System for fastening the back end of the guide rail of a drawer slide

A mounting system for the carcase-interior end of the guide rail (10) of a drawer guide for drawers and the like in the carcase of a cabinet at a distance from the inside surface of the associated carcase side wall. The guide rail (10) is formed as a channel which is fitted from underneath into a corresponding runner rail which can be fastened to the drawer and is formed by an inverted channel inside of which tracks are formed for rolling bodies. In the portion of the guide rail (10) engaged in the runner rail, tracks are also formed for the rolling bodies, so that the runner rail is displaceable relative to the guide rail. The section of the guide rail (10) engaged in the runner rail is bent from the horizontally disposed web of the rail. In the carcase-interior end portion of the guide rail (10) a tab (16) stands up from its horizontal web and is aligned transversely of the length of the guide rail, and is provided with detent teeth (18) on its edge pointing away from the web. A mounting piece (12) which can be fastened in the interior of the carcase serves to accommodate the guide rail; it has a supporting surface (24) extending under the back end of the horizontal web of the guide rail (10), and has a resilient tongue (26) which is provided above the supporting surface (24) at the level of the tab (16) on the guide rail, and bears parallel grooves (28) on its bottom running in the direction of the length of the guide rail, and it is forced against the detent teeth (18) of the tab (16).

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a system for fastening the carcase-interior, 
rearward end of the guide rail of a slide for drawers and the like in the 
carcase of a cabinet at a distance from the inside surface of the 
associated carcase side wall, wherein the guide rail is configured as a 
shaped rail which enters from below into corresponding runner rail formed 
by an open-bottomed channel and fastenable to the drawer, and inside of 
the runner rail tracks are formed for rolling bodies which during a 
longitudinal displacement of the runner rail relative to the guide rail 
can roll on these runner rail tracks on the one side and in tracks formed 
in the portion of the guide rail that is engaged in the runner rail, the 
section of the profile of the guide rail that enters from below into the 
runner rail being bent down from a substantially horizontal limb of the 
guide rail profile. 
Guide rails of drawer guides, by means of which drawers, slides, appliance 
holders and the like are mounted in a cabinet carcase so as to be able to 
be drawn out and pushed back in, are normally screwed directly onto the 
inside surface of the associated cabinet side wall. In certain cabinet 
types manufactured mostly by kitchen cabinet manufacturers in and for the 
United States of America, the front cabinet opening is, however, narrowed 
by a face frame running around it, with the result that drawers or the 
like can have only a width corresponding to the clear width between the 
vertical front edges of the frame. In this case, however, the guide rail 
of a drawer guide, which is to be fastened to the carcase, cannot be 
fastened to the cabinet side wall, but has to be set back into the carcase 
interior by the amount by which the frame projects beyond the inside 
surface of the associated cabinet side wall. The front end of the guide 
rail in this case is in an appropriate manner screwed to the inside 
surface of the free front edge of the frame, while its rearward end inside 
of the carcase has to be fastened to the back wall of the cabinet or 
carcase. 
2. Description of the Related Art 
For so-called "roller drawer guides" a fastening system has been developed 
for the carcase-interior end of the guide rail for mounting in cabinets of 
the kind described (DE-OS 38 32 701), in which a tab attached to the web 
of the guide rail and bent at right angles to a horizontal position can be 
inserted into an opening in a mounting piece which can be fastened to the 
carcase back wall and can be fixed at selectable displacement positions. 
This solution, however, in the case of the drawer guides here in question, 
in which the guide rail configured as a shaped rail is engaged from below 
in a corresponding runner rail formed by an open-bottomed channel, the 
runner rail being mounted on rolling bodies on the portion of the guide 
rail that is engaged in it, is difficult to realize in practice, and in 
particular the mounting of the guide rail would be problematical. 
SUMMARY OF THE INVENTION 
The invention is therefore addressed to the problem of creating a fastening 
system for the rearward end of the guide rail of drawer guides of the kind 
here in question, which will permit a quick and simple installation of the 
guide rail as well as any necessary horizontal adjustment of the position 
of the carcase-interior end of the guide rail, so as to be able to 
compensate for any inaccuracies that may have occurred in the production 
of the cabinet carcase or due to external influences. 
