AU608568B2 - Lockable elevating mechanism for the continuous adjustment of furniture and guide sleeve for such an elevating mechanism - Google Patents

Description

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AUSTRALIA

Patents Act CCHPLETE SPCIFICAT~ION

(ORIGINAL)

608 568 Int. Class Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority mhe ~:dnieltS ade- under IS 2etion 49 and is correct for P-It d r Related Art: APPLICANT'S REFEREN4CE. Ba .Name(s) of Applicant(s): Fritz Bauer Sohne oHG Address(es) of Applicant(s): industriestrasse 12-14, D-8503 Altdorf, FEDERAL REPUBLIC OF GERMANY.

Address for Service is: PHILLIPS ORMONDE FITZPATRICK C Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: LOCKABLE EMMvATU PlECHANISM FOR THE OQ~MJ(XJS ADJUSTMENT OF FUNITURE AND GIDE SLEEVE FOR SUCH AN E[EATING MECHANISM Our Ref 85660 POP Code: 1611/48125 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 6003q/ 1 1 1 or other witness required a~ PHILLIPS ORMONDE AND FITZPATRICK Patent and Trade Mark Attorneys Melborn, AStralia 367lollns Astreta P 17/2/83 4 *1* Lockable Elevating Mechanism for the Continuous Adjustment of Furniture and Guide Sleeve for such an Elevating Mechanism The invention relates to a lockable elevating mechanism for continuous adjustment of seats, table tops or the like and to a guide sleeve for such an elevating mechanism.

0 ar ot I af a 2 0 0 0 0 000004 0a so a 4 39Y50 MJp -a -la- To: The Commissioner of Patents (Hans-Peter Bauer) President P18/7/78 PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne, Australia STUART TAYLDo ~mm V. 4> i' 1 -i -__~iii.i.;ii~LI i I. TI1,-1-, A r Al A 4-*nn 4 -'ClM-j R l. -l Adjustment of Furniture and Guide Sleeve such an Elevating Mechani The invention ates to a lockable elevating mechanism accordip o the precharacterizing part of claim 1 s ~n t^ -p t. r^ i~ m 'iT4i- 0 o0 oB 00 0 0 00 0 8 9 o0 a Do 0 0 0 00 0 0 0 0 00 0 00 0 00 00 00 00 P O 66 e1U Ls-U 4Ji cm 1-1 Such an elevating mechanism is known from German patent 19 31 012 (corresponding to U.S. patent 3 711 054 and Japanese patent 892 209). The cylindrical outer, surface of the housing of the gas spring is directly guided in a guide sleeve connected to the guide tube.

The gas spring is not only a supporting and length-adjustable element of a chair or table column, but also a leading and a pivoting element. Since the piston rod is attached to the bottom plate of the guide tube not only freely pivoting, but also with sufficient radial play, the gas spring can adjust to any possible change in stress direction of the seat or the table top, respectively, so that, on the whole, there is little risk of bracing in the guide sleeve. In another elevating mechanism equally according to the first part of claim 1 the housing of the gas spring is surrounded by an additional tube, in which the housing of the gas spring is arranged axially unslidable. In this case the additional tube is guided pivoting and longitudinally slidable in the guide sleeve (European patent 0 133 524 corresponding to Japanese utility model 60-54446).

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L~L r II I 2 The known embodiments have one-piece guide sleeves consisting of high-quality wear-resistant material.

They are pressed into the guide tubes. Subsequently .the guide surface of the sleeve serving as a slide surface is adapted to the precise dimensions by turning or rubbing. This is necessary because, due to their size, the guide sleeves have wide tolerances and o because they are deformed differently when they are 0 0: on o pressed into the guide tube. This treatment is expen- 0 0 0 o 9 sive. Furthermore, the demands on the guide sleeve o 0 0 0 to have good slide qualities, to be resistant to 00 0 0°o O, wear and still to offer the possibility to be pressed 0oo t the guide itube. wi-thorresponding hard -last ic; deofe-rmation, arc vry difficult te be realEizcd altogether in terms of material.

a 00 0o o 0 00 0 00 9°B 4 g #'1-e-ob j@Gt f the present-inven n to embody the guide sleeve of a lockable eleva ng o mechanism of the generic kind in such a way hat on the one hand the guiding of the gas s ing is attained free of bracing, resistant wear and with ooo good slide qualities, and that on e other hand O 0 o 0 the man,ifacturing of the guide eeve is favorable in terms of material expendi re.

