Coupling for connecting two perpendicular rods

Abstract: This invention concerns a coupling for connecting two rods (A,B), said coupling being characterised by a cylindrical hollow body (1) closed at one end with a jaw-shaped bottom wall (2) and a clamp consisting of two jaws (5) housed and sliding in a sleeve (3) placed in a off-centre and slanted position with respect to said body.

Description: This patent application concerns a coupling for connecting two orthogonal rods. The coupling in question is designed expressly to resolve a specific requirement of keyboard players who generally use a stand for their keyboards. These stands consist of a crossed pair of legs realised in general with tubular rods at whose ends an arm consisting of a bar having circular cross-section, is welded transversally. The bottom pair of transverse arms obviously act as feet which support and stabilise the stand on the ground, while the upper pair of arms are used to support the keyboard. These keyboard stands are often fitted with accessories which make it possible to place a second keyboard above the first, or to apply upright supporting rods to the stand arms for microphones, music-stands or lamps. Although these accessories have different structures according to their function, they are all provided with an upright rod acting as a supporting element, which is fixed orthogonally to the two arms of the stand on which the keyboard is placed. In order to fix the same, a metal sleeve is generally applied to the base of the upright element and positioned with its longitudinal axis orthogonal to the rod. Said sleeve is dimensioned in order to fit precisely on the supporting arm of the keyboard, and in order to prevent said sleeves from rotating freely around the relevant connection arm, each sleeve is provided with a radial dowel with relevant clamping knob. The sleeve is therefore fixed firmly to the arm simply by friction caused by the pressure that the tip of the dowel exercises on the outer wall of the arm. This fixing system is however far from safe and stable in that often the vibrations - to which the stand is inevitably subject when the keyboard is used or when the same is moved from one place to another - cause the fixing dowel to loosen in time consequently making the fixing of the sleeve to the arm unstable. It was in order to resolve this problem that the coupling according to the invention was expressly designed, and which, though being as easy to use and inexpensive as the above couplings, however ensures a much more secure and stable fixing of the upright rod to the arm of the stand. The coupling known from FR-A-2 589 534 consists of a cylindrical hollow body having horizontal axis in use, closed at only one end by an end wall provided at the centre with a through hole, whose outer side is shaped as a part cylindrical jaw whose longitudinal axis is vertical in use and thus perpendicular to that of the above cylindrical hollow body. According to the invention, the through hole is threaded, the part cylindrical shaped outer face is semi-cylindrical, an outer sleeve is realised in a single moulding piece with the body and placed in an off-centre and slanted position with respect to the body, the axial hole of the sleeve intersecting the axial hole of the hollow body perpendicularly, thereby creating a slot which makes the internal holes of the hollow body and the sleeve intercommunicating, a pair of adjacent cylindrical slides are housed in the hole of the sleeve and fitted along the threaded shank of a bolt, whose hexagonal head is housed in a conforming housing realised on the outer face of one of the two slides which is also provided with an outer flange acting as abutment element against the mouth of the hole of the sleeve, said two slides being provided at their adjacent ends with a pair of deep mirror image notches, whose profile as a whole is arched and housed in the slot, a nut is embedded in a fixing knob designed to be screwed on the threaded shank of the bolt, and a bolt, having its head embedded in a fixing knob, is designed to be screwed in the threaded through bore of the end wall. It should be noted that the upright rod with which all these accessories are provided, as mentioned above, may be embedded into said semi-cylindrical jaw. The secure fixing of this upright rod is assured by means of a bolt fitted diametrically through the rod and screwed in the through hole at the centre of the end wall of the cylindrical hollow body. This means that the upright rod must have a diametrical through hole into which the shank of the fixing bolt is fitted; said upright rods being in general provided with a series of regularly spaced diametrical holes which make it possible to regulate the height at which the accessory with respect to the keyboard below is fixed. A sleeve thus has an axis horizontal but orthogonal to that of the cylindrical hollow body and is provided outside the lateral surface of said body, moulded in a single piece with the first. Said outer sleeve virtually intersects said cylindrical body so that the single through slot has an almost elliptical arrangement. The sleeve is fitted internally with a clamp consisting of the two special jaw-like slides fitted and free to slide along the threaded shank of a bolt, whose nut is embedded in a fixing knob and whose hexagonal head is housed precisely in a special housing realised on the outer face of one of the two slides, and which are drawn together simply by screwing the nut along the threaded shank of the bolt. Said two slides are substantially cylindrical, bored axially so that the same may be fitted, one after the other, along the threaded shank of the above bolt. Once the end section of one of the arms of the stand is fitted in the cavity of the cylindrical body it is sufficient to screw the fixing nut of the above bolt to draw the two jaws of the clamp together and consequently fix the arm, which is tightened firmly between the above pair of mirror image notches. For major clarity the description of the invention continues with reference to the enclosed drawings which are intended for purposes of illustration and not in a limiting sense, where: fig. 1 is an axonometric view and exploded view of all the components of the coupling according to the invention. With reference to the above figure, the coupling in question consists of a cylindrical body (1), having horizontal axis, closed only at one end by an end wall (2), provided at the centre with a threaded through hole (2a). Said wall (2) being provided with an outer face (2b), shaped like a semi-cylindrical jaw, having vertical axis. A sleeve (3) having a smaller diameter, and placed in an off-centre and slanted position with respect to the body (1) is realised outside the cylindrical hollow body (1) in a single moulded piece with the body; in other words the axial hole (3a) the sleeve (3) intersects the axial hole of the hollow body (1) perpendicularly, thereby forming a slot (4) which makes the inner holes of the hollow body (1) and the sleeve (3), intercommunicating. The axial hole (3a) of the sleeve (3) may house a pair of adjacent cylindrical slides (5), bored axially, fitted and free to slide along the threaded shank (6a) of a bolt (6), whose hexagonal head (6b) is housed precisely in a conforming housing realised on the outer face of one of the two slides (5), and which is also provided with an outer flange (5a), acting as abutment element against the mouth of the hole (3a) of the sleeve (3). The nut fitted on the threaded shank (6a) of the bolt (6) is embedded in a fixing knob (7), which when screwed, gradually draws the above pair of slides (5) together; said pair of slides (5) being provided at their adjacent ends with a pair of deep mirror image notches (5b), whose profile as a whole is arched and housed in the above slot (4). Said notches (5b) are provided with a splined surface which improves its hold. This pair of slides (5), having said mirror image notches (5b), create a pair of jaws which hold the arm (B) of the stand fitted in the hole of the hollow body (1), securely. On the semi-cylindrical jaw (2b) of the coupling in question it is possible to fix an upright rod (A) by means of a bolt (8), provided with fixing knob (8a), whose threaded shank, after being fitted into a diametrical hole (F) of the rod (A), may be screwed into the above hole (2a), provided at the centre of the end wall (2) of the body (1). Considering the above description which refers to the enclosed drawings, it is now evident that the coupling in question makes it possible to fix the upright rod (A) of an accessory for keyboard stands to the arms (B) on which the keyboard rests. Obviously if the cross-section of the upright rod (A) is not circular, the profile of the jaw (2b) should also be changed so that it may be joined to that of the upright rod. In addition, even if the coupling in question is expressly designed for keyboard stands, it may be used just as effectively in all those cases where it is necessary to fix the end of a cylindrical bar to a second bar, in an orthogonal direction to the first.

