[0001] The invention relates to a return spring arrangement for a handle in a door lock
or door latch in accordance with the preamble of claim 1.
[0002] This kind of return spring arrangement is often needed for the reason that the spring
in the lock casing of a door lock or door latch is too weak in view of the size and
weight of the door handle, so that the handle does not easily stay in horizontal position.
One solution is disclosed in the Finnish patent 104007. In this case the handle spring
arrangement is an integrated part of the handle plate itself, and the handle plate
also needs to be replaced, if the spring force should be found too weak and is to
be compensated by a return spring arrangement of the aforementioned kind.
[0003] An object of the invention is to provide such a novel return spring arrangement that
may be applied with advantage also to retrofits, independently of the handle plate
itself. A further aim is that the installation should be simple to carry out and should
not require further machining of the door. The return spring arrangement should also
be installable independently of whether the door is a right-hand or a left-hand door,
and of the side of the lock casing, on which it will be installed.
[0004] The object of the present invention is achieved by return spring arrangement as set
out in claim 1. Preferred or optional features of the invention are defined in the
other claims. According to the invention, a spring casing is adapted, at least substantially,
to be embedded in a body part so that it forms a compact unit, which is arranged to
be installed entirely into a countersink made in a door or the like, between a handle
plate and a door lock or door latch, and to be fastened by utilizing the fastening
screws of the handle plate.
[0005] The basic idea of the invention relies on the fact that for installing a handle,
the door is in any case provided with an opening of a particular size, typically having
a diameter of 40 mm. When the return spring arrangement is dimensioned so that its
diameter is suitable and its structure is in accordance with the invention, it may
be installed into such an opening, whereby the space it requires is as small as possible
in the direction of the spindle of the handle. Thus, it is simple to install the return
spring arrangement even afterwards as a separate accessory.
[0006] In practice, the diameter of the return spring arrangement is preferably slightly
shorter than that of the handle plate, whereby there is enough space for it under
the handle plate and at the same time it can be ensured that the handle plate covers
the installation opening. In addition, the return spring arrangement is provided with
a number of openings for the lead-through of the fastening screws of the handle plate.
In this way the installation into various kinds of operating environments can be secured.
[0007] The spring casing has, in a manner known per se, an opening provided with guide surfaces
for the spindle of the handle. The spring is preferably a helical spring, which is
installed around the said opening.
[0008] The periphery of the body part is preferably provided with at least one, preferably
with two recesses, in which separate sleeve members have been arranged before the
installation. During the installation a suitable sleeve member is released and mounted
into position for the fastening screws of the handle plate, i.e. into one opening
of a given pair of opposite openings, whereby one of the fastening screws passes through
the sleeve member. Thus, the positioning of the return spring arrangement is provided
by the sleeve member and the fastening screw therethrough, together with the spindle
of the handle installed through the opening in the spring casing. The length of the
inner diameters of the sleeve members may preferably vary so that they can be used
conveniently in conjunction with screws of various diameters.
[0009] For guiding the ends of the spring, the shell surface of the spring casing preferably
comprises an installation opening, which has separate branches for each end so that
the branches have slightly different positions with respect to each other in the direction
of the rotation axis of the spring casing. This, among other things, makes it possible
to dimension the return spring arrangement so that it is as space saving as possible
in the direction of the rotation axis of the spring casing, i.e. in the direction
of the spindle of the handle.
[0010] In the following the invention is described in more detail, by way of example only,
with reference to the attached drawings, in which
- Figure 1 is an exploded view of a return spring arrangement according to an embodiment
of the invention; and
- Figure 2 shows the arrangement according to Figure 1 fully assembled.
[0011] In Fig. 1 the reference number 1 indicates the body part of the return spring arrangement,
into which a spring casing 2 is installed so that a spring 3 is located between these
parts. The body part 1 is provided with an opening 4 for the spindle of the handle,
restricting members 5 and 6 for spring ends 3a and 3b, and holes 7 - 14 for the lead-through
of fastening screws and for sleeve screws to be used in conjunction with them. The
body part is also provided with recesses 15 and 16, into which releasable sleeve members
17 and 18 with different inner diameters may be installed. The spring casing 2 has
a hole 19 provided with guiding surfaces for the spindle. In addition, the spring
casing 2 has an installation opening 20, which comprises two branches 20a and 20b,
onto which the spring ends 3a and 3b are supported.
