SHOWER STRUCTURE

ISOLOIR DE DOUCHE SUR BAIGNOIRE

English Abstract

ABSTRACT
In renovating bathrooms, it is known to form a unitary
tub and shower enclosure out of a suitable plastic material,
usually acrylic. However because of the large size of these
enclosures, it is necessary to cut them into, for example, three
pieces so that they can be taken through the bathroom door. Once
in the bathroom, they are re-assembled, with joints between the
pieces. One type of joint utilizes an H-shaped sealing member of
vinyl material which is softer than acrylic and not as attractive
in appearance, particularly after some time when it deteriorates.
Also, the joint thus formed is not entirely satisfactory. The
present invention provides an improved joint between the pieces in
which mateable surfaces extending backwards from the front surfaces
are mechanically joined, preferably with silicone sealant between
the surfaces. The surfaces can slope so that any moisture tends
to drip down into the tub. Also, each joint can have an over-
hanging lip so that water running down the wall of the enclosure
will drip into the tub and not go into the joint. The enclosure
is made by thermoforming a sheet of thermoplastic material to
include mateable surfaces between different sections, but with
regions of waste material extending between the mateable surfaces.
This material is simply cut away so that the mateable surfaces can
be joined together mechanically.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of forming a tub and shower enclosure of
thermoplastic material comprising thermoforming a sheet of thermo-
plastic material to include top, middle and bottom pieces with
first and second mateable surfaces on the top and middle pieces,
respectively, spaced apart by a first section of waste material
and third and fourth mateable surfaces on the middle and bottom
pieces, respectively, spaced apart by a second section of waste
material, removing said first and second sections of waste
material, and then mechanically joining together the top and
middle pieces at said first and second mateable surfaces to form
a first joint and mechanically joining together said middle and
bottom pieces at said third and fourth mateable surfaces to form
a second joint, wherein said top, middle and bottom pieces have
front and back surfaces and said mateable surfaces are provided
on portions of said pieces which project outwardly and upwardly
from said back surfaces and wherein the front surface of said top
piece, in the region of said first joint, extends forwardly of
the front surface of said middle piece, and the front surface of
said middle piece in the region of said second joint, extends
forwardly of the front surface of said bottom piece.
2. A method as claimed in claim 1 wherein said thermo-
plastic material is acrylic.
3. A method as claimed in claim 2 wherein said mateable
surfaces are substantially flat.

4. A method as claimed in claim 1, 2 or 3 wherein silicone
sealant is provided between said mateable surfaces.

Description

9~
This invention relates to a novel method of forming a
joint between two pieces of thermoplastic material and to a novel
method of forming a tub and shower enclosure of thermoplastic
material.
It is known, particularly in connection with bathroom
renovations, to produce a tub and shower enclosure of thermoplas-
tic material, such as acrylic material. The enclosure includes an
integral bathtub and wall and ceiling portions. However, the
structure is obviously quite large, and such a large structure
cannot be taken through the doors of most houses, particularly the
bathroom door. Therefore, i-t is necessary to cut the structure
into, for example, three pieces and then re-assemble them in the
bathroom, Joints are formed between the pieces, for example tub,
middle and bottom pieces. The joints can be formed by H-shaped
vinyl extrusions with the bottom of one part fitting in the top
portion of the H-shaped extrusion and the top portion of the next
lower section fitting in the bottom portion of the ~shaped vinyl
extrusion. This type of joint is not entirely satisfactory for a
number of reasons. For one thing, moisture can get into the joint
and may promote bacterial growth. Also, the vinyl is softer than
acrylir, wears faster, deteriorates after a time and looks consi-
derably less attractive than the harder acrylic.
The present invention provides a unique joint construc-
tion which eliminates the need for any vinyl extrusions. The
joint effectively prevents moisture penetration and is at-tractive

