AU463577B2 - Extendible tube assembly - Google Patents

Description

50,382 n2 The invention relates to a locking, telescoping

tubular memiber assembly and, in particular, to such an

assembly for use with carpet installation equipment. Carpet is commonly installed by stretching it

across a floor with tools that have a head which grips the

carpet and a pole which extends to a base or wall plate

that is placed against a wall to provide the support for the stretcher. The pole is commonly formed of steel tupes

which are furnished in units of two concentric tubes which

are approximately three and one half feet long. These

tubes can be extended and interlocked at set intervals up to about five to six feet. The inner tube carries a pair

of spring biased buttoms at each end while the outer carr- ies apertures at its ends so that the tubes can be connec-

ted, head-to-tail, to provide a rigid load bearing pole. This conventional construction prevents the most

efficient use of the stretcher equipment. The tubes can be

interconnected only at certain lengths which are determined by the location of the apertures. For maximum usefulness,

a stretcher head should be capable of being located at any

point from the base, however, the limitation of the exten- sions to distances that are fixed by the location of the apertures often results in gaps or blind spots where the head can not be located. The present invention provides an assembly of ex-

tendible, telescoping tubular members having lock means preventing their retraction which comprises: an outer tub-

ular member; an inner tubular member concentric in said

outer tubular member; an elongated locking member secured

at one of its ends in one of said members with its opposite

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50,382 /72 end projecting within the other tubular member and exten-

ding a substantial distance therealong; lock means com- prising a collar about said elongated member and loosely carried by the other of said members by attachment means affixed to one edge of said collar to provide a free edge thereof that is movable to permit tilting of said collar between a first position in locking engagement with said elongated locking member to prevent relative movement in one direction between said tubular members and a second position releasing said collar from said elongated locking

member and permitting relative movement between said tubu- lar members in a direction opposite to said one direction;

resilient means engageable by seat means carried by said other of said tubular members and biased against said col-

lar to urge it into said first position; and release means engageable with said collar whereby the collar can be manually moved from its said first to its second posi-

tion. The invention will now be decribed by reference to the FIGURES, of which: FIGURE 1 illustrates the assembly of the inven-

tion; FIGURE 2 illustrates the assembly in a carpet

stretcher assembly; FIGURE 3 illustrates the details of a preferred ratchet locking stretcher to be used with the assembly of

the invention; FIGURE 4 is a cross sectional view of the assem-

bly of FIGURE 1;

FIGURE 5 is a view of an alternate embodiment of

0.382, the invention; and FIGURES 6 through 8 show various alternate embod-

iments.

Referring now to FIGURE i, the device is shown as an assembly of two concentric tubular members, outer

tube 10 and inner tube 12 which telescopes within tube Preferably these tubes are compatible with the conventional

carpet stretcher tubes. Any of various means to interlock the tubes can be used and such means are carried at the

ends of the tubes. As illustrated, the outer tube 10 bears the con- ventional apertures 14 at its free end which are spaced at 180 degrees in the same plane and are positioned about 3.75 inches from the end. These are female interlocking means to provide attachment whereby the tube 10 can be inter- locked to smaller diameter tubes of pole units which bear male interlocking means comprising opposed and spring bi-

ased buttons at their ends to engage the apertures. One or more sets of such apertures can be provided at the standard spacings from the end of the tube to insure the universal compatibility of the assembly with all stretcher

poles. The small diameter tube 12 bears, at its free end, a pair of spring biased buttons 18. These buttons are conventional in structure and purpose; they are the male interlocking means to permit the tube assembly to be

interconnected with standard stretcher components. the buttons are commonly secured to the free ends of a bifur-

cated, resilient leaf spring which fits into the end of

the tube.

