The synthetic resin covering is made of a hard and durable plastic to provide a good frictional grip against the floor or any other lower surface with which the pole means is engaged. The plate 50 is welded or otherwise fixedly secured to the end of the shaft 46, so that the foot piece and shaft turn in unison. On the other hand, the plug member 38 is tightly frictionally engaged with the lower end 26 of the pole means so that the plug member 38 turns with the pole means when the foot member 48 and threaded shaft 46 are fixed with respect to a support surface.

Disposed over the section of the pole means and under the section 12 thereof is a means generally designated 54, formed as a collar which vertically supports the pole section 12 in telescoping vertical engagement over the pole section 10. The body 56 has a transverse threaded aperture 60 extending from its periphery to the bore 58. A set screw 62 is threaded into the aperture 6|) and is engageable with the exterior of the pole section 10 to lock the collar means 54 in place thereon, at any selected location along the length of the pole section 10.

As can best be seen in FIGURE 1, the body 56 of the collar means 54 includes a fiat top edge surface 64 and downwardly and inwardly tapering surface 68 extending toward the bore 58. The lower edge of the pole section 12 seats upon the surface 68, thus supporting the entire pole section within the collar means 54. However, with manufacturing tolerances for structures of this type being none too critical, it is recognized that the diametral size of any two pole sections 12 might not be identical. Yet, because of the tapering surface 68, the collar means 54 enables the pole sections to be telescoped in the desired manner since the outer edge of the pole section 12 will seat somewhere along the tapering surface 68. Also, since the body 56 is fabricated of nylon, Teflon (polytetrafluoroethylene) or some other suitable partially resilient plastic material, there can be a slight outward deformation of the body when the lower end of the pole section 12 is inserted therein.

The pole unit of the present invention is adapted to be extended across a vertical span and tightly engaged against upper and lower supporting surfaces, preferably horizontal planar surfaces, such as a floor and ceiling. The pole sections can be initially manually expanded and retained in such expanded condition by tightening the collar 54 at the proper location. Thereafter, the final adjustment can be made by rotating the lower pole section to operate the jack means '36.

However, even though the pole unit can 'be initially tightened into position, any minute relative separation of the supporting surfaces occurring at some subsequent time, tends to weaken the support of the pole. For example, if the upper end of the pole abuts against an acoustical ceiling tile, any slight warping, tipping, give or other deviation in such a tile can loosen the contact between the title and the pole upper end. Similarly, if the lower end of the pole rests upon the floor, and the floor sags or settles slightly, the pole will also settle and the upper end thereof will tend to lower away from the ceiling. Such movement of the floor or ceiling, or both, need only be a fractional amount to materially weaken the strength and stability of the pole unit.

Therefore, in an effort to prevent any loss in stability or strength, the pole unit should be provided with a means which compensates for the deviation described above, when and if such deviation actually does occur. The compensation means generally designated 140 is mounted to the enlarged portion 18 of the upper pole section 14 by means of a cup member generally designated 142 having a cylindrical body wall 144 sized to fit tightly with the pole portion 18. At its upper end, the body wall has an outwardly extending integral web 146 which merges into an integral downwardly depending skirt 148. The web serves to space the skirt 148 away from the body wall 144. thereby defining an annular channel 150. As shown in FIGURES 1 and 2., when the cap member 142 is applied over the upper end of the pole portion 18, the body portion 144 extends downward interiorly thereof, the skirt 148 extends downward exteriorly thereof, and the upper edge thereof is disposed within the channel 6 in abutting relationship against the underside of the web 146.

