EP0185230B1 - Construction of a supporting arm for dental purposes - Google Patents

Abstract

The present invention is directed to a bracket structure which has one or more tubular members interconnected by elbow members. At least one of the tubular members is connected to an elbow member by a plug-type connection having a socket receiving a pin part with the socket and pin part being constructed so that no twisting will occur between the two parts in the assembled position but the two parts can be disassembled and reassembled with the position of the parts being rotated through at least 180 DEG relative to each other. This provides the advantage of enabling easy changing of the bracket from being adapted for a floor mounting to a ceiling mounting.

Description

From US-A-39 02 246 a support arm construction for a dental instrument table is known, in which on a bottom-side vertical support tube (stand) a first and in turn a second horizontal support arm carrying the instrument table at its free end, each by means of a swivel joint are articulated. Such a support arm construction can only be used in the intended arrangement, i.e. the support arm construction shown there with the base-side stand is not readily usable for ceiling mounting. Conversely, a support arm construction designed for ceiling mounting would not be readily usable for floor mounting. Furthermore, the addition, omission or shortening of support tubes in the known construction is not possible or not possible without complex modification of the construction.

The invention specified in claim 1 is based on the object to provide an improved support arm construction. Due to the construction according to the invention of the support arm construction explained in more detail below, it is possible to put together an individual support arm construction with regard to the bends and support tubes to be provided and their lengths, using the same components in each case.

An embodiment of the invention is explained below with reference to the drawing.

• Figur 1 die erfindungsgemässe Tragarmkonstruktion alternativ für Boden- oder Deckenbefestigung verwendbar,
• Figur 2 den Querschnitt eines Tragrohres,
• Figur 3 einen Teil des Rohrbogens im Längsschnitt,
• Figur 4 eine Frontansicht auf den Rohrbogen nach Figur 3,
• Figur 5 eine obere Verkleidungshalbschale für den Rohrbogen nach Figur 3,
• Figur 6 eine Frontansicht von der oberen Verkleidungshalbschale,
• Figur 7 eine untere Verkleidungshalbschale für den Rohrbogen nach Figur 3 im Längsschnitt,
• Figur 8 eine Frontansicht von der unteren Verkleidungshalbschale,
• Figur 9 das eine Ende eines Rohrbogens in schaubildlicher Ansicht,
• Figur 10 das zu Figur 9 passende Ende eines Tragrohres.

Show it:

• FIG. 1 the support arm construction according to the invention can alternatively be used for floor or ceiling fastening,
• FIG. 2 shows the cross section of a support tube,
• FIG. 3 shows part of the pipe bend in longitudinal section,
• FIG. 4 shows a front view of the pipe bend according to FIG. 3,
• FIG. 5 shows an upper cladding half-shell for the pipe bend according to FIG. 3,
• FIG. 6 shows a front view of the upper cladding half-shell,
• FIG. 7 shows a lower cladding half-shell for the pipe bend according to FIG. 3 in longitudinal section,
• FIG. 8 shows a front view of the lower cladding half-shell,
• FIG. 9 shows one end of a pipe bend in a diagrammatic view,
• Figure 10 shows the end of a support tube matching Figure 9.

FIG. 1 shows a schematic representation of an embodiment of the support arm construction according to the invention for the pivotable mounting of a dental instrument table. The support arm construction consists of a vertical support tube 2 fastened to a base-side stand 1, two horizontal support tubes 3 and 4 as well as pipe bends 5 to 8 for connecting the support tubes to one another or to the instrument table 9. ...._._.._. ..,

in which, using the same components, the support arm construction is provided for ceiling mounting and for this purpose also contains a vertical support pipe 2 'and a pipe bend 5' which is offset by 180 ° with respect to the previously explained arrangement.

The support arms 3 and 4 can be pivoted at the points shown by arrows, otherwise the parts are rigid, i.e. non-rotating, connected to each other. In order to enable a certain height adjustment of the instrument table 9, either an additional height-adjustable support arm can be provided, or the support arm designated by 4 can be designed as a parallelogram support arm.

An essential characteristic of the support arm construction is that the support tubes 2, 3, 4 have a constant profile, preferably extending over their entire length, which, as will be explained in more detail later, fits a correspondingly designed counter profile on the tube bends 5 to 8, so that a rotationally fixed connection between the pipe bend and the support pipe can be established by axially plugging together. The profile is designed in such a way that the pipe bend can alternatively preferably be used offset by 180 ° with respect to the support tube, so that, as shown in dashed lines in FIG . The profile of the support tubes is shown in Figure 2. It is formed by a tube with a cylindrical outer circumferential surface and four evenly distributed on the circumference and over the entire length of the support tube extending inner elevations 11 and intermediate recesses 12 which form axially parallel webs and grooves in between. A corresponding counter profile has one end of the pipe bends 5 to 8, as will be explained with reference to FIGS. 3 and 4 using the example of the pipe bend 7. The pipe bend consists of a base body 13 (blank), which has a plug pin 14 at one end and a bore 15 at its other end for receiving a pivot pin of a further pipe bend adjoining it (e.g. pipe bend 6). The pivot is axially secured by means of an angle plate 25 screwed onto the base body 13. The plug pin 14 is provided with a counter profile matching the profile according to FIG. on the spigot 14 there are also on the one hand four evenly distributed longitudinal grooves 16 that fit the elevations 11 of the support tube profile, and intermediate webs 17 that match the longitudinal grooves 12 of the support tube profile.