This object is attaine in accordance with the features of the characterizi part of claim 1. The steps according to the invention ensure that the slide sleeves can b made from a material with high resistance to abrasio on the one hand and with good slide qualities vi a-vis metal on the other hand. Due to the fact at the slide sleeves are arranged spaced apart, AL1 t gas spring or the additional tube surrounding I t r tr i u' v -rp crii dFd wi thcnt. h rni no n According to one aspect of the present invention there is provided a lockable elevating mechanism for continuous adjustment of seats, table tops or the like, including a guide tube connectable to a pedestal and a length-adjustable, lockable gas spring, of which the piston rod is axially firmly but removably connected to a bottom plate of the guide tube, of which the housing can be axially firmly, but in principle removably connected to the seat or the table top in the area opposite the piston rod, of which the housing possibly surrounded by an additional tube is guided laterally firmly and axially c ct slidably by means of a guide sleeve held in the guide "'tt tube, and which has an activating rod for lengthadjustment of the gas spring, wherein the guide sleeve has a central carrying tube, in which two slide sleeves are arranged with space, and which central carrying tube is tt surrounded by a carrying sleeve held in the guide tube.

According to a further aspect of the present invention there is provided a guide sleeve for an elevating mechanism for continuous adjustment of seats, table tops or the like, said mechanism including a guide o tube connectable to a pedestal wherein the guide sleeve oao has a central carrying tube, in which two slide sleeves 0 0 are arranged with a space and which central carrying tube oo is surrounded by a carrying sleeve, which is held in the guide tube.

The slide sleeves may be made from a material with high resistance to abrasion on the one hand and with good slide qualities vis-a-vis metal on the other hand. Due to the fact that the slide sleeves may be spaced apart, the gas spring or the additional tube surrounding it, j respectively, may be guided without bracing. On i 39 MJP -2a- 3 the other hand, it is sufficient to embody the carrying sleeve only with regard to its being pressed into the guide tube, i.e. comparatively cheap plastics may be chosen as material, since wear-resistance and slide qualities are of no importance. Due to the fact that a carrying tube of metal i-~arranged between the slide sleeves on the one hand and the carrying sleeve on the other hand, deformations of 0o the carrying sleeve when pressed into the guide tube 0 0 o 0 odo not affect the dimensions and the shape of the guide surfaces of the slide sleeves.

o 0 o o The sub-claims reflect several advantageous embodiments ooenS of the guide sleeve.

o o0 vention will become apparent from the ensuing descri a 00 n 0a tion of an embodiment, taken in conjunction with the drawings.

fa a:e ti 00 Fig. 1 is a longitudinal section of an evating mechanism; o o a l s e o o Fig. 2 is a longitudinal sec on of a guide sleeve according to the vention; Fig. 3 is a longi inal section of a slide sleeve; Fig. 4 is ongitudinal view of a semi-sleeve of e guide sleeve; and g. 5 is a cross-section of the semi-sleeve according i- h-e i ni- qPgrc--i nn i ni V-17 in Fi 4- zYL.

The following description refers in more detail to the various features of the elevating mechanism and guide sleeve of the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the elevating mechanism and guide sleeve is illustrated in a preferred embodiment. It is to be understood that the elevating mechanism and guide sleeve of the present invention is not limited to the preferred embodiment as illustrated in the drawings.

Fig. 1 is a longitudinal section of an elevating mechanism.

Fig. 2 is a longitudinal section of a guide sleeve 0 00 I0 according to the invention; 0oo o Fig. 3 is a longitudinal section of a slide sleeve; o o Fig. 4 is a longitudinal view of a semi-sleeve of o00ooo the guide sleeve; and o Fig. 5 is a cross-section of the semi-sleeve S° according to the intersection line V-V in Fig. 4.

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L -3 a-i *C i The lockable elevating mechanism for the continuous adjustment of seats or table tops, shown in the drawings, has a lower guide tube 1, generally designed in cylindrical form, which has in its lower part a section 2, conically tapered downwardly, which contains a corresponding collar 3 of a pedestal 4.

The guide tube 1 has a bottom plate 5 near its lower end showing an opening 7 whici is concentric to the Sa. central longitudinal axis 6 of the entire elevating 0 00 00 0 mechanism and therefore also to the guide tube 1.

