EP0183065B1 - Desk lamp - Google Patents

Description

The invention relates to an electric desk, table or floor lamp which has a hinged cantilever arm which struts from a base part and which carries an articulated lamp at its free end part, the cantilever arm consisting of at least three identical, parallel rods and each of these rods is pivotally pivotably pivoted on the base part and on the housing of the lamp.

Such a lamp is known from FR-A-394 278.

With this arrangement, pivoting of the lamp housing relative to the base plate is possible, the lamp housing being able to rotate relative to the base plate.

Based on this prior art, the invention has for its object to improve a generic desk lamp in such a way that the cantilever remains unlimitedly pivotable in all directions relative to the base part, but at the same time simplifies handling for setting the lamp.

To solve this problem it is proposed that rotations of the rods mutually exclusive, articulated connections are arranged.

With this design, the lamp is always adjusted parallel to the base part when the cantilever arm is pivoted relative to the base part, regardless of the direction, so that the originally selected direction of the lamp to the base surface is always retained.

It is advantageous if all rods are arranged at the same distance from one another in order to ensure holding forces of equal magnitude in all pivoting directions.

EP-A0168159 has made known an older proposal, which has not been published beforehand, and describes a lamp in which two of the three rods present there are connected to one another by a cross connection. This document constitutes a state of the art according to Article 54 (3) EPC.

A preferred, technically particularly inexpensive and at the same time robust design of the table lamp described above is characterized in that spherical thickenings are arranged on all rods, both in the area of the base part and the lamp at a distance from the rod end, each in the base part or at the lamp arranged, spherical cap-like and more or less to the spherical thickened frictionally mountable brackets are pivotally mounted, and that preferably at the ends of all rods, both in the area of the base part and in the area of the lamp each have a two-axis joint with a first for longitudinal extension of the rods perpendicular to the articulation axis and with a second articulated axis perpendicular to the latter and to the associated rod radially directed articulation axis and that the free ends of the second articulation axis at each end of the cantilever arm in a common, rigid connecting member are rotatably mounted.

For this purpose, it is also advantageous if the first axes of the two-axis joints are arranged diametrically penetrating and that the flanges of a U-shaped link are articulated on each first joint axis, in the web of which the end part of the second joint axis facing this is rotatably mounted.

A preferred design of the holder for the spherical thickening of the rods is characterized in that a bore is arranged in the facing wall parts of the base part and the lamp for each rod, the diameter of which is on the one hand larger than the diameter of a rod and on the other hand slightly smaller than that is the largest diameter of a spherical rod thickening, furthermore each of the aforementioned wall parts is assigned a pressure plate which can be clamped to the latter, in which the bores of the aforementioned wall parts in shape, dimension and position are arranged opposite each other and that the rods are each a pair opposite one another Reach through the holes while the rod thickenings are arranged so that they can be clamped between the edge parts of the wall and the pressure plate holes, the pressure plates also preferably being arranged within the base part or the lamp.

By means of these measures, the above-mentioned holders are simple and inexpensive to manufacture.

On the other hand, the above-mentioned brackets, including the devices preventing a rotation of the rods relative to one another, are securely shielded from the outside without additional means and measures being required, which also results in a high level of functional reliability of the entire adjustment mechanism.

To further improve the functional reliability, tubes can be provided as rods through which the electrical leads are passed.

In the case of electric lights which are applied to a low voltage of, for example, 24 volts, it is advantageous if the rods are made of electrically conductive material, the rods on the base part and on the lamp are held in an electrically insulated manner, and in particular are arranged within the base part and the lamp Have conductor connection devices so that there is no need for electrical lines in the aforementioned area.

Another object of the invention is to improve the desk lamp described above in such a way that while maintaining the advantage already achieved, namely that when pivoting of the cantilever arm relative to the base part, regardless of the direction in which the lamp is always adjusted parallel to the base part, an essential simplification and cost reduction of the devices can be achieved, which preclude the rods from rotating relative to one another.

The solution to this problem is characterized in that the spherical thickenings each have at least one groove which is parallel to the longitudinal extension of the rods in the direction of their longitudinal extension, the grooves in both spherical thickened portions of each rod are arranged in the same direction to one another, guide pins on the spherical cap-like holders are arranged, each engage in a groove along this adjustable and that the spherical thickenings are rotatable about the longitudinal axes of the guide pins engaging in the grooves.

