Electromagnetic active brake

Abstract

An electromagnetic active brake which is de-energized in the brake standby state, includinga brake body (1), a brake device with at least two opposing brake shoes (9, 12) which are spaced from a component to be braked in the de-energized state of the active brake, and an electromagnet (5) which is arranged in the brake body (1) and the armature (6) of which interacts with a brake lever (2). The armature (6) of the electromagnet (5) is rigidly connected to a spring compressor (3) which is guided in the brake body (1) and which is moved by the armature (6) in the axial direction of the armature (6) when the electromagnet (5) is energized and in this manner clamps a spring (16) against an abutment (20) that interacts with the brake lever (2) and is arranged in an axially adjustable manner in the direction of the path of the spring compressor (3). The active brake according to the invention is highly energy-saving and thus economical.

Claims

1. An electromagnetic active brake, comprising: a brake body; a brake device with at least two opposite brake shoes, which in a power-off state of the active brake are distanced from a part to be braked, wherein in order to initiate a braking process one of the brake shoes is movable via a brake lever in a direction towards the other brake shoe, that is mounted fixed in position relative to the brake body; an electromagnet arranged in the brake body, with an armature thereof being in an indirect operative connection with the brake lever via a spring compressor, compression spring and abutment; the armature of the electromagnet is connected rigidly to the spring compressor; the spring compressor is guided in the brake body, and upon energizing the electromagnet, the spring compressor is movable by the armature in an axial direction of the armature and compresses the compression spring against the abutment, until the armature reaches an end stop position defined by an armature endplate; and the abutment is in operative connection with the brake lever such that in an energized state of the electromagnet the compression spring being compressed by the spring compressor forces the abutment against the brake lever thereby transmitting the spring force of the compression spring to the brake lever to exert a braking force.

2. The electromagnetic active brake according to claim 1, wherein the electromagnetic active brake is a floating caliper brake.

3. The electromagnetic active brake according to claim 1, further comprising a base plate, and the brake body and the other brake shoe are mounted to the base plate.

4. The electromagnetic active brake according to claim 3, wherein the operative connection of the abutment to the brake lever comprises a guide pin arranged in the brake body coaxially to the compression spring and axially movable, said guide pin is connected rigidly to a brace, which is connected in an articulate fashion via cams to the brake lever.

5. The electromagnetic active brake according to claim 4, wherein the abutment is axially adjustable and fixed at the guide pin.

6. The electromagnetic active brake according to claim 5, wherein a pre-load of the compression spring is adjustable by changing an axial position of the abutment at the guide pin.

7. The electromagnetic active brake according to claim 4, wherein the guide pin is received in a guide bore of the spring compressor and is axially guided in the brake housing via a clamping sheath connected rigidly to the guide pin.

8. The electromagnetic active brake according to claim 1, wherein an axial position of the spring compressor is fixable in reference to the brake body of the active brake.

9. The electromagnetic active brake according to claim 8, wherein the axial position of the spring compressor is fixable via a threaded pin that is screwed into the brake body.

10. The electromagnetic active brake according to claim 9, wherein a return spring is arranged between the brake lever and the brake body.

11. The electromagnetic active brake according to claim 10, wherein the return spring is arranged coaxially in reference to the threaded pin.

12. The electromagnetic active brake according to claim 4, wherein an axial position of the spring compressor is fixable in reference to the brake body of the active brake via a threaded pin that is screwed into the brake body, a return spring is arranged between the brake lever and the brake body coaxially in reference to the threaded pin, and the brace is supported via at least one additional return spring at the brake body of the active brake.

13. The electromagnetic active brake according to claim 1, wherein the effective connection of the abutment with the brake lever comprises a spring spindle guided through the spring compressor coaxially in reference to the compression spring, said spring spindle is guided axially in a mobile fashion, and has a collar at an upper end thereof projecting from the spring compressor, which rests via a pressure roll on the brake lever.

