FIELD OF THE INVENTION
[0001] The present invention refers to a machine for tile cutting, or tile cutter, provided
with an adjustable tool-carrier.
BACKGROUND
[0002] As known for some time, manual tile cutters occupy a very specialised sector, wherein
few manufacturers have the necessary expertise to manufacture improved cutting systems
which meet market requirements.
[0003] The manual tile cutters traditionally on the market consist of a base whereon a tile-resting
area is provided, wherefrom two end posts project which support one or two guiding
bars for a tool carrier. Said tool carrier is shaped to be able to slide freely on
the bars and generally has a handle portion and, below, an engraving tool (usually
comprising a wheel made of an extremely hard material) apt to engrave the tile.
[0004] The engraving occurs by pressure application by the operator, of the tool on the
tile.
[0005] In order to facilitate the next tile-breaking operation, i.e. separating the tile
along the engraving line, the base typically comprises a pair of floating plates on
both sides of a central longitudinal rib, arranged in a lowered position in correspondence
of the engraving line. Thereby, once the engraving has been completed, it is possible
to impart a pressure on the tile - with a suitable tile-breaking device integral with
the tool carrier - to bring it in abutment with the longitudinal rib and cause the
opening of the engraving.
[0006] Single-bar manual tile cutters are traditionally divided into so-called pull-type
or push-type machines, depending on the shape of the tool carrier which is intended
to perform the engraving while the user pulls or pushes it, respectively.
[0007] In the following of the description the pull-type machine will be addressed.
[0008] The shape of the tool carrier, in particular of the handle thereof, is defined by
taking into account rather stringent ergonomic requirements, since the operator must
be able to perform a traction and at the same time a forward torsion on the tool carrier
to be able to perform correctly the tile engraving. The shape and especially the inclination
of the handle of the tool carrier therefore play a very important role for the acceptance
by the user.
[0009] However, the ideal handle attitude is maintained only when design technical requirements
are met, i.e. when the thickness of tile matches the one considered during the design
phase. However, it is intuitive to realise that for all other tile thicknesses the
handle does not take on the ideal design attitude.
[0010] As a matter of fact, the attitude of the tool carrier during the engraving is determined
by two resting points, one defined by the engraving wheel on the tile top surface
and the other defined by a lower guiding wheel which rests on the lower edge of the
sliding bar. Clearly, if these two points come closer to each other (upon tile thickness
increase) or move away from each other (upon tile thickness decrease) a corresponding
variation of the inclination of the entire tool carrier and of the corresponding handle
is also determined.
[0011] Furthermore, there is to be noted that on the rear of the engraving tool (wheel)
- i.e. in the user's direction - there is normally provided an tile-breaking foot
integral with the tool carrier. When the tile is very thick, the inclination taken
up by the tool carrier can be such to cause the tile-breaking foot to come excessively
close to the tile, up to a measure which makes the machine unusable (beyond a certain
thickness, the tile-breaking foot and not the engraving tool would come in contact
with the tile). On the other hand, the tile-breaking foot cannot be mounted too high
either, because one could not manage to break small-thickness tiles. As a matter of
fact, with low-thickness tiles, the tile-breaking travel would become so large that
the handle of the tool carrier would end up interfering with the guiding bar before
the tile-breaking foot manages to rest on the tile.
[0012] In order to solve this problem, according to the prior art it has been suggested
to arrange a mechanism for the raising/lowering of the longitudinal guiding bar. Thereby,
the user can act to raise/lower the upper resting point of the tool carrier, i.e.
the resting point against the lower edge of the bar, and hence to restore the design
distance between the two resting points of the tool carrier, even in case of tile
thickness changes.
[0013] However, this solution provides to lessen somewhat the constraint between the bar
and of two end posts of the base, which makes the support structure labile. Therefore,
in order to avoid undesired plays in the machine, the sizing and stiffness thereof
must be increased, or complicated locking means must be provided, which affect negatively
machine weight and economy.
[0014] The object of the present invention is hence to solve the problems set forth above
without acting on the height adjustment of the longitudinal guiding bar.
[0015] Such object is achieved by providing a tool carrier for a tile-cutting machine which
has the innovative features set forth in their peculiar terms in the attached claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Further features and advantages of the device according to the invention will in
any case be more evident from the following detailed description of some preferred
embodiments of the same, given by way of example and illustrated in the accompanying
drawings, wherein:
fig. 1 is a perspective view with parts removed, of a first embodiment of the invention;
fig. 2 is an elevation side view of the sole tool-carrier of fig. 1;
figs. 3 and 4 are perspective views of a tool-carrier according to a further embodiment
similar to the one of fig. 1, in the engraving phase of a tile and of a thicker one,
respectively;
fig. 5 is an elevation side view, partly in section, of a third embodiment of a tool-carrier
according to the invention;
figs. 6 and 7 are perspective side and front views, respectively, of a fourth embodiment
similar to that of fig. 5; and
figs. 8 and 9 are elevation side and exploded views, respectively, of a further embodiment
similar to that of fig. 5.