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50,382, n externally, The remainder of the tube assembly, extendible units of appears the same as the conventional of many apertures stretcher systems except for the absence except for the tube lock along the length of tube 10 and collar 20. As will be de- release means which is shown as the collar 20 can scribed in greater detail hereinafter, unlock the assembly and per- be urged toward the tube 10 to be withdrawn from tube mit tube 12 to telescope into or is shown in Referring to FIGURE 2, the assembly head unit comprises a carpet stretcher unit. The stretcher the carpet. The plate a plate 11 bearing teeth to engage slides within tube 15. This is attached to shaft 13 which and has a link member 17 tube is the base of the head unit pivotably attached thereto. The other end of the link provide a fulcrum support member is attached to lever 19 to attached to therefor. The end of lever 19 is pivotably

head plate 11. Preferably, the head unit has means to permit multiple of extensions in tube locking shaft 13 at any of a means 21 shown cut into Such means can comprise rack carried by tube 15 which also into shaft 13 with pawl means the pawl into engagement with carries spring means to bias lever 23 carried by the rack means and actuation means, such as cable 25 that is oper- lever 19 with linking means the rack. preferably such ative to retract the pawl from internally of tube rack and spring means are carried

means can be posi- Alternatively, arcuarate rack pivotable conncction to tioned on link 17 adjacent its means can be carried by lever 19 and the pawl and spring

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50,382/7 lever 19. Such a construction is shown in FIGURE 3 where

the arcuate rack 24 is placed on link 17 on a radius about

pin 27 and pawl 29 is pivotably connected between the side-

walls of lever 19 and biased into engagement with the rack

by spring 31 which is secured to arm 33 that is rigidly

linked to the pawl. A push rod 35 extends to lever 33 to

retract the pawl 29. Referring again to FIGURE 2, the remainder of

the stretcher unit comprises one or more of the extendible

tube assemblies of this invention, tubes 10 and 12.

Although the assembly can be interlocked in the pole unit

at any place in its length, it is preferred to place one

of the assemblies of the invention directly behind the stretcher head. unit so that the manual release means can be readily available to the operator of the stretcher.

The forward end of tube 12 is interlocked by its buttons

18 into the end of tube 15 of the head unit. Tube 10 is

also connected to a tube extension that is shown as a con-

ventional extendible tube unit formed of inner tube which bears a first set of spring biased buttons to inter-

lock in apertures 14 and a second set of buttons to inter-

lock within any set of a plurality of apertures 37 along outer tube 39 of the unit. The tubes are shown in FIGURE 2 with a disproportionately large diameter for ease of illustration. A conventional wall block or plate 41 is carried

at the end of tube 39 by shaft 43 which fits within tube to 39 and which also has a pair of spring biased buttons interlock within the last of apertures 37 in this tube. Preferably, shaft 43 is attached to plate 41 with bracket

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50,382.,72 means permitting it to pivot in a horizontal plane relat- ive to plate 41. Referring now to FIGURE 4, the assembly of this

invention is shown in longitudinal section. The outer tube

carries a block 22 intermediate its length, preferably

adjacent one end as shown and spaced inwardly from aper- tures 14 sufficiently to avoid any interference with the

end of a mating tube and thereby permit interlocking by

buttons carried by such tube engaging apertures 14. Typi-

cally, this distance is from 1.25 to about 2 inches from the apertures. Block 22 comprises a cylindrical member

that fits inside tube 10 and is secured thereto by suit- able means such as set screws, welding or equivalent means. The block has means for the attachment of the locking elon- gated member which is in the form of tube 26. A solid

shaft is shown for this member, however, it is preferably

tubular. The cross section of this member can also be

of any shape, square, oval, etc.

The preferred attachment means to secure me mbcr

26 to block 22 has means that permits a limited r~idial dis-

placement of tube 26. This is preferred since the assembly

of the tubes to an exact axial alignment requires a high precision in manufacture. If however tube 26 is free to

"float" slightly while still secured to block 22 thc manu- facture is easier. The means permitting this radial dis-

placement of the tube assembly comprises end plugs 6 and 7 in tube 26 which are bored and thireaded along the center- line of the tube. Block 22 bears a large diameter bore 8

and a screw 9 having a shank of lesser diameter than bore

8. The screw extends through the bore and into threaded

4 635,77 engagement with the threaded bore in plug 6 and the tolerance between the shank of the screw and the bore in plug 22 provides the limited degree of radial movement to tube 26 which imparts a selfaligning action to the entire assembly.

