fig1 shows a retraction apparatus such as the one used , for example , in drawers . utilization in other components to be moved , such as doors , hatches , etc ., is also conceivable . the retraction apparatus encompasses a base part 40 and a housing 10 , each of which is mountable on a housing enclosure ( not depicted ). also provided is an extending arrangement 20 that is arranged on a drawer ( likewise not depicted ). housing 10 is equipped with screw receptacles 11 . 1 that make possible enclosure - side mounting . housing 10 has two side walls 11 , spaced in parallel fashion apart from one another , into which guides 11 . 2 are recessed . guides 11 . 2 comprise a slot - shaped aperture that opens into a widened recess 11 . 21 . guides 11 . 2 of the two side walls 11 align with one another . a damper 12 is accommodated in housing 10 . damper 12 is embodied as a fluid damper , in the present case as an air damper . the use of an air damper has the advantage that in the event of damage , liquid cannot emerge and contaminate the drawer contents . damper 12 comprises a cylinder 12 . 6 in which a piston 12 . 2 is pulled out starting from the inserted position shown in fig1 . in the context of the return motion of piston 12 . 2 , it works against an air cushion , the air pressure being continuously dissipated . for this purpose , a small opening is present in an insert 12 . 3 , through which opening the compressed air can escape in controlled fashion . at its end facing away from insert 12 . 3 , piston rod 12 . 1 possesses a head segment 12 . 4 that forms a pivot bearing 12 . 5 . a coupling piece 13 in the form of a tilting element is held pivotably on pivot bearing 12 . 5 . the pivoting motion proceeds around a pivot axis extending perpendicular to the image plane in accordance with fig2 . a spring holder 13 . 1 , which holds one end of a spring 14 , is arranged on coupling piece 13 . the other end of spring 14 is suspended on the housing side . coupling piece 13 possesses a trigger 13 . 2 that is arranged at a distance from the pivot axis . also present on coupling piece 13 is a follower 13 . 4 that is shaped via a spring element 13 . 5 on an arm 13 . 3 . a connecting part 30 of an extending arrangement 20 is detachably connectable to follower 13 . 4 . extending arrangement 20 encompasses connecting part 30 , the purpose of which is to create the detachable coupling to coupling piece 13 . for this , connecting piece 30 has , on a holder 32 , a latch 33 that can be coupled in in the region between trigger 13 . 2 and follower 13 . 4 . holder 32 further carries , by means of a pivot bearing point 34 , a control element 35 in the form of a lever . at its free end facing away from holder 31 , control element 35 is fitted with a rotatable track roller 37 and a rotatable locking roller 38 . a stop 36 is shaped on between pivot bearing point 34 and locking roller 38 . a carrier 31 adjoins holder 32 . a plunger 24 is held via a threaded connection on carrier 31 at the end facing away from holder 32 . for this , plunger 24 is screwed with an external thread 24 . 1 into a threaded receptacle of carrier 31 . plunger 24 carries a snap - lock ring 24 . 2 . the latter is held , freely rotatably in a circumferential direction , in a bearing receptacle of plunger 24 . snap - lock ring 24 . 2 comprises a snap - lock element that is guided in a control cam 23 of a hollow cylinder of a sliding piece 21 . control cam 23 is recessed , in the form of a groove , into the inner wall of sliding piece 21 . control cam 23 and snap - lock ring 24 . 2 of plunger 24 form an overtravel mechanism . the mode of operation in this context is similar to that in a ballpoint pen , plunger 24 constituting the pushbutton of the ballpoint pen . a spring element 22 in the form of a helical spring is inserted into sliding piece 21 and is secured against the walls of the hollow cylinder to prevent buckling . holder 32 is guided , with a hinge pin constituting pivot bearing 34 , displaceably in a linear guide 34 . 1 . the wall constituting linear guide 34 . 1 carries a shaped element 39 that constitutes a countersurface 39 . 1 and a running surface 39 . 2 . fitting part 40 is u - shaped in cross section . it comprises a mounting segment 41 having bores 43 for bolting to a furniture enclosure . a partition 42 adjoins mounting segment 41 perpendicularly . partition 42 , mounting segment 41 , and a further partition parallel to the latter carry a shaped - on , obliquely oriented blocking surface 46 as well as a holding piece 47 . in addition , a blocking element 44 is articulated pivotably on mounting segment 41 and is held , by gravity and / or by a spring element , in the initial position shown in fig1 . blocking element 44 comprises two oppositely oriented control cams 44 . 