[0001] The subject of the invention is a putty knife intended for use in construction works,
such as filling and smoothing of missing wall materials, initial surface levelling
or surface cleaning by coating removal. Putty knives are also used in finishing works,
mainly at the stage of the final application, modelling and final surface levelling.
[0002] A solution described in
FR2969192B1 is known in the field, which discloses a blade for coating and application, with
a catching unit containing a support forming the working part together with the first
side and the second side, wherein the sides are tilted at an angle determined by the
user. The blade is removable and foldable, such that it forms the first side and the
second side, which is tilted at an angle set by the user, similar to the angle of
the supporting part. The first side of the catching unit is placed on the outer side
of the product applying blade. The second side of the catching unit fixes the second
side of the blade. The second side of the blade is used to apply the product.
[0003] Another solution is known from the
FR3020389 document, which discloses a tool including an elongated smoothing element intended
for spreading and smoothing of render and a support, to which the elongated smoothing
element is attached. The support includes a part intended for affixing a holder including
two chucks intended for clamping the affixing part. The chuck is provided with functional
elements intended for moving the chuck, once attached. These elements adapted to connecting
or moving the chucks remotely, while the affixing part has a circular cross-section
in a plane virtually perpendicular to the length of the blade.
[0004] Another solution is known from the international application
WO0032893, which discloses a smoothing rack intended for attachment on an elongated handle,
one end of which is provided with a cylindrical head supporting the blade. The head
is provided with a flange and a lever arm on one end, intended for connection with
the handle, and a pair of strictly opposite pads and a rotating pin on the other end,
intended for coupling with the blade supporting plate. The support catching the base
of the blade is attached to the supporting plate. The plate is wide and flexible,
and protrudes away from the support, at a right angle to the longitudinal axis of
the knife handle. The blade is curved away from the blade support at a right angle,
such that the plane of the working edge of the blade is parallel to the longitudinal
axis of the handle.
[0005] The next known solution comes from the European patent
EP2471608, which discloses a putty knife with a rear part for fixing a handle, a blade handle
and a blade, wherein the blade is made of a thermoplastic polymer with hardness between
45 and 75 degrees in the Shore scale. The thermoplastic polymer is selected from thermoplastic
polyurethanes and thermoplastic olefin polymers. Rigid plastics include high-density
polyethylene, polypropylene or PVC. Two sides of the blade are smooth surfaces used
to smooth varnish coatings.
[0006] The objective of the invention is to provide an economic model of a construction
putty knife, the working elements of which, subject to natural wear and tear, may
be fully replaced and their design includes as small number of elements as possible.
The main design element according to the invention is a blade with an assembly profile.
The design of the putty knife according to the invention is intended to be disassembled
to the maximum possible degree. The ability to remove individual design elements was
ensured by the use of an assembly kit in the form of a bolt with a butterfly nut,
with the kit directly cooperating with openings provided in the main elements of the
putty knife design. This design solves the main problem with previously known solutions
- mitigates the issue of spare parts unavailability to the minimum degree.
[0007] According to the invention, the construction putty knife. Includes a metal blade
and a handle placed inside a connector, wherein the connector is an angle-adjusted,
removable connection between the handle and the fixing profile, in which the working
blade is placed.
[0008] According to the invention, the construction putty knife is characterised in that
the connector includes a support, which is flat in the connection area with the flat
profile fixing the blade, where the support is connected to the blade fixing profile,
using connectors. The connector is provided with a socket with an opening for the
element connecting the connector with the handle. The handle is provided at the end
with a socket cooperating with the connector socket using a connecting element. Sockets
are provided with complementary, radial protrusions at cooperating contact surfaces
of these sockets.
[0009] According to the invention, the radial protrusions at the socket contact surfaces
preferably have triangular cross-section.
[0010] According to the invention, the putty knife support is preferably provided with stiffening
elements in the form of ribs.
[0011] According to the invention, the putty knife support preferably has an aperture intended
to introduce the fixing profile.
