Pinching device

Abstract

The invention describes a pinching device for controlling flows in elastic tube lines. The pinching device comprises two wheels, wherein the first wheel is designed as an eccentric wheel and is fastened eccentrically on a drive shaft and the second wheel is fixed in a predefined position relative to the eccentric wheel, wherein the position of the second wheel can be adjusted. The eccentric wheel can be rotated via the drive shaft about the eccentric axis of the eccentric wheel in the direction of the second wheel in order to pinch a tube positioned between the two wheels.

Claims

1. A pinching device for controlling flows in elastic tube lines, wherein the pinching device comprises two wheels and a base plate, wherein a first wheel of the two wheels is designed as an eccentric wheel having a circular outer periphery and rotatably driven about an eccentric axis offset from a center of the eccentric wheel and within the outer periphery of the eccentric wheel, the outer periphery of the eccentric wheel being defined by a ring slidably mounted on the eccentric wheel for rotation about the center of the eccentric wheel, and a second wheel of the two wheels is arranged in a predetermined position relative to the eccentric wheel and is fixed to the base plate, wherein the position of the second wheel is adjustable, and wherein the eccentric wheel is rotatable via a drive shaft about the eccentric axis of the eccentric wheel in the direction of the second wheel in order to bring a circular outer periphery of the ring on the eccentric wheel into engagement with a tube positioned between the wheels and pinch the tube, wherein the pinching device comprises at least one guide rail with a recess opening on one side to receive the tube and which the at least one guide rail serves to attach the pinching device at any desired position on the tube.

2. The pinching device according to claim 1, wherein a peripheral edge of one of the first and second wheels has a convex shape and a peripheral edge of the other of the first and second wheels has a concave shape.

3. The pinching device according to claim 1, wherein the ring mounted on the eccentric wheel comprises a ring of slidable material having a peripheral edge with a convex shape.

4. The pinching device according to claim 1, wherein the device comprises an electric drive for driving the eccentric wheel via the drive shaft.

5. The pinching device according to claim 4, wherein the electric drive comprises an electronic control system which is connected to the drive shaft via a motor and a reduction gear.

6. A method for controlling the device according to claim 5, wherein current consumption of the motor is used as a control variable for the electronic control system.

7. The pinching device according to claim 1, wherein the second wheel comprises at least two spacer bushings, via which the position of the second wheel on the base plate is adjustable.

8. The pinching device according to claim 1, wherein the pinching device comprises two guide rails, wherein the two wheels are arranged between the two guide rails.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The drawings show as follows:

(2) FIG. 1 shows the pinching device in a view from the front,

(3) FIG. 2 shows the pinching device in a view from above according to II, as shown in FIG. 1,

(4) FIG. 3 shows the pinching device in perspective view from the front.

(5) In the figures, the same reference numerals have been used for the same elements, and initial explanations apply to all figures unless explicitly stated otherwise.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) FIG. 1 shows the pinching device 14 with an eccentric wheel 5 and a second wheel 8. The eccentric wheel 5 is connected via a drive shaft 7 to a reduction gear 11 (shown in FIG. 2) and, in order to pinch the tube 4, can be rotated via the drive shaft 7 around the eccentric axis in the direction of the second wheel 8 in the direction of arrow A. The second wheel is thereby fixed in its position to the eccentric wheel 5. To open the tube 4, the eccentric wheel 5 can be turned in the opposite direction of arrow A. Around the eccentric wheel 5 there is a sliding ring 6, which is held in position axially relative to the wheel axis by two disks 15 (whereof only one is visible). If the eccentric wheel 5 is turned clockwise, the sliding ring 6 presses on the tube 4 and against the second wheel 8, pinching the tube 4 between the two wheels. The second wheel 8 is fastened to the base plate 1 using a bushing 9 and a stud bolt (not shown). The bushing 9 is arranged eccentrically. The position of the second wheel 8 can be adjusted relative to the first wheel around the eccentric axis of the bushing 9. In this exemplary embodiment, the second wheel 8 comprises four spacer bushings 10 which can be used to adjust the position of the second wheel 8 and to adapt it to the tube diameter and fix it in the desired position. In addition, the base plate 1 is shown with two guide rails 2 arranged parallel to each other and fixed to the base plate 1. The guide rails 2 with the recesses 3 serve to guide a tube 4 into position.

(7) FIG. 2 shows the pinching device 14 as described in FIG. 1 with the reduction gear 11, the motor 12 and the electronic control system 13. To close the flow in the tube line 4, a control signal can be given to the electronic control system 13 which switches on the motor 12. This motor drives the eccentric wheel 5 via the reduction gear 11 and the drive shaft 7 and presses via the convex ring 6 on the center axis of the tube line 4. Thus, the center axis of the tube can be deformed towards the second wheel 8. The convex shape of the wheel edge of the eccentric wheel 5 has a profile which is tapered towards the center of the wheel axis and has a rounded end. The tube 4 presses against the concave shape of the second wheel 8 until the tube cross-section is closed. The concave shape of the wheel edge of the second wheel 8 has a circular arc profile. A central role in this process is played by the sliding ring 6, which is made of a slidable material and is held in position by two disks 15 to prevent it from slipping off the eccentric wheel 5. This greatly reduces the axial frictional resistance that builds up during the pinching process. If the sliding ring 6 is in contact with the tube 4 to be pinched, the sliding ring 6 remains in position relative to the tube 4, so that essentially no friction occurs between tube 4 and sliding ring 6. If the eccentric wheel 5 continues to rotate, the eccentric wheel 5 moves relative to the sliding ring 6, while the sliding ring stops. When the tube 4 is completely compressed, the power consumption of motor 12 increases to such an extent that it can be used as a control variable for the electronic control system to cut off the power supply to motor 12. When the power consumption of motor 12 reaches a limit value, the power supply is interrupted. The tube 4 thus remains closed.

(8) To open the flow, the control signal to the electronic control system is interrupted again. Thus, the electronic control system controls the electric motor and the drive shaft in the opposite direction. Thus, the eccentric wheel turns counterclockwise and the cross-section of the tube increases until the full cross-section is reached again. The motor is switched off by time or an end position signal.

(9) FIG. 3 shows the pinching device 14 with the eccentric wheel 5 and the second wheel 8 as described in FIG. 1. The tube is not shown in FIG. 3. By rotating the drive shaft 7 clockwise, the convex shape of the sliding ring 6 of the eccentric wheel 5 can be moved in the direction of the concave shape of the second wheel 8 with the bushing 9 and the other bushings 10 and pinch a tube. The two guide rails 2 arranged in parallel on the base plate 1 with the recesses 3 for guiding a tube are also shown.

(10) Although various embodiments of the present invention have been described and shown, the invention is not restricted thereto, but may also be embodied in other ways within the scope of the subject-matter defined in the following claims.