Pivot actuator

Abstract

A pivot actuator comprising: a housing; a piston supported in the housing; a drive shalt protruding from the housing wherein the piston engages the drive shaft to rotate the drive shaft about a drive axis by a pivot angle between two end positions; and a switching cam coupled to the drive shaft and configured to contact a stop element in the two end positions, wherein the switching cam includes two discs arranged adjacent to one another along the drive axis.

Claims

1. A pivot actuator, comprising: a housing; a piston disposed within the housing and displaceable along a longitudinal axis of the housing; a drive shaft rotatably coupled to the housing, wherein the piston engages the drive shaft so that movement of the piston within the housing causes the drive shaft to pivot in a first direction about a drive axis within a first pivot angle to a first end position and to pivot in a second direction about the drive axis within a second pivot angle to a second end position; a first stop element configured to adjustably select the first end position; a second stop element configured to adjustably select the second end position; a switching cam configured to be coupled to and pivot with the drive shaft about the drive axis in the first and second directions, the switching cam including: a first disc configured to be coupled to and pivot with the drive shaft about the drive axis, the first disc including a first central region and a first radial protrusion extending outwardly from the first central region, the first central region having a thickness parallel to the drive axis and configured to be coupled to the drive shaft and the first radial protrusion having a thickness parallel to the drive axis and including a first stop surface configured to contact the first stop element to limit rotation of the drive shaft in the first direction about the drive axis to the first end position, wherein the thickness of the first radial protrusion is greater than the thickness of the first central region; and a second disc configured to be coupled to and pivot with the drive shaft about the drive axis, the second disc including a second central region and a second radial protrusion extending outwardly from the second central region, the second central region having a thickness parallel to the drive axis and configured to be coupled to the drive shaft and the second radial protrusion having a thickness parallel to the drive axis and including a second stop surface configured to contact the second stop element to limit rotation of the drive shaft in the second direction about the drive axis to the second end position, wherein the thickness of the second radial protrusion is greater than the thickness of the second central region.

2. The pivot actuator of claim 1, wherein the first end position is adjustably selected by moving the first stop element along a first adjustment axis transversal to the drive axis.

3. The pivot actuator of claim 1, wherein the first disc and the second disc are offset along the drive axis.

4. The pivot actuator of claim 1, wherein the first disc is configured to be coupled to the drive shaft prior to the second disc being coupled to the drive shaft.

5. The pivot actuator of claim 1, wherein a combined thickness of the first and second central regions is substantially the same as the thickness of either the first or second radial protrusions.

6. The pivot actuator of claim 1, wherein the first and second discs are configured to be coupled to and nested along the drive shaft.

7. The pivot actuator of claim 1, the thickness of the first and second radial protrusions is substantially the same and a combined thickness of the first and second central regions is substantially the same as the thickness of the first and second radial protrusions.

8. The pivot actuator of claim 1, wherein the first central region and the second central region are configured to contact each other when the first disc and the second disc are coupled to the drive shaft.

9. The pivot actuator of claim 1, wherein the first central region has a first top surface and a first bottom surface, and wherein the first radial protrusion has a first upper surface coextensive with the first top surface and a first lower surface which extends beyond the first bottom surface in a first direction parallel to the drive axis when the first disc is coupled to the drive shaft; and wherein the second central region has a second top surface and a second bottom surface, and wherein the second radial protrusion has a second upper surface coextensive with the second top surface and a second lower surface which extends beyond the second bottom surface in a second direction parallel to the drive axis and opposite to the first direction when the second disc is coupled to the drive shaft.

10. The pivot actuator of claim 1, wherein the first central region includes a first axial receiving opening and wherein the second central region includes a second axial receiving opening.

11. The pivot actuator of claim 10, wherein the first and the second axial receiving openings include a star shape.

12. The pivot actuator of claim 10, wherein the first and the second axial receiving openings include an eight pointed star.

13. A pivot actuator, comprising: a housing; a piston configured to be moveably disposed within the housing; a drive shaft rotatably coupled to the housing, wherein the piston engages the drive shaft so that reciprocal movement of the piston within the housing causes the drive shaft to pivot in a first direction about a drive axis to a first end position and to pivot in a second direction about the drive axis to a second end position; a first stop element configured to adjustably select the first end position; a second stop element configured to adjustably select the second end position; a switching cam including: a first disc configured to be removable secured to the drive shaft and rotate about the drive axis, the first disc including a first central region and a first radial protrusion extending outwardly from the first central region, the first central region having a thickness parallel to the drive axis and configured to be coupled to the drive shaft, the first radial protrusion having a thickness parallel to the drive axis and including a first stop surface configured to contact the first stop element to limit rotation of the drive shaft in the first direction about the drive axis to the first end position; and a second disc to be removable secured to the drive shaft and rotate about the drive axis, the second disc including a second central region and a second radial protrusion extending outwardly from the second central region, the second central region having a thickness parallel to the drive axis and configured to be coupled to the drive shaft, the second radial protrusion having a thickness parallel to the drive axis and including a second stop surface configured to contact the second stop element to limit rotation of the drive shaft in the second direction about the drive axis to the second end position; wherein a combined thickness of the first and second central regions is substantially the same as the thickness of either the first or second radial protrusions; and wherein the first disc may be secured to the drive shaft independently from securing the second disc to the drive shaft.