Claims: A coupling for the connection of two orthogonal rods, comprising: a cylindrical hollow body (1), having a horizontal axis in use, closed at only one end by an end wall (2), provided at the centre with a through hole (2a) and having a part cylindrical shaped outer face (2b) with a vertical axis in use; characterised by the through hole (2a) being threaded; the part-cylindrical shaped outer-face (2b) being semi-cylindrical an outer sleeve (3) realised in a single moulding piece with the body (1) and placed in an off-centre and slanted position with respect to the body (1); it being provided that the axial hole (3a) of the sleeve (3) intersects the axial hole of the hollow body (1) perpendicularly, thereby creating a slot (4) which makes the internal holes of the hollow body (1) and the sleeve (3), intercommunicating; a pair of adjacent cylindrical slides (5), housed in the hole (3a) of the sleeve and fitted along the threaded shank (6a) of a bolt (6), whose hexagonal head (6b) is housed in a conforming housing realised on the outer face of one of the two slides (5) which is also provided with an outer flange (5a), acting as abutment element against the mouth of the hole (3a) of the sleeve (3); it being provided that said two slides (5) are provided at their adjacent ends with a pair of deep mirror image notches (5b), whose profile as a whole is arched, and housed in the slot (4); a nut embedded in a fixing knob (7), designed to be screwed on the threaded shank (6a) of the bolt (6); a bolt (8), having its head embedded in a fixing knob (8a), designed to be screwed in the threaded through hole (2a) of the end wall.

Inventors: MALIZIA MARIO, MALIZIA, MARIO
Applicants: TAM S R L, TAM - S.R.L.
Application year: 1998
Main classification: F16B7
IPC codes: F16M11