The free end of tube 26 projects substantially the entire length of tube 10 and is concentrically disposed within inner tube 12. The free end of this tube, preferably but not necessarily, bears a short sleeve 28 that can be'formedof brass, aluminum, or more preferably of a plastic having a low coefficient of friction such as Nylon, Teflon (Registered Trade Mark) or Deldrin. This sleeve has a diameter sufficient to engage the inner wall of tube 12 and is attached to tube 26 by screw 34 and plug 7, the latter being secured to the tube by set screws, welding or equivalent means. As with block 22, the bore through sleeve 28 is slightly oversized to permit self alignment of the tube assembly.

As thus described, the unit has two concentric and telescoping tubular members with the inner tubular member being Supported by an internal bearing sleeve carried by a central member that is secured at one end to the outer tube. While this construction could be reversed, the illustrated embodiment is preferred. This construction provides a telescoping assembly having a very smooth action with little or no tendency for the elements to bind or become misaligned even at full extension. Sleeve 28 also servies as means limiting the extension of the tubular members to prevent their separation. The rear face of this sleeve will butt against the fore face of collar 32 and stop further extension of the

4 635 77

0. 82,7' is reached. assembly when its full-extension the lock means The inner tubular member carries and locking member 26 in a slip which engages the elongated comprises a collar 32 which hold manner. The lock means is free to tilt to a slight surrounds tube 26. This collar to a plane perperi- angle, from 2 to about 30 degrees collar can be used as shown icular to tube 26. one solid collars can be stamped from or a stack of several thin purpose. sheet metal and used for this fixed in the assem- one side of the collar 32 is means comprising bly. This is accomplished by attachment a finger or projection an aperture in tube 12 and providing that extends into the aper- on one side of the collar 32 means shown can be used ture. Alternately, the attachment and a pin such as 36 can be wherein the collar is bored turned into a threaded engage- placed through the bore and as collar 30 that is also car- ment with fixed means such Pin 36 has a shank 38 of re- ried by tubular member 12. through bore 45 and a head duced diameter that passes for the edge of collar 32 and to provide retaining means tilt slightly about this re- thereby permit the collar to a first, tilted position taining attachment means between a lock that prevents retrac- where it engages tube 26 in -mewber 10 and a more tion of tubular member 12 within tube 26 and permits tilted position where it releases within membet tubular memvber 12 to retract spring 42 is provided A resilient means such as This tilted, locking pos3ition. to bias collar 32 into its means carried by tubular member spring seats against seat be provided in the 12, collar 30 and a bore 44 can 463.2'

3 82 face of this collar to secure the spring. The face of

collar 32 is also bored and threaded at 46 and the threaded

end of rod 48 is turned into this bore. This rod comprises

the release means operative to unlock collar 32 and it ex-

tends substantially the length of tubular member 12 and terminates adjacent collar Sleeve 28 is bored at 50 and rod 48 extends

through this bore. The rod is attached to collar 20 by

screw 52 and tubular member 12 bears an elongated aperture 54 through which screw 52 extends, Screw 52 is secured to

rod 48 by suitable means, by passing it through a

mating aperture in the rod. This aperture permits sliding

of collar 20 for a slight distance on tubular member 12 and, through rod 48, the retraction of the free edge of collar 32 against the bias of spring 42.

The abutment or seat means for spring 42 com- prises the collar 30 which has a diameter slightly greater than tubular locking member 26 and which is secured to tub-

ular member 12 adjacent its inside end in the assembly with set screw, welding or equivalent means. The set of spring biased buttons 18 which com-

prise the male interconnecting means for attachment of the assembly to conventional stretcher tubes are shown at the left of tubular member 12. The member bears opposed aper-

tures and buttons 18 project through these apertures. The

buttons are supported at the free ends of bifurcated leaf spring 58. The latter is conventional in construction,

and any other means for spring biasing buttons 18 can be used such as by mounting the buttons in a sleeve with a compression spring positioned between the inboard ends of