The lower end of the cup member body wall 144 is curled inwardly at 152 to provide a seat for a compensated helical compression spring 154. The spring 154 extends upwardly from its seat 152 in the cup member 142 and a cap means generally designated 156 is disposed over the upper end of the spring. The cap means includes an enlarged flat base portion 158 and a cylindrical skirt portion 160 depending therefrom, with the skirt portion having an effective diameter just large enough to accommodate the cup skirt 148. Spaced inwardly somewhat from the skirt portion 160 is a cylindrical or circular rib portion 162 which likewise depends from the underside of the base portion 158. The rib portion 162 circumscribes a positioning means for the upper end of the spring 154, to keep the spring properly centered within the cap means with the spring upper end abutting against the underside of the base portion 158. The upper surface of the base portion 158 is suitably roughened, as shown at 164, for good gripping action against the upper supporting surface or ceiling C. Preferably, the cup member 142 and cap means 156 are both fabricated of nylon or other similar material.

As shown, the cap means 156 is telescopically nested over the cup member 142 with the spring 154 disposed in nesting relationship therebetween. When the spring expands or compresses, the upper pole section 14 and the cap member 142 carried thereby move axially relatively to one another. In operation, the pole unit is initially erected to the condition of FIGURE 1 by means of adjustment of the collar 54, previously described. It will be noted that in FIGURE 1, screw 46 and foot 48 on the jacking means 36 are screwed substantially into the plug member 38. Then, the lower pole section 10 is rotated, causing the plug 38 to rotate while the foot 48 remains in frictionally engaged, non-rotating contact with the floor F. Thus, the rotation causes the screw 46 to unscrew out of the plug 38, thereby com pressing the spring 154. The length of the spring is substantially twice the depth of the cup member 142 so that the spring can compress substantially thereinto. This jacking action continues until the lower edge of the rib portion 162 abuts tightly against the upper face of the Web 146, as shown in FIGURE 2. At this time, jacking action will be completed, the spring will be fully compressed, and all parts of the pole unit will be tightly pressed axially against one another, thereby firmly and strongly mounting the pole unit with the foot 48 pressed tightly against the floor F and the roughened base surface 164 pressed tightly against the ceiling C.

After such firm mounting, if the ceiling C should raise slightly, or if the floor F should settle slightly, or both, the spring 154 will expand and will keep the top 164 of the base portion 158 firmly pressed against the ceiling. Still, even at this time, the pole will be strongly mounted and can support the load applied thereto without any danger of sudden tipping or toppling. Another feature provided by the compensation means 142 is the assurance that the pole unit will not walk during the jacking action which erects the same. Since the cap means 156 is not firmly fixed to any portion of the pole unit, but instead, merely freely overlies and surrounds the upper end thereof, the roughened surface 164 can firmly and non-rotatably mount the cap means against the ceiling C so no twisting or spinning can occur, even if the pole section 14 and the cup member 142 were to rotate during jacking action.

After reading the foregoing detailed description, it should be apparent that the objects set forth at the outset thereof have been successfully achieved by the present invention. Accordingly, what is claimed is:

7 1. A pole device adapted to be fixedly positioned between spaced apart first and second supporting surfaces; said device comprising:

' said first and second pole sections being disposed in at least partially telescoped relationship;

collar means slidably engaged upon one of said pole sections;

said collar means including a supporting portion for engaging the other of pole sections to thereby adjust the amount of telescoping of said pole sections and to permit relative rotation between said pole sections;

said collar means further including locking means to selectively fix said collar means at any desired location along the extent of said one pole section;

said first pole section having an end portion adjacent said first supporting surface;

gripping means reacting between said first pole section end portion and said first supporting surface;

7 said gripping means including a member engageable with said first supporting surface, biasing means, and mounting means for mounting said biasing means to said first pole section end portion;

said biasing means reacting between said mounting means and said member to normally urge said member into contacting relationship with said first supporting surface;

said second pole section having an end portion adjacent said second supporting surface;

screw jack means reacting between said second pole section end portion and said second supporting sur- 'face;

said screw jack means including a plug means with a threaded aperture secured to said second pole section end portion and an element coupled with a threaded shaft engaged within said threaded aperture;

said plug means and said element being relatively rotatable to move said element into contacting relationship with said second supporting surface;

