[0001] The present invention relates to a machine for colouring miscellaneous articles of
leather and leatherette.
[0002] In particular, the present invention finds application in the field of colouring
of the side edge of various articles, for example small leather items such as details
for bags, saddlery or edges of shoe soles, shoe uppers, for colouring briefcases,
purses and wallets, watch straps and irregularly shaped objects made of leather or
leatherette, and having indentations or elbows to be coloured.
[0003] Generally, leather or leatherette products undergo a colouring process, and finally
a drying process to fix the colour.
[0004] The machines for colouring similar articles can be in line systems, comprising consecutive
processing stations, or single machines with which the operator must interact directly.
[0005] In other words, for the colouring of small products or details of leather or leatherette,
it is preferable to use machines comprising a colouring unit mounted on a body containing
a driving engine.
[0006] The colouring unit comprises a colouring roller having a cylindrical shape, rotatable
about a preferably vertical axis. The colouring roller, properly fed with liquid colour,
spreads a uniform layer of dye on the article which the operator approaches.
[0007] Under the colouring roller, there is a tray collecting the collecting the colour,
fixed to the colouring unit by screws.
[0008] In fact, the colour is poured directly inside the tray and a colour transport device,
such as a screw conveyor, a suction pump system connected to a diffuser nozzle or
a pad (as already known in
patent WO 99/57327), draws the colour directly from the tray to pour it on the colouring roller. The
colour is distributed on the surface of the colouring roller, falling by gravity from
above or sprayed through a nozzle directly to the whole surface of the roller.
[0009] The excess liquid, which is not transferred on the product, drips from the roller
and is recovered into the appropriate tray.
[0010] A scraper or doctor blade evenly distributes the colour on the entire surface of
the colouring roller to avoid excessive colour deposits in discrete points of the
product.
[0011] The skill and experience of the operator, who transfers the product appropriately,
contribute to an optimal distribution of the liquid colour on the product surface
and to avoid unsightly accumulations.
[0012] In known machines, in fact, the doctor blade and the transport device are placed
at the sides of the roller, or one behind and the other laterally, creating in each
case a certain encumbrance around the colouring head. Therefore, despite the operator's
ability, ease of interaction with the machine is limited by the presence of the doctor
blade and the device for transporting the colour, which reduce the area available
for the operator to manoeuvre the product.
[0013] Moreover, the doctor blade is generally made with flat bristles, like the head of
a brush. Due to this, the realization of scrapers suitable to be coupled to rollers
having special shapes is difficult.
[0014] After the colouring process, finally, it is necessary to wash thoroughly all the
parts that have come into contact with the colour, so that they can be used later
also with different colours and avoiding colour changes with alteration of pigmentation.
[0015] Therefore it is necessary to clean also the doctor blade and the device for transporting
the colour. The more pieces are present, the greater the time required for removing
the colouring unit and washing each component. What has just been described makes
clear the need to provide a machine for colouring miscellaneous articles of leather
and leatherette that is able to overcome the above-described drawbacks.
[0016] The object of the present invention is to provide a machine for colouring miscellaneous
articles of leather and leatherette which overcomes the drawbacks of the described
prior art.
[0017] Another object of the present invention is to present a machine for colouring miscellaneous
articles of leather and leatherette which has a large working area free of components
that may interfere with the colouring operations and hinder the free movement of the
product by the operator.
[0018] A further object of the present invention is to provide a machine for colouring miscellaneous
articles of leather and leatherette which avoids long downtime.
[0019] Lastly, an object of the present invention is to propose a machine for colouring
miscellaneous articles of leather and leatherette that has a limited number of components
to be washed at the end of the colouring process.
[0020] These and other objects are substantially achieved by a machine for colouring miscellaneous
articles of leather and leatherette as described in one or more of the appended claims.
[0021] Further features and advantages will become clearer from the detailed description
of a preferred and non-limiting embodiment of a machine for colouring miscellaneous
articles of leather and leatherette according to the present invention.
