Note: Descriptions are shown in the official language in which they were submitted.
CA 02628702 2008-04-09
1821
UNIVERSAL TROWEL
FIELD OF THE INVENTION
This invention relates to a universal trowel for manual use, having a bottom
surface
for generally smoothing, sanding, spreading fluid materials, and the like,
particularly,
grouting, glue, sanding, thin-set and the like trowels, and having a
replaceable substrate.
BACKGROUND OF THE INVENTION
The process of laying tiles, particularly ceramic tiles on a flat wall or
floor surface
typically involves the spreading of an adhesive cement, on the floor surface
or wall with a
trowel.
One form of trowel has a handle affixed to a rectangular thin metal plate
having
indentations on each of the two longitudinal edges for spreading out the "thin
set", to a
desired thickness intermittent of the area covered to leave a roughened uneven
surface.
An alternative trowel has a handle and rectangular metal plate of similar
dimensions
affixed to a rectangular non-abrasive, rubber foam pad of the same surface
area as the metal
plate and a thickness of about 1cm. This pad trowel may be used in the same
manner as the
metal trowel in spreading thin set adhesive on the surface.
Further, once the tiles are laid out on the surface, grout is spread on and
between the
tiles by the trowel and the excess subsequently removed. Since the grout
contains rough
particulate filler, although the pad trowel is more gentle and minimize
abrasion of the tile
surface than the metal trowel surface, the soft pad suffers from being worn
down by the grout
particles. Such a prior art grout trowel with a pad, generally, only last for
between 30-40 hrs.
of utilization, before a replacement trowel is needed and the current trowel
discarded.
Further, uneven wear of the pad particularly at its edges and corners can
cause damage to a
tile by a metal plate corner or edge.
Similarly, glue trowels having a planar metal base with edge teeth are known
for
applying a layer of glue to the walls, floors and ceilings to which is,
subsequently, adhered
tiles, wood, wallpaper, flooring materials and the like.
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Also known as mentioned, hereinabove, are thin-set trowels having a base
formed of
metal or a plastics material for applying concrete, mortar, bonding cement and
the like to
which tiles and the like are subsequently adhered. The edge teeth are of
different sizes for
use in installing different types of flooring, such as marble, granite,
ceramic and the like.
Similarly are known mudding trowels for applying plaster, drywall
compositions,
stucco cement and the like.
Also known are "floats" used to smooth out walls, floors, and the like having
a
rubber, wood or foam lower layer of the trowel.
Further is known sponge sanding blocks having particulate sand grits of
various sizes
on the surface of the lower layer and each vertical side of the block.
Similarly, scouring pads for scrubbing surfaces of walls, floors and the like
comprising abrasive metal of plastic wire mesh and the like are known.
However, invariably, after a limited time period the substrate bottom part of
the
trowels becomes worn in view of having a low disadvantageous operative life.
This results in
the whole trowel being discarded.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a trowel having a handle
affixed to a
replaceable and substitutable working substrate to avoid having to discard the
full trowel
when the working substrate reaches its useful working life, or when a
different duty of action
requiring a different substrate is needed. The present invention negates
disposal of the
handle, and, thus, a concomitant reductions in costs, as well as a significant
increase in
convenience. The universal handle negates for the skilled person to possess
and carry a
plurality of trowels.
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Thus, it is an object of the present invention to provide a universal trowel
that does
not require the disposal of the handles and metal plate members once a
cooperable substrate
is no longer satisfactory.
The invention provides in a preferred aspect a universal trowel having a
handle
affixed to a base place to which is adhered a replaceable substrate, wherein
the lower surface
of the base plate and the upper surface of the substrate have complimentary
fiber-engaging
strips engageable and disengageable one strip with another. Disengagement of
the strips
allows for the substrate to be discarded when required and replaced with
another substrate.
This negates the need to discard the full trowel with a significant saving in
monetary cost and
inconvenience.
Accordingly, the invention provides in one aspect a universal trowel
comprising
(a) a handle means;
(b) a planar base plate having an upper face and a lower face, and affixed
to said handle at said upper face;
(c) a substrate having a top surface and a bottom surface;
(d) retaining means affixing said top surface to said base plate lower face;
characterized in that said retaining means comprises engageable and dis-
engageable adhering member means.
