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The present patent application for industrial invention relates to a trolley to support and handle sliding panels of furniture or doors, provided with articulated wheels adapted to make oscillations on two orthogonal planes, a vertical plane and a horizontal plane, where the vertical plane is orthogonal to the traveling direction of the trolley.
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As it is known, in most applications, sliding panels are hung to one or more support trolleys, provided with wheels with horizontal axis and coupled to the same guide track lying on a horizontal plane and having a rectilinear or slightly arched profile, according to the specific case.
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In order to obtain the perfect silent sliding of the trolley, without jamming or friction, it is indispensable that the track is installed and stopped firmly on a perfectly horizontal plane and this requires great care and skill from the operator in charge of mounting the sliding panel.
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In any case, a great amount of care when fixing the track is not sufficient, if equivalent care is not provided when fixing each trolley on the upper edge of the sliding panel.
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The latter fixing operation must be carried out in such manner that the axis of rotation of the wheels of the trolley is perfectly perpendicular to the panel, in case of flat panels, or in case of arched panels, orthogonal to the vertical plane of tangency to the curvilinear profile of the panel in the intersection point between said curvilinear profile and axis of rotation of the wheel.
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While these precautions must be taken when mounting the sliding panel in order to guarantee perfect operation, it must be noted that, after the initial installation, other events may intervene and impair such perfect operation.
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For example, the track may be accidentally subject to external stress of bending or torsional type with respect to its longitudinal axis, able to cause respectively slight bending or torsional deformation of the track, with immediate production of frictioned noisy sliding of the wheels along the track, thus wearing out, if not blocking, the sliding parts.
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FR 2 285 276 discloses a trolley comprising two main bodies that must be connected jointly and rigidly by means of a connection beam, blocked at the bodies by means of at least two bolts and disposed outside the guide track of the trolley. The single body with only two lateral wheels, by itself, cannot work inside the guide track, because without the connection beam each single body would rotate on its vertical axis. In order for such a system to work, preventing the panel from pitching during opening and closing operations, the two main bodies must be connected jointly and rigidly outside the guide track.
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Moreover, blocking of the two bodies with the connection beam must be made precisely, otherwise the front border of the bodies can slide inside the guide track, if said bodies rotate slightly with respect to their vertical axis. For this reason, the head of the bodies is rounded off, such as the prow of a boat, in the sliding point in the center of the lower open part of the track.
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The union of said two bodies by means of connection beam and bolts creates a cumbersome volume under the guide track and above the panel. Said volume is not accepted by the market, which requires the panel to pass as close as possible to the lower part of the guide track.
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FR 2 285 276 discloses articulation means composed of a conical bush. Said articulation means allow for inclination of the axis of the pin of the wheels only according to a vertical plane (up/down), and not for inclination of the axis of the pin of the wheels on a horizontal plane (front/back). Therefore, said trolley cannot follow a curved sliding track, for curved panels, or a bending or helical track and cannot be mounted on the panels of sliding doors, wherein the panels must rotate mutually by approximately 90°.
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US 3,155,051 discloses a trolley provided with body made of two joined parts and single axis with two wheels. Such a trolley allows for movement/adaptation of the pin of the wheels, but only works if its body is firmly fixed to the panel. In fact, if the body of the trolley is not firmly fixed to the sliding panel, the single trolley cannot operate because it makes the panel pitch during opening and closing operations. The body of the trolley, which must come out of the guide track, can rotate on its axis, therefore sliding against the guide track. In order to make the trolley independent from the panel, it is necessary to connect at least two trolleys to the panel outside the track, thus causing cumbersome volumes that are not accepted by the market.
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The present invention derives from the critical examination of such a problem, with the main purpose of eliminating the occurrence of the aforementioned drawbacks, after the installation of the sliding panel, and also reducing the accuracy level imposed during mounting to the operator in charge of installing the panel.
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These objectives are achieved by the present invention, the main innovative characteristics of which are disclosed in the first claim, whereas the dependent claims disclose preferred embodiments of the invention.
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The present invention relates to a trolley used to support and handle sliding panels for furniture or doors, of the type comprising a bearing body to which two horizontal pins are coupled to support two or four wheels.
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Said two pins are parallel and orthogonal to the longitudinal axis of said bearing body.
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In case of only two wheels, the wheels are aligned and lying on the same vertical plane, e.g. a front wheel and a back wheel, whereas in case of four wheels, the trolley comprises a first opposite pair of front wheels and a second opposite pair of back wheels.