[0017] Fig. 1 shows part of the components forming a tile cutter. It consists, in a manner
known per se, of a base 1 whereon a pair of support plates 2 are floatingly mounted.
At one end of the base there is rotatably mounted a scaled abutting square 3.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] At the two ends of base 1 there are further provided two posts 4 (fig. 1 shows one
only) which securely support a longitudinal guiding bar B. Bar B typically is a thin
elongated steel plate, having a rectilinearity and parallelism of the two opposite
sides suited to act as precise sliding guide for a tool carrier P.
[0019] Tool carrier P consists, in a manner known per se, of a main body 5, from the upper
portion whereof a handle 6 projects. The main body is shaped so as to precision-slide
along bar B, with a wide play in a vertical direction (i.e. on the lying plane of
bar B). Typically, body 5 has a through-cavity or slot 5a, which runs through it longitudinally,
within which bar B is intended to slide.
[0020] In the lower portion of body 5 the actual engraving tool 7 is mounted, typically
in the shape of a small hard-steel wheel. On the rear of tool 7 - i.e. in the direction
in which also handle 6 prolongs - a tile-breaking foot 8 is provided.
[0021] As stated, tool-carrier P can slide on bar B with a remarkable vertical play; the
limit of these displacements being determined, downwards, by an upper support wheel
9 and, upwards, by a lower support wheel 10.
[0022] Wheels or pins 9 and 10 run through main body 5 of tool-carrier P and are partially
housed within inner cavity 5a: thereby they are intended to cooperate with the upper
and lower edges, respectively, of guiding bar B.
[0023] In this embodiment there is furthermore a third support point, not visible in figs.
1 and 2, which consists of a front abutment block or pin, which is arranged inside
slot 5a, immediately above the position of tool 7.
[0024] Traditionally, the average distance between these upper and lower support points
is greater by 20 mm than the height of bar B. Thereby a freedom of vertical movement
of tool carrier P on bar B is guaranteed, which allows to cause the tool-carrier to
take up at least the two extreme attitudes of engraving and of tile-breaking.
[0025] In particular, by bringing fully forward handle 6 - i.e. according to arrow F - lower
wheel 10 is brought resting on the lower edge of the bar, which wheel acts as rearward
fulcrum to bring tool 7 in pressure on the top plane of an underlying tile. On the
contrary, by rotating backwards the handle (direction opposite to arrow F), the front
abutment block surface or pin (not shown) arranged immediately above tool 7 is brought
to rest on the lower edge of bar B, so as to cause it to act as forward fulcrum to
pressurise the rear tile-breaking foot 8 on the tile. Upper wheel 9 guarantees, in
this tile-breaking phase, a lower end-of-travel, so that the tile-breaking foot does
not drop excessively, which would cause tile shattering.
[0026] According to the invention, engraving tool 7 and lower support wheel 10 are mounted
relatively mobile with respect to each other in a substantially vertical direction,
so as to be able to adjust their mutual distance.
[0027] According to a first embodiment shown in fig. 1, lower support wheel 10 is rotatably
mounted at the lower end of a fork 11 outside body 5 of the tool carrier. The two
side walls or cheeks of body 5 further have, in correspondence of the position of
lower wheel 10, guiding slots 12 (fig. 2) wherein the rotation axis of wheel 10 can
slide in a guided manner.
[0028] Fork 11 ends above in a small block 11a which is constrained, free in rotation, to
a threaded stem 13. At the other end of threaded stem 13 there is integrally provided
a manoeuvring knob 14. Threaded stem 13 is furthermore engaged with a threaded hole
(not shown) obtained in a front protrusion 15 of handle P.
[0029] The engagement of stem 13 with protrusion 15 determines and maintains fixed the coupling
also of fork 11, and hence of wheel 10, with the tool-carrying body 5. By rotating
manoeuvring knob 14 a displacement of threaded stem 13 is determined with respect
to handle P and hence also a translation of wheel 10 inside its guiding slot 2.