0 00 0 o0 Disposed parallel to the longitudinal axis 6 is a 0 o o length-adjustable, hydraulically or pneumatically oo o 014 lockable gas spring 8. The cylindrical housing 9 0ooOsS of the spring is located in the upper area of, and 0 0 extends upwardly through, the guide tube 1. The piston rod 10 of the spring extends downwardly through the o o oo00° housing 9 and is removably connected with the bottom 0 00 °0 plate 5. For this purpose, the free end of the piston rod 10 is designed with a tang 11, which has a reduced 00 0 o °0 diameter, on which is disposed an axial ball bearing 12, the upper race 13 of which is supported against the collar 14 formed in the transition area between the 0000 tang 11 and the piston rod 10, while the lower race o is supported against the bottom plate 5. In addition, a securing collar 16, mounted on the tang, holds the axial ball bearing 12 in the position shown, even if the lower race 15 is not supported against the end plate The tang 11 is placed into the opening 7 with sufficient play of from some tenth of a millimeter to a millimeter, so that the piston rod 10 is not radially braced with respect to the guide tube 1. From the outside, i.e. at the bottom, a spacer 17, having a diameter larger than that of the opening 7, is placed on the ii L 1 -II-- :I tang 11. A securing element 18 is pushed against the spacer 17 so that the piston rod 10 of the gas spring 8 is firmly connected to the guide tube 1 axially, but removably. On the piston rod 10 there is an end positioning, or impact, damper 19 made from rubber, which rests witn its underside against the upper race 13 of the axial ball bearing 12.

o The continuously circular cylindrical housing 9 of co oa the gas spring 8 is disposed with sliding fit in 9 a tube 20, which is also circular cylindrical in 0 "0 its essential length. The radial play between the o00 o o housing 9 and the tube 20 is some one hundredth of a millimeter to maximally one or two-tenth of a millimeter. The play is therefore just sufficient to insert the housing 9 of the gas spring 8 into the tube o o or to pull it out therefrom and, at the same time, o 0 to guide the housing 9 in the tube 20 radially and to hold it. This tube 20, forming a removable part o° a 0 of the gas spring 8, is provided in its upper part, which extends above the housing 9, with a conically tapered fastening segment 21, which forms a solid, a G simply made plug connection with a corresponding collar 22 fastened to the underside of a chair, armchair, table top or the like. At the transition of the fastening segment 21, a casing 23, designed in accordance with the tapering of the tube 20, is disposed in the latter and is therefore fixed axially in the direction towards the fastening segment 21. The housing 9 of the gas spring 8 is axially firmly supported against this casing 23, At the lower free end of the tube 20, the housing 9 is axially held by means of a removable fastening element 24. This can be in the form of a so-called 6 claw, i.e. a ring provided with resilient tabs, which can be pushed into the tube 20 in one direction, namely until it rests against the housing 9, whith relative ease, but which resists movement in the opposite direction by barb-like bracing against the tube. With sufficient force, for instance by the use of a screw driver, it can be easily taken out in a downwardly direction, thus breaking the connection co between the housing 9 and the tube 20 in a simple oo manner. Naturally, many other kinds of fastening elements, including screw connections, can be considered.

0 09 00 4 S°o This tube forms a removable part of the gas spring 8 o oand is axially movable in the usual manner in the guide tube 1. This guide tube is provided in its o 0 upper area with a guide sleeve 25, which will be described in detail below. The guide tube 1 and the 0 oC0 tube 20 are made of steel. The same is the case for the housing 9 of the gas spring 8, while the casing 23 9 consists of a softer material, for instF.nce die cast zinc.

oo00 Longitudinal adjustment of the gas spring 8 and corre- 0 0 o 0o sponding height adjustment of the entire elevating mechanism is achieved with the help of an activating rod 26 of the gas spring 8, which extends from the upper end of gas spring 8 away from the piston rod and which is pushed into the housing 9 in order to make possible the respective adjustment in length.

For this purpose, an upward extending slide 27 is disposed in the conically tapering fastening segment 21 and rests against the activating rod 26 with a face 28.

Furthermore, this slide 27 is supplied with securing

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i U--L 7 prongs 29, which elastically grip the back or underside of a corresponding ring 30 of the casing 23, and permit the slide 27 to be secured against inadvertent falling out of, or removal from, the fastening segment 21 while, at the same time, assuring the seating with little play of the face 28 against the activating rod 26. Activation is accomplished by means of a swivelable activating lever, not shown, which is disposed in the collar 22 in the usual manner and which rests against the outer surface of the slide 27, as is known, for instance, from U.S. patent 3790119.

Q 0 0 0 The gas spring 8 need not forcibly be arranged in an additional cylindrical tube 20; it can also be directly guided with its housing in the guide sleeve and fastened to the underside of a chair, a table-top oor the like. This is for example known from German Q' °Q patent 19 31 012 corresponding to U.S. patent 3 711 054 and Japanese patent 892 209, respectively, which °are renferred to.

The guide sleeve 25 consists of several parts. It S" comprises a carrying tube 31 with slide sleeves 32, 33 C inserted and an outer two-piece carrying sleeve 34.

