Tensioning mechanism for clamping a pre-loaded spring of a spring-loaded accumulator drive

Abstract

A tensioning mechanism for tensioning a pre-loaded spring of a spring-loaded accumulator drive. The tensioning mechanism includes a tensioning wheel coupled to the pre-loaded spring, an intermediate shaft coupled to the tensioning wheel, an idler gear that can be driven by a clamping motor, a freewheel coupled to the idler gear, a locking mechanism for detachably locking the tensioning wheel in a tensioned state of the pre-loaded spring, and a dog clutch configured to couple the freewheel to the intermediate shaft in order to tension the pre-loaded spring and to uncouple same from the intermediate shaft in the tensioned state of the pre-loaded spring.

Claims

1. A tensioning mechanism for tensioning a pre-loaded spring of a spring-loaded accumulator drive, the tensioning mechanism comprising: a tensioning wheel coupled to the pre-loaded spring; an intermediate shaft coupled to said tensioning wheel; an intermediate gear to be driven by a tensioning motor; a freewheel coupled to said intermediate gear; a locking mechanism for releasably locking said tensioning wheel when the pre-loaded spring is in a tensioned state; a dog clutch configured to couple said freewheel to said intermediate shaft in order to tension the pre-loaded spring, and to decouple said freewheel from said intermediate shaft when the pre-loaded spring is in the tensioned state; said dog clutch having a first clutch jaw coupled rotationally fixedly to said intermediate shaft, and a second clutch jaw connected to said freewheel, wherein said first clutch jaw is movable between a first end position in which said first clutch jaw bears against said second clutch jaw and a second end position in which said first clutch jaw is separated from said second clutch jaw and which said first clutch jaw assumes when the pre-loaded spring is in the tensioned state; and a coupling element coupling said first clutch jaw to said intermediate shaft, wherein said coupling element is guided through a transverse opening formed in said intermediate shaft, running perpendicularly to a longitudinal axis of said intermediate shaft, and is movable in said transverse opening parallel to the longitudinal axis of said intermediate shaft between a first position defining the first end position of said first clutch jaw and a second position defining the second end position of said first clutch jaw.

2. The tensioning mechanism according to claim 1, wherein said coupling element is a tube or a bolt having a longitudinal axis, and where the longitudinal axis of said coupling element is arranged perpendicularly to the longitudinal axis of said intermediate shaft and having ends that project into recesses in said first clutch jaw.

3. The tensioning mechanism according to claim 1, further comprising a switching pin which is slideably mounted in said intermediate shaft in a longitudinal opening running along the longitudinal axis of said intermediate shaft and coupled to said coupling element.

4. The tensioning mechanism according to claim 3, wherein said switching pin has a deactivation end that protrudes out of said longitudinal opening, and wherein a deactivation element is arranged on the tensioning wheel for moving said deactivation end of said switching pin towards the longitudinal opening when the pre-loaded spring is in the tensioned state, so that said coupling element is moved from a first position into a second position thereof.

5. The tensioning mechanism according to claim 4, wherein said deactivation element has a contact end which protrudes radially from the tensioning wheel and which is formed with an oblique contact face that bears on said deactivation end of said switching pin upon movement of the said switching pin.

6. The tensioning mechanism according to claim 5, wherein each of said first and second clutch jaws runs in a ring form around said intermediate shaft.

7. The tensioning mechanism according to claim 1, wherein each of said first and second clutch jaws runs in a ring form around said intermediate shaft.

8. The tensioning mechanism according to claim 1, further comprising a return spring coupled to said first clutch jaw, and wherein said return spring, in the second end position of said first clutch jaw, exerts a spring force on said first clutch jaw in a direction of the first end position.

9. The tensioning mechanism according to claim 1, wherein said freewheel has a freewheel ring running around said intermediate shaft, and said second clutch jaw is connected to said freewheel ring.