This eliminates the previously required rod end parts, which extend beyond the spherical thickenings, and the biaxial joints and their connections arranged on the latter, which among other things results in the desired simplification and cheaper manufacture. A further development in the sense of the task consists in that the guide pins arranged in the area of the base part or the lamp on the brackets are each made together in one piece to form an assembly unit and fastened to the respective brackets.

In a desk lamp, in which the spherical thickenings between a wall part of the base part or the lamp and a pressure plate are clamped in a spherically pivotable manner and the rods bore through in the aforementioned wall parts and in the pressure plates with play, while the spherical thickenings attach to those assigned to them Supporting edge parts of the smaller holes compared to the spherical thickenings, it is advantageous to insert the guide pins, which are each combined to form an assembly unit, between a aforementioned wall part and a pressure plate.

If the wall parts and the pressure plates assigned to them are penetrated by a clamping screw arranged in the center of the rods, it is advantageous to provide the guide pin mounting unit with a bore adapted to the clamping screw, and to attach it to the clamping screw, so that the clamping screw also the guide pin assembly unit is held in the correct position.

It is also possible to attach the guide pin mounting unit, which has a hole in the middle, to a pin, in particular in a non-rotatable manner, in particular in the center between the rods on a wall part or a pressure plate.

In this case, it is advantageous if the guide pins for the bore are arranged in a radially directed manner, so that relatively short and highly bending-resistant guide pins can be achieved with relatively little material.

A possibly preferred variant is characterized by radially inwardly directed guide pins formed on the spherical cap-like holders.

An embodiment of the invention is shown in the drawings and will be described in more detail below.

• Fig. 1 eine schematische Darstellung einer Schreibtischleuchte in der Vorderansicht, teilweise aufgebrochen, wobei der Kragarm senkrecht angeordnet ist ;
• Fig. 2 desgleichen von oben gesehen, teilweise aufgebrochen ;
• Fig. 3 desgleichen in der Vorderansicht, ebenfalls teilweise aufgebrochen, mit seitwärts verschwenktem Kragarm ;
• Fig. 4 desgleichen in der Seitenansicht, entsprechend der Linie IV-IV der Fig. 2 gesehen ;
• Fig. 5 eine schematische Darstellung einer Schreibtischleuchte in der Vorderansicht, teilweise aufgebrochen, wobei der Kragarm senkrecht steht ;
• Fig. 6 desgleichen gemäß der Linie VI-VI der Figur 5 gesehen ;
• Fig. 7 desgleichen im Schnitt der Linie VIIVII der Figur 6 gesehen.

It shows:

• Figure 1 is a schematic representation of a desk lamp in the front view, partially broken away, the cantilever is arranged vertically.
• Fig. 2 likewise seen from above, partially broken away;
• Fig. 3 likewise in the front view, also partially broken away, with the cantilever arm pivoted sideways;
• Fig. 4 also seen in side view, taken along the line IV-IV of Fig. 2;
• Fig. 5 is a schematic representation of a desk lamp in front view, partially broken away, with the cantilever arm being vertical;
• Fig. 6 also seen along the line VI-VI of Figure 5;
• Fig. 7 also seen in section on the line VIIVII of Figure 6.

This electric desk lamp essentially comprises a base part 1 designed as a foot, a cantilever arm 2 articulated thereon and an electric lamp 3 articulated at its upper end.

A clamp can also be provided on the base part 1 in order to be able to clamp the desk lamp, for example, on the desk.

The base part can also be designed as a fastening plate.

The cantilever arm 2 is assembled from three mutually identical and mutually parallel rods 4.

The bars 4 are equidistant from each other. A spherical thickening 5 is provided on both end parts of each rod 4.

For this purpose, the spherical thickenings 5 each have a diametrically directed bore through which a rod 4 is at least secured with static friction.

The thickenings 5 can also be integrally formed on the rods 4.

By means of the thickenings 5, the rods 4 are articulated in a spherically limited manner on the base part 1 or on the lamp 3.

For this purpose, a bore 8 is provided in the facing wall parts 6 and 7 of the base part 1 and the lamp 3, which are at least partially box-shaped, for each spherical thickening 5, the diameter of which is slightly smaller than the largest diameter of a spherical thickening 5. At the edge parts of these bores, the spherical thickenings 5 are pivotally supported and rotatable about the longitudinal axis of the rods 4.

