This invention relates to steplees joint, especially for upholstered furniture, for blocking movable position of an element of a piece of furniture in any position. The invention is used especially for regulating position of headrests, arm-rests, leg-rests and back in chairs, armchairs, sofas, beds. Moreover the invention may also be used in other types of furniture, for example for flaps and doors of kitchen cupboards and bathroom cases. The invention may be used also in automotive industry, in engineering industry, in household goods etc.

They are known furniture joints used for bloking position of a movable element of a piece of furniture, for example of a head-rest or an arm-rest, after its setting up to a required position for a user.

The known joint is made of a stable arm fixed to an immovable element of a piece of furniture and a movable arm joined with a movable element of a piece of furniture such as head-rest or arm-rest. These arms are joined with each other rotationally by means of a bolt. Within this connection there is a ratchet mechanism made of teeth which are on the end of one arm. The teeth mate with the pawl joined with a second arm.

The known joint enables blocking of a movable element of a piece of furniture in at least several settled positions by stepwise lifting and lowering of that element. After taking proper position by a movable element its bloking takes place by operations of the pawl. The angle of position of a movable element of a piece of furniture, determing number of positions, in which blocking takes place, is a result of a pitch of the pawl.

Stepwise change of position of a movable element of a piece of furniture and its bloking in this position make inconvenience in usage of the known furniture joint. Operational use of known joint generates irritating noise . Moreover, teeth of ratchet mechanism, owing to limitation in transfer of force, at overload of the joint, may be destroyed - cut down.

In order to eliminate above mentioned inconveniences one made a stepless joint, which construction enables fluent regulation of position of a movable element of a piece of furniture by shifting and blocking it in any position. Steplees joint, especially for upholstered furniture, according to the invention, having a stable arm fixed to a stable element of furniture and a movable arm joined with a movable element of furniture, moreover the movable arm is fixed rotationally towards the stable arm, and to one of the arms, advantegously to the movable arm, one-way grip is mounted which has a hole and a through groove which divides up the grip into two parts, characterised in that, places of fixing of parts of one -way grip with a movable arm make points, which make a lever during motion under the influence of force action, the lever by the grip causes expansion or compression of a sleeve in holes of a stable arm, and one way grip has expanding nibs towards a hole of the grip and it has a through recess, in which there is a pin placed slidably, moreover each of parts of the grip has an expanding nib.

Expanding nibs influence a sleeve which is placed simultaneously in holes of flat bars of a stable arm and in a hole of a grip.

A pin is influenced by resistance elements of a stable arm and a pin influences protruding ends of a movable arm.

A sleeve is expandible and it has a through recess situated along side surface of a sleeve, moreover a sleeve is situated in a hole of a grip in such a way that expanding nibs pass through a recess in a sleeve and they, with their surfaces of contact are in contact with a sleeve.

Advantegously a joint, besides a grip it has a strengthening grip mounted from outside at least from one side of the joint, moreover the strengthening grip has expanding nibs towards a hole of a strengthening grip.

Construction of a furniture joint, according to the invention enables locking of position of a movable element of a piece of furniture in any position suitable for a user. There is not indirect angle limit of position of a movable element, as regulation of position of that element comes fluently. During operational use of a joint there is no noise - work of the joint is noiseless. Moreover the joint, according to the invention is characterised by large strenght.

Object of the invention is shown in the example, on the drawing, on which fig. 1 presents a joint in front view, fig.2 - a joint from above , fig.3 - a joint in front view, without strenghtening grips, fig.4 - a joint in perspective view, without strenghtening grips, fig.5 - a stable arm in front view, fig.6 - a stable arm in a side view, fig.7 - a stable arm in perspective view, fig.8 - a movable arm in a front view, fig.9 - a movable arm from a side view, fig.10 - a movable arm in perspective view, fig 11 - a grip in front view, fig.12 - a grip in a side view, fig.13 - a grip in perspective view, fig.14 - a sleeve in front view, fig.15 - a sleeve in a side view, fig.16 - a sleeve in perspective view, fig.17 - strenghtening grip in a front view, fig.18 - a pin in front view, fig.19 - a pin in side view, fig.20 - a pin in perspective view, fig.21 - a joint in initial position of regulation (position 1), fig.22 - a joint in indirect position of regulation (position 2), fig.23 - a joint just before extreme position -final position of regulation (position 3), fig.24 - a joint in extreme, unlocked position (position 4), fig.25 - a joint in return, indirect position (position 5), fig.26 - a joint in return position just before locking (position 6), fig.27 - a joint in final position (blocking is turned on) corresponding to initial position (position 7).