[0012] According to the invention, the construction putty knife is provided with connecting
elements, preferably bolts with butterfly nuts.
[0013] According to the invention, the blade fixing profile and the connector are preferably
provided with at least two cooperating openings.
[0014] Thanks to the use of universal sizes of the assembly openings and the elements of
the assembly kit, the putty knife according to the invention is a flexible construction
tool. The blade, namely the part subject to natural wear and tear, is removable and
can be fully replaced. A blade with a specific length may be replaced with a longer
or a shorter blade, as necessary. The other part of the putty knife comprising an
adjustable connector and a handle is a reusable tool, with the option of replacing
only the used blade is provided. The universal sizes as well as the ability to adjust
the angle at which the putty knife handle is set against the connector with a fixed
blade, allows adjustment of the angle o incidence of the putty knife against the wall,
onto which the filler coat is applied using the putty knife. This enables the use
of a long putty knife handle for application of the coat at high parts of the walls,
which require adjustment of the angle between the handle and the putty knife blade
plane in order to achieve the correct angle of incidence of the putty knife blade
against the wall. In the previously known solutions, the putty knife modules include
a set of permanently connected elements, such as the blade and the handle, for which
the connector with the handle is an additional accessory.
[0015] The use of the construction putty knife according to the invention also allows the
blade itself to be executed as a replaceable element, wherein it is a consumable part
requiring less material than the entire putty knife. The replacement cost of the blade
itself is significantly lower than the purchase of the complete putty knife, in which
various connectors were an additional, functional accessory. In addition, the metal
blade and the assembly kit made of metal make the design eco-friendly, as a product
fully recyclable after blade replacement.
[0016] The design of the putty knife according to the invention additionally enables the
use of a varied length handle with the option of changing the angle of incidence against
the rendered surface by loosening the connecting screw, rotation on the radial protrusions
of the sockets and connecting the sockets together again with the blade in the new
position.
[0017] The object of the invention is presented in an embodiment in the attached drawing,
in which individual figures of the drawing represent as follows:
- Fig. 1 -
- a connector including a support with the assembly aperture, the head and reinforcing
ribs,
- Fig. 2 -
- a connector according to Fig. 1 in a different embodiment,
- Fig. 3 -
- a blade with a fixing profile, in a side view, according to the blade plane,
- Fig. 4 -
- a blade with a fixing profile, in a top view,
- Fig. 5 -
- the construction putty knife in an axonometric view,
- Fig. 6 -
- a complete putty knife, in a side view,
- Fig. 7 -
- a putty knife in a bottom view,
- Fig. 8 -
- the head placed inside the handle, when looked towards the radial protrusions,
- Fig. 9 -
- the head placed inside the handle, in an axonometric view,
- Fig. 10 -
- the head placed outside the handle, when looked towards the radial protrusions,
- Fig. 11 -
- the head according to Fig. 10 viewed from the other side,
- Fig. 12
- -the head placed on the putty knife handle, in an axonometric view.
[0018] Fig. 1 and Fig. 2 present the connector 4, comprising an element connecting the blade
2 shown in Fig. 3 and Fig. 4 with the handle 3, the end part of which is shown in
Fig. 8 to Fig. 12. These Figures show only the part of the handle 3 cooperating with
the connector 4 because of the fact that one of the tasks of the invention is to use
the handle 3 with a significant length, enabling the use of the putty knife at higher
parts of walls of a building without the use of a ladder. Thus, the Figures show only
the part of the handle 3 cooperating with the connector 4 in order to clearly present
the unit connecting the connector 4 with the handle 3.
[0019] The work of a putty knife at various heights using the handle 3, the length of which
may be variable or which may be held by the operator at various levels, within a wide
range of heights, requires the blade 2 of the putty knife to be always set at the
same or a similar angle against the wall in order to achieve the required quality
of the render. Thus, when working on different heights, the angle at which the connector
4 with the fixing profile 5 fixing the blade 2 placed on it against the handle 3 must
be different, according to the length of this handle 3 or to the level at which it
is held by the operator.
