Pneumatic pivoting fixture with friction element

In a pivot fixture for pivotable parts, comprising a guide unit with a guide tube and an arrest unit with an engagement rod slidably disposed in the guide tube, the engagement rod is provided with control cam structures and an expansion body with a friction surface is slidably disposed on the engagement rod, the friction surface being arranged adjacent an inner wall section of the guide tube for engagement with the wall section upon expansion of the expansion body by the engagement rod.

This is a Continuation-In-Part application of pending international patent application FCT/DE2011/001421 filed Jul. 5, 2011 and claiming the priority of German patent application 10 2010 026 128.9 filed Jul. 5, 2010.

BACKGROUND OF THE INVENTION

The invention resides in a pivoting fixture for pivotable components including at least one guide unit with a guide tube and an arresting unit guided in the guide tube as well as an arresting rod.

Pivot fixtures are used for example for pivoting open windows or doors permitting to secure them in their open position that is prevent them from being unintentionally closed.

It is the object of the present invention to provide a pivot fixture which, when installed, permits a noiseless rapid opening and closing of the pivotable part as well as an essentially stepless position adjustment.

SUMMARY OF THE INVENTION

In a pivot fixture for pivotable parts, comprising a guide unit with a guide tube and an arrest unit with an engagement rod slidably disposed in the guide tube, the engagement rod is provided with control cam structures and an expansion body with a friction surface is slidably disposed on the engagement rod, the friction surface being arranged adjacent an inner wall section of the guide tube for engagement with the wall section upon expansion of the expansion body by the engagement rod.

The invention will become more readily apparent from the following description of an exemplary embodiment thereof described below with reference to the accompanying drawings.

DESCRIPTION OF AN EXEMPLARY EMBODIMENT

FIGS. 1 and 2show a pivot fixture10as installed for example on a hinged pivot window2or a skylight. The hinged window2in the example has a horizontally oriented pivot axis3which extends for example at one side of a travel trailer parallel to a parking place of the travel trailer. InFIG. 1fthe hinged window is shown in a closed position and inFIG. 2it is shown in an open position.

The pivot fixture10, seeFIG. 3, comprises a guide unit20attached to the travel trailer body1and an arrest unit40attached to the window2. The pivot fixture10may also be installed in such a way that the guide unit20is attached to the window and the arrest unit40is attached to the body1. Instead of a flap window2, which is pivoted outwardly against the gravity forces thereof the window may also be a window hinged by a hinge with a vertical pivot axis. The pivot fixture10may also be used in connection with a door.

The length of the inserted fixture10is for example 235 mm, the stroke is for example 100 mm in the exemplary embodiment.

FIGS. 3 and 4show the pivot fixture10in a longitudinal cross-sectional view with the window closed. The guide unit20comprises in the exemplary embodiment an attachment structure21and a guide tube22. In the arrangement as shown inFIGS. 1 and 2, the guide attachment21is attached at the body1.

The attachment structure21is inserted into the guide tube22and closes the front end thereof. The guide tube22has in the exemplary embodiment a constant wall thickness and, at least at its inner wall23, two cylindrical sections24,25of different diameters with smooth transitions. The length of the widened area (24) of the inner wall23of the attachment structure21is for example 25% of the length of the guide tube22. The diameter of the widened area24is for example 4% greater than the diameter of the adjustment area25.

The adjustment area25is provided at the end opposite the attachment structure21with a guide sleeve26. It is shown inFIG. 5as a single component. This sleeve26is firmly engaged in the guide tube22and extends around the arrest unit40. At one end, it is provided with a locking ring27. In the exemplary embodiment, the locking ring comprises four segments29, which are separated by axial gaps28. The individual segments29are elastically deformable and can engage the arrest unit40when extended.

The arrest unit40comprises an engagement rod41and an expansion body71. The engagement rod41consists for example of a cylindrical section42, a carrier section43connected to the cylindrical section42and a mounting member44. Those sections42-44may be firmly interconnected for example in a force and/or form-locking manner. The carrier section43is for example pressed into the tubular cylindrical section42. With the pivot fixture10installed, the mounting member44is for example connected to the window2. The engagement rod41may also be in the form of a single piece.

The carrier section43, seeFIG. 6, comprises a stop flange45, an annular groove46, a support flange47and an annular bulge54. The stop flange45delimits the installation area of the carrier section43by which it is accommodated in the cylindrical, section42after installation.

The support flange47together with a cylindrical guide ring51forms in the assembled state of the fixture a support structure for a spring101, seeFIG. 3.

Adjacent the support flange47, there is a control area52of the carrier section43. Its length corresponds about to half the stroke length of the pivot fixture10. This control area52includes a constriction53, the annular bulge54which forms for example a control cam arranged in the longitudinal direction15of the pivot fixture10and a guide section55.