A furniture joint, especially for upholstered furniture, according to the invention is constructed from a stable arm 1 fixed to a stable element of a piece of furniture and a movable arm 2 fixed to a movable element of a piece of furniture, for example to a head-rest, or to an arm-rest. The movable arm 2 is fixed rotationally towards the stable arm L

To one of the arms, advantageously a movable arm 2 , one-way grip 4 is mounted in two points by means of rivets 3 .

The grip 4 is situated between bent flat bars 17 of a movable arm 2 and bent flat bars 13 of a stable arm L The grip 4 is a flat element having a hole 5 and a through groove 6 which divides up the grip 4 into two parts 7 , 8. On one side surface of a groove 6 there is a protrusion 23 towards second side surface of the groove 6. Each of parts 7 , 8 of the grip 4 is joined with an arm, advantageously with a movable arm 2 by means of rivets 3. From each part 7 , 8 an expanding nib 9 is led towards a hole 5 . Each expanding nib 9 has a surface of contact 20 with a sleeve JT . The grip 4 has a through recess 10, in which there is a pin 1_5 placed slidably.

A joint has a sleeve Π. placed in holes 12 of flat bars 1_3 of a stable arm 1 and in a hole 5 of a grip 4 . A sleeve JT has a through recess 14 on its whole height resulting from longitudinal cut of a side surface of a sleeve 1 1. A sleeve 1_1 is placed in a hole 5 of a grip 4 in such a way that expanding nibs 9 pass through a recess 14 and they, with their surfaces of contact 20 have contact with a sleeve IT . Expanding nibs 9 mate with an expanding sleeve JT .

On front surfaces 2! of flat bars Γ7 of a movable arm 2 , from side of a stable arm there are protruding ends 18 .

On front surfaces 22 of flat bars 13 of a stable arm 1 there are resistance elements 16A , 16B.

Advantegously, from ouside to the joint strengthening grip 19 are mounted. Each of the strengthening grips 19 is a flat element having a hole 5 and a through groove 6 which divides up the grip 4 into two parts 7 , 8. Each of parts 7 , 8 of the grip 4 is joined with an arm, advantageously with a movable arm 2 by means of rivets 3. From each part 7 , 8 an expanding nib 9 is led towards a hole 5 .The strengthening grip 19 may be mounted at one or at both sides of the joint. Stepless joint, according to the invention makes possible stoppage in each position chosen at user's choice. Blocking of position is a result of pressure of an expanding sleeve jj _. in holes 12 of a stable arm I . That pressure is caused by widening of expanding nibs 9 of a grip 4 as a result of movement of an element of furniture for instance an arm -rest.

Places of joint of parts 7 , 8 of a grip 4 with a movable arm 2 by means of rivets 3 make points 3A and 3B , which make a lever during motion under the influence of force action on a movable arm 2 . This lever expands or compresses a sleeve Π. by a grip 4 .

It is essence of blocking in one direction - when a sleeve JJ_ expands itself thanks to leverage and free movement in opposite direction - when a sleeve 1 1 compresses itself thanks to leverage.

Joint action, according to the invention is shown on fig.23 to fig.29 on which respective positions of a movable arm 2 are marked from 1 to 7.

During making a rotational movement with a movable arm 2 into bloking, a sleeve 1_1 , rotating in holes 12 of a stable arm \ meets frictional resistance and moment of a force, opposite to rotational movement arises. This, in turn causes relocation of parts 7 and 8 of a grip 4 towards themselves, joined with a movable arm 2 by rivets 3 and widening of a through groove 6 in a grip 4. Then a grip 4 , by means of expanding nibs 9 influences a sleeve H making larger and larger expanding and tightening of a sleeve 1J_ in holes!2 of a stable arm L

As a result of this effect locking of possibility of motion of a movable arm 2 towards blocking follows.

But during motion towards regulation the same effect takes place but in opposite direction.

A gap of a through groove 6 in a grip 4 decreases itself during motion and thereby, a grip 4 , with its expanding nibs does not expand a sleeve JJ. enabling it a free turn in holes 12 of a stable arm L As a result there is a possibility of a free motion of a movable arm 2 towards regulation.

During working of a joint, in an extreme position towards regulation, resistance elements 16A of a stable arm 1 effect a pin j_5 which is in a recess 10 of a grip 4 causing relocation of a pin 5 to an extreme position of a recess 10 . A pin 15 effects protruding ends j_8 of a movable arm 2 . As a result there is a shift of points 3A and 3B towards themselves and there is an approach of parts 7 , 8 of a grip 4 to each other. Then a sleeve JT is compressed by a grip 4 in holes 12 of a stable arm I and thanks to it, a free return motion of a movable arm 2 to initial position is possible .

Resistance elements 16B push out a pin 15 from extreme position in a recess 10 during return of a movable arm 2 to initial position in the final stage . The pin j_5_ stops to influence protruding ends 18 of a movable arm 2. This way a joint returns to initial position and regulation of position of a movable element of furniture is possibile from the begining.