[0020] Thus, a system of cooperating sockets 9.1 and 9.2 is provided in the solution according
to the invention, at the point of connection between the handle 3 and the connector
4. Sockets 9.1 and 9.2 are provided on cooperating surfaces with complementary, radial
protrusions 12 shown in Fig. 1, Fig. 2, Fig. 8 and Fig. 10 to Fig. 12. Once the connecting
element 11 in the form of a bolt with a butterfly nut is loosened, the protrusions
12 enable to change the angle between the handle 3 and the connector 4, and finally,
between the plane of the blade 2 and the wall, and after tightening this connecting
element 11, they enable restoration of a stable connection between these two elements
9.1, 9.2, but at a different angle,
[0021] Fig. 3 and Fig. 4 show the blade 2 of a construction putty knife fixed permanently
inside the fixing profile 5. The blade 2 is usually made of flexible steel sheet enabling
adaptation of the edge spreading the rendering mass on the wall in order to achieve
a smooth effect. The blade 2 is provided with openings 14 in the fixing profile 5,
as shown in Fig. 4, in order to facilitate blade attachment in the manual handle,
not shown in these Figures, or to the (not shown in the Figures) support 6 of the
connector 4. Openings 14 in the fixing profile 5 cooperate with openings 14 in the
support plate 6, shown in Fig. 1 and Fig. 2. In this embodiment, attachment involves
screwing the fixing profile 5 with the blade 2 to the support 6 of the connector 4
using connecting elements 8 in the form of bolts with butterfly nuts. This is shown
in Fig. 5 and Fig. 6, as well as in Fig. 7, in a view towards the bottom surface of
the blade 2.
[0022] The support 6 is shown in the attached Fig. 1 and Fig. 2, in two embodiments. In
both embodiments, it comprises a flat element, to which the blade 2 fixed permanently
in the fixing profile 5 is attached, as shown in Fig. 3 and Fig. 4. Openings 14 are
made in the support 6, corresponding to openings 14 in the fixing profile 5 shown
in Fig. 4. This flat element provided as support 6 is provided with stiffening ribs
7 shown in Fig. 1, Fig. 2 and Fig. 5. In other example embodiments, if the replaced
support 6 is made of a different material, not shown in the attached figure, it may
not require the use of ribs 7. In the described embodiment, the support plate 6 is
provided outside the ribs 7 with a circumferential stiffening 16 of two side edges,
as well as of the rear edge, to which the socket 9.1 of the connector 4 is attached.
[0023] Fig. 1 and Fig. 2 show two different embodiments of the support 6. The embodiment
of the support 6 in Fig. 1 is characterised in that the support panel 6 is provided
with an aperture 13, into which the fixing profile 5 with the blade 2 is placed between
placement inside the openings 14 of the connecting elements 8 provided as bolts with
butterfly nuts, connecting the blade 2 with the connector 4. On the other hand, in
the case of the support 6 presented in Fig. 2, the plate of the support 6 is not provided
with an aperture 13 and in this embodiment of the construction putty knife 1, with
the fixing profile 5 with the blade 2 screwed on to the plate of the support 6 through
the openings 14, from the bottom side, using the aforementioned bolts.
[0024] The removable connections of the construction putty knife 1 use connectors 8 and
11 in the form of bolts with butterfly nuts. This is shown in Fig. 5. Such connections,
with precisely tightened nuts, are stable connections, at the sme time easy to loosen
in order to change the angle between the plane of the support 6 and the handle 3,
followed by stabilisation of this connection by re-tightening of the connecting element
11. On the other hand, the connecting elements 8 in the form of bolts with butterfly
nuts enable easy replacement of a fixing profile 5 with a blade 2 without a use of
tools, with a new and identical part, or with a fixing profile 5 with a blade 2 of
a different type, for example with a blade 2 with a different length, if necessary.