10. The tensioning mechanism according to claim 1, further comprising a bevel gear mechanism configured for said intermediate gear to be driven by the tensioning motor.

11. The tensioning mechanism according to claim 1, wherein said locking mechanism comprises a cam disk roller fixedly connected to said tensioning wheel, and a latching mechanism disposed to fix said cam disk roller for locking said tensioning wheel.

12. A spring-loaded accumulator drive, comprising a tensioning mechanism according to claim 1.

Description

(1) The above-mentioned properties, features and advantages of this invention, and the manner in which they are achieved, will become clearer and more comprehensible in connection with the following description of exemplary embodiments, which are explained in more detail in connection with the drawings. The drawings show:

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(2) FIG. 1 a perspective and partially sectional depiction of a tensioning mechanism, and

(3) FIG. 2 an enlarged extract from FIG. 1.

(4) Parts corresponding to each other carry the same reference signs in the figures.

DETAILED DESCRIPTION OF THE INVENTION

(5) FIGS. 1 and 2 show a tensioning mechanism 1 for tensioning a pre-loaded spring (not shown) of a spring-loaded accumulator drive, in a perspective and partially sectional depiction, wherein FIG. 2 shows an enlarged extract from FIG. 1. The pre-loaded spring is for example an operating spring of a spring-loaded accumulator drive which stores energy for closing a current path of a circuit breaker. The tensioning mechanism 1 comprises inter alia a tensioning wheel 9, an intermediate shaft 2 and an intermediate gear 4.

(6) The tensioning wheel 9 is fixedly connected to a cam disk 17 and a tensioning shaft 18, and coupled to the pre-loaded spring via the tensioning shaft 18.

(7) The intermediate gear 4 can be driven by a tensioning motor (not shown) via a bevel gear mechanism 19.

(8) The intermediate shaft 2 is coupled to the tensioning wheel 9 and the intermediate gear 4 in order to transmit rotations of the intermediate gear 4 to the tensioning wheel 9 for tensioning the pre-loaded spring. The coupling between the intermediate shaft 2 and the tensioning wheel 9 is a geared coupling, which is formed by a sprocket of the tensioning wheel 9 and a corresponding toothed ring of the intermediate shaft 2.

(9) The intermediate gear 4 is coupled to the intermediate shaft 2 via a freewheel 3 and a dog clutch 20, wherein the freewheel 3 connects the intermediate gear 4 to the dog clutch 20. The dog clutch 20 has a first clutch jaw 12 coupled rotationally fixedly to the intermediate shaft 2, and a second clutch jaw 11 connected to a freewheel inner ring 13 of the freewheel 3. Both clutch jaws 11, 12 run in a ring form around the intermediate shaft 2.

(10) The first clutch jaw 12 can be moved axially, i.e. parallel to a longitudinal axis 21 of the intermediate shaft 2, between a first end position in which it bears against the second clutch jaw 11 and which it assumes during tensioning of the pre-loaded spring, and a second end position in which it is separated from the second clutch jaw 11 and which it assumes when the pre-loaded spring is in a tensioned state. In this way, the dog clutch 20 couples the freewheel 3 and the intermediate gear 4 onto the intermediate shaft 2 in order to tension the pre-loaded spring, and decouples the freewheel 3 and the intermediate gear 4 from the intermediate shaft 2 when the pre-loaded spring is in the tensioned state.

(11) The freewheel 3 decouples the intermediate gear 4 from the intermediate shaft 2 on tensioning of the pre-loaded spring, when the tensioning shaft 18 runs over a top dead center.

(12) In order to couple the first clutch jaw 12 rotationally fixedly and axially movably to the intermediate shaft 2, the first clutch jaw 12 and the intermediate shaft 2 have for example a toothing.