Inside of the wall parts 6 and 7 are closed the latter parallel pressure plates 9 are provided (Fig. 1 to 4).

Or else the wall parts 6 and 7 are assigned pressure plates 9 running parallel to the latter (FIGS. 5 to 7).

These have the bores 8 in the shape, dimension and position of the same bores 10 and the spherical thickenings 5 are arranged on the edge parts of the bores 8 and 10 to be supported between the wall parts 6 and 7 and a pressure plate 9. To enlarge the pivoting range limited by the bores 8 and 10 for the rods 4 which also penetrate the bores 8 and 10, the bores 8 and 10 can have conical depressions (not shown) which, however, move outwards with the bores 8 and with the bores 10 expand inside.

Furthermore, effective clamping devices, not shown, are provided on the pressure plate 9, with the aid of which the spherical thickenings 5 can be clamped between the edge parts of the bores 8 and 10 such that, on the one hand, a manual adjustment of the rods 4 relative to the base part 1 and the lamp 3 is possible, but on the other hand the cantilever arm 2 and the lamp 3 are held frictionally in the respective preselected position without additional funds being required.

The tensioning devices are preferably tensioning screws, in particular to be operated from the outside, penetrating through the wall parts 6 or 7 and engaging on the pressure plates 9. In order to also ensure a translational adjustment of the lamp 3 relative to the base part 1, it is still necessary to provide articulated connections which prevent the rods 4 from twisting at both ends of the cantilever arm. For this purpose, a two-axis joint 11 is provided at the end of each rod, a first axis 12 of which extends through the rod 4 diametrically. The flanges of a U-shaped link 13 are articulated on the axle 12 and one end part of a second axle 14 is rotatably mounted in the web of the link 13.

The free end parts of the axes directed at right angles to the axes 12 and radially to the rods 4 are rotatably mounted on both ends of the cantilever arm 2 in a common connecting member 15.

In addition, all axes are immovably supported in the axial direction.

The joints 11 as well as the thickenings 5 are also identical to one another.

The electrical lead to the lamp 3 can for example be passed through the rods 4 if the latter are designed as tubes.

Instead of the ball joints, three-axis joints can also be provided to implement the invention, but three-axis joints are, among other things, considerably more complicated and expensive than ball joints.

5 to 7, in order to ensure a translational adjustment of the lamp 3 with respect to the base part 1, a groove 16 is arranged in each of the spherical thickenings 5, which runs parallel to the longitudinal extension of the rod 4 in the direction of its longitudinal extension.

In addition, the grooves 16 of the two spherical thickened portions 5 of each rod 4 are arranged in the same direction as one another.

In each of the grooves 16, a cylindrically profiled guide pin 17 held on the base part 1 or on the lamp 3 engages with little movement play.

The three guide pins 17 held on the base part 1 or on the lamp 3 are each combined to form an assembly unit, in particular in such a way that the guide pins 17 are radially braced from a common hub part 18 and are each formed in one piece in the direction of the center of a spherical thickening 5.

The hub part 18, which has a square bore 19 in the middle, is non-rotatably fitted onto a square-profiled pin 20 formed on the wall part 6 or 7 and is held securely in the axial direction between the wall parts 6 and 7 and a pressure plate 9.

The grooves 16 have the same depths over their entire length and, as can be seen from FIG. 7, each follow the curved surface of the spherical thickenings 5.

It is also possible to provide grooves 16 with a straight groove base, the latter extending parallel to the longitudinal extension of the rod 4.

In this case, the greatest depth of a groove 16 is greater than the insertion depth of a guide pin 17.

Claims (16)

1. An electric desk, table or standard lamp which comprises a pivoted cantilever (2) projecting from a base section (1), which cantilever carries a pivoted lamp (3) at its free end, where the cantilever (2) consists of at least three equal parallel rods (4) and each of these rods (4) is linked to the base section (1) and to the lamp (3) housing so that it can be swivelled spherically, characterized in that articulated connections are provided which prevent rotation of the rods (4) relative to one another.

2. A lamp according to Claim 1, characterized in that all the rods (4) are arranged at the same distance from one another.

3. A lamp according to Claim 1 or 2, characterized in that on all the rods (4), both near the base section (1) and near the lamp (3), there are spherical enlargements (5), at a distance from the ends of the rod, which are pivotably fastened in bearings in the form of a section of a sphere, which are situated in the base section (1) and the lamp (3) respectively, and which can be tightened to provide a greater or lesser frictional bearing for the spherical enlargements (5).