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The peculiarity of the trolley of the invention is the adoption of articulated wheels that are free to make oscillations on two orthogonal planes, e.g. a vertical plane and a horizontal plane, where the vertical plane is orthogonal to the traveling direction of the trolley.
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According to the preferred embodiment of the invention, the trolley comprises a central body, provided on the sides with two pairs of external wheels: a first opposite pair of front wheels and a second opposite pair of back wheels.
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The wheels of each opposite pair of wheels are fit at the two ends of a horizontal pin crossing the central body, which is provided with housing for passing the pin and supporting it by means of articulated means that allow the pin to make oscillations on two orthogonal planes, e.g. a vertical plane and a horizontal plane, where the vertical plane is orthogonal to to the traveling direction of the trolley.
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According to an alternative embodiment of the invention, the trolley comprises a bearing body with box-shaped structure, which houses an aligned consecutive pair of wheels, e.g. a front wheel and a back wheel.
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The hub of each wheel is crossed by a horizontal pin, the ends of which are exactly housed inside corresponding holes obtained on the two opposite longitudinal edges of the boxed body, so that no oscillation is allowed for said pin.
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According to said second embodiment, said articulated means are positioned between the hub of each wheel and the corresponding support pin, so that the wheel (not the pin) makes said oscillations on two orthogonal planes, a vertical plane and a horizontal plane, where the vertical plane is orthogonal to the traveling direction of the trolley.
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The trolley of the invention is self-aligning and concealed inside the sliding track. Moreover, said trolley is independent from the panel, e.g. the body of the trolley is connected to the panel by means of standard/commercial means, such as pins or screws or fixing parts for standard/commercial panels. With these standard/commercial means, the panel does not pitch during opening/closing operations because the body of the trolley remains parallel to the sliding plane of the wheels.
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The trolley of the invention allows for rotation of the axis of the wheels also on a horizontal plane with respect to a vertical plane orthogonal to the sliding of the trolley. Such a feature is essential, for example, in case of curved guide tracks for curved panels, or in case of curvature or torsion of the guide track because of wall mounting.
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For explanatory reasons, the description of the trolley assembly of the invention continues with reference to the attached drawings, which only have an illustrative, not limiting value, wherein:
- Fig. 1 is a perspective view of the trolley of the invention mounted on the upper edge of a panel;
- Figs. 2, 3 and 4 are three exploded axonometric views of the trolley of Fig. 1, comprising a central body provided with four wheels and various articulation means;
- Figs. 2A, 3A and 4A are exploded views of the articulation means cut with a plane passing through the axis of rotation of the wheels that are equally cut, together with the support pin;
- Figs. 5A, 5B are two partially sectional front views of the angles of free oscillation of the articulated wheels of the trolley of Fig. 1;
- Fig. 6 is a top view of the trolley of the invention showing the angles of free oscillation of the articulated wheels of the trolley;
- Fig. 7 is an exploded axonometric view of a different embodiment of the trolley of the invention, which comprises a box body that contains one aligned pair of wheels;
- Figs. 8A, 8B and 9 show the angles of free oscillation of the articulated wheels of the trolley of Fig. 7;
- Fig. 10 is a sectional view of the trolley of Fig. 7 with a vertical plane passing through the axis of rotation of one of said two aligned wheels;
- Fig. 11 is the same view as Fig. 1 showing the trolley partially inside a guide track; and
- Fig. 12 is a partially sectional perspective view showing the trolley of the invention, mounted on a portion of panel of a folding door.
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Referring to the figures, the trolley of the invention is disclosed, being generally indicated with numeral (1).
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Referring to Figs. 1 to 4, according to a first preferred embodiment, the trolley (1) comprises a bearing body (2) provided on the sides with two pairs of external wheels, e.g. a first opposite pair of front wheels (3) and a second pair of back wheels (4). The bearing body (2) is intended to be connected to a sliding panel (A).
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The front wheels (3) are fit at the two ends of a horizontal pin (3a) crossing the bearing body (2), which is provided with housing (5) for passage of pin (3a). The back wheels (4) are fit at the two ends of a corresponding horizontal pin (4a) crossing the bearing body (2), which is provided with housing (6) for passage of pin (4a).
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Fig. 11 shows a guide track (B) intended to be fixed to a fixed frame (not shown) or directly to a ceiling or to a side of a wall. The guide track (B) consists of a profile with rectangular cross-section comprising two lower wings (B1) separated by a central longitudinal opening (B2). The wheels (3, 4) of the trolley can roll on the lower wings (B1) of the guide track and the body (2) of the trolley is totally housed in the guide track (B).
