Technical Field

The invention relates to an axial electromagnetic brake, in particular to the axial electromagnetic brake of the rotatable arm of a ceiling tripod arranged at the conjunction of the supporting axis and the rotatable arm of the ceiling tripod, on which are arranged supported medical apparatus and instruments.

State of the Art

Currently, a large number of design solutions of various types of electromagnetic brakes are known.

From patent document CS79941 there is known an annular electromagnetic brake whose electromagnet is designed to be a non-rotating circular or annular magnet for alternating current, divided by an oblique air slot on a conical non-rotating core and a non-rotating stator ring, which is known in itself as a way of shifting in an axial direction with its displacement causing the brake disk to brake or release.

From another patent CS164327, there is known an electromagnetic friction brake for electric motors, provided with an additional hydraulic device for downforcing the braking elements by means of an armature of electromagnets. The auxiliary hydraulic device is slidably mounted in the electromagnet housing and is engaged via a forked arm and a stop ring with the electromagnet core, while the core is secured against accidental displacement by friction inserts.

Another electromagnetic brake is known from patent document CS174939. The electromagnetic brake comprises an armature and a core in the form of a ring having an axial cross-section in an E-shape, provided with a winding. The core ring is composed of at least one moulding of sintered soft ferromagnetic material, with the winding being fastened in the grooves of the friction ring core by a grouting compound.

From patent document CS 274792 is further known a static electromagnetic brake, consisting of a bearing shield with an outer half-ring and an inner half-ring, to which the armature holder adjoins across an air gap. A nut is screwed into the shaft of the electric motor, on which the first spring is supported, its other end being supported by one face of the armature holder and, to the second face of the armature holder, is located a second spring whose opposite end is supported on the shoulder of the shaft.

From another patent document CZ 304251 is further known a twin electromag netically released spring brake provided with two, equally spaced electromagnets arranged coaxially with the brake rotor coils, between which axially movable braking armatures are arranged. The braking armatures are pushed from the electromagnets by spring assemblies mounted in brackets. The spacing of the electromagnets is ensured by spacers. The brake rotor is arranged between both brake armatures and is axially slidably mounted on the mounting hub by means of a system of support pins distributed around the perimeter of the mounting hub. The braking armatures are axially slidably mounted on fastening bolts that pass through both carriers.

The main disadvantage of current technology is that the braking effect is usually created only while supplying energy from an external source.

The object of the invention is to design a simple and fully functional axial electromagnetic brake which will not be, in the braked state, dependent on external energy sources and which will likewise be usable in medical facilities.

Principle of the Invention

The above-mentioned disadvantages are largely removed, and the objectives of the invention are fulfilled by an axial electromagnetic brake, specifically an axial electromagnetic brake of the rotatable arm of a ceiling tripod arranged at the conjunction of the supporting axis and the rotatable arm of the ceiling tripod, on which are arranged supported medical apparatus and instruments, according to the invention whose basis is that it comprises, attached to the support axis, a ring with an electromagnetic core which is, by means of at least one guide element, connected to a brake flange which abuts a braking counterpart to which a rotatable arm is connected, with the ring being divided into at least two annular sections. The advantage of this design is that the brake generates continuous frictional braking resistance without the need to supply power from an external source, while in the braked state there is no need to supply electricity to the brake which could permanently interfere with sensitive electrical devices. Electricity is only supplied to the brake to induce release. Another advantage is that it is a ring composition of two halves and thus enables its assembly or disassembly on the assembled ceiling tripod, which eliminates the time needed for assembly and disassembly of other parts during assembly as well as for inspection and service.

It is to advantage that on the guide element a compression spring is mounted. The advantage being that two functions are combined in one structural detail.

Furthermore, it is to great advantage if the brake flange is divided into at least two flange sections. The advantages are the same as the above noted two-part ring composition.

In terms of simplicity and full functionality of the structure it is to further advantage when the guide element is a pin which is fixedly mounted in the brake flange and slidably mounted in a guide opening arranged in the ring. The guide element may alternatively be fixedly mounted in the ring and slidably mounted in the brake flange. According to a further possible variant, the guide element can also be mounted directly on the support axis.

Advantageously, additionally mounted in the ring is at least one coupling means, with which the ring is connected to the braked counterpart. Alternatively, the coupling means may be mounted in the braked counterpart and instead be connected to the ring.

It is also to advantage if the brake flange is provided with a braking segment. The advantage is longer service life of the contact surfaces and higher efficiency.