Setting out from a fastening system of the kind described above, this 
problem is solved in accordance with the invention in that, in the 
carcase-interior end portion of the guide rail a tab is turned up from its 
horizontal web and is aligned transversely of the length of the guide 
rail, and it is provided with detent teeth on its edge pointing away from 
the flange, and in that a mounting piece is provided which can be fastened 
in the carcase interior, and has a supporting surface reaching beneath the 
rearward end of the horizontal web of the guide rail, and it has a 
resilient tongue at a level above the supporting surface corresponding to 
the level of the tab provided on the guide rail, the tongue being provided 
on its bottom with parallel grooves running in the longitudinal direction 
of the guide rail and urged against the detent teeth of the tab. 
In order to guide the carcase-interior end of the guide rail positively 
into the correct mounting position during its first installation, the 
configuration is made such, in a desirable further development of the 
invention, that on the carcase-interior end of the horizontal web of the 
guide rail a projection extending toward the supporting surface of the 
mounting piece is provided, and that in the supporting surface a 
groove-like recess is provided which is open at the end remote from the 
back wall of the carcase, and which on its mouth side and in its end 
portion facing the back wall of the carcase, in which the projection of 
the guide rail is in the proper mounting position, is made wider 
transversely of the direction of the insertion of the guide rail than the 
projection, but in the intermediate portion diminishes gradually from the 
mouth to approximately the width of the projection, the position of the 
reduced-width portion of the recess with respect to the projection of the 
guide rail being selected such that, when the carcase-interior end is 
inserted between the supporting surface and the resilient tongue, it is 
positively guided to the correct mounting position. 
The projection that, during installation, brings about the alignment of the 
guide rail relative to the mounting piece can be a tab cut from the 
carcase-interior end of the guide rail's horizontal web and bent downward. 
The supporting surface, in a preferred further development of the 
invention, is formed by the inside surface of the bottom side of an open 
socket facing toward the front of the carcase, with the back end of the 
socket terminating in a mounting flange on the inside of the back wall of 
the carcase, and the resilient tongue reaches into the socket from the 
mounting flange toward the open end of the socket, i.e., toward the front 
of the carcase. 
The force with which the resilient tongue is urged against the detent teeth 
of the upright tab provided at the end of the guide rail, and hence the 
resistance which the guide rail opposes to any horizontal shifting for the 
purpose of alignment in the carcase, can be increased--if necessary--by 
providing a spring means between the top of the resilient tongue and the 
inside surface of the portion of the socket wall above it, to increase the 
resilient resistance of the tongue against flexure. If it should be found 
that the tongue is too flexible for a particular application, it can be 
further stiffened afterward by inserting an appropriately resilient body 
between the upper side of the tongue and the inside surface of the socket. 
On the other hand an excessively weak tongue--possibly due to reasons 
associated with injection-molding--can also be stiffened from the outset 
by forming the spring means of a thin web disposed between the upper side 
of the tongue and the inside surface of the wall of the socket. 
The mounting flange is best made larger than the socket, so that it extends 
beyond it at least vertically, and then at least one, preferably two or 
more holes can be provided in the part of the flange outside of the 
socket, one for each of the mounting screws to be driven into the back 
wall of the carcase. 
Alternatively, or additionally, at least one, preferably two studs at a 
distance apart, can project from the surface of the mounting flange facing 
the back wall of the carcase, so that they can be inserted into mating 
holes in the back wall of the carcase. These studs serve on the one hand 
for the precise alignment of the mounting piece at the given mounting 
point, but they can also provide additional retaining and fastening if 
they are oversize for the holes in the back wall that are to receive them, 
i.e., they can be in the form of "push-in" studs. 