The length of the constriction53is for example one fifth of the length of the control area52. In this area, the diameter of the carrier section43is for example 75% of the diameter of the guide area56of the support flange47. The length of the guide area56is for example 15% of the stroke of the arrest unit40relative to the guide unit20. This corresponds for example to the outer diameter of the guide tube22. The transition57of the constriction to the guide section56is for example cone-shaped. The tip angle of the virtual cone is for example 30%. But a continuous transition57may also be provided.

The annular bulge54acting as a control cam is shown in the exemplary embodiment to foe symmetrical with respect to a plane extending normal to the center line63. It has a central cam surface area64joined in each longitudinal direction by a control flank58,59. The two control flanks58,59are for example steadily differentiate surfaces which change over tangentially into the adjacent surfaces53,54,55. The control flanks58,59may also be in the form of outer cone surfaces.

The length of the control cam54corresponds in the exemplary embodiment to its diameter which corresponds about to the diameter of the guide area56.

The control cam54may also foe in the form of a section of an annular bulge. This section may extend for example over10angular degrees. It is also possible to provide several circumferentially displaced control cams54.

The guide section55has in the shown embodiment a constriction53. Its length corresponds for example to the outer diameter of the guide tube22. At its end, it is provided with engagement grooves61which accommodate a disc-like stop member62.

The expansion body71is disposed between the support flange47and the stop member62on the carrier section43of the arrest unit40. Here, it supports the end of the spring101remote from the support flange47. The expansion body71extends in the exemplary embodiment around a base body72and a friction element91.

FIG. 4shows the base body72in an isometric view andFIG. 8shows the base body72in a longitudinal sectional view. The length of the base body72is for example one fourth of the stroke of the arrest unit40relative to the guide unit20. The base body has an annular flange area73on which the spring101is supported and an expansion area74. The latter comprises for example three elastically deformable expansion wings76which are separated from each other by parallel gaps75. The expansion wings76may also be connected to the annular flange area73by flexible joint structures. The gaps75are arranged parallel to a virtual center line15of the pivot fixture10. Their length is 80% of the length of the base body72.

The inner wall77of the base body72comprises a cylindrical section78and an inner constricted area79. When the base body72is not deformed, the inner diameter of the cylindrical body section78is for example a few tenths of a millimeter larger than the diameter of the guide area56. The diameter of the constricted area79is less than the diameter of the guide area56. In the exemplary embodiment, the diameter of the constricted area79is larger, by two tenths of a millimeter than the diameter of the constriction53. The constricted area79forms a rod cover79whose flank surface areas81,82are for example continuously differentiable surface segments81,82. The surface segments81,82may also be cone-shaped. The constricted area79may be a segment of an inner. Also the base body72may have several constricted areas at the inner walls thereof.

The outer diameter of the base body72in the annular flange area is for example 95% of the inner diameter of the guide tube22.

As shown inFIGS. 4 and 13, in the exemplary embodiment the friction element91is a pot-shaped sleeve with a mounting ring92and a support ring93. The support ring93is seated for example in an annular groove84of the base body72. The distance between the support ring93and the mounting ring92corresponds for example to the inner diameter of the guide tube22. The length of the friction element91is for example two thirds of the length of the base body72.

The friction element91may for example have an end face which is essentially in radial alignment with the end of the base body72opposite the spring101. When not pressurized, the friction element91has an outer diameter which is for example the same as the inner diameter of the guide tube22.

In the exemplary embodiment, the circumferential surface of the friction element91is a friction surface94. This radially outwardly facing friction surface94has for example eight axial grooves95. They form communication paths between the two front face areas96,97of the friction element91. In the representation ofFIG. 3, the friction element91does not abut the widened area24of the inner wall23.

During assembly for example first the engagement rod41is put together. After the expansion body72and the friction element91have been installed, the disc-like stop member62can be mounted onto the carrier section43. The guide sleeve26can foe disposed on the engagement rod41. After installation of the arrest unit40, the constricted, area79surrounds the expansion body72surrounds the guide section55of the arrest rod41.

Next, the arrest unit40pre-assembled in this way is inserted into the guide tube22. In the process, the guide sleeve26may be attached in the guide tube22. Before or after the installation of the arrest unit40, the attachment structure21may be mounted to the guide tube22.

The pivot fixture10preassembled in this way is then—for example as shown in FIG.1—connected via the guide unit20to the body and via the arrest unit40to the pivot window of a travel trailer or a motor home.

