The present invention relates to an articulation device for an awning arm elbow, said awning arm being of the type formed by a forearm and an arm articulated in said elbow, where the free end of the forearm is provided with a configuration for articulated attachment to a load bar fixed to a front edge of the awning canvas and the free end of the arm is provided with a configuration for articulated attachment to a fixed support adjacent to a winding tube for the canvas, and where inside the arm there is arranged at least one elastic traction member connected to flexible tie rod element having an end anchored in the mentioned articulation device for the elbow.
International patent application WO 2005/017278 discloses an articulated arm for awnings of the type described above, formed by a forearm and an arm articulated in an elbow by means of an articulation device. This articulation device comprises a forearm elbow part and an arm elbow part. The forearm elbow part defines a fork between the branches of which a core configured around an axis is fixedly supported. In the mentioned core there is formed an anchoring configuration adapted to couple an enlarged end of the mentioned flexible tie rod element connected to said elastic traction member. The mentioned flexible tie rod element is described in patent ES-A-2159211. The arm elbow part defines a surrounding wall arranged around the core, a clearance being provided between both to accommodate said flexible tie rod element.
To guide a relative rotation between the forearm and arm elbow parts around said axis, and to support the forearm on the arm in a cantilevered manner, the articulation device includes bearing means formed by a pair of annular parts, made of a plastic material, assembled on the surrounding wall of the arm elbow part. These annular parts define a pair of first conical surfaces which in an operative situation face one another and are in contact with a corresponding pair of second conical surfaces formed in the core and in a centering part, respectively, which are integral with the forearm elbow part. The first and second conical surfaces are conjugated and provided for a relative sliding.
A tubular shank coaxial with the axis is inserted in a hollow interior of the core. One of the branches of the fork of the forearm elbow part defines a hole for an end of said shank and the other branch of the fork defines an opening into which the mentioned centering part is fitted, which centering part in turn has a hole for the other end of the shank. The centering part is configured to block the rotation of the core. Once the assembly is completed, the ends of the shank are flared against the holes in the branch of the fork and the centering part, whereby the shank is retained and the assembly is firmly packed.
This construction has several drawbacks. For example, the forearm and arm elbow parts, as well as the core and the centering part, are generally obtained by the injection moulding of a lightweight metal alloy, such as aluminium, and the correct adjustment of the conical surfaces demands strict manufacture and assembly tolerances that are difficult to achieve by means of such moulded aluminium parts without a subsequent machining. The lack of a correct adjustment can give rise to squeaks while bending and straightening the elbow. Furthermore, a play, however small it is, in the articulation of the elbow can cause a misalignment of the correct position of the forearm with respect to the arm, and this can create interferences, for example, when the articulated arm must be automatically introduced in a bent position into a box during an operation for drawing in the awning. This misalignment will be greater the longer the forearm is. Therefore, a lack of adjustment in the articulation of the elbow limits the maximum length that the forearm can have to be supported in a cantilevered manner by the bearing means in a suitable position. In addition, the friction forces existing in the articulation device for the elbow are to the detriment of the force exerted by the elastic traction member, and as a result there is a decrease in the tension of the canvas.
It is therefore desirable to increase the adjustment and precision to a maximum and to decrease the friction forces to a minimum in the bearing means of the articulation device for the elbow of an articulated arm for an awning.
The present invention contributes to overcoming the previous and other drawbacks by providing an articulation device for an awning arm elbow, said awning arm being formed by a forearm and an arm articulated in said elbow. The articulation device is of the type comprising a forearm elbow part, an arm elbow part and bearing means arranged to guide a relative rotation between said forearm elbow part and said arm elbow part around an axis, and to support the forearm on the arm. The mentioned forearm elbow part defines a fork between the branches of which a core configured around said axis is fixedly supported. In the mentioned core there is formed an anchoring configuration adapted to couple an enlarged end of a flexible tie rod element connected to one or more elastic traction members secured at a fixed point inside said arm. The mentioned arm elbow part defines a surrounding wall arranged around said core, with a clearance arranged between both to accommodate said flexible tie rod element. The articulation device of the present invention is characterized in that said bearing means include at least one bearing unit which comprises a first annular element which is fixed to the forearm elbow part and a second annular element which is fixed to the arm elbow part. These first and second annular elements include respective facing surfaces adapted to mutually cooperate in the functions of the bearing means.
In one embodiment, the articulation device includes two bearing units, at least one of which is a roll bearing in which said first annular element fixed to the forearm elbow part defines an inner roll track and said second annular element fixed to the arm elbow part defines an outer roll track. These inner and outer roll tracks form part of the mentioned facing surfaces, and a plurality of rolling elements are arranged therebetween to roll on both. The roll bearing can be of different types, including ball bearings, needle bearings, cylindrical or tapered roller bearings, etc. A suitable type of roll bearing is, for example, a single-row rigid ball bearing, preferably of stainless steel and sealed or provided with side protections. The single-row rigid ball bearing withstands both radial and axial forces and is commercially available.