In the area of the bend, the base body 13 contains a recess 18, which provides access to the inside of the pipe, as a result of which, for example, lines laid inside can be replaced more easily. The outer surface of the basic body 13, which is not machined per se, is covered by two art shown in FIGS half-shells, an upper half-shell 19 (Figure 5) and a lower half-shell 20 (Figure 7). The two half-shells 19 and 20 contain suitable coupling elements 21, 22 which come into engagement with one another when the half-shells are placed on the base body 13. Such coupling elements, which are preferably designed as snap connection elements, are known per se. The lower half-shell 20 can be fastened to the base body 13 by suitable fastening means, for example also in the form of snap elements 23, 24. In the attached state, the recess 18 in the base body 13 is covered by the half-shell 19. A major advantage of this construction is that the surface of the base body 13 does not need to be finely machined, since the two half-shells 19 and 20 can already have the necessary surface properties as plastic injection-molded parts which can be produced very cheaply. Another advantage is that the customer's different color requirements can be taken into account in the creation of the plastic half-shells, so that time-consuming painting work on the elbow itself is no longer necessary. Another advantage, as already mentioned, is that cables that are installed in the entire support arm construction can also be very easily retrofitted or replaced, because by removing the upper half-shell 19, good access to the recess 18 in the critical area of the pipe bend the cables laid inside are given.

The connection of the pipe bend 5 or 5 'to the vertical support pipe 2 or 2' is explained in more detail with reference to FIGS. 9 and 10. This connection is a rotatable connection, i.e. the pipe bend can be rotated around 360 ° around the support pipe. Such a connection can also exist between the arch 7 and the arch 6.

A pipe 26 protruding in the form of a pin is screwed or otherwise fastened into the bore 15 according to FIG. A plastic bushing 27 is placed thereon and axially secured by means of washer 28 and spring ring 29. The plastic bushing 27 together with the tube 26 forms a slide bearing, i.e. the socket is freely rotatable relative to the tube 26. At 30 circumferentially arranged locking elements are designated, which correspond in profile to the profile of the pin 14 at the other end of the bend, so that they match the tubular profile shown in FIG. As shown in FIG. 10, the tube contains a recess or undercut 31, the depth of which corresponds to that of the latching elements 30, so that when tube 2 and bend 5 are joined together, the parts are inserted axially via the recesses 12 and after the two parts are rotated Bayonet-like connection is created, which absorbs the axial forces when suspended. To secure the connection, a set screw 32 can be provided in the support tube 2, which engages in a thread or in a blind hole 33 in the plastic bushing 27 and thus prevents the bayonet connection from being unscrewed.

To prevent overtightening of the two parts 2 and 5, the turning range can be limited to a maximum of 360 °, e.g. in the form of a stop pin or the like. Be present, which are then attached at the point marked 34 in the support tube and at a corresponding point in the tube 26.

Claims (9)

1. Supporting arm construction assembled from one or more straight bracing tubes and one or more tube bends, characterised in that the bracing tube (2 to 4) and tube bend (5 to 8) have an insertion profile adapted to each other (Figure 2), which is constructed in such a way that a torsionally strong connection of the parts (5, 3; 3, 6; 7, 4; 4, 8) is made possible in positions displaced by 180° or a smaller angle.

2. Supporting arm construction according to claim 1, characterised in that the profile (Figure 2) contains four bars and slots which are arranged evenly distributed on the perimeter, are formed by projections (11,17) and cavities (12,16) and run lengthwise.

3. Supporting arm construction according to claim 1 or 2, characterised in that the bracing tube (2 to 4) has a continuous profile which stretches along its entire length (Figure 2).

4. Supporting arm construction according to one of claims 1 to 3, characterised in that the tube bend (5, 7, 8) is provided at one end with an insertion pin (14) having the profile (16,17) and at the other end with a receiving hole (15) for a turning pin (26).,

5. Supporting arm construction according to claim 4, characterised in that the tube bend (5 to 8) is formed by a basic body (13) with overlaid half shells (19, 20) which cover the outer surface.

6. Supporting arm construction according to claim 5, characterised in that the basic body (13) contains a recess (18) in the region of the bend.

7. Supporting arm construction according to claim 5, characterised in that the half shells (19, 20) are connected with each other by means of clip elements (21, 22).

8. Supporting arm construction according to one of claims 4 to 7, characterised in that a tube (27), which is provided with bayonet coupling links (30) adapted to the profile (Figure 2) and can be freely turned with respect to the turning pin (26), is placed on the turning pin (26) and axially secured (Figure 9), and in that the bracing tube (2) which is to be connected to the tube bend (5) contains corresponding opposite links (31 ) on at least the end on the connecting side.

9. Supporting arm construction according to claim 8, characterised in that the opposite links (31 ) are formed by a recess or relief of the profile (11,12).

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