[0022] This description is provided with reference to the accompanying figures, also provided
only by way of a non-limiting example, wherein:
- Figure 1 is a perspective view of a machine for colouring miscellaneous articles of
leather and leatherette as described and claimed in the present invention;
- Figure 2a is a perspective view of a colouring unit, belonging to the machine illustrated
in Figure 1, represented in non-operative position and according to a first configuration;
- Figure 2b is a perspective view of a colouring unit, belonging to the machine illustrated
in Figure 1, represented in non-operative position and according to a second configuration;
- Figure 3 shows a perspective view of a detail of the machine object of the present
invention, specifically the magnification of the colouring unit;
- Figure 4 shows a rear view of the machine object of the present invention with some
removed parts to be able to view the otherwise hidden interior;
- Figures 5 and 6 show the machine object of the present invention with the colouring
unit in two different positions;
- Figure 7 shows a magnification of a detail of the machine object of the present invention.
[0023] The numeral 1 globally indicates a machine for colouring miscellaneous articles of
leather and leatherette.
[0024] The machine 1 for colouring miscellaneous articles of leather and leatherette comprises
a colouring unit 2 and a supporting frame 3 for the colouring unit 2.
[0025] The supporting frame 3 also acts as a housing for a driving system 4, for example
an engine adapted to actuate the colouring unit 2.
[0026] The colouring unit 2 comprises a colouring head 5, adapted to apply by contact a
liquid layer of colour directly on the detail to be treated.
[0027] Below the colouring head 5, the unit 2 comprises a tray 6 for collecting colour within
which the colour used for the colouring of the product is contained.
[0028] The tray 6 serves both to contain the colour that is to be transferred on the colouring
head 5, and to collect the colour that falls from the colouring head 5 during the
colouring of the article to be treated.
[0029] The colour is transferred from the tray 6 to the colouring head 5 through a device
7 for transporting and dosing the colour, which will be described later.
[0030] The colouring head 5 is a roller, rotatable about a preferably vertical axis of rotation
5a that coincides with its own axis of symmetry.
[0031] The roller 5 has a conical or frusto-conical shape. Advantageously, the tip 51 or,
in case of frusto-conical shape, the smaller base 52 of the roller can be turned downwards.
Consequently, in both cases, the larger base 53 is facing upward. The roller 5 may
have an outer side surface 5b having different geometries.
[0032] The outer side surface 5b is obtained by rotating a right-angled triangle about one
of the cathetuses. Depending on whether the hypotenuse is rectilinear or has a concave
or convex shape, it is possible to have different geometries of the outer side surface
5b, while always maintaining the conical or frusto-conical geometry.
[0033] The conical or frusto-conical shape with the tip 51 or the smaller base 52 facing
downwards preferably improves the visibility of the working area L, in that the source
of light that comes from above does not create shadow zones.
[0034] Advantageously, the lighting is represented by an illumination source 16 placed vertically
on the working area L with a diffusion that completely surrounds the colouring roller
5. Preferably, a plurality of LEDs positioned around the perimeter of the colouring
roller are used. The layout and the type of lighting enhance the ergonomic aspect
for the operator.
[0035] The tip 51 or the smaller base 52 of the colouring roller 5 are completely contained
within the tray 6 for collecting colour.
[0036] The tray 6 for collecting colour is movable relative to the colouring head 5, in
such a way as to be easily moved away from the latter in order to allow emptying.
[0037] The tray 6 can be vertically translatable or rotatable, in both cases towards or
away with respect to the colouring roller 5.
[0038] In the appended figures, only the latter configuration was represented, without any
intention to exclude also the first solution with a translatable tray. As can be seen
in Figures 2 and 3, the tray 6 for collecting colour has a side 6a hinged along a
horizontal axis 3a parallel to a front wall 31 of the frame 3, to which the colouring
unit 2 is connected.
[0039] The side 6a around which the tray 6 is pivoted is the rear side of the tray and is
adjacent to the front wall 31 of the frame 3.
[0040] The tray 6 is movable rotatably with respect to such horizontal axis 3a between a
working position (Figures 1 and 5) in correspondence of which it is arranged horizontally
and contains the colouring roller 5, and an emptying position (Figures 2 and 6) in
correspondence of which it is rotated about the horizontal axis 3 of hinging and is
inclined downwards, away from the colouring roller 5. The arrow F in Figure 6 illustrates
the direction of rotation.