The parts forming the structure of the articulation device for the elbow, i.e., the forearm and arm elbow parts, as well as the core and centering parts, are generally obtained by the injection moulding of a lightweight metal alloy, such as, for example, an aluminium alloy, and are usually completely coated with a layer of paint or lacquer. In the core and in the surrounding wall defined by the arm elbow part there are seats for the first annular element and the second annular element, respectively, of the roll bearing. These seats are formed during the moulding operation and coated with the layer of paint or lacquer. Due to the demands of the moulding technique, specifically to facilitate the demoulding, the surfaces oriented in the demoulding direction must be slightly conical. For this reason, in other applications, the seats for roll bearings and other components generally require being machined after the moulding to eliminate or rectify the mentioned conicity, which makes the manufacturing process considerably more expensive.
According to one embodiment of the present invention, the seats for the roll bearings are configured such that the roll bearings can be directly housed in the housings as they are obtained in the parts shaped by injection moulding, even having been subsequently lacquered or painted, without needing a prior machining.
To that end, each of the seats in the device of the present invention comprises a conical surface, coaxial with the axis of the articulation and provided with a degree of conicity, from which there project ribs defining radial support surfaces, each of which has at least one edge coinciding with a cone coaxial with the axis of the articulation and also provided with a degree of conicity. The degrees of conicity of the conical surface and of the radial support surfaces of the ribs are small and no more than those necessary to allow a correct demoulding of the core and/or of the arm elbow part after the operation for obtaining them by injection moulding. The radial support surfaces of the ribs are adapted to receive by pressurized insertion a cylindrical radial support surface of the roll bearing. The mentioned ribs are sized for the purpose of at least one part of their radial support surfaces being adjusted with interference with the radial rest surface of the roll bearing, taking into account the thickness of the layer of paint or lacquer when there is one. Given that the material of the annular elements of the roll bearing, typically steel, is harder than the material of the parts defining the seats, for example, an aluminium alloy, the roll bearing sweeps an amount of material of the ribs during an operation for installing the roll bearing by pressurized insertion in the axial direction in the seat until an axial rest surface of the roll bearing makes contact with an axial support surface of the seat perpendicular to the axis of the articulation. In said axial support surface and in a position adjacent to the ribs there is formed a circumferential channel adapted to receive and house the possible material of the ribs of the seat pulled off by the roll bearing, whether it is aluminium alloy or paint or lacquer, or a combination of both, during the operation for installing the roll bearing by pressurized insertion.
In another embodiment, the articulation device includes two bearing units, at least one of which is a friction bearing in which the mentioned facing surfaces comprise respective first and second cylindrical surface portions in contact, to withstand forces in the radial direction, and respective first and second annulus surface portions in contact, to withstand forces in the axial direction. The first and second annular elements are preferably made of different materials with a low coefficient of friction between one another. Steel and bronze, steel and plastic, bronze and plastic, for example, among others, can be mentioned as suitable pairs of materials for the first and second annular elements of the friction bearing.
When one of the annular elements of the friction bearing is made of a hard material, for example steel, in relation to the softest material of the structural part, for example aluminium, the corresponding structural part of the articulation device, whether it is the arm elbow part or the core, defines a seat similar to that described above in relation to the bearing, for receiving the annular element of the friction bearing by pressurized insertion.
When one of the annular elements of the friction bearing is made of a material that is less hard and/or can be shaped by moulding, for example bronze, a reverse construction can be made in which the ribs are formed in the annular element of the friction bearing instead of the conical surface of the seat. Thus, in one embodiment, the seat for the annular element of the friction bearing comprises a conical radial support surface, coaxial with the axis of the articulation, provided with a small degree of conicity suitable for facilitating the demoulding of the part during its manufacture by injection moulding. This conical radial support surface is adapted to receive by pressurized insertion radial rest surfaces formed in ribs projecting from a surface of the friction bearing. Each of these radial rest surfaces of the ribs has at least one edge preferably coinciding with a cylinder. The housing also includes an axial support surface perpendicular to the axis, adapted to receive an axial rest surface of the friction bearing. A circumferential channel adjacent to said conical surface is formed on this axial support surface to receive and house the possible material pulled off by the annular element of the friction bearing from the conical surface of the seat during the operation for installing the annular element by pressurized insertion in the axial direction.
When one of the annular elements of the friction bearing is made of a relatively soft and/or elastic material, for example a plastic polymer, the seat is preferably machined to provide a cylindrical radial rest surface ensuring a complete backing for a cylindrical radial rest surface of the annular element.