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Referring to Figs. 2-4, the pins (3a and 4a) are coupled with housings (5 and 6) by means of articulated means (MS) that allow each pin to make oscillations on two orthogonal planes, e.g. a vertical plane (PV) and a horizontal plane (PO), where the vertical plane (PV) is orthogonal to the traveling direction of the trolley, indicated by arrow (F) in Fig. 1.
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Figs. 5A and 5B show the oscillation angles (α) on the vertical plane (PV). The angle (α) represents the inclination of pins (3a, 4a) with respect to a horizontal axis.
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As shown in Figs. 5A and 5B, in spite of the fact that track (B), inside which the trolley (1) slides, is laterally inclined by an angle (α), the longitudinal plane of symmetry (P1) of the trolley (1) maintains perfect perpendicularity, in alignment with the sliding panel (A), in view of the fact said anomalous inclination of the track (B) is compensated for by the identical oscillation in the same direction of the pins (3a and 4a).
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Fig. 6 shows the oscillation angles (β) on a horizontal plane (PO) orthogonal to the vertical plane (PV) on which oscillations of the pins of the wheels take place according to angles (α).
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Figs. 3 and 3A shows an embodiment of the trolley (1), wherein said articulated means (MS) comprise only one articulation (7), such as for example a spherical articulation, which is commonly found on the market. The articulation (7) comprises:
- an internal part (70) fixed to the pin (3a, 4a) of the wheels and
- an external part (71) fixed to the housing (5, 6) of the body of the trolley.
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Figs. 2 and 2A show an embodiment of the trolley (1) wherein said articulated means (MS) comprise:
- an articulation (7) inserted in the housing (5, 6) of the body of the trolley; and
- a radial bearing (8) inserted on the pins (3a, 4a) and engaged inside said articulation (7).
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Figs. 4 and 4A show an embodiment of the trolley (1) wherein said articulated means (MS) comprise only one adjustable bearing (9) of roller or ball type.
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In Fig. 7, according to a second embodiment of the invention, the trolley (100) comprises a box body (200) that houses an aligned consecutive pair of wheels, e.g. a front wheel (300) and a back wheel (400).
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Each wheel (300, 400) comprises a cylindrical central body and two cylindrical lateral portions with higher diameter than the central body. The cylindrical lateral portions are intended to roll on the lower wings (B1) of the guide track (B).
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Each wheel comprises a hub (M) provided with axial hole crossed by a horizontal pin (300a, 400a), the ends of which are housed inside holes (500, 600) obtained on the two opposite longitudinal edges (201) of the box body (200), so that no oscillation of said pins (300a and 400a) is allowed.
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According to said second embodiment, said articulated means (MS) are positioned between the hub (M) of each wheel (300, 400) and the support pin (300a, 400a), so that the wheel (not the pin) makes said oscillations on two orthogonal planes, a vertical plane and a horizontal plane, where the vertical plane is orthogonal to the traveling direction of the trolley.
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As shown in Fig. 10, only one adjustable bearing (9) of ball type is preferably interposed between the hub (M) of the wheel (300) and the pin (300a).
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Fig. 12 shows a panel (A) of a folding door. In this case, the folding door provides for a plurality of panels (A), wherein two adjacent panels must rotate mutually by approximately by 90°. Therefore the trolley (1) must allow for said rotation of the panels.
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To that end, the trolley (1) comprises a vertical pin (V) revolvingly mounted, in central position, in the body (2) of the trolley. The vertical pin (V) is provided with lower end coupled with a flange (FL) fixed jointly to the upper edge of the panel (A), for example with screw means (S). For example, the vertical plane (V) can be a bolt with head (V1). Therefore, the flange (FL) is fixed between the head (V1) of the bolt and a nut (D) screwed onto the bolt.
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Moreover, the vertical pin (V) can be a screw with threaded stem screwed into the body (2) of the trolley and a head (V1) faced downwards, intended to be connected to the flange (FL) joined with the panel (A). In such a case, the central part of the body (2) of the trolley has a threaded vertical hole wherein the stem of the screw (V) is screwed.
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In this way, the panel (A) can rotate freely with respect to the body (2) of the trolley around the axis of the vertical pin (V).
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The provision of the vertical pin (V) makes the body (2) of the trolley independent from the panel (A), preventing the panel (A) from pitching when the trolley slides.
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Referring to Fig. 12, the body (2) of the trolley comprises at least one front housing (20) in lower position (in front of the front wheels (3)) and at least one back housing (21) (behind the back wheels (4)). Brushes or seals (22) are inserted in the front and back housings (20, 21) of the body of the trolley, protruding lower for sliding on the lower wings (B1) of the guide track in order to clean the guide track.