in appearance.
~ According to ~}~ff~ broad aspect of the invention,
there is provided a method of forming a tub and shower enclosure
..,. ~.
of thermoplastic material compris:ing thermoforming a sheet of
thermoplastic material to include top, middle and bottom pieces
with first and second mateable surfaces on the top and middle
pieces, respectively, spaced apart by a first section of waste
material and third and fourth mateable surfaces on the middle and
bottom pieces, respectively, spaced apart by a second section of
waste material, xemoving said first and second sections of waste
material, and then mechanically joining to~ether the top and
middle pieces at said first and second mateable surfaces to form
a first joint and mechanically joining together said middle and
bottom piec~s at said third and fourth mateable surfaces to form
a second joint, wherein said top, middle and bottom pieces have
front and back surfaces and said mateable surfaces are provided
on portions of said pieces which project outwardly and upwardly
from said back surfaces and wherein the front surface of said
top piece, in the region of said first joint, extends forwardly
of the front surface of said middle piece, and the front surface
of said middle piece, in the region of said second joint~ extends
forwardly of the fron-t surface of said bottom piece.
The preferred embodiment of the invention will now be
described in detail in conjunction with !the accompanying
drawings in which:
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Figure 1 is a front view of a tub and shower enclosure
constructed according to the present invention,
Figure 2 is a front view of the enclosure as it comes
from the mould, prior to being cut apart and re-assembled,
Figure 3 is a cross-sectional view of a mould, u~eful in
explainin~ the operation of the present invention, and
Figure 4 is a cross-sectional view of a joint formed
according to the present invention.
Referring to Figure 1, the tub and shower enclosure is
seen to include a bottom portion 10, a middle portion 11 and a
top portion 12. The bottom portion 10 includes a bathtub 14 and
a curved back wall portion 16. The middle portion 11 includes a
curved wall portion 18 and preferably includes soap dishes 20.
The top portion 12 includes a wall portion 22 and a ceiling portion
23. It will be noted that there is a first joint 25 between the
top and middle portions 12 and 11 and a joint 26 between the
middle and bottom portions 11 and 10.
Figure 2 illustrates the structure of Figure 1 as it
comes from the mould, that is before being cut into three pieces
and re-assembled. It will be not~d that there is a rather wide
band~ e.g. six inches, between the upper portion 12 and the middle
portion 11. Similarly~ there is a relatively wide band 31 between
the middle portion 11 and the bottom portion 10. These wide bands
are cut out, after which the portions 10, 11 and 12 may be joined
together. It is to be noted, however, that it is the provision of
these wide bands 30 and 31 that enables the joints to be formed
between the portions 10, 11 and 1~. This may be more readily
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appreciated by referring to Figure 3, a cross-sectional view of
the mould used in producing the structure shown in Figure 2.
Referring to Figure 3, a sheet of thermoplastic material,
such as ABS, PVC or, preferably, acrylic, is placed across the
mouth 35 of the mold and then subjected to heat and vacuum. At a
first stage of the process, the sheet assumes a shape roughly as
shown at 36. Subsequently, it assumes approximately the shapes
shown at 37, 38 and 39. In the final stage, stage 39, the sheet
deforms into the recesses 40 and 41 to form the waste sec-tions 30
and 31. The recesses 40 and 41 have correspondingly sloped upper
and lower surfaces and the portions of the sheet drawn against
these surfaces of the mould comprise mateable surfaces which can
be mated after the waste portions 30 and 31 are cut away. Even
though the sheet may not conform to the innermos-t corners of the
portions 40 and 41, this is of no consequence because these por-
tions of the sheet are cut away and form waste material~ All that
is necessary is that sufficient material be drawn into the recesses
40 and 41 so that the upper and lower portions form mateable
surfaces, as will be readily appreciated by those skllled in the
art. Thus, after cutting away portion 30, the upper surface 45
will mate with the lower surface 46. Similarly, the upper surface
5~ will mate with the lower surface 52.
Turning to Figure 4, a joint is shown in cross-section.
It can be seen that the surface 45 mates with the surface 46, the
waste portion 30 having been cut away. The surfaces 45 and 46 are
secured together by any suitable mechanical fasteners such as the
rivet 55 shown, although other fasteners such as screws could be
used. Preferably silicone sealant, or other suitable sealant,
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g~
is provided between the surfaces 45 and 46. Preferably, the mould
is so shaped that the upper portion 12 has an overhanging lip 60.
That is, at the region of the joint, the front surface of upper
portion 12 extends forwardly of the front surface of middle portion
11. A similar arrangement is, of course, provided for -the joint
between the middle portion 11 and the bottom portion 10. In this
manner, water flowing down the surface 12 cannot flow into the
joint bu~ rather drips off the overhanging portion 60.
The portions forming the joint slope upwardly away from
the front surfaces of portions 11 and 12 so that moisture cannot
flow into the joint.
It may also be noted that the joint seal is tamper-
proof, i.e. it is not possible to tear, dislocate or damage the
joint or seal as it is with the vinyl extrusion type of seal. The
joint is smooth virgin acrylic and therefore cleaning is no special
problem. There is no transition from smooth to rough surface or
from acrylic material to ~inyl (or other) material.