According to the present invention, a feature common to the embodiment with a roll bearing and to the embodiment with a friction bearing is that a structural part of the articulation device includes a seat for at least one of the two annular elements of the roll bearing or friction bearing, where the mentioned seat has one or more surfaces coinciding with a cone coaxial with the axis of the articulation provided with a degree of conicity suitable for facilitating demoulding, and adapted to receive by pressurized insertion one or more surfaces coinciding with a cylinder coaxial with the axis of the articulation, formed in the corresponding annular element of the roll bearing or friction bearing.
The present invention contemplates the possibility of the articulation device including a single bearing unit, either in the form of a roll bearing or of a friction bearing, provided that the single roll bearing or friction bearing is of a suitable type and is properly sized.
The previous and other features and advantages will be more fully understood from the following detailed description of several embodiments with reference to the attached drawings in which:
Referring first to
The forearm and arm elbow parts 1, 2 include plug-in configurations 44, 45 adapted to be inserted in the open ends of the tubular sections of the forearm 1 and the arm 2, respectively. The mentioned plug-in configurations 44, 45 can be delimited by inclined flanges 46, 47 adapted to abut against inclined cut ends of the tubular sections of the forearm 1 and the arm 2, respectively, according to international patent application WO 2005/017279. The connecting parts 27 and 28 can be coupled to the respective tubular sections of the forearm 1 and the arm 2 by means of plug-in configurations provided with inclined flanges similar to those mentioned.
The forearm elbow part 4 defines a fork between the branches 4a, 4b of which a core 6 configured around the axis 7 is fixedly supported. In said core 6 there is formed an anchoring configuration 8 (
The tubular sections of the forearm 1 and the arm 2 can be extruded profiles made of a lightweight metal alloy, for example, an aluminium alloy, and the structural parts of the articulation device, i.e., the forearm and arm elbow parts 4, 5, the core 6 and centering parts 23 are designed to be obtained by injection moulding of a lightweight metal alloy, for example, an aluminium alloy.
With specific reference now to the embodiment shown in
The mentioned roll bearing 15 is of a conventional type and comprises a first annular element 16 which is fixed to the forearm elbow part 4 and a second annular element 17 which is fixed to the arm elbow part 5. These first and second annular elements 16, 17 include respective facing surfaces defining inner and outer roll tracks, respectively, on which a plurality of rolling elements 18 arranged therebetween roll. The facing surfaces of the first and second annular elements 16, 17 are thus adapted to mutually cooperate in the functions of the bearing means. The rolling elements 18 can be balls, cylindrical rollers, tapered rollers, needles, etc. In the embodiment shown in
As best shown in
When the roll bearing 15 is inserted by pressure in the axial direction to the inside of the seats formed in the core 6 and the arm elbow part 5, the first and second annular elements 16, 17 of the roll bearing 15 interfere with the support surfaces of the ribs 31 pulling off some of the material and/or coating thereof, until the axial rest surfaces of the roll bearing 15 make contact with the axial support surfaces 32 of the seats. The material or coating of the seats pulled off by the roll bearing 15 is received and retained in the corresponding channels 33 in order to not interfere in the contact between the corresponding axial rest surfaces of the roll bearing 15 and the axial support surfaces 32 of the seats. The roll bearing 15 is thus perfectly seated in the seats.
With reference still to
As best shown in the enlarged detail of
Here also the core 6 and the surrounding wall 13 define seats for the first annular element 20 and the second annular element 21, respectively. In the embodiment of
The mentioned perimetric flange 26 of the first annular element 20 has a decreasing thickness to compensate an inclination of the inner faces of the branches 4a, 4b of the fork necessary for demoulding the forearm elbow part 4 while it is obtained by injection moulding. Likewise, the perimetric flange 26 and the corresponding branch 4a of the fork have respective mutually fitting configurations to prevent a relative rotation.
A reverse construction has been provided for the installation of the bronze second annular element 21 of the friction bearing 19 in the surrounding wall 13. Here, the seat comprises a conical radial support surface 38, coaxial with the axis 7, provided with a degree of conicity and adapted to receive by pressurized insertion radial rest surfaces formed in ribs 39 projecting from a surface of the friction bearing 19, as best shown in the detail of
Given that the structural parts of the articulation device are obtained by the injection moulding of a lightweight metal alloy, for example, an aluminium alloy, the degree of conicity of the conical surface 34 and of the radial support surfaces of the ribs 35 in the seat for the first annular element 20, as well as the degree of conicity of the radial support surface 38 in the seat for the second annular element 21, are adapted to facilitate the demoulding during the process for obtaining the core 6 and the arm elbow part 5 defining the surrounding wall 13 by injection moulding. The materials of the first and second annular elements 20, 21 of the friction bearing 19 could obviously be reversed or be others than steel and bronze, in which cases the constructions of the first and second annular elements 20, 21 and of their seats could be reversed in relation to those described with reference to
In the embodiments of
A person skilled in the art will be able to make modifications, variations and different combinations from the embodiments shown and described without departing from the scope of the present invention as it is defined in the attached claims.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/ES06/00532 | 9/27/2006 | WO | 00 | 7/20/2009 |