Preferably, the adhering means comprises fiber-engaging member means, which
are
repeatably engageable and disengageable one member to another member.
In one aspect, the invention provides a trowel as hereinabove defined wherein
said
adhering means comprises
(i) a first retainer member having a first surface and a second surface,
wherein (a)
said first surface is adhered to and covers in whole or in part said lower
face of said base
plate, and (b) said second surface comprises a fiber-engageable face; and
(ii) a second retainer member having (a) a first surface adhered to said
substrate
top surface, and (b) a fiber-covered second surface, whereby said fiber-
engageable surface of
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said first retainer member and said fiber-covered second surface of said
second retainer
member are each adherably engageable with and disengageable from the other.
In an alternative aspect, the invention provides a trowel as hereinabove
defined
wherein said adhering means comprises
(i) a first retainer member having a first surface and a second surface,
wherein (a)
said first surface is adhered to and covers in whole or in part said lower
face of said base
plate, and (b) said second surface comprises a fiber-covered second surface;
and
(ii) a second retainer member having (a) a first surface adhered to said
substrate
top surface, and (b) a fiber-engageable second surface; whereby said fiber-
engageable second
surface of said second retainer member and said fiber-covered second surface
of said first
retainer member are each adherably engageable with and disengageable from the
other.
The first and second retainer members are preferably planar.
Preferably, in a further embodiment the invention provides a trowel wherein
said
lower face of said base plate is adhered to a plurality of said first retainer
members.
In preferred embodiments, the substrate top surface is adhered to a plurality
of said
second retainer members.
In alternative embodiments, the substrate of the trowel is of a size and shape
as to
overlap all or a part of at least one edge of said planar base plate.
The replaceable substrate may be selected from, but is not so limited, to
units for use
as grouting, sponge sanding, glue, plaster, "thin set", concrete and scrubbing
trowels.
In a preferred aspect, the invention provides a grout trowel assembly wherein
the
substrate is a replaceable soft pad unit, comprising in combination
(A) a handle;
a planar base plate having an upper face and a lower face and affixed to said
handle at said upper face;
a base plate retainer member having (i) a first surface adhered to and
covering
in whole or in part said lower face of said base plate, and (ii) a second
surface; and
(B) a replaceable soft pad unit comprising
a soft pad member having a pad top surface and a pad bottom surface; and
a pad retainer member having (i) a first surface adhered to and covering in
whole or in part said pad top surface, and (ii) a second surface comprising
adhering means.
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Preferably, an assembly as hereinabove defined has said base place retainer
member
second surface adhering means and said pad retainer member second surface
adhering means
adapted to cooperate in operable engagement and disengagement.
Preferably, the assembly as hereinabove defined has said base plate retainer
member
second surface adhering means comprising fiber-engaging means.
The base plate preferably has the retainer member second surface adhering
means
comprising fiber-covered surface.
In further embodiments, the assembly has said substrate second surface
adhering
means comprising a fibered-covered surface.
In preferred embodiments, the assembly has said substrate second surface
adhering
means comprising fiber-engaging means.
In a further aspect, the invention provides a replaceable substrate unit
adapted to
cooperate in operable engagement and disengagement with said base plate
retainer member
second surface adhering means.
Preferably, the replaceable substrate unit as hereinabove defined has said
second
surface adhering means adapted to cooperate in operable engagement and
disengagement
with complementary adhering means.
Preferably, the replaceable substrate unit as hereinabove defined has said
second
surface adhering means comprising fiber-engaging means.
Preferably, the replaceable substrate unit as hereinabove defined has said
second
surface adhering means comprising fiber-engaging means.
