Pull-out guide assembly for drawers or the like

A pull-out guide assembly includes, for each side of a drawer, a pull-out rail, a support rail and an intermediate roller carrier together forming an inseparable unit. A locking member is provided on each drawer side wall and has a catch which secures the pull-out rail on the drawer side wall. The locking member also keeps the closed drawer in the closed position by clamping the support rail.

FIELD AND BACKGROUND OF THE INVENTION 
The invention relates to a pull-out guide assembly for drawers or the like, 
and of the type including on each side a supporting rail at the side of 
the body and a pull-out rail at the side of the drawer, a roller carrier 
being arranged between the supporting rail and the pull-out rail and 
carrying load-transmitting rollers and preferably compensating rollers for 
ensuring lateral stability of the pull-out guide assembly. 
DESCRIPTION OF THE PRIOR ART 
Two kinds of pull-out guide assemblies are known in the art in which the 
rollers are not directly fastened to the rails but are arranged in a 
separate roller carrier. Best known are the so called ball roller pull-out 
guides in which the load is transmitted between the rails by means of 
steel balls which are held in a roller carrier designed as a roller cage. 
Such pull-out guides are very precise, i.e. they ensure excellent running 
of the drawer and permit at the same time good fitting of the drawer in 
the body, i.e. the drawer is laterally as well as vertically guided in a 
very stable manner. Such pull-out guide assemblies are employed 
particularly with high-quality furniture, e.g. office furniture. 
A disadvantage of such pull-out guide assemblies is that the rails must 
have complicated profiles to define the rolling tracks for the balls. It 
is a further disadvantage that such pull-out guide assemblies do not 
provide a self closing effect, so a drawer which has not been correctly 
closed is not automatically fully pulled into the body but remains in the 
half-open position. 
The other known type of pull-out guide assembly has been on the market for 
a short time only and has cylindrical rollers, namely of the same kind as 
normally mounted directly on the rails. Such pull-out guide assemblies 
also have very good running properties and can easily be provided with 
automatic closing means, but their stability, in particular the lateral 
stability, is not satisfactory. In the past, such pull-out guides have 
therefore been provided with lateral slides. This solution has never 
proved entirely satisfactory because it provides lateral alignment for the 
drawer in the inserted position only, but does not provide lateral 
stability of the drawer when the latter is being pulled out. 
SUMMARY OF THE INVENTION 
It is the object of the invention to provide an improved pull-out guide 
assembly of the above mentioned type, but which has the advantages of ball 
guiding means with respect to lateral stability, as well as the advantages 
of a pull-out assembly with cylindrical rollers, i.e. simple rail 
profiles, and a draw-in effect for a not fully closed drawer. 
According to the invention this is achieved by providing the supporting 
rails and the pull-out rails with lateral front and rear stops so that the 
stops and the roller carriers form at each side of the drawer a unit which 
is movable relative to one another but which cannot be disassembled. 
The pull-out guide assembly further has the advantage that it is supplied 
as a closed unit for the mounting of the piece of furniture and can be 
fastened to the body side wall. The drawer can, after the body of the 
piece of furniture has been completely mounted, be fitted onto the 
pull-out guide assembly, which substantially helps to facilitate furniture 
production. 
The lateral stability of the pull-out guide assembly is obtained in a 
constructionally simple manner in that the supporting rails have Z-shaped 
profiles and the pull-out rails have U-shaped profiles with an upper outer 
vertical limiting flange. 
Compensating rollers are mounted on the roller carrier between the limiting 
flange and a corresponding vertical flange of the supporting rail so that 
lateral guiding of the pull-out guide assembly is provided. It is 
advantageously provided that the supporting rails, the pull-out rails and 
the roller carriers are guided in one another without clearance. 
To anchor the drawer securely on the pull-out rail, and, furthermore, to 
make the transmission of greater loads possible, it is provided in a 
conventional manner that the pull-out rails are held in grooves in the 
drawer side walls. 
A preferred embodiment of the invention has at each side of the drawer a 
locking member for the pull-out rails which is fixed or moulded to the 
drawer side wall and carries a resilient bolt or catch which is adapted to 
engage behind a projection or in a recess of the pull-out rail. 
In such a pull-out guide assembly, the drawer can easily be fitted onto the 
pull-out rails, and due to the resilient bolt the drawer is automatically 
locked in the inserted position. The locking member is preferably mounted 
at the front end of the drawer directly behind the front plate and has at 
least one lateral stop for the pull-out rail. Generally two lateral stops 
are provided, an upper and a lower one. 