4635.77

50.382 72 the buttons, etc. An alternate embodiment of the invention is shown

in FIGURE 5. This embodiment uses a concentric tube rather

than the rod 48 and a lever rather than collar 20 of the embodiment of FIGURES 1 and 4. As illustrated, outer tub-

ular member 10 is to the left of FIGURE 5 and bears block

22 and inner locking elongated member 26 with sleeve 28 and screws 9 and 34, all identical to those of FIGURE 4,

with exception that sleeve 28 is of slightly lesser dia-

meter to fit within tube 60. As with the embodiment shown

in FIGURE 4, the inner tube 26 has attachment means permit-

ting radial movement of the individual tubes, thereby in- suring that the assembly is in axial alignment. These mean

means are the same as those described with regard to FIGURE 4. The inner tubular member 12 and collar 30 sup-

o ported thereon by set screws such as 62 are also identical to the same elements of FIGURE 4 with the exception that tubular member 12 bears an aperture 64 near its inboard

end. Collar 66 is slipped over member 26 and fits within

tubular member 12 and has a tail 68 that fits into aper-

ture 64. A single large diameter compression spring

is placed between collars 30 and 66 and comprises the re-

silient means to bias collar 66 forward into a locking

position on tube 26. The forward face of collar 66 has a maximum

height above the face of the collar on the side opposite finger 68. Tube 60 which engages against the leading edge

of rim 70 and projects forward in tubular member 12 termin-

ates therein near the opposite end of this member. At the

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50,382 /7

extreme outboard end of the tubular member 12, not shown, are positioned male interlocking means such as buttons 18

and spring 58 shown in FIGURE 4. A collar 72 is fitted on tubular member 12 and

secured thereto by set screws, welding or equivalent means.

This collar bears bracket means 74 for the pivotable sup- port of lever means 76. Lever 76 has a pin 78 or equiva-

lent finger means which projects through an elongated aper- ture 80 in and a similar aperture in tubular member 12. The free end of pin.78 projects into engagement with tube which can have a small aperture in which the pin is

seated. The lever means and tube 60 thus comprise release

means whereby the locking engagement of collar 66 about

tube 26 can be disengaged. Pressing down on lever 76 will

move tube 60 inwardly and force collar 66 against the bias of spring Referring now to FIGURE 6, a preferred embodiment

of the invention is shown. In this embodiment, the outer

tube 10 bears block 22 by set screws. The block is the

same as that described with regard to FIGURE 4 and it sup-

ports the elongated lock rmember, tube 26 with radial ad-

justment means comprising oversized bore 8 in block 22.

and cap screw 9. The screw 9 is engaged in a threaded bore

of plug 6 which is secured to the end of tube 26. Tube 26

projects within the tube assembly and bears a short sleeve 28 which serves as a bearing support for the tube. The inner tube 12 carries end plate 90 which has

a rim 91 that bears against the end of tube 12 and a body which fits within the tube and is locked thereto by set

screws, welding or equivalent means. A second plate 92 is

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50.382/72

positioned transversely within tube 12 a short distance

from the end of this tube and secured thereto by any con- venient attachment means such as plug welds 93. Both

plates 90 and 92 have a central, large diameter aperture

which surrounds tube 26 with a sufficient tolerance to permit the tube to be slightly displaced in a radial direc-

tion in the assembly, the diameter of this aperture

if from 0.065 to about 0.125 inch greater that the outside

diameter of tube 26. Collar 28 has a greater diameter than

the aperture in plate 92 to provide means to limit the ex- tension of the assembly when the rear face of sleeve 28 butts against plate 92. Collar 103 is a generally circular plate having

a central aperture which is at a slight angle, from

to about 30 degrees, preferably, from about 2 to 8 de-

grees, to its face. This aperture fits loosely about tube

26. A pin 94 is placed in a bore on one face of the collar

103. This face of the collar 103 can be slightly raised

as shown, however, this is not critical. Plate 92 also

has an aperture 95 which is placed at the same radial dis-

tance from the center of plate 92 as pin 94 is from the center of collar 103 so that the pin will project through

the plate when collar 103 is placed within the tube 12 as shown in FIGURE 6. The aperture 95 should be of sufficient

diameter to permit pin 94 freedom of movememt as collar 103 is moved between its varied angular positions in the

assembly. If desired, pin 94 need not be secured on collar

103, but instead, it could be placed in aperture 95 and be

provided with a head of larger diameter than aperture to prevent the pin from being displaced from this aperture.