The replaceable substrate unit as hereinabove defined is preferably planar,
which may
cover in whole or in part said pad top surface; and comprise a plurality of
said substrate
retainer members.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be better understood, preferred embodiments
will
now be described, by way of example only, wherein:
Fig. 1 is a perspective view of a grouting pad trowel according to the prior
art;
Figs. 2 and 3 are perspective views of a grouting pad trowel, in an engaged
and
disengaged assembly combination, respectively, according to the invention;
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Fig. 4 - 9 are perspective views of alternative embodiments of a universal
trowel
according to the invention; and wherein the same numerals denote like parts.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Fig. 1 shows generally as 10, a trowel having a rectangular metal planar base
place 12
having an upper face 14 and a lower face 16 affixed to a handle 18 at upper
face 14 by screws
(not shown). Lower face 16 is permanently affixed by an adhesive layer (not
shown) to the
upper face 20 of a soft pad member 22.
Figs. 2 and 3 show generally as 30 and 40, respectively, a grout trowel
assembly in an
engaged and a disengaged combination, respectively.
Lower face 16 of base place 12 has a plurality of planar, rectangular fiber-
engaging
fiber strips 32 suitably located at peripheral portions of face 16. A
preferred strip 32 is
formed of VELCRO fiber-engaging material, permanently affixed to face 16 by a
suitable
bonding adhesive.
Upper face 20 of pad 22 also has a similar plurality of planar, rectangular.
strips 42 of
VELCRO material suitably located on and bonded to face 20 as to be operably
engageable
and disengageable with strips 32.
The shapes, thicknesses, sizes, numbers and locations of strips 32 and
cooperable
opposing strips 42 may be suitably varied, if desired. The shapes, sizes and
numbers of fibers
per unit area of strips 32, 42 are such as to effect sufficient engagement
with opposing fibers
of the opposing strip as to permit manual use of the assembly for its rubbing
and cleaning
duty on and between the tiles to be cleaned. However, the engagement between
strips 32, 42
should not be too strong as to prevent disengagement of strips 32, 42 by
vertically manually
pressing base plate 12 from pad member 22. Aforesaid VELCRO fiber material of
strips
32, 42 is most satisfactory in providing the desired and required engagement-
disengagement
physical properties.
In operation, when pad 22 has been sufficiently worn as to be replaced,
disengagement from base plate 12 is effected and a new pad 22 engaged.
Analogous embodiments are constructed as described below.
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Fig. 4 shows generally as 50 a trowel having metal planar base 12 with upper
face 14
affixed to handle 18. Lower face 16 of base plate 12 has the plurality of
fiber strips 32
bonded to face 16 as described with reference to Fig. 2.
However, in this embodiment Fig. 4 has soft pad member 22 of Fig. 2
substituted with
rectangular shaped float substrate 52 of a thermoplastic foam in the
embodiment shown.
Alternative materials for float member 52 are wood and rubber. Upper face 54
of member 52
has a plurality of planar, rectangular strips 42 of VELCRO material suitably
located on and
bonded to face 20 as to be operably engageable and disengageable with strips
32.
Fig. 5 describes generally as 60 a sponge sanding trowel having a replaceable
sponge
substrate 62 impregnated on its lower face 64 and sides 66 with particulate
grit 68.
Fig. 6 describes generally as 70 a glue trowel having a rectangular planar
metal
substrate 72 having an array of horizontal co-planar teeth 74, by which glue
may be suitably
spread on a floor, ceiling, wall and the like.
Fig. 7 describes generally as 80, a trowel having a plastics or wood
rectangular planar
substrate 82 for spreading and smoothing plaster, drywall, stucco or cement
compounds.
Fig. 8 describes generally as 90, a trowel for use with thin-set mortar, i.e.
bonding
cement having a rectangular planar metal or plastics substrate 92 having an
array of
horizontally aligned co-planar rectangular teeth 94 by which the bonding
cement is applied
and suitably spread.
Fig. 9 describes generally as 100, a scrubbing trowel having a rectangular
planar
abrasive substrate 102 formed of a scouring wire or plastics fibre for
scrubbing walls, floors,
countertops and the like.
Although this disclosure has described and illustrated certain preferred
embodiments
of the invention, it is to be understood that the invention is not restricted
to those particular
embodiments. Rather, the invention includes all embodiments, which are
functional or
mechanical equivalence of the specific embodiments and features that have been
described
and illustrated.
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