said device being fixedly positioned between said first and second supporting surfaces by sliding said collar means along said one pole section to a selected position whereat said member contacts said first supporting surface and said element contacts said second supporting surface, engaging said locking means to fix said collar means at said selected position and thereafter rotating one of said pole sections to cause said threaded shaft to unthread from said plug means thereby increasing the contacting pressure of said element against said second supporting surface, said rotation continuing, against the biasing effect of said biasing means, until said member contacts firmly against said first supporting surface and said element simultaneously firmly contacts against said second supporting surface;

said mounting means for said biasing means including a cup member having a first end engaged against the end of said first pole section and a second end spaced therefrom and disposed interiorly of said first pole section;

said biasing means being a spring means, one end of which seats against said cup member second end and the other end of which seats against said member;

' said member being telescoped with respect to said cup member and axially movable relatively thereto, and including a rib portion .at least partially surrounding said spring means other end, said rib portion engaging against said cup member one end when said spring means is fully compressed within said cup member.

2. A pole device as defined in claim 1 wherein said cup member first end includes an outwardly directed web and a skirt attached to said web and surrounding at least a portion of said cup member to define an annular channel, with the end of said first pole section being disposed in said annular channel and with said web abutting against the end of said first pole section.

3. A pole device as defined in claim 2 wherein said rib portion engages against said outwardly directed Web when said spring means is fully compressed within said cup member.

4. A pole device as defined in claim 3 wherein said cup member second end includes an inwardly directed portion defining an annular groove into which said other end of said spring means is fitted.

References Cited UNITED STATES PATENTS 899,349 9/ 1908 Steiber 52-726 1,875,977 9/ 1932 -Beckwith 248-356 2,261,061 10/1941 Horton 248-354 2,584,015 1/ 1952 Hawes 248-354 2,903,227 9/ 1959 Key 211-86 X 3,018,898 1/ 1962 Frazelle 211-86 3,043,642 7/ 1962 Nelson et al. 108-114 3,101,849 8/1963 Osborn 211-131 3,111,723 11/1963 Bates 211-177 3,164,260 1/1965 Seemann 211-177 3,167,292 1/ 1965 Meyerwitz 108-144 3,179,257 4/ 1965 Tassell 211-148 3,273,519 9/1966 Du Bofi 108-105 FRANCIS K. ZUGEL, Primary Examiner.

CASMIR A. NUNBERG, Examiner.