The carrying tube 31 is of circular cylindrical shape, having, in particular, a relatively precise inner.

diameter Di with.only little tolerance. The two slide sleeves 32, 33 are identical. Prior to insertion into the carrying tube 31 they have an outer diameter of some one hundredth of a millimeter more than the inner diameter Di of the carrying tube 31, for example of from 0.02 to 0.09 mm. At one end the circular cylindrical slide sleeves 32, 33 have an outwardly extending\ ol1ar 35. The slide sleeves 32, 33 are exteni~pX 8 inserted in the carrying tube 31 in such a way that each of its two ends presses in one slide sleeve 32 or 33, respectively, to such point where the-collar rests against the face 36 of the carrying tube. Fig. 2 shows that the two slide sleeves 32, 33 extend over a one fourth to one third of the length of the carrying tube 31, so that a space 37 of about one third to i two fourths of the length of the carrying tube 31 j Si is formed between the two slide sleeves 32, 33. The inner surfaces of the slide sleeves 32, 33 serving i as guide surfaces 38 for the houm of a gas spring or the tube 20, respectively, are thus also spaced cc o o0 apart so that the tube 20 or a housing of the gas oooo o spring, respectively, are guided only by these spaced apart guide surfaces 38. The inner diameter di of the slide sleeves 32, 33 corresponds to the outer 0 00 aB diameter of the housing of a gas spring or to the (1 0 outer diameter of the tube 20, respectively, with the usual guide play. 0 0 The two-piece carrying sleeve 34 consists of two semi-sleeves 39, 40 of the same kind, which basically *ooa consist of a- semi-circular cylindrical section 41, *a from which ribs 42 extend outwards running parallel to the axis 6. The semi-sleeves 39, 40 have longitudinal flanges 43, 44, which rest against each other when the semi-sleeves 39, 40 are joined together. They rest against tach other in a plane through the central longitudinal axis 6. These longitudinal flanges 43,. 44 are provided with tangs 45 and matching openings 46, so that the tangs 45 of one semi-sleeve 39, 40 engage with the opening 46 of the other semi-sleeve 40 or 39, respectively, when the two semi-sleeves 39, 40 are joined together.

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One end of the semi-sleeves 39, 40, namely the lower end, is provided with an in each. case semi-circular abutment 47 extending radially inwards. Fig. 2 shows that the collar 35 of the corresponding slide sleeve 32 rests against the abutment 47 when the guide sleeve is assembled, so that the carrying tube 31 with the two slide sleeves 32, 33 is axially arrested in one direction. In the opposite direction the carrying tube 31 with the two slide sleeves 32, 33 is arrested in such a way that an in each case semi-circular abutment 48 is provided at the two semi-sleeves 39, equally extending inwards over the semi-circular cylindrical section, against which the collar of the adjacent slide sleeve 33 rests axially. Fig, 2 shows that this upper abutment 48 is slightly resilient in axial direction, so that, on the one hand, it compensates length tolerances of the carrying tube 31 with the two slide sleeves 32, 33 and, on the other hand, holds the carrying tube 31 with the two slide sleeves 32, 33 axially without play, thus firmly arresting it. For this purpose this abutment 48 is given the shape of a semi-ring disk reaching to the radial outside area of the ribs 42, where it is secured to a semi-ring land 49, which extends outwards and has an outer diameter that corresponds to the inner diameter of the guide tube 1. At the juncture of this semi-ring land 49 and the abutment 48 is further provided a ring collar 50 resting against the corresponding face 51 of the guide tube 1 when the completely assembled guide sleeve 25 is shoved in.

The carrying tube 31 already equipped with the slide sleeves 32, 33 is inserted in one of the semi-sleeves 39, 40. Then the other semi-sleeve 40 or 39, respectively, is installed and the tangs 45 engage with the matching openings 46. This completely assembled guide sleeve 25 is then shoved into the guide -tube to i; i: 1 :j i i i i i i i r

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5 rl i uA, ix. wuD i ,Av u -~cve are arrangea with a space and which central carrying tube is surrounded by a carrying sleeve, which is held in the guide tube.

:i the point where the ring collar 50 rests agai. st the face 51. The ribs 42 are thus slightly elastically deformed so that the whole guide sleeve 25 is firmly arrested in the guide tube 1. Since the carrying tube 31 is practically not deformable consisting Sof steel or aluminum or of a comparable metal, the tolbrance-caused deformations of the carrying sleeve 34 do not affect the inner diameter di of the slide sleeves 32, 33 and thus the precise dimensions of 0 00 0 the guide surfaces 38.

