Safety brakes for the latest medical technology to protect the patient

Details: Released: 03.06.2015; Last updated: 25.11.2023; Hits: 5772

Electromagnetic spring-loaded brakes precisely ensure the function of high-quality medical devices such as X-ray machines, surgical microscopes or electric wheelchairs. Mayr Antriebstechnik offers application-optimized and efficient solutions for the high requirements of medical technology such as the "Roba-stop-M".

Medical devices must meet the highest technical and quality requirements. The safety of the patient at all times, an exact positioning of the equipment, a reliable hold in a certain position as well as a quiet and smooth operation have top priority. The electromagnetic Roba-stop-M-Safety brakes easily meet these requirements. In addition, these brakes are characterized by minimal energy consumption, very low self-heating and extremely short switching times. The long service life, the low maintenance requirements and the quick and easy installation also make the brake a particularly economical solution.

Safe grip with fail-safe principle

The electromagnetic, quiescent current-operated spring-applied brakes work according to the fail-safe principle. After the power is switched off, in the event of a power failure or emergency stop, the brakes ensure that machines and systems are held reliably and safely in any position. But even if there is damage - caused, for example, by a broken cable or failure of the solenoid coil - the braking torque is retained.

If the power is turned on, the brake a magnetic field builds up. The armature disc is thereby drawn against the spring pressure to the coil carrier. The rotor is connected via a gear hub to the motor shaft is free so, that is, the brake is released and the shaft can rotate freely.

With respect to operational reliability and ease of maintenance, the ROBA-stop-M brakes crucial points when compared to many other spring-applied brakes. They impress with their closed design and the consequent high degree of protection IP or IP 54 65 in sealed design. Designed for a duty cycle of 100% they are maintenance-free service life of the friction linings. In addition, the compact and functionally reliable construction allows fast and economical installation. By constructively predefined, tested and unchangeable working air gap also mounting and adjustment errors are avoided. The variable spring configurations for different torques makes the brakes particularly flexible.

High-tech devices in the field of medical technology often require individual brake solutions. The drive specialist offers a broad portfolio of application-optimized safety brakes based on market-tested series. These meet individual customer requirements and have the same quality, technical maturity and safety as the standard product.

Mobile in the electric wheelchair

For mobile use in electric wheelchairs (pictured above), for example, the safety brakes are equipped with a suitable for 12 VDC battery voltage solenoid. Simple Permanent magnetic brakes which are not designed for frictional work, come here as an engine brake for the single wheel is not in question: For electric wheelchairs are not only accelerated and decelerated during the drive, but the unit must be placed when the battery voltage in a short time automatically to a standstill and stopping on gradients safely and reliably. However, it must also be possible if the power fails, to move the vehicle manually. For the case of ROBA-stop-M usual manual release bracket has been replaced by a Bowden cable, with which the brake can be opened manually.

The brakes are sealed and operate extremely quietly. For additional corrosion protection there are hard-chrome plated versions. Precise switching times ensure synchronous operation of the two individual wheel. To prevent accidental bends that would otherwise arise, especially in Notabbremsungen.

The surgical microscope stand

Their high reliability and flexibility, the Roba-stop-M safety brake even when used in surgical microscope stands the test. These serve to bring a microscope in position during a medical operation. Such microscope stands are made up of a mobile base frame, two boom arms and the optical microscope itself. The arms are connected to joints. The safety brakes, the tripod arms are fixed in position. For moving the microscope stand, the brake opens, the doctor can then move the tripod arms manually. Is the correct position is reached, closes the brake.

During the operation, the brake must hold the position without play. In addition, brake noise is a problem. Should there be a power failure, the doctor has the microscope joint but can move with a certain effort manually. Therefore, the maximum torque of the brakes must not significantly exceed the set braking torque. Featuring precision components for safe torque transmission, integrated noise reduction and clearance-free conical bush as a connection between the hub and shaft, the ROBA-stop-M brake therefore is very well suited for use in the described surgical microscope stands.

Other applications

The brakes ensure freedom from play and low-noise operation in telescopic treatment tables for ophthalmologists and opticians alike. The double extension of the telescopic table has a on the underside Timing beltsgear that retracts and extends the two telescopic segments. A holding brake in a noise-damped design on a toothed belt pulley ensures that the telescopic extension is held without play and thus guarantees optimal patient treatment.

In X-ray machines with C-shaped cross-member, which is driven by a ball screw assembly up and down, safety brakes are used. In this C-arm, the patient bed is retracted, the also can move up and down. In the event of an operator error, it can happen that the sun strikes the C-arm and this damaged. The prevent two brakes: An engine brake is used to brake the movement and moves the C-arm thus in position. A second additional safety brake, which is attached to the ball screw, then think of the weight of the arch keeps reliable, slips in through collision with the sun. The applied brake extremely quiet and could be tuned by the variable spring configurations specific to the required braking torque.

Similar requirements are met by safety brakes in tomography are also problems. For the investigation with computed tomography, an exact positioning of the patient and absolute cessation of Liege are indispensable. A lying structure is up for example, a ball screw assembly and drove down. Once the correct position is reached, the drive must lock reliably. Even when you switch off the engine or power failure, the deck has to be kept exactly in position to prevent injury to the patient or damage to the machine.

Here two safety brakes are used in the package, a motor on and at the opposite end of the ball screw. Both brakes hold the spindle with the required braking torque. The brake on the spindle combined with a rear clutch, allowing upward movement of the sun and with the brake closed. If the current is switched off, the deck is secured against slipping back. Another advantage is the compact design of the brakes, with the required here, particularly flat, space-saving design was achieved.