Claims

1. A POLE DEVICE ADAPTED TO BE FIXEDLY POSITIONED BETWEEN SPACED APART FIRST AND SECOND SUPPORTING SURFACES; SAID DEVICE COMPRISING: AT LEAST TWO ELONGATED POLE SECTIONS DEFINING A FIRST POLE SECTION SPACED CLOSEST TO SAID FIRST SUPPORTING SURFACE AND A SECOND POLE SECTION SPACED CLOSEST TO SAID SECOND SUPPORTING SURFACE; SAID FIRST AND SECOND POLE SECTIONS BEING DISPOSED IN AT LEAST PARTIALLY TELESCOPED RELATIONSHIP; COLLAR MEANS SLIDABLY ENGAGED UPON ONE OF SAID POLE SECTIONS; SAID COLLAR MEANS INCLUDING A SUPPORTING PORTION FOR ENGAGING THE OTHER OF POLE SECTIONS TO THEREBY ADJUST THE AMOUNT OF TELESCOPING OF SAID POLE SECTIONS AND TO PERMIT RELATIVE ROTATION BETWEEN SAID POLE SECTIONS; SAID COLLAR MEANS FURTHER INCLUDING LOCKING MEANS TO SELECTIVELY FIX SAID COLLAR MEANS AT ANY DESIRED LOCATION ALONG THE EXTENT OF SAID ONE POLE SECTION; SAID FIRST POLE SECTION HAVING AN END PORTION ADJACENT SAID FIRST SUPPORTING SURFACE; GRIPPING MEANS REACTING BETWEEN SAID FIRST POLE SECTION END PORTION AND SAID SUPPORTING SURFACE; SAID GRIPPING MEANS INCLUDING A MEMBER ENGAGEABLE WITH SAID FIRST SUPPORTING SURFACE, BIASING MEANS, AND MOUNTING MEANS FOR MOUNTING SAID BIASING MEANS TO SAID FIRST POLE SECTION END PORTION; SAID BIASING MEANS REACTING BETWEEN SAID MOUNTING MEANS AND SAID MEMBER TO NORMALLY URGE SAID MEMBER INTO CONTACTING RELATIONSHIP WITH SAID FIRST SUPPORTING SURFACE; SAID SECOND POLE SECTION HAVING AN END PORTION ADJACENT SAID SECOND SUPPORTING SURFACE; SCREW JACK MEANS REACTING BETWEEN SAID SECOND POLE SECTION END PORTION AND SAID SECOND SUPPORTING SURFACE; SAID SCREW JACK MEANS INCLUDING A PLUG MEANS WITH A THREADED APERTURE SECURED TO SAID SECOND POLE SECTION END PORTION AND AN ELEMENT COUPLED WITH A THREADED SHAFT ENGAGED WITHIN SAID THREADED APERTURE; SAID PLUG MEANS AND SAID ELEMENT BEING RELATIVELY ROTATABLE TO MOVE SAID ELEMENT INTO CONTACTING RELATIONSHIP WITH SAID SECOND SUPPORTING SURFACE; SAID DEVICE BEING FIXEDLY POSITIONED BETWEEN SAID FIRST AND SECOND SUPPORTING SURFACES BY SLIDING SAID COLLAR MEANS ALONG SAID ONE POLE SECTION TO A SELECTED POSITION WHEREAT SAID MEMBER CONTACTS SAID FIRST SUPPORTING SURFACE AND SAID ELEMENT CONTACTS SAID SECOND SUPPORTING SURFACE, ENGAGING SAID LOCKING MEANS TO FIX SAID COLLAR MEANS AT SAID SELECTED POSITION AND THEREAFTER ROTATING ONE OF SAID POLE SECTIONS TO SAID CAUSE SAID THREADED SHAFT TO UNTHREAD FROM SAID PLUG MEANS THEREBY INCREASING THE CONTACTING PRESSURE OF SAID ELEMENT AGAINST SAID SECOND SUPPORTING SURFACE, SAID ROTATION CONTINUING, AGAINST THE BIASING EFFECT OF SAID BIASING MEANS, UNTIL SAID MEMBER CONTACTS FIRMLY AGAINST SAID FIRST SUPPORTING SURFACE AND SAID ELEMENT SIMULTANEOUSLY FIRMLY CONTACTS AGAINST SAID SECOND SUPPORTING SURFACE; SAID MOUNTING MEANS FOR BIASING MEANS INCLUDING A CUP MEMBER HAVING A FIRST END ENGAGED AGAINST THE END OF SAID FIRST POLE SECTION AND A SECOND END SPACED THEREFROM AND DISPOSED INTERIORLY OF SAID FIRST POLE SECTION; SAID BIASING MEANS BEING A SPRING MEANS, ONE END OF WHICH SEATS AGAINST SAID CUP MEMBER SECOND END AND THE OTHER END OF WHICH SEATS AGAINST SAID MEMBER, SAID MEMBER BEING TELESCOPED WITH RESPECT TO SAID CUP MEMBER AND AXIALLY MOVABLE RELATIVELY THERETO, AND INCLUDING A RIB PORTION AT LEAST PARTIALLY SURROUNDING SAID SPRING MEANS OTHER END, SAID RIB PORTION ENGAGING AGAINST SAID CUP MEMBER ONE END WHEN SAID SPRING MEANS IS FULLY COMPRESSED WITHIN SAID CUP MEMBER.