S0 0 0 0 0 Beyond that, the semi-sleeves 39, 40, which are com- 0 paratively expensive in material and which consist 0 0 of one piece each, can be made of less expensive plastic material with especially good sliding qualities vis-a-vis metal, in particular steel. The tube 0 00 o'o0 and the housing of a directly guided gas spring, Soo0 respectively, consists of metal. Polyacetal is considered to be a plastic material with especially good 00 6 0 0 0 0 sliding qualities.

The outer diameter Da of the carrying tube 31 is 0oo0 chosen in such a way that it is held in the carrying 0 o0 sleeve 34 without play.

Claims (14)

1. A lockable elevating mechanism for continuous "Al r2C\O\ adjustment of seats, table tops or the like, iti-"a gti ide tube connectable to a pedestal and 4- a length-adjustable, lockable gas spring, of which the piston rod is axially firmly but removably connected to a bottom plate of the guide tube, of which the housing can be axially firmly, but in principle removably connected to the seat or the table top in the area opposite the piston rod, of which the housing possibly surrounded by an additional tube is guided laterally firmly and axially ct slidably by means of a guide sleeve held in the guide 1.tube, and which has an activatng mechanismod for length- C adjustment of the gas sprinats, table tops or the guide sleeve has a central carrying tube, iockab wich two slide sleeves are arranged with space, and which central carrying tube is surrounded by a carrying sleeve held in the guide tube 2 tube, An elevating mechanism according to claim wherein the carrying sleeve consists of two identical one-piece semi-sleeves.

3. An elevating mechanism according to claim 2, wherein the semi-sleeves have abutments extending radially inwards S rr in the area of their axial ends, against which the i S s ucarrying tube with the slide sleeves rests without play.

4. An elevating mechanism according to claim 3, wherein C 2 at least one abutment is made axially elastically resilient. C S 5. An elevating mechanism according to claim 2, wherein I I0 the semi-sleeves are provided with longitudinal flanges, said flanges having tangs and matching openings.

6. An elevating mechanism according to claim 3, wherein the slide sleeves are each axially held by means of a ring collar between the adjacent face of the carrying tube and the adjacent abutment of the carrying sleeve.

7. An elevating mechanism according to claim I, wherein the slide sleeves are held with pressure or adhesion in the carrying tube.

8. An elevating mechanism according to claim 1, wherein -11- i I IJ the carrying tube consists of metal.

9. A guide sleeve for an elevating mechanism for continuous adjustment of seats, table tops or the like, said mechanism including a guide tube connectable to a pedestal wherein the guide sleeve has a central carrying tube, in which two slide sleeves are arranged with a space and which central carrying tube is surrounded by a carrying sleeve, which is held in the guide tube. iI cc the carrying tubeconsists of metal t to 00 0 i 0 0j Ai A 0 -lla- Li 9. A guide sleeve for an elevating mechan according to the precharacterizing part of c 1, wherein the guide sleeve has a centra rrying tube, in which two slide sleeves are anged with space and which central carrying is surrounded by a carrying sleeve, which is -h!i A guide sleeve according to claim 9 wherein the carrying sleeve consists of two identical one-piece semi-sleeves.

11. A guide sleeve according to claim 10, wherein the semi-sleeves have abutments extending radially inwards in the area of their axial ends, against which the carrying I a S tube with the slide sleeves rests axially without play.

12. A guide sleeve according to claim 11, wherein at least one abutment is made axially elastically resilient.

13. A guide sleeve according to claim 10, wherein the e o semi-sleeves are provided with longitudinal flanges, said flanges having tangs and matching openings.

14. A guide sleeve according to claim 11, wherein the slide sleeves are each axially held by means of a ring 00 the adjacent abutment of the carrying sleeve. 0000

15. A guide sleeve according to claim 9, wherein the S slide sleeves are held with pressure or adhesion in the o o carrying tube. S 16. A guide sleeve according to claim 9, wherein the S carrying tube consists of metal.

17. An elevating mechanism according to claim 1 I0 substantially as hereinbefore described with reference to what is shown in the accompanying drawings. -12- -LY i- Y I. i-1 pU- MJP -2a-

18. A guide sleeve according to claim 9 substantially as hereinbefore described with reference to what is shown in the accompanying drawings. Dated: 14 December 1990 PHILLIPS ORMONDE FITZPATRICK Attorneys for: FRITZ BAUER SOHNE oHG 25911 C 9(9 tC 0 C 0 C t 9 C 0 0 0 e o C 0 0 C 00 0 0 t1 C C C 4 1 it ttf C CO t C c C r C 'C t C C C t) -13-