14. The electromagnetic active brake according to claim 13, wherein the abutment is axially adjusted and fixed at the spring spindle.

15. The electromagnetic active brake according to claim 1, wherein in a de-energized state of the electromagnet, the compression spring is pre-loaded and wherein upon energizing the electromagnet, the spring compressor is movable by the armature in an axial direction of the armature to initially move the compression spring together with the abutment, without further compression of the spring, to a brake ready state in which a clearance between the brake pads and the part to be braked is taken up, and then compresses the spring against an abutment, which is moved into operative connection with the brake lever for braking of the part to be braked.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following the objective of the invention is shown in the drawing using the example of a floating caliper brake and is explained in greater detail. Shown are:

(2) FIG. 1 a cross-section through an electromagnetic active brake according to the invention in the open state,

(3) FIG. 2 a cross-sectional illustration of the effective connection between the brake lever and the spring compressor,

(4) FIG. 3 the electromagnetic active brake in the active state,

(5) FIG. 4 the detail of the cam of FIG. 2 in the active state,

(6) FIG. 5 a second embodiment of the locking of the brake lever,

(7) FIG. 6 a cross-sectional illustration of a second embodiment of the effective connection between the brake lever and the spring compressor, and

(8) FIG. 7 a rear view of the second embodiment in a cross-sectional detail.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(9) FIG. 1 shows in a cross-section an electromagnetic floating caliper brake in the open or the disengaged state, thus ready to brake. It comprises a brake body 1, a brake lever 2, connected thereto with one end and pivotal in the vertical direction, a spring compressor 3, mobile perpendicularly in reference to the brake body 1, a pressure part 4 guided perpendicular in the brake body 1, as well as an electromagnet, with its magnetic coils 5 being arranged inside the brake body 1 and with its armature spindle 6 engaging rigidly the spring compressor 3 and being guided vertically mobile in the brake body 1. From the cross-sectional illustration of FIG. 5 it is discernible that the armature spindle 6 is connected in its axial extension rigidly to the armature 6 of the electromagnet, which in turn is guided in a armature spindle 6 arranged rigidly inside the brake body 1. The brake body 1, the brake lever 2, the brake compressor 3, and the pressure part 4 encase the magnetic coils 5 as a compact unit.

(10) The brake body 1 is fastened on a base plate 7, which accepts in a vertical extension of the pressure part 4 via a lower adjustment screw 8 a lower brake shoe 9 in a rigid, but adjustable fashion. A lower brake pad 10 is fastened on the lower brake shoe 9. An upper brake pad 11 is fastened above it via an upper brake shoe 12 at the pressure part 4. In the interim space, limited by the upper and the lower brake pad 10, 11, a brake means to be braked, not shown here, can be positioned, for example a rotating brake disk or a linearly moving part, e.g., a rope, a chain, or a rod.

(11) As mentioned above, a brake lever 2 is supported pivotally in the brake body 1. The support occurs at the end of the brake lever 2, at which the pressure part 4 is located, via a pivotal pin 13. Directly next to the pivotal pin 13, above the pressure part 4, the brake lever 2 comprises an adjustment pin 14 projecting through it, with its lower face resting on a pressure pin 15, supported in a groove of the pressure part 4.

(12) In the area opposite the pivotal bearing the brake lever 2 is connected in an articulate fashion via a cam, not shown in greater detail in FIG. 1, as well as a compression spring 16 to the spring compressor 3, guided axially in the brake body 1, so that in case of an axial motion of the spring compressor 3 by the cam it is moved in the same direction and thus executes its pivotal motion about its pivotal pin 13 upwards or downwards. Depending on the setting of the compression spring 16 this pivotal motion occurs simultaneously to the spring compressor 3 or in a delayed fashion.