4. A lamp according to any one of the preceding Claims, characterized in that on each end of all the rods (4), both near the base section (1) and near the lamp (3), there is a two-axis joint (11) having a first joint pin (12) which is perpendicular to the longitudinal direction of the rods (4) and with a second, radially directed, joint pin (14) which is perpendicular to the first and to the associated rod (4), and in that the free ends of the second joint pins at each end of the cantilever arm are fastened rotatably to a common rigid connecting element (15).

5. A lamp according to Claim 4, characterized in that the first joint pins (12) of the two-axis joints (11) are each arranged to pass through the rods (4) diametrically, and that each of the first joint pins (12) is coupled to the flanges (13) of a U-shaped element in the cross-piece of which the facing end part of the second joint pin (14) is rotatably fastened.

6. A lamp according to any one of the preceding Claims, characterized in that in the facing wall parts (6 and 7 respectively) of the base section (1) and the lamp (3) a through hole (8) is provided for each rod (4) the diameter of each of which holes is, on the one hand, larger than the diameter of a rod (4) and, on the other hand, slightly smaller than the greatest diameter of a spherical enlargement on a rod (5) and, furthermore, a pressure plate (9) is associated with each of the above-mentioned wall parts (6 and 7) which plates can be tightened on the latter and in which plates there are through holes (10) which correspond in shape, size and position to the respective through holes (8) located opposite them in the above-mentioned wall parts (6 and 7), and in that the rods (4) each pass through a pair of opposite through holes (8, 10) whilst the enlargements on the rods (5) are arranged between the peripheral portions of the through holes (8, 10) in the wall parts and the pressure plates so that they can be clamped.

7. A lamp according to Claim 6, characterized in that the pressure plates (9) are located inside the base section (1) and the lamp (3) respectively.

8. A lamp according to any one of the preceding Claims, characterized in that the rods (4) are tubes through which electric wires can be led.

9. A lamp according to any one of the preceding Claims, where the lamp can be connected to a low electric voltage, characterized in that the rods (4) are made of material which conducts electricity, and the rods (4) are fastened in an electrically insulated manner to the base section (1) and to the lamp (3) and comprise electricity supply connectors especially located in the base section (1) and the lamp (3).

10. A lamp according to any one of Claims 1 to 9, characterized in that the spherical enlargements (5) each comprise at least one groove (16) the longitudinal direction of which is parallel to the longitudinal direction of the rods (4), the grooves (16) in both spherical enlargements (5) of each rod (4) being disposed in the same direction as one another, and in that guide pins (17) are arranged in the bearings which are in the form of a section of a sphere, which pins engage in a respective groove (16) so that they can be moved along the groove, and in that the spherical enlargements (5) can rotate about the longitudinal axes of the guide pins (17) which are engaged in the grooves (16).

11. A lamp according to Claim 10, characterized in that the guide pins (17) located in the bearings in the base section (1) region or the lamp (3) region are each produced connected together in a single one-piece mounting unit and they are attached to the respective bearings.

12. A lamp according to Claim 11, wherein the spherical enlargements are clamped between a wall part of the base section, or of the lamp, and a pressure plate so that they can be swivelled spherically, and the rods pass with clearance through through holes in the above-mentioned wall parts and in the pressure plates, whereas the spherical enlargements bear on the peripheral parts which face them of the through holes which are smaller in diameter than the spherical enlargements, characterized in that the guide pins (12) which are assembled into a mounting unit are each inserted between the appropriate above-mentioned wall part (6 or 7) and pressure plate (9).

13. A lamp according to Claim 12 wherein a tightening screw located in the centre of the rods passes through, amongst other things, the wall plates and the associated pressure plates, characterized in that the guide pin-mounting unit comprises a through hole adapted to the tightening screw and is mounted on the tightening screw.

14. A lamp according to Claim 13, characterized in that the guide pin mounting unit which comprises a through hole (19) in the middle is mounted, especially so that it cannot rotate, on a lug (20) which is formed, especially in the centre between the rods (4), on a wall part (6 or 7) or a pressure plate (9).

15. A lamp according to Claim 13 or 14, characterized in that the guide pins (17) are arranged radially to the through hole (14).

16. A lamp according to any one of the preceding Claims, characterized by guide pins (17) which are formed directed radially inwards on the bearings in the form of a section of a sphere.

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