14. The pivot actuator of claim 13, wherein the first disc and the second disc are offset along the drive axis.

15. The pivot actuator of claim 13, wherein the first and second discs are configured to be coupled to and nested along the drive shaft.

16. The pivot actuator of claim 13, wherein: the first central region and the second central region include a first and a second axial receiving opening, respectively, the first and the second axial receiving openings being configured to be advanced over and aligned in a plurality of positions relative to the drive shaft.

17. The pivot actuator of claim 13, the thickness of the first and second radial protrusions is substantially the same and the combined thickness of the first and second central regions is substantially the same as the thickness of the first and second radial protrusions.

18. A pivot actuator, comprising: a housing; a piston that is supported in the housing and displaceable along a longitudinal axis of the housing; a drive shaft rotatably coupled to the housing, wherein the piston engages the drive shaft so that the drive shaft is pivoted about a drive axis by a pivot angle between two end positions through a displacement of the piston; and a switching cam including a first disc arranged on top of and contacting a second disc along the drive axis, each disc configured to be coupled to and pivot with the drive shaft about the drive axis and including a contact surface, wherein the pivot angle can be adjusted by arranging the first and second discs on top of each other along the drive shaft in different angular orientations.

Description

EMBODIMENTS

(1) The invention is subsequently described based on embodiments with reference to drawing figures, wherein:

(2) FIG. 1 illustrates a pivot actuator according to the invention;

(3) FIG. 2a/b illustrates two sectional views of the pivot actuator;

(4) FIG. 3a/b illustrates an internal view of the pivot actuator in two end positions;

(5) FIG. 4a illustrates a switching cam of the pivot actuator; and

(6) FIG. 4b illustrates an exploded view of the switching cam.

(7) The pivot actuator 1 according to the invention shown in FIGS. 1, 2a/b, 3a/b includes a housing 2, two pistons 3 included in the housing 2 and a drive shaft 4 that protrudes from the housing 2 and two stop elements 5.

(8) The pistons 3 define one pressure tight chamber 6 between each other and two pressure tight chambers 6 in cooperation with the housing 2. The pistons 3 are displaceable in the housing 2 counteracting along a longitudinal axis 7 of the housing 2 and the driveshaft 4 is pivotable about its driveshaft axis 8.

(9) The pistons 3 and the driveshaft 4 include teethings 9 that engage each other by form locking. Loading the chamber 6 through non-illustrated pressure connections at the housing 2 with compressed air moves the pistons 3 and the drive shaft 4 is pivoted by the teethings 9 by a pivot angle 10 between two end positions at 0 degrees and 60 degrees illustrated in FIGS. 3a/b.

(10) A switching earn 11 is attached at the drive axis 8 in the housing 2 and illustrated in detail in FIGS. 4a/b, and 5. The switching cam 11 has a circular disc shaped base structure with a diameter 12 of 30 mm and a thickness 13 of 9 mm and includes an axial receiving opening 14. The receiving opening 14 is shaped as an eight pointed star with rounded corners that fixes the switching cam 11 on the drive shaft 4 through a longitudinal teething.

(11) The switching cam 11 includes two discs 15 that are rotated relative to each other transversal to the drive axis 8 and that are loosely placed on top of each other made from the case-hardened material 1.0503/C45 respectively including a radial protrusion 16 that has a thickness of the switching cam 11 and a radius 17 of 24.5 mm. A respective contact surface 18 is configured at the protrusion 16.

(12) The stop elements 5 respectively include a set screw 19 that is threaded along an adjustment axis 20 into the housing 2 and a locking nut 21 that locks the set screw 19 at the housing 2. The pivot actuator 1 has a nominal pivot angle of 90 degrees.

(13) Two other advantageous pivot actuators differ from the pivot actuator 1 according to the invention only in that one of the discs 15 is pivoted by 45 degrees or 90 degrees about the drive axis compared to the pivot actuator 1 according to the invention. The latter two pivot actuators thus have a nominal pivot angle of 135 degrees or 180 degrees.

REFERENCE NUMERALS AND DESIGNATIONS

(14) 1 Pivot Actuator 2 Housing 3 Piston 4 Drive shaft 5 Stop element 6 Chamber 7 Longitudinal axis 8 Drive Axis 9 Teething 10 Pivot Angle 11 Switching Cam 12 Diameter 13 Thickness 14 Receiving Opening 15 Disc 16 Protrusion 17 Radius 18 Contact Surface 19 Set Screw 20 Adjustment Axis 21 Locking Nut