[0041] Advantageously, the tray 6 may present in the front, in the opposite position to
the hinging side 6a, 6b, a spout in such a way as to create a guide to facilitate
the discharge of the residual colour when the tray is in the emptying position.
[0042] The rotation of the tray and the front spout part 6b make the emptying of the colouring
liquid at the end of work both quick and easy. Advantageously, the colouring unit
2 can comprise a basin 8, preferably disposable and insertable within the tray 6.
[0043] The basin 8 is supported inside the tray 6 without particular constraints, in such
a way as to be easily removed at the end of work.
[0044] The basin 8 has substantially the same internal shape of the tray 6 with which it
is coupled.
[0045] The colour can be physically collected inside the tray 6 or inside the basin 8, so
as to leave the tray 6 clean. In this case, there is a significant improvement in
terms of cleanliness and greater speed to perform the washing operations at the end
of the job, or to change the type of liquid. The presence of the basin 8 prevents
the tray 6 from being affected by the colour, so as to remain clean and to avoid having
to disassemble and wash it.
[0046] The basin 8 with the residual colour can be easily removed from the tray 6 and washed,
if required, or thrown away.
[0047] The liquid colour is taken from the tray 6 or from the basin 8 to the colouring head
or roller 5 by the mentioned device 7 for transporting and dosing.
[0048] Such a device 7 for transporting and dosing the colour comprises a colour feed channel
9 inside which the liquid colour flows.
[0049] The feed channel 9 is placed behind the roller 5, in the opposite position to the
working area L at which there is contact between the roller 5 and the article to be
coloured. Advantageously, the feed channel 9 comprises a first end 9a and a second
end 9b, opposite to the first and positioned at the top, then close to the larger
base 53 of the colouring roller 5. The feed channel 9 is disposed almost horizontally,
with a slight downward inclination, so that the liquid colour coming from the first
end 9a, placed higher, flows by gravity towards the second end 9b, placed lower.
[0050] Once arrived on the top 53 of the conical or frusto-conical roller 5, the colour
always flows downwards by gravity. The rotation of the roller 5 around its vertical
axis of rotation 5a causes the complete fouling of the entire outer side surface 5b
of the roller 5.
[0051] Advantageously, the device 7 for transporting and dosing the colour also comprises
a scraper or doctor blade 10.
[0052] The doctor blade 10 is positioned below the feed channel 9 and is coupled to the
colouring roller 5 so as to follow its side profile.
[0053] The doctor blade 10, in fact, serves to dose the liquid colour on the surface of
the roller 5: cooperating with the rotation of the roller 5 about its axis 5a, the
doctor blade 10 distributes the colour uniformly over the entire outer side surface
5b of the colouring roller 5 and avoids localized excesses of colour.
[0054] The doctor blade 10 is preferably made of hard but flexible plastic material which
functions as a spatula.
[0055] The doctor blade 10 is positioned immediately below the feed channel 9, occupying
in projection, on a horizontal plane, the same rectilinear space of the feed channel
9.
[0056] The doctor blade 10 and the feed channel 9 have reduced size and volume: in fact,
they are contained in the same component placed in line just behind the roller 5,
in the opposite position to the working area L inside which contact between the roller
and the article made of leather or leatherette to be coloured occurs.
[0057] In this way there is no interference between this component and the working area
L, which remains completely free to give the operator the maximum freedom of movement
of the product during the colouring step. The device 7 for transporting and dosing
the colour also comprises a transport element 11 adapted to remove the colour from
the tray 6 or from the basin 8 to convey it to the colour feed channel 9.
[0058] In particular, the transport element 11 is a wheel or disc, rotatable about a horizontal
axis 11 a, that draws the colour from the tray 6 or from the basin 8 and brings it
at the top of the colour feed channel 9, pouring it in correspondence of the first
end 9a of the feed channel 9. Colour transport takes place simply by contact. Advantageously,
the device 7 for transporting and dosing the colour presents a system for fixing and
removing of the rapid type, for example magnetic. Specifically, the disc 11 can be
maintained in position by a magnetic coupling system which allows a quick removal
as well as a smooth engagement. Also the feed channel 9 can be placed in operative
position by means of a fixing and removal system of the rapid type.