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50.382/72

The head end of the pin would then bear against the collar 103. A plate 87 is placed within tube 12 and this

plate bears against the side and edge of collar 103 which are opposite from pin 94.so that the extremity of collar

103 is locked between this plate and transverse plate 92. Resilient means, compression spring 96 is placed around tube 26 and the lock housing is closed by securing plate to tube 12. Plate 90 has one or more tapped bores 97

that are spaced at the radius of spring 96 and set screws can be inserted into these bores to urge washer 102 against the tension of spring 96 and thereby serve as means for ad- justment of the tension of this spring. The free end of pin 94 projects through plate 92

and is engaged by the inboard end of tube 60 which sur- rounds tube 26. The inboard end of this tube can bear a

plate such as 98 that serves to align the tube and to bear against the end of pin 94. The opposite end of tube

bears collar 104 which is bored and fitted at 99 with pin means 100. The latter projects through an elongated aper-

ture 101 of tube 12 and serves as the manual release or as a linking member to the manual release. Various modifications can be made in the illus-

trated erbodiments. FIGURE 7 shows a stack of thin sheets

120 which can be cut or stamped from sheet metal and which can be assembled on tube 26 rather than collar 103. These

sheets would provide a multiple of gripping edges as shom at 123 and 124 and thus could improve the locking action of the device. FIGURE 8 shows an alternate manual release which

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50.382/72

of a "hair trigger" action has a less sensitive or less In this embodiment, tube 12 than that shown in FIGURE 4. its inside surface adjacent carries bracket means 105 on bracket the end of tube 60. A lever 106 is mounted on the against collar 104 of tube and has a cam 107 which bears through an elonga- The free end of lever 106 projects so serve as the manual release ted aperture in tube 12 to will, through cam 107, urge. that movement of the lever the locking collar 32. tube 60 rearwardly and release use of a link 110 FIGURE 8 also illustrates unit and which can be which is carried by the stretcher to achieve remote actuation. connected to the manual release a such as 25 is extended from In this embodiment, a cable by in FIGURE 2 that is carried hand lever such as 23 shown 111 cable extends to a housing the stretcher handle. The by tube 112 of the stretcher which is attached to the end means such as band 113. in its side walls and Housing 111 has a slot 114 into the housing where link 110 passes through the slot and of cable 25. The opposite end it is secured to the end of the end of lever 106 so that link 110 can be dropped over actuate the lever and force retraction of the cable will the bias of the spring, e.g., the tube 60 rearwardly against

spring 96, and unlock the collar. a spring means 115 Housing 111 also can contain biases the link rearwardly. shown through slot 114 which form against slide means in the This spring is shown biased with link 110 being passed of block 116 within the housing Cable 25 is secured to this through a bore in this block. by a shaft or pin. block, either directly or

4635.77

50,-382 /7

In the illustrated embodiments, the pole exten- sion is shown as a separate unit that can be removably at- tached to a stretcher as shown in FIGURE 2. The extension unit, however, could be an integral portion of the stretch-

er, tube 15 could be the same as tube 12 as shown in FIGURE 2.

The operation of a stretcher equipped with a pole extension of this invention is fairly apparent from the preceding discussion. The stretcher assembly as shown in FIGURE 2 can. be placed in approximately the desired posi- tion on the carpet to be stretched with the head of the

stretcher dropped close to the final position. The oper- ator can than pull on the outer tube of the assembly to move the base plate against the opposite wall. The teeth of the stretcher can than be engaged in the carpet and the

handle can be pumped to take up the slack in the carpet.

No difficulty is experienced in setting the exact bite necessary for the last movement of the handle since if an

excessive bite is taken and the carpet is stretched taut

before the handle is fully depressed, the operator can simply touch the manual release of the pole unit and the remaining arc of the handle movement can be taken up by the sliding or retraction of the pole assembly. The operator also need not repeatedly engage and reset the teeth in the carpet while taking up the slack in the carpet since the telescoping tube assembly will provide ample extension with a single setting, from about 20 to 40 inches or more

can be obtained, depending on the overall length of the assembly in use. Since the sliding lock' on the unit per-

mits locking of the assembly against retraction at any

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50,38 2 /72

point along its extension, the handle of the stretcher can

be used throughout the last portion of its arc, dur-

ing the last 450 to 150 of its arc where the maximum lever

advantage exists. As the operator moves across the room,

resetting the head in successive steps along the wall, the

base plate can remain set at its original position against

the opposite wall and the increasingly greater lengths of

the pole that are required can simply be obtained by ex-

tending the sliding pole assembly. This increase in length

of the pole can be made almost unconsciously by the oper- ator simply by picking up the head, moving it to the new position and dropping it into the carpet at the new posi-

tion. The weight of the pole extension and the base will

generally be sufficient to retain the base against the wall during this operation; if the base should be dragged from

the wall, it can be easily returned by pulling on the outer tube of the assembly.