(13) The spring compressor 3 extends horizontally from the armature spindle 6 along the brake lever 2 beyond the brake body 1 and has in this area a second guide in reference to the brake body 1. In FIGS. 1 and 3 this guide is ensured by a guide pin 17, arranged axially mobile in the base plate 7, which pin is coaxially guided through the compression spring 16 and projects with its free end into a guide bore 18 of the spring compressor 3. The face of the spring compressor 3 remaining by the guide bore 18 rests on an upper spring abutment 19, arranged coaxially in reference to the guide pin 17, with the compression spring 16 abutting it with its upper end. At its lower end the compression spring 16 rests on a lower abutment 20, which is adjustable and can be fixed at the guide pin 17 in the axial position. In the present example the guide pin 17 is provided with an external thread so that the abutment 20 can be screwed onto it like a nut. The fixation of the abutment 20 occurs in a self-locking fashion by the force of the compression spring 16.

(14) In the present exemplary embodiment, a threaded pin 21 is provided with an upper return spring 22 for the manual operation of the floating caliper brake in the brake body 1, which upon the conclusion of the braking process returns the spring compressor 3 into its normal position.

(15) FIG. 2 shows the detail of a cam for the articulate connection of the spring compressor 3 to the brake lever 2. The cam comprises two parallel guided centering flanges 23, which are connected rigidly to each other via a brace 24. With their free ends they are connected in an articulate fashion via a brace bearing 25 to the brake lever 2. The brace 24 is supported via lower return springs 26 on the base plate 7. The brace 24 is provided centrally with an aperture, through which the guide pin 17 is guided. On its end projecting through the aperture a clamping sheath 27 is screwed on, by which the pin is connected rigidly to the brace 24. The clamping sheath 27 is received in the base plate 7 in an axially mobile fashion, so that the guide pin 17 is also guided in an axially mobile fashion in reference to the base plate 7 and, as mentioned above, consequently also in the brake body 1.

(16) The brake body 1 is fastened with its base plate 7 via screws 28 and damping springs 29 at an arrangement, not shown in greater detail, in a vibration-cushioning fashion.

(17) In the active state, thus in the braking state of the electromagnetic floating caliper brake shown in FIGS. 3 and 4, as well as in the embodiments according to FIG. 5, in order to identify the same components the same reference characters were used as in FIGS. 1 and 2. The variant of FIG. 5 differs from the one shown in FIG. 1 by the separate arrangement of the upper return spring 22 in the brake lever 2 between the armature spindle 6 and the bearing of the brake lever 2. Further, the threaded pin 21 provided for fixing the spring compressor 3 in reference to the brake body 1 is connected to the guide pin 21, which can be screwed into the brake body 1. The threaded pin 21 is fixed in reference to the brake body 1 via a set screw 21.

(18) In this cross-sectional illustration the guide of the armature 6 is also discernible in the interior armature spindle 6 as well as the connection of the armature spindle 6 to the armature 6.

(19) In the following, the operation of the electromagnetic floating caliper brake is described:

(20) FIGS. 1, 2, and 5 show the electromagnetic floating caliper brake in the opened and/or disengaged state, in which it is de-energized. When energizing the magnetic coils 5 the armature 6 moves in the direction of its armature endplate 30, which is located in the lower area of the electromagnet, also causing the spring compressor 3 to move perpendicularly downwards, as discernible from FIGS. 3 and 4, while it simultaneously moves the guide pin 17, guided through the clamping sheath 27 in the base plate 7 and the pre-loaded compression spring 16 between the upper spring endplate 19 and the lower abutment 20, without compressing the latter due to its adjusted pre-loading. In the variant of FIG. 2 the pre-adjusted force of the compression spring 16 is transmitted to the brake lever 2 via the brace 24 connected rigidly to the guide pin 17 as well as the two cams 23 fastened at the brace 24. Here, the adjustment pin 14, connected rigidly to the brake lever 2, presses upon the pressure pin 15 such that the upper brake pad 11 is moved in the direction of the lower brake pad 10, reducing the clearance between the two brake pads 10, 11 and the brake pads 10, 11 contact the brake means, not shown. At this point of time and/or this position of the brake lever 2 the armature 6 has not yet reached the armature endplate 30 so that from now on, thus at the time the brake pads 10, 11 contact the brake means to be braked, during the remainder of the path towards the armature endplate 30 it overcomes the pre-loaded clamping force of the compression spring 16 and compresses the compression spring 16 via the spring compressor 3. In this further downward motion of the spring compressor 3 only the compression spring 16 and/or in the variant of FIG. 2 the lower return springs 26 are further compressed, causing the compression of the brake pads 10, 11 to increase upon the brake means to be braked, i.e. the actual braking processes to occur. The guide pin 17 itself and thus also the brake lever 2 are not moving any longer.