[0012] The spring casing 2 may be turned with respect to the body part 1 (cf. the rotation
axis A in Fig. 2) by means of the spindle of the handle (not shown) installed in hole
19, whereby the turning is effected against the force of the spring 3. The freedom
of motion of the ends 3a and 3b of the spring 3 is determined and their return to
the initial position effected by the restricting members 5 and 6, which guide the
spring ends.
[0013] Since the return spring arrangement according to the invention is not as such a part
of the handle plate, it may be sold and installed as a separate accessory. The installation
into the opening in the door, under the handle plate, is carried out by utilizing
the fastening screws (not shown) of the handle plate, which screws are mounted, depending
on the situation, in one of the opposite pairs of openings 7 - 14. A suitable sleeve
member 17 or 18 is installed into one of the openings of such an opening pair, through
which sleeve member one of the fastening screws is inserted. In this manner, by means
of the spindle of the handle installed into hole 19 and the screw inserted through
the sleeve member 17 or 18 the installation clearances may be eliminated and a precise
positioning of the return spring arrangement in the installation opening of the door
accomplished.
[0014] As shown in Fig. 2, the thickness, i.e. the extent, of the return spring arrangement
in the direction of the rotation axis A of the spring casing 2, i.e. in the direction
of the spindle of the handle, corresponds to the thickness of the body part 1 and
is typically about 7.5 mm, whereby it may be installed in various kinds of applications.
The optional openings 7 - 14 make the arrangement installable in conjunction with
several kinds of lock casings and latches. The variety of installation angles is further
increased by the fact that the arrangement is symmetric and it enables the elimination
of clearances.
[0015] The invention is not limited to the above-described application, but several other
modifications are conceivable within the scope of the appended claims.
1. A return spring arrangement for a handle in a door lock or a door latch, the arrangement
comprising a body part (1) provided with restricting members (5, 6) for a spring (3),
and a spring casing (2) to be rotatably connected to the body part, which spring casing,
when installed, encloses both said restricting members (5, 6) and the return spring
(3) of the handle, the ends (3a, 3b) of which spring are arranged to cooperate with
said restricting members (5, 6), characterised in that the spring casing (2) is adapted, at least substantially, to be embedded in the body
part (1) so that it forms a compact unit, which is arranged to be installed entirely
into a countersink made in a door or the like, between the handle plate and the door
lock or the door latch and to be fastened by utilizing the fastening screws of the
handle plate.
2. A return spring arrangement according to claim 1, characterised in that its diameter is slightly shorter than that of the handle plate, and that it is provided
with a number of openings (7 - 14) for the lead-through of the fastening screws of
the handle plate.
3. A return spring arrangement according to claim 1 or 2, characterised in that the spring casing (2) has, in a manner known per se, an opening (19) provided with
guide surfaces for the spindle of the handle, and that the spring (3) is a helical
spring, which is installed around said opening (19).
4. A return spring arrangement according to claim 3, characterised in that it comprises a sleeve member (17, 18), which is arranged to be installed for the
fastening screws of the handle plate into one opening (7 - 14) of a given pair of
opposite openings (7 - 14), whereby said sleeve member (17, 18) together with the
fastening screw and the spindle of the handle installed through the opening (19) in
the spring casing effects the positioning of the return arrangement.
5. A return spring arrangement according to claim 4, characterised in. that the periphery of the body part (1) is provided with at least one, preferably with
two recesses (15, 16) for keeping the separate sleeve members (17, 18) before the
installation.
6. A return spring arrangement according to claim 5, characterised in that sleeve members (17, 18) with inner diameters of various lengths for screws of various
sizes are included in the arrangement.
7. A return spring arrangement according to any of the preceding claims, characterised in that for guiding the ends (3a, 3b) of the spring the shell surface of the spring casing
(2) comprises an installation opening (20), which has separate branches (20a, 20b)
for each end (3a, 3b) so that the branches (20a, 20b) have slightly different positions
with respect to each other in the direction of the rotation axis (A) of the spring
casing (2).