In a preferred embodiment of the invention the mounting piece is entirely 
one integral injection molding of plastic.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows in perspective, on the one hand the front and the back end of 
a guide rail 10 of a drawer guide, which is to be fastened in the interior 
of a cabinet carcase, and on the other hand a mounting piece 12 which is 
to be fastened to the back wall of the cabinet carcase, accommodating the 
carcase-interior end of the guide rail 10 and into which the inner end of 
the guide rail can be inserted undisplaceably in the vertical direction, 
but to a given degree adjustably horizontally and parallel to the back 
wall of the carcase. The front end of the guide rail can be fastened in 
some suitable manner to a frame rail, not shown, defining the free opening 
to receive the drawer, a slot 14 for this purpose being represented 
diagrammatically on this front end. In the scope of the present invention, 
however, we are concerned only with the fastening of the back end of the 
guide rail by means of the mounting piece 12. As it can be seen in FIG. 1 
and FIGS. 2 and 3, a tab 16 is cut and bent upward from its horizontal web 
at the rear end of the guide rail 10, and is provided with detent teeth 18 
on its top edge. The mounting piece 12 receiving the inner end of the 
guide rail has, in turn, the form of a socket 22 open at the end 
confronting the guide rail and projecting from a mounting flange 20; the 
socket 22 has a flat bottom and top, and at a distance above the inside 
surface of the bottom wall of the socket, which has a surface 24 for 
bearing the bottom of the horizontal web of the guide rail 10 there is 
provided a resilient tongue 26 projecting from the mounting flange 20, 
which is provided on its bottom with parallel grooves 28 running in the 
direction of the length of the guide rail (FIGS. 4 and 6), whose cross 
section and pitch complements the detent teeth 18 of the tab 16. After the 
rear end of the guide rail 10 has been inserted into the mounting piece 
12, the resilient tongue 26 is forced with bias onto the detent teeth of 
the tab 16 and fixes the guide rail in the vertical direction and in the 
horizontal direction. However, a transverse shifting of the end of the 
guide rail in the horizontal direction is possible whenever a horizontal 
pressure is exerted in the desired direction of adjustment against the 
guide rail end such that the inclined flanks of the grooves 28 of the 
resilient tongue are urged upward and the tongue flexes upwardly, so that 
then a detented displacement of the guide rail is accomplished. The force 
necessary for the horizontal displacement does not have to be applied 
manually by the person installing the guide rail, but can be produced by 
the runner rail fastened to the drawer as it is pushed onto the guide rail 
when the drawer is closed. In other words, the precise alignment of the 
guide rail is produced by the closing of the corresponding drawer. 
In order to achieve a very precise alignment of the guide rail 10 in the 
mounting piece when the guide rail is installed therein, a narrow 
projections tab 30 is cut from the rear edge of the horizontal web of the 
guide rail and bent to point downwardly, and with it there is associated, 
in the supporting surface 24 of the mounting piece 12, a slot-like or 
groove-like recess 32 open at the front end, which is made decidedly wider 
than the tab 30 at the mouth end and in the back end facing the back wall 
of the carcase, in which the tab 30 is in the intended position for 
mounting the guide rail, while in the portion in between it gradually 
narrows to about half the width of the tab 30. Thus, when the 
carcase-interior end of the guide rail is inserted, the tab 30 is guided 
to a predetermined correct mounting position by the portion of reduced 
width of the recess. Since the detent teeth 18 of the upturned tab 16 do 
not come into engagement with the grooves 28 of the resilient tongue 26 
until the transverse alignment of the guide rail in the narrow portion of 
the recess 32 has been accomplished, upward flexing of the tongue to the 
degree required for a transverse adjustment is unnecessary when the guide 
rail 10 is installed in the mounting piece 12, but only the slight flexure 
needed to produce the required bias of the tongue. A resilient spring 
element increases the resilient resistance of the tongue 26 to flexure and 
is provided between the upper side of the resilient tongue 26 and the 
inside surface of the section of the wall of the socket above it. The 
resilient spring element is formed by a thin web disposed between an upper 
side of the tongue 26 and an inside surface of the wall of the socket 22. 
The mounting piece 12 can be fastened to the back wall of the carcase by 
screwing, and for this purpose, in the case of the mounting piece 12 
represented in the drawings, two holes or openings 34 are provided in the 
mounting flange 20, and through them mounting screws can be driven into 
the back wall of the cabinet. In addition, two studs 36 provided at a 
vertical distance apart protrude from the back of the mounting flange and 
are forced into mating holes predrilled in the back wall of the carcase. 
These studs serve for the precise positioning of the mounting flange 20 
when it is installed on the back wall of the carcase, and can furthermore 
also provide support in addition to the screws for the weight of the 
drawer transmitted by the guide rail to the mounting piece. 
It can be seen that, in the embodiment represented, mounting pieces of 
mirror-image symmetry are required for the right and left guide rails. It 
is apparent, however, that if the resilient tongue were centered in the 
socket 22 and if the aligning recess 32 were also centered in supporting 
surface 24, a mounting piece suitable both for a right-hand and for a 
left-hand guide rail can be developed, which then would only have a 
greater width. For the sake of economy of material, therefore, the use of 
two mirror-image mounting pieces 1 is preferred at the present time for a 
pair of drawer guides. The mounting pieces 12 are manufactured by 
injection molding from an appropriate thermoplastic.