Furthermore, it is also advantageous if the electromagnetic core is connected to a source of electricity.

The ring and the brake flange are to advantage made of metal.

The main advantage of the design solution according to the invention is that in the braking mode, there is no need to supply electricity to the brake which could permanently interfere with sensitive electrical devices, while the brake, even when in the release mode, fulfils the electromagnetic interference values in accordance with current norms for electrical medical devices. The brake can be used to advantage where compressed air is not available for operating pneumatic brakes. Another advantage is that the power of the electromagnetic core and the force of the compression springs can be easily combined to achieve the optimum braking effect. The braking effect can be adjusted so that in the event of an electricity outage, the rotatable arm is able to be adjusted by only exerting a manual force on it, thus reducing the risk of limited access to the patient. Overview of the Figures

The invention will be more closely elucidated using drawings, in which Fig. 1 is a perspective view of a partial breakdown of individual parts of an axial electromagnetic brake, Fig. 2 shows a frontal view of a section of an axial electromagnetic brake, Fig. 3 shows a detailed perspective view of a breakdown of individual parts connecting the ring and brake flange, Fig. 4 shows a detailed cross- sectional view of a ring with a single electromagnetic core, Fig. 5 shows a detailed cross-sectional view of a ring with two electromagnetic cores and Fig. 6 shows a perspective view of the breakdown of individual parts of an axial electromagnetic brake including a breakdown of the covering.

Examples of the Performance of the Invention

An axial electromagnetic brake 1 of the rotatable arm H of a ceiling tripod (Fig. 1 , Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6) is arranged in conjunction with the support axis 12 of the ceiling tripod and the rotatable arm 1_1 on which are arranged supported medical apparatus and instruments.

The axial electromagnetic brake (Fig. 1 , Fig. 2) comprises, attached to the support axis 12, a metal ring 2 with an electromagnetic core 3 which is by means of a whole series of guide elements 8 connected to a metal brake flange 6, which abuts the braked counterpart 10, to which is connected the rotatable arm I T On the guide elements 8 are mounted compression springs 5, which push the brake flange 6 against the braking counterpart 10, thereby causing friction and thus leading to mutual braking. The compression springs 5 are also arranged beyond the guide elements 8.

The ring 2 is divided into at least two annular sections 13, 14.

Both the annular sections 13, 14 (Fig. 2, Fig. 5) contain two electromagnetic cores 3.

Alternatively, the two annular sections 13, 14 (Fig. 4) comprise a single electromagnetic core 3.

The brake flange 6 is divided into at least two flange sections 15, 16. The guide elements 8 (Fig. 3) are pins which are fixedly mounted in the brake flange 6 and slidably mounted in a guide opening 9 arranged in the ring 2. The guide elements 8 ensure fluid movement of the brake flange 6.

In the ring 2 are mounted a whole series of coupling means 4 by which the ring 2 is connected to the braked counterpart 10.

The brake flange 6 is provided with a braking segment 7.

The electromagnetic core 3 is connected to a source of electricity.

The axial electromagnetic brake 1 is provided with a split cover 17.

To the support axis 12 is fixed a connecting piece 18 by which the entire ceiling tripod is attached to the ceiling.

The axial electromagnetic brake 1 operates in such a way that at the moment when, through the electromagnetic core 3, electricity begins to flow, magnetic forces are exerted by the electricity which overcome the force of the compression springs 5, with the metal brake flange 6 containing the braking segment 7 being pulled towards the metal ring 2 so that by removing the pressure of the brake flange 6, friction force is no longer exerted on the braked counterpart 10 and the rotatable arm 1_1 can be moved. After the electric supply to the electromagnetic core 3 has been interrupted, the magnetic forces cease and the compression springs 5 again press the metal brake flange 6 containing the braking segment 7 onto the inner face of the support axis 12.

Industrial Application

The axial electromagnetic brake according to the invention can especially be used as an electromagnetic axial brake of the rotatable arm of a ceiling tripod, on which are arranged supported medical apparatus and instruments.

List of Reference Marks

1 axial electromagnetic brake

2 ring

3 electromagnetic core

4 coupling means

5 compression spring

6 brake flange

7 braking segment

8 guide element

9 guide opening

10 braked counterpart

11 rotatable arm

12 support axis

13 annular section I

14 annular section II

15 flange section I

16 flange section II

17 covering

18 connecting piece