[0059] Advantageously, the feed channel 9 may be formed integrally with the doctor blade
10 or may be applied on the latter or, vice versa, the doctor blade 10 may be applied
on the feed channel 9.
[0060] In the first case, that is, integrally made doctor blade 10 and feed channel 9, the
doctor blade may define a side edge of the feed channel 9. In the second case, it
can be placed also at a distance from the channel 10. It is still preferable that
the space occupied by the feed channel 9 and doctor blade 10 unit, in both possible
configurations, is less than 18% of the circumference of the colouring head 5.
[0061] In this way, the working area, clear for the operator, is very wide, without having
structural components scattered around the same colouring head 5. The transport element
11 is also placed behind the roller 5, and in particular behind the feed channel 9,
so as not to hinder any operational step. Advantageously, the transport element 11
is symmetrical with respect to the longitudinal axis of the feed channel 9 and placed
behind the latter.
[0062] Therefore, the whole device 7 for transporting and dosing has a very compact appearance
that groups together in line the feed channel 9 and the doctor blade 10 in a single
component. Moreover the compactness of the device 7 for transporting and dosing is
also given by the position of the transport element 11, symmetrical with respect to
the feed channel 9 and placed behind the latter.
[0063] Altogether, the device 7 for transporting and dosing occupies an optimal position
within the colouring unit 2 relative to the working area L, placed in front of the
roller, since it is placed exactly on the opposite side with respect to the axis 5a
of the roller 5, in the rear part of the roller. The doctor blade 10, the feed channel
9 and the transport element 11 are in a position opposite to the contact zone between
the roller 5 and the product to be coloured, so as not to hinder the movement of the
product around the roller 5.
[0064] The colours used are water-based, thus very sensitive to the ambient temperature
and to the degree of humidity.
[0065] To allow the use of the machine even in very hot areas, a protective screen 13 applicable
to the sides of the colouring roller 5 is provided, to leave uncovered only the working
area L.
[0066] In this way, the colour inside the tray 6 is protected from dust or any other foreign
body, in addition to being less subject to evaporation phenomena. Advantageously,
the temperature control and the protection provided by the protective screen 13 also
prevent the formation of a thickened colour film on the surface of the colour within
the same tray 6.
[0067] The formation of this film is very detrimental to the quality of the colouring because
it changes the percentage of concentration of colour compared to water and can generate
lumps in the colour, if crushed, with consequent problems of quality and appearance
of colour application on the product.
[0068] All this requires a downtime for colour cleaning.
[0069] The protective screen 13 is removable to be able to freely enter the colouring unit
2. It can be made of plastic material, preferably transparent, to be able to constantly
monitor the inside of the colouring unit 2.
[0070] The protective screen 13 protects the colour avoiding unnecessary waste and limiting
its evaporation so as to significantly reduce the downtime for the recovery of the
liquid during processing.
[0071] During the processing step, the detail to be coloured is moved by the operator's
hands and placed in front of the machine.
[0072] The height of the colouring unit 2 compared to the operator is therefore an important
factor for the ergonomics of the machine.
[0073] In known machines, the colouring unit is at a fixed and invariable height. This forces
the operator to find improvised solutions to bring the colouring unit 2 to its height,
or vice versa.
[0074] The colouring machine 1 object of the present invention is able to solve this drawback,
by providing a colouring unit 2 that can be adjusted in height.
[0075] The colouring unit 2 is slidably constrained to the supporting frame 3, to be able
to be moved vertically at will, until the optimal height is reached for the operator
who at that time must interact with the machine 1.
[0076] The frame 3 has, on its front wall 31, a linear sled 14 mounted in vertical position.
The colouring unit 2 can slide on this sled 14, so as to regulate the height position
of the unit 2 with respect to the front wall 31 of the frame 3.
[0077] Locking systems, not illustrated, are provided, which allow to fix the colouring
unit at the established height.
[0078] The colouring unit 2 is connected to the power supply engine 4 through a plurality
of components 15, such as return cylinders, tensioning rollers and a drive belt, which
ensure the constant contact with the same driving engine 4, at the same time allowing
the vertical translation along the sled 14.