1 , 44 . 2 . the mode of operation of the retraction apparatus according to the present invention will be explained in further detail below with reference to fig1 to 10 . fig1 shows the initial position of the retraction apparatus , i . e . the position in which the drawer is located when closed . this represents the position in which coupling piece 13 is in the retracted position . the overtravel mechanism is in a snap - lock position , snap - lock ring 24 . 2 being locked against a snap - lock projection of control cam 23 . blocking element 35 is held by means of a stop 35 . 1 on holder 32 in an elevated unlatched position . to release the overtravel mechanism , an overtravel u is introduced into , for example , the drawer front in the direction of the actual drawer closing motion . this overtravel u is introduced via a sliding piece 21 bolted to the drawer . in this context , sliding piece 21 shifts a small amount farther , against the pre - tension of spring element 22 , in the direction of overtravel u with respect to plunger 24 . as a result , the snap - locked position of snap - lock ring 24 . 2 in control cam 23 is disengaged , and snap - lock ring 24 . 2 is rotated in a circumferential direction until it arrives in a linear segment of control cam 23 . to allow overtravel u to be carried out , latch 33 is braced against trigger 13 . 2 . once the drawer has been pushed and unloaded , sliding piece 21 is brought , as a result of the released snap - lock connection between snap - lock ring 24 . 2 and control cam 23 , out of its inserted position ( fig1 ) into the extended position ( fig2 ). this displacement s is brought about by spring element 22 , which holds sliding piece 21 under pre - tension in the inserted position . the total displacement distance traveled by sliding piece 21 in this context is subdivided into a first displacement distance and a second displacement distance . within the first displacement distance , spring element 22 is effective . it is braced at its one end against sliding piece 21 and at its other end with respect to plunger 24 . once plunger 24 has been unlatched by means of overtravel mechanism u , spring element 22 can slacken , sliding piece 21 being guided through the first displacement distance in response to spring element 22 . at the end of the first displacement distance , spring element 22 is in its completely slackened state . this is then followed by the second displacement distance as a free - running portion f . in this region , no spring force acts on sliding piece 21 . instead , the kinetic energy of sliding piece 21 , generated in the first displacement distance , is utilized to travel through free - running portion f . at the end of the second displacement distance , the displacement motion of sliding piece 21 is limited with a stop . the stop couples sliding piece positively to plunger 24 in the direction of sliding motion s ( according to fig2 ). fig2 shows the completely extended position of sliding piece 21 after the first and the second displacement distance have been traveled through . because the drawer is coupled to sliding piece 21 , it is partly opened in accordance with the displacement travel of the sliding piece . when the position shown in fig2 has been reached , the drawer can be conveniently grasped and pulled manually into a further partly open position or completely into the open position . the extending arrangement coupled to the drawer is then , in this context , moved in opening direction ö . because coupling piece 13 is coupled , with latch 33 , to extending arrangement 20 , coupling piece 13 is also moved in opening direction ö ( see fig3 ), coupling piece 13 being guided in guide 11 . 2 . coupling piece 13 entrains piston rod 12 . 1 of damper 11 and thus displaces piston 12 . 2 . at the time , the spring is also tensioned . coupling piece 13 is pulled by extraction apparatus 20 until follower 13 . 4 , guided in guide 11 . 2 , arrives in the region of recess 11 . 21 . because spring 14 acts eccentrically with respect to pivot axis 12 . 5 , coupling piece 12 is tilted around pivot axis 12 . 5 , and follower 13 . 4 drops into recess 11 . 