17 4 635,7 7

Claims (2)

50,382 72 FOLLO.iS:- THE CLAIMS3 DEFINHIHG THE INENTION ARE AS

1. An assembly of extendible, telescoping their tubular members having lock means preventing

retraction which comprises: an outer tubular member;

said outer tubu- an inner tubular member concentric in secured at lar member; an elongated locking member with its one of its ends in one of said members tubular opposite end projecting within the other distance there- member and extending a substantial about said along; lock means comprising a collar by the other elongated member and loosely carried affixed to one of said members by attachment means edge thereof edge of said collar to provide a free of said collar bet- that is movable to permit tilting with ween a first position in locking engagement relative said elongated locking member to prevent said tubular members movement in one direction between collar from said and a second position releasing said relative move- elongated locking member and permitting in a direction oppo- ment between said tubular members means engageable site to said one direction; resilient of said tubular by seat means carried by said other to urge it into members and biased against said collar means engageable with said first position; and release be manually moved said collar whereby the collar can

from its said first to its second position. said

2. The assembly of claim 1 wherein

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50.382 /72

elongated locking member is secured to said outer

tubular member and said lock means is carried in

said inner tubular member.

3. The assembly of claim 1 or 2, wherein

said elongated locking member is secured to said one

of said members by attachment means permitting a

limited degree of radial movement of said tubular

and elongated locking members whereby said members

will be in axial alignment.

4. The assembly of claim 2 wherein said

elongated member bears, at said opposite end, bearing

means in contact with the inner periphery of said

inner tubular member and wherein said bearing means

is attached to said elongated locking member by lock-

ing member attachment means permitting a limited de-

gree of radial movement of said tubular and elongated

locking members whereby said members will be in axial

alignment.

The assembly of claim 2, 3 or 4 wherein

said locking member is secured to said outer tubular

member by attachment means comprising a plug carried

by said outer member adjacent one end thereof, a

central bore through said plug and a screw of lesser

diameter than said bore projecting therethrough and

into a threaded tap in the end and on the centerline of

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50,382 /7

said elongated member.

6. The assembly of any one of claim 1 to

wherein said ielease means comprises a rod extend-

ing along the inner member and eccentric thereto and

having one end engageable with the free edge of said

collar, actuating means carried adjacent the free end

of said inner member and link means interconnecting

the opposite end of said rod with said actuating

means.

7. The assembly of any one of claims 1 to

wherein said release means comprises a third tubular

member concentrically disposed within said inner tubu-

lar member with one end thereof engageable against the

free edge of said collar, hand lever means carried

at the free end of said inner member, and link means

interconnecting the opposite end of said third tubu-

lar member with said lever means.

8. The assembly of any one of the preceding

claim wherein said seat means comprises a second

collar surrounding said elongated locking member in

a freely sliding relationship and attached rigidly

to said inner tubular member.

9. The assembly of any one of the preceding

claims, in which one of the tubular members is attach-

ed to the base of a power carpet stretcher having a

carpet engaging head, a handle pivotably attached to

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50,.382 /n

to said head, a link member having one end attached at one end

in a fulcrum relationship to said handle and pivotably attached

at its other end to said base, said handle having adjacent its

outer end a hand lever attached by a cable to the release means

of the assembly and movable to operate said release means.

An assembly of extendible, telescoping tubular members according to claim 1 and substantially as herein described

with reference to any one of the embodiments shown in the accom-

panying drawings.

DATED this EIGHTEENTH day of DECEMBER, 1972 ROBERTS CONSOLIDATED INDUSTRIES, INC.

PATENT ATTORNEYS FOR THE APPLICANT SPRUSON FERGUSON

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