(21) In order to remove the braking process the electromagnet is switched to be de-energized, causing the armature endplate 30 to lose its adhesive force in reference to the armature 6. This way the compression spring 16 relaxes, with simultaneously the spring compressor 3, the armature 6 with the armature spindle 6, and the brake lever 2 being compressed into the normal state. In the alternative embodiment according to FIG. 2 the lower return springs 26 support the reverse pivoting of the brake lever 2 into its normal state.

(22) FIGS. 6 and 7 show a second embodiment of the effective connection between the brake lever 2 and the spring compressor 3. Instead of the guide pin 17 guided in the brake body 1, a spring spindle 31 is guided through the spring compressor 3 and coaxially through the compression spring 16. It is axially guided in the spring compressor 3 via friction bearings 32 and has at its upper end a collar 33 projecting from the spring compressor. It is further guided through the brake lever 2 as well as a pressure roll 34 resting thereupon, on which the annular area of the collar 33 is supported. Similar to the first embodiment, the upper spring step 19 and the abutment 20 are fastened at the spring spindle and the compression spring 16 is clamped between the two of them.

(23) The general function of this embodiment is equivalent to the variant already described regarding FIGS. 1 to 5. The advantage is given here in that the effective connection between the brake lever 2 and the spring compressor 3 occurs directly in an axial connection via the spring spindle 31 as well as the pressure roll 34, and thus over a considerably shorter path than in the first variant via the brace 24 and the cams 23. In this embodiment as well the spring compressor 3 presses with its annular area upon the upper spring stop 19 when the electromagnet is energized, causing the spring spindle 31 connected thereto in a rigid fashion to move axially downwards and here pivoting the brake lever 2 via the pressure roll 34 downwards until the brake pads 10, 11 contact the part to be braked. In a further downwards motion of the armature 6 the spring compressor 3 compresses the compression spring 16 until it contacts the armature endplate 30, resulting in the braking force developing, as already described. After the power has been shut off, the armature 6 separates from the armature end plate so that the spring compressor 3 and the armature 6 are pressed back into their normal position during the relaxing of the compression spring 16, causing the pressure roll 34 also to be released from the collar 33 of the spring spindle 31 such that the upper return spring can move the brake lever 2 back into its normal position.

(24) All features shown here may be relevant for the invention either individually or in any combination with each other.

LIST OF REFERENCE CHARACTERS

(25) 1 Brake body 2 Brake lever 3 Spring compressor 4 Pressure part 5 Magnetic coil 6 Armature spindle 6 Armature 6 Internal armature spindle 7 Base plate 8 Lower adjustment spring 9 Lower brake shoe 10 Lower brake pad 11 Upper brake pad 12 Upper brake shoe 13 Pivotal bolt 14 Adjustment pin 15 Pressure pin 16 Compression spring 17 Guide pin 18 Guide bore 19 Upper spring endplate 20 Lower abutment 21 Threaded pin 21 Guide pin 21 Set screw 22 Upper return screw 23 Cams 24 Brace 25 Brace bearing 26 Lower return spring 27 Clamping spring 28 Screws 29 Damping screw 30 Armature endplate 31 Spring spindle 32 Friction bearing 33 Collar 34 Pressure roll