21 , in that context coming out of engagement with holder 32 . because the connection between extending arrangement 20 and coupling piece 13 is now disengaged , the drawer can be further pulled out in free - running mode , as fig4 illustrates . in this context , track roller 37 also deflects blocking element 44 against its control cam 44 . 1 and lifts it upward against the direction of gravity . track roller 37 moves past blocking element 44 , and control element 35 departs from fitting part 40 through opening 45 . upon closing of the drawer ( closing direction s ) and thus in the context of the transition of the retraction apparatus from fig4 to fig5 , track roller 37 encounters control cam 44 . 2 of blocking element 44 , which is blocked in this direction . the roller proceeds there against the direction of gravity until locking roller 38 encounters running surface 39 . 2 , as shown by fig6 . connecting part 30 can now be pushed no farther in closing direction s . closing motion s now causes plunger 24 to become inserted into sliding piece 21 ; plunger 24 then firstly travels through free - running portion f , and spring element 22 is then tensioned until plunger 24 has arrived at its snap - locked position ( snap - lock ring 24 . 2 and control cam 23 ). extending arrangement 20 is then tensioned again , and is in its inserted position . in the course of this operation , locking roller 38 rolls on running surface 39 . 2 until , at the end of running surface 39 . 2 , it travels over an edge 39 . 3 that conveys it into countersurface 39 . 1 . control element 35 then , as shown in fig7 , pivots into its blocked position because of the fact that contact roller 37 is continuing to run onto blocking element 44 . locking roller 38 abuts against countersurface 39 . 1 and blocks any inadvertent triggering of the extending arrangement out of the inserted position . as fig7 shows , immediately after extending arrangement 20 has been tensioned , latch 33 encounters trigger 13 . 2 and tilts it around pivot bearing 12 . 5 . in that context , guide elements 13 . 2 are lifted out of recess 11 . 21 and coupling piece 13 is disengaged . guide elements 13 . 6 then arrive in the region of guide 11 . 2 , and spring 14 can pull coupling piece 13 back into the retracted position . damper 12 damps this retraction motion . with the coupling piece , latch 33 is pulled against follower 13 . 4 ( see fig8 ); and the drawer is also automatically pulled , via sliding piece 21 , into the closed position . in the context of this motion operation illustrated by fig8 and 9 , contact roller 37 travels over holding piece 47 . with the drawer in the closed position , control element 35 drops , by gravity and / or by spring action , into the region below holding piece 47 , as fig1 shows . fig1 is once again identical to fig1 , and shows the initial position in which the drawer is ready for another actuation . housing 10 and fitting part 40 are usually mounted on the furniture enclosure . it is also conceivable , however , to mount these parts on the drawer . extending arrangement 20 is then also attached to the other respective furniture component . the arrangement according to the present invention can be arranged laterally in the region of one or both of the drawer walls extending in the drawer motion direction . the retraction guide can also be part of the drawer &# 39 ; s pulling - out guide . it can furthermore also be arranged centrally under the drawer bottom . extending arrangement 20 is then , for example , held on the drawer front below the drawer bottom . housing 10 is then arranged laterally on the furniture enclosure . coupling of these components then takes place by incorporation of a crossmember or drawer as a connecting member . references herein to a spring being “ tensioned ” may also be described as loading of the spring . this refers to the storing of potential energy in the spring and may include either tensile or compressive loading of the spring depending on the type of spring used .
a sliding arrangement , in particular an extension apparatus for drawers , sliding doors , hinged doors , etc ., has an extending arrangement which comprises a sliding piece that is displaceable by means of a spring element between an inserted position and an extended position . in order to enable user - friendly opening of the drawer , provision is made according to the present invention that the sliding piece is displaceable over a first displacement distance in spring - impinged fashion , and in an adjacent second displacement distance is displaceable without spring impingement in a free - running portion of the extension apparatus .