[0079] The colouring unit 2 is completely dismantled for routine maintenance and a quick
wash.
[0080] The invention allows to achieve the intended purposes in addition to ensuring enormous
advantages.
[0081] The compactness of the device for colour transport and dosing allows to place the
device in a colouring unit in which it does not interfere with the operator.
[0082] The device for transport and dosing is placed behind the roller, leaving the working
area completely free. These components do not even interfere with the diffuse light
coming from above, avoiding the formation of shadow zones around the roller.
[0083] The compactness of the device for transport and dosing also limits the number of
components to be washed. In the prior art machines, in fact, the feed system and the
doctor blade are separate elements. The simplicity of the device for transport and
dosing also makes its cleaning and maintenance very simple.
[0084] Finally, downtimes are limited.
[0085] The material with which the doctor blade is made simplifies the realization of the
same according to different geometries that best fit the profile of the colouring
roller.
1. Machine for colouring miscellaneous articles of leather and leatherette comprising:
- a supporting frame (3);
- a colouring unit (2), supported by said frame (3) and comprising
- a colouring head (5) adapted for applying a layer of liquid colour directly in contact
with the article being processed,
- a tray (6) collecting the colour adapted for containing the colour to be deposited
in the article,
- a device (7) for transporting and dosing the colour on said colouring head,
- characterized in that said transport device (7) for transporting and dosing the colour comprises a colour
feed channel (9) having a doctor blade (10), coupled to said colouring head (5), placed
immediately below said feed channel (9).
2. Machine according to the preceding claim, characterized in that the space occupied by the feed channel (9) and the doctor blade (10) is less than
18% of the circumference of the colouring head (5).
3. Machine according to the previous claim, characterized in that said device (7) for transporting and dosing the colour comprises a transport element
(11) suitable to remove the colour from the tray (6) and to deliver it to the colour
feed channel (9).
4. Machine according to the previous claim, characterized in that said transport element (11) is a wheel, rotatable around a horizontal axis (11 a),
that draws the colour from the tray (6) and brings it at the top of the colour feed
channel (9).
5. Machine according to the previous claim, characterized in that said doctor blade (10) follows the side profile of said colouring head (5) such that
to uniformly deliver the dyeing liquid on the entire outer side surface (5b) of the
colouring head and to remove the possible excess liquid colour.
6. Machine according to one of the preceding claims, characterized in that said feed channel (9) is made in one piece with said doctor blade (10).
7. Machine according to one of the preceding claims, characterized in that said doctor blade (10) is preferably made of hard but flexible plastic material which
functions as a spatula.
8. Machine according to one of the previous claims, characterized in that said colouring head (5) is a conical or frusto-conical shaped roller having an axis
of symmetry coincident with an axis of rotation (5a), preferably placed in a vertical
position.
9. Machine according to one of the preceding claims, characterized in that said colouring head (5) with a conical or frusto-conical shape has a larger base
(53) facing upwards and a tip (51) or a smaller base (52) contained within said tray
(6) collecting the the colour.
10. Machine according to one of the preceding claims, characterized in that said tray (6) collecting the the colour is hinged along a horizontal axis (3a) parallel
to one front wall (31) of said supporting frame (3); said tray (6) being movable between
a working position at which it is arranged horizontally and contains the colouring
head (5), and an emptying position at which it is rotated around the hinging horizontal
axis (3a) and tilted downwards, away from the colouring head (5).
11. Machine according to the preceding claim, characterized in that said tray (6) has, at the portion that couples with the colouring head (5), a nozzle
(6b) in order to facilitate the emission of colour residue when the tray is in the
emptying position.
12. Machine according to the preceding claim, characterized in that said tray (6) comprises a basin (8) insertable therein.
13. Machine according to one of the previous claims, characterized in that it comprises a protective screen (13) applicable to the sides of the colouring head
(5) in order to protect the colour in the tray (6) and to limit its evaporation.
14. Machine according to any one of the preceding claims, characterized in that said colouring unit (2) is slidably constrained to said supporting frame (3).
15. Machine according to the preceding claim, characterized in that said colouring unit (2) is mounted on a linear sled (14) mounted in vertical position
on said supporting frame (3), so that said colouring unit (2) can be adjusted for
height.