With the window2closed, the pivot fixture10is shortened, seeFIGS. 1 and 3. For opening the window2, the operator can—after unlocking the window if necessary—push the window from the inside or pull it from the outside outwardly.

During opening of the window2, the arrest unit40is moved relative to the guide unit20as shown inFIG. 3to the left. This relative movement occurs against a small friction resistance which is caused by the guide sleeve26and the friction element91sliding along the guide tube22.

FIG. 9shows in a partial longitudinal cross-section, the pivot fixture10in a partially extended position but not locked by the arresting unit40. The expansion body71is now in the adjustment area25of the guide tube22. The friction surface94is in contact with the inner wall23of the guide tube22.

When the window is now released by the operator, the weight of the window2then compresses the arresting unit40relative to the guide unit20whereby the friction element is radially expanded and engages the inner wall23of the guide tube22in a force-locking manner. The base body72is now held, in its position relative to the guide unit20as shown inFIG. 10. Upon continued compression, the pivot feature10is further compressed whereby the engagement rod41is further moved into the base body72. The distance of the stop member62from the base body72is thereby increased so that the control, flank58adjacent the annular bulge54slides along the flank surface section82adjacent the constricted area79. The expansion wings76are thereby elastically deformed and radially pressed apart. The friction element91is widened so that the friction surface92is pressed onto the inner wall23of the guide tube22with an increased force. The expansion body71consequently acts as a ram which is controlled by the annular bulge54. The position of the window2is now secured by the force locking engagement between the ram71and the guide tube22. The window cannot move to a closed, position.

If the window2is now further opened the arrest unit40and the guide unit20are pulled even further apart. The engagement rod41slides along the expansion body71which initially is retained by the guide tube22. Hereby the constricted area79is moved to the area of the guide section55. The spring101supports the movement of the expansion body71relative to the engagement rod41. The expansion wings76and the friction element91are elastically returned to their original shape as shown inFIG. 9. The force locking engagement is eliminated. The guide unit20and the arrest unit40can now be moved further apart with little resistance.

For closing the window2out of the force-locked position, the pivot fixture is farther compressed. The force applied for closing the window is greater than the gravity force of the window2. The expansion body71is now pressed further onto inner wall23of the guide tube22. The engagement rod41slides along the expansion body71until the constricted, area79radially abuts the annular bulge54. The expansion wings76and the friction element91are now maximally deformed. Upon further compression of the pivot fixture10, the annular bulge54slides further along the inner wall77of the expansion body71. It then reaches the area of the flank surface section82. For example at the same time, the constricted area79reaches the control flank58of the engagement rod41. In the representation ofFIG. 11, the expansion body71is disposed in the constriction area53. The expansion body71is now elastically re-deformed. The engagement pressure of the friction element31to the inner wall23of the guide tube22is reduced. The distance between the stop member62and the base body72is further increased. The arrest unit40can now be further moved into the guide unit20taking along the expansion body71.

If the window is closed only partially, the force locking engagement as described above is re-established.

Upon complete closing of the window2, with a residual opening angle of for example five degrees, the friction element91reaches the widened area24of the inner wall23of the guide tube22, seeFIGS. 3 and 4. The friction element is now released from the inner wall23. The sliding friction of the engagement body71relative to the guide unit20is eliminated. The spring101presses the expansion body71against the stop member62. The window2can now be closed without resistance—except for the friction between the guide sleeve26and the engagement rod41.

The window can be arrested at any angle which is greater than the mentioned residual opening angle. If the window2is fully opened, the guide sleeve26engages with its locking ring27the annular groove46between the stop flange45and the support flange47, seeFIG. 12. When fully opened, the pivot fixture10is arrested in a form-locking manner.

When the window is to be closest out of this position first, the segments29of the locking ring27are elastically deformed. They bend outwardly and release the arrest unit40from the guide unit20. The further closing proceeds as described above.

The expansion body71is slidable on the engagement rod41between two end positions. The two end positions are formed, in the exemplary embodiment by the guide ring51and the stop member62.

With the pivot fixture according to the invention, the tilt angle of the window2can be steplessly adjusted from within or without. If two travel trailers or motor homes are parked for example closely together, damage to a window2can easily be prevented, by a rapid closing of the window2. The operator does not need to touch the pivot fixture10.

In the pivot fixture10as described, the control arrangement comprising the annular bulge54and the expansion body71may be arranged in a common partial segment of the circular cross-sectional, area.

The guide unit20as well as the arrest unit40may have a square, rectangular, multi-cornered, oval, elliptical, etc. cross-section. For example in an embodiment of the pivot fixture10with a square cross-section the control arrangement of cams and the expansion body may be arranged only at one side whereas the other three sides are used for guiding the guide unit and the arrest unit.

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