[0025] Fig. 5, Fig. 6 and Fig. 7 present a complete, assembled construction putty knife
1 according to the invention. These figures show connected and cooperating surfaces
of the socket 9.1 of the connector 4 and of the socket 9.2 of the handle 3, according
to Fig. 1 and Fig. 2. The connection between surfaces 9.1 and 9.2 is particularly
shown in Fig. 5 and Fig. 7. Fig. 6 shows that the support 6 is flat within the area
of connection with the flat fixing profile 5 of the blade 2.
[0026] The subsequent Figs. 8 to Fig. 12 show the end of the handle 3 in two embodiments.
Fig. 8 and Fig. 9, the hand 3 has a larger diameter and the invisible here pin of
the socket 9.2 is placed inside the tube comprising the handle 3. This solution may
be used with a shorter handle 3, thus with a smaller total weight. If the handle 3
is longer than 1.5 metre, however, its total weight is excessive and its diameter
has to be decreased in order to decrease the overall weight. This requires the use
of a socket 9.2 with a clamp 15 including the handle 3 inserted inside the clamp 15.
This is shown in Figs. 10 to Fig. 12.
[0027] The attached figures show that complementary radial protrusion 12 are provided on
the cooperating surfaces of the socket 9.2 of the handle 3 and of the socket 9.1 of
the connector 4. This means that once the socket 9.1 shown in Fig. 1 and the socket
9.2 shown in Fig. 9 are combined and once the connection is tightened using the connecting
element 11 in the form of a screw with a butterfly nut, as shown in Fig. 5 and Fig.
6 and Fig. 7, the radial protrusions 12 with a triangular cross-section mesh and complement
one another, forming a cohesive and detachable connection. The connecting element
11 is passing through the openings 10 in the sockets 9.1 and 9.2. When the connecting
element 11 is loosened, the connection can be disconnected and the handle 3 may be
rotated around the connector 4 in order to achieve a different angle between the handle
3 and the blade 2 attached to the support 6. The connection of both those elements
is then fixed at the adjusted angle, by pressing both sockets 9.1 and 9.2 together
using the connecting element 11 in the form of the aforementioned screw with a butterfly
nut, passing through openings 10 in the sockets 9.1 and 9.2.
Designations used in the figures
[0028]
- 1.
- Putty knife
- 2.
- Blade
- 3.
- Handle
- 4.
- Connector
- 5.
- Fixing profile
- 6.
- Support
- 7.
- Stiffening rib
- 8.
- Connecting element
- 9.1.
- Socket
- 9.2.
- Socket
- 10.
- Opening
- 11.
- Connecting element
- 12.
- Radial protrusion
- 13.
- Aperture
- 14.
- Opening
- 15.
- Clamp
- 16.
- Circumferential stiffening
1. A putty knife with a metal blade and a handle placed in a connector, wherein the connector
is a detachable connection with an adjustable angle between the handle and the fixing
profile, in which the working blade is placed, characterised in that the connector (4) is provided with a support (6), which is flat in the area of the
connection with the flat fixing profile (5) of the blade (2), wherein the support
(6) is connected with the fixing profile (5) of the blade (2), using connecting elements
(8), wherein the connector (4) includes a socket (9.1) with an opening (10.1) for
the fixing element (11) of the connector (4) with the handle (3), while the handle
(3) is provided at the end with a socket (9.2) cooperating with the socket (9.1) of
the connector (4) via a connecting element (11), wherein the sockets (9.1,9.2), are
provided with complementary radial protrusions (12) on cooperating contact surfaces
of those sockets (9.1,9.2).
2. A putty knife according to Claim 1, characterised in that the radial protrusions (12) have triangular cross-section at the contact surfaces
of the sockets (9.1,9.2).
3. A putty knife according to Claim 1, characterised in that the support (6) included stiffening elements provided as ribs (7).
4. A putty knife according to Claim 1, characterised in that the support (6) is provided with an aperture (13) for insertion of the fixing profile
(5).
5. A putty knife according to Claim 1, characterised in that the fixing elements (8,11) are provided as bolts with butterfly nuts.
6. A putty knife according to Claim 1, characterised in that the fixing profile (5), the blade (2) and the connector (4) include at least two
cooperating openings (14) each.