[0030] By acting on knob 14 it is hence possible to adjust the mutual distance between support
wheel 10 and engraving tool 7, advantageously without affecting the mutual position
of tool 7 and tile-breaking foot 8. This makes it possible to reestablish the desired
attitude of the tool carrier based on the tile height to be engraved, i.e. based on
the distance which tool 7 takes up with respect to guiding bar B when it rests on
the tile, without this negatively affecting the operativity of tile-breaking foot
8.
[0031] Fig. 3 shows a tool-carrier according to an embodiment similar to the one just described.
The elements corresponding to the ones of fig. 1 have like reference numbers.
[0032] In this case, actuating fork 11' is shaped as a rocker arm and is hinged on a horizontal
pivot 11a' fixed with respect to the tool-carrier.
[0033] The operation principle is equivalent to the one described for the previous embodiment.
The rotation of knob 14 determines the displacement of threaded stem 13 and hence
of the end of the rocker-arm fork 11': a rotation about pivot 11a' is thus determined
which drops or raises the support wheel (not visible) carried at the lower end of
the rocker-arm fork 11'.
[0034] In fig. 3 it is shown that the distance between the lower edge of bar B and the tile
is of 4 cm and threaded stem 13 is substantially unthreaded, i.e. raised. In fig.
4 the tile is of a greater thickness and hence stem 13 has been threaded to lower
the upper end of the rocker-arm lever 11' and to raise the support wheel with respect
to engraving wheel 7.
[0035] Fig. 5 shows a third embodiment of the invention.
[0036] In this case, a lower support wheel 110 is mounted integral with body 105 of the
tool carrier, i.e. in a fixed position. Integral with body 105 there is also a front
abutment pin 110', intended to act as fulcrum against the lower edge of bar B during
the tile-breaking phase (inverse rotation with respect to arrow F). In this case too,
a lower end-of-travel is defined - which intervenes in the tile-breaking phase - due
to the presence of an upper edge of the cavity of tool-carrier 105 which is intended
to rest on the upper edge of bar B.
[0037] According to this embodiment, the tool-carrier has a substantially vertical, linear-movement,
guided sliding element 111, said guided movement being obtained by the engagement
of two upper and lower slots, 111a and 111b respectively in an upper pin 105a and
in a lower pin 105b integral with body 105. Preferably, the lower guiding pin 105b
coincides with the pin whereon the lower support wheel 110 is mounted and upper pin
105a coincides with the upper support pin of tool-carrier P.
[0038] With sliding member 111 there are integral, in the lower portion, both engraving
tool 107 and tile-breaking foot 108.
[0039] According to a preferred embodiment, the vertical adjustment of sliding member 111
with respect to tool-carrier body 105 is accomplished through a threaded pin 113 provided
with an upper manoeuvring knob 114 engaged with a threaded hole of tool-carrier 113a.
In order to simplify the cooperation between pin 113 and sliding member 111, with
respect to the previous embodiment, the end of pin 113 is simply resting on the upper
end of member 111, which determines the upper end-of-travel thereof. An elastic member
120 is furthermore provided, fastened on one side to body tool-carrying body 105 and,
on the other side, to sliding member 111, which keeps said sliding member raised and
abutting against the inner end of pin 113, as shown in fig. 3.
[0040] Sliding member 111 can be mounted on one side only of tool-carrier P or, preferably
it is fork-shaped, so as to arrange itself across the tool-carrier.
[0041] As can be guessed, in this case too it is possible to adjust the distance between
lower support wheel 110 and engraving tool 107 without affecting the mutual position
of said engraving tool with respect to tile-breaking foot 108.
[0042] Fig. 6 shows a further embodiment of the invention.
[0043] This embodiment is fully similar to the first embodiment. In this case fork member
211 is arranged entirely across the tool-carrier and ends above the handle. Fork 211
is further guided in its movement relative to the tool-carrier by guiding members
211a and 211b obtained externally on body 205.
[0044] Tile-breaking foot 208 in this case has two side legs.
[0045] According to this embodiment, the support wheel bearing on the lower edge of bar
B is a single one, shown by the pin 210 thereof.
[0046] In figs. 8 and 9 another embodiment operating similarly with that of fig. 5 is instead
shown.
[0047] On the tool-carrier there is provided a single lower fulcrum wheel 310, integral
with the tool-carrier body and with the handle thereof. In the inner upper portion
of the tool-carrier there is provided an abutting body 305, intended to cooperate
with the upper edge of bar B to define, among other things, the lower end-of-travel
in the tile-breaking phase. In particular, due to the relative fixed position of body
305 and of lower support wheel 310, the rotation of the tool-carrier in the tile-breaking
phase is always constant, regardless of the height adjustment of the engraving wheel:
this prevents tile shattering during the dropping/breaking phase.