A special embodiment of this kind provides that the upper lateral stop 
extends between the central flange of the pull-out rail and the upper 
outer limiting flange. 
When the locking member is designed as a separate member with respect to 
the drawer, the member may be provided with lateral bolts or plugs which 
project into holes located in the bottom of the recess receiving the 
pull-out rail. As a load acts on the pull-out rail, apart from the 
vertical load by the weight of the drawer, only in the direction of the 
depth of the drawer, simple locking means of this kind are sufficient. 
A further embodiment provides that the locking members have stop cams for 
the running flanges of the supporting rails. The stop cams may be designed 
such that they form a kind of brake or holding means at the body rail, 
when the drawer is in the inserted position, so that the drawer is 
prevented from moving out of the body by itself and is always fully closed 
by the slight pressure which is necessary to press the drawer with the 
stop cams onto the body rail.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The pull-out guide assembly according to the invention comprises on each 
side a supporting rail 1 at the side of the body and a pull-out rail 2 at 
the side of the drawer, with a roller carrier 3 mounted therebetween. 
Rollers 4 with horizontal axes of rotation are located in the roller 
carrier 3 and serve for the actual load transmission of the pull-out 
assembly. Compensating rollers 5 have vertical axes of rotation and are 
provided for the stabilization of the pull-out guide assembly and the 
drawer. 
As can particularly be seen in FIG. 2, the supporting rail 1 is designed 
with a Z-shaped profile, a vertical flange 1' serving as a fastening 
flange and a second vertical flange 1'" as a lateral guiding flange. A 
central horizontal flange 1" forms the actual running flange of the 
supporting rail 1. 
The pull-out rail 2 has a U-shaped profile with two horizontal flanges 2', 
2"' and a vertical central connecting flange 2" and an outer limiting 
flange 6. 
While the rollers 4 of the roller carrier 3 roll at the flange 2', 1" and 
2'", the compensating rollers 5 roll at the flanges 1', 2" and 1'" and at 
the limiting flange 6. Since the supporting rail 1, the pull-out rail 2 
and the roller carrier 3 are designed without clearance, the complete 
pull-out guide assembly is laterally stable. 
Moreover, the supporting rail 1 is provided with a front stop 7, and the 
pull-out rail 2 with a rear stop 8, so that the pull-out rail 2 cannot be 
pulled unintentionally from the supporting rail 1. 
In the illustrated embodiment, the supporting rail 1 is further provided 
with a rear stop 9. 
The pull-out rail 2 is fastened in a groove in the drawer side wall 10. At 
the front end of such groove, directly behind a front plate 11 of the 
drawer, is arranged a locking member 12. In the illustrated embodiment, 
locking member 12 has two plugs or bolts 13 projecting into corresponding 
holes 14 in the bottom of the groove, thus holding the locking member 12 
in the direction of the depth of the drawer. 
The locking member 12 further has a resilient latch member 21 carrying a 
catch 15. 
When the drawer has been fitted onto the pull-out rail 2, catch 15 engages 
in a recess 16 in the lower flange 2' of the pull-out rail 2, flange 2' 
having an angular portion or raised abutment 17 directly in front of the 
recess 16. Thus, the pull-out rail 2 is rigidly secured to the drawer. 
Due to the fact that the pull-out rail 2 need not be fastened to the drawer 
side wall 10 in a conventional manner prior to the final mounting of the 
pull-out guide assembly and then fitted with side wall 10 onto the roller 
carrier 3 and the supporting rail 1, it is possible to design the complete 
pull-out guide assembly substantially without clearance, thus essentially 
improving the running properties of the pull-out guide assembly. 
Since rollers 4 are formed of plastic material and steel balls are not 
required to be mounted in the roller carrier 3, the rails 1, 2 may be 
coated in any desired manner. 
In FIG. 1 dotted lines show a stop cam 18 on the resilient latch 21. Cam 18 
clamps the stop 7 of the running flange 1" of the supporting rail 1 when 
the drawer is in the closed position. 
The locking member 12 further has an upper lateral stop 19 which projects 
between the vertical flange 2" and the limiting flange 6 of the pull-out 
rail 2 when the pull-out rail 2 has been pushed in. 
At the front end, the locking member 12 is provided with a flange 20 which 
defines the end of the inserting path of the drawer.