[0048] As in fig. 5, in this case too an engraving wheel 307 and the tile-breaking foot
308 are mounted integral with the same support bracket 311 which embraces externally
the main body of tool-carrier P. Bracket 311 is slidingly mounted on the tool-carrier
body and the relative position thereof is determined by a threaded stem 313 which
is introduced more or less entirely into the tool-carrier by means of a knob 314.
Bracket 311 is kept upwards by an elastic member 320 which is inserted in a seat P'
of the tool carrier and operates in opposition to threaded stem 313. The adjustment
operation, in substance, is fully equivalent to the one relative to fig. 5
[0049] As can be guessed from the above-reported description, the tool-carrier according
to the invention allows to fully achieve the desired object, i.e. to define an adjustment
which adapts the cutting conditions to the chosen tile height, without affecting the
relative arrangement between cutting tool and tile-breaking foot and without having
to intervene to change the position of the guiding bar.
[0050] However, it is understood that the invention is not limited to the particular arrangements
illustrated above, which represent only non-limiting examples of the scope of the
invention, but that a number of changes can be made, all within the reach of a person
skilled in the field, without departing from the scope of the invention as defined
in the appended claims.
[0051] For example, although the support elements bearing on the guiding bar have always
been shown in the form of cylindrical pins or wheel, it is not ruled out that they
are configured with different surfaces, for example planar or cam-like.
1. Pull-type tool-carrier for a tile-cutter of a type comprising a tool-carrier body
(5, 105), apt to slide on a guiding bar (B), provided above with a handle (6, 106)
and below with an engraving tool (7, 107) and with a tile-breaking foot (8, 108),
behind the engraving tool (7, 107) a lower support pivot (10, 110) being further arranged,
apt to act as fulcrum against the lower edge of said guiding bar (B), characterised in that the relative position between the mounting axis of said lower support pivot (10,
110) and said engraving tool (7, 107) with said tile-breaking foot (8, 108) is adjustable.
2. Tool-carrier as claimed in claim 1), wherein said lower support pivot (10, 110) is
shaped as a pin running across said tool-carrier body (5) and is slidingly mounted
in opposite guiding slots (12) on both sides of said body (5).
3. Tool-carrier as claimed in claim 2), wherein said pivot (10) is fastened to the opposite
ends of a fork element (11) which partly embraces said body (5) and ends with a connecting
element (11a) which is joined to a portion of said handle (6) through adjustment means.
4. Tool-carrier as claimed in claim 3), wherein said adjustment means comprise a threaded
stem (13) joined to said fork element (11a, 11) in a freely rotatable manner and provided
at one end with a manoeuvring knob (14), said threaded stem (13) engaging with a corresponding
threaded hole in a front protruding portion (15) of said handle.
5. Tool-carrier as claimed in claim 1), wherein said lower support pivot (110, 310) is
integral with said tool-carrier body (105) and a sliding element (111, 311) is further
provided, apt to slide on said tool-carrier body (105) which carries on a lower end
below said engraving tool (107) and said tile-breaking foot (108).
6. Tool-carrier as claimed in claim 5), wherein said sliding element (111) is height-adjustable
with respect to the tool-carrier body (105) through guiding means (111a, 111b, 105a,
105b) and adjusting means (113, 114, 113a, 120, 313, 314, 320).
7. Tool-carrier as claimed in claim 6), wherein said guiding means comprise an upper
slot (111a) and a lower slot (111b) obtained in said sliding body (111) and guided
by an upper pivot (105a) and by a lower pivot (105b), respectively, which are integral
with the tool-carrier body (105).
8. Tool-carrier as claimed in claim 5), wherein said adjusting means comprise a threaded
stem (113, 313), engaged with a threaded hole (113a) provided in said tool-carrier
body (105), which determines an upper abutment position and an elastic element (120,
320) constrained between said tool-carrier body (105) and said sliding element (111,
311) apt to push said sliding element (111, 311) towards said threaded stem (113,
313).
9. Tool-carrier as claimed in any one of the preceding claims, wherein a lower end-stop
element (9, 305) is further provided, intended to come in contact with said guiding
bar (B) upon a rotation of the tool-carrier opposite to the one produced for the engraving.
10. Pull-type, manual tile-cutting machine comprising a base wherefrom two end posts (4)
rise, between which a guiding bar (B) of a tool-carrier (P) extends, characterised in that said tool-carrier (P) is as claimed in any one of the preceding claims.