(13) In order to move the first clutch jaw 12 from its first end position into the second end position, the intermediate shaft 2 has a slot-like transverse opening 22 in the region of the first clutch jaw 12, which runs perpendicularly to the longitudinal axis 21 through the intermediate shaft 2. A coupling element 23 which is connected to the first clutch jaw 12 is guided through the transverse opening 22, and can be moved in the transverse opening 22 between a first position defining the first end position of the first clutch jaw 12 and a second position defining the second end position of the first clutch jaw 12. In the exemplary embodiment shown in the figures, the coupling element 23 is formed as a tube, the ends of which protrude into recesses 24 in the first clutch jaw 12. Alternatively, the coupling element 23 may however also for example be configured as a bolt.

(14) Furthermore, the intermediate shaft 2 has a longitudinal opening 25 running along its longitudinal axis 21, and extending from the transverse opening 22 to an end of the intermediate shaft 2 on the tensioning wheel side. A switching pin 10, having a deactivation end 26 protruding from the longitudinal opening 25, is mounted in the longitudinal opening 25 so as to be axially movable and extends in the longitudinal opening 25 up to the coupling element 23.

(15) A deactivation element 8 is arranged on the tensioning wheel 9 and, in the tensioned state of the pre-loaded spring, moves the deactivation end 26 of the switching pin 10 towards the longitudinal opening 25, so that the coupling element 23 is moved from its first position into its second position. The deactivation element 8 has a contact end protruding radially from the tensioning wheel 9 with an oblique contact face 27 which bears against the deactivation end 26 of the switching pin 10 on movement of the latter. The deactivation element 8 is arranged for example at a position on the tensioning wheel 9 in which the contact face 27 makes contact with the deactivation end 26 of the switching pin 10, when the tensioning wheel 9 has turned further through approximately three degrees after the tensioning shaft 18 has reached the top dead center.

(16) Furthermore, a return spring 14 is coupled to the first clutch jaw 12 and runs in helical fashion around the intermediate shaft 2. The return spring 14 acts on an end of the first clutch jaw 12 facing away from the second clutch jaw 11, and in the second end position of the first clutch jaw 12 exerts a spring force on the first clutch jaw 12 in the direction of the first end position.

(17) The tensioning mechanism 1 also comprises a locking mechanism 28 for releasable locking of the tensioning wheel 9 in the tensioned state of the pre-loaded spring. The locking mechanism 28 of the exemplary embodiment shown in the figures has a cam disk roller 5 arranged on the cam disk 17, and a latching mechanism 6 which fixes the cam disk roller 5 in order to lock the tensioning wheel 9. After separation of the clutch jaws 11, 12, the cam disk roller 5 runs against the latching mechanism 6 and is locked in this position by the latching mechanism 6, for example when the tensioning wheel 9 has turned further through around ten degrees after the tensioning shaft 18 has reached the top dead center. A rebound of the cam disk roller 5 away from the latching mechanism 6 is prevented by the freewheel 3 and a return block on an additional shaft 7 coupled to the intermediate gear 4.

(18) Since, in tensioned state of the pre-loaded spring, the clutch jaws 11, 12 are separated from each other, the intermediate shaft 2 and the components coupled thereto, such as a latching mechanism 6 and the cam disk roller 5, are decoupled from the intermediate gear 4 in the tensioned state of the pre-loaded spring, and not loaded and tensioned by the intermediate gear 4, for example when the tensioning motor runs on. In this way advantageously, in particular the load on the latching mechanism 6, the cam disk roller 5 and the freewheel 3 is reduced, preventing wear or damage to said components of the tensioning mechanism 1 because of said load.

(19) To dissipate the energy stored in the tensioned pre-loaded spring, the coupling of the latching mechanism 6 to the cam disk roller 5 is released. The relaxing pre-loaded spring turns the tensioning wheel 9 in the same rotational direction as during tensioning of the pre-loaded spring, whereby the deactivation element 8 releases the switching pin 10 again, and the first clutch jaw 12 is moved by the return spring 14 from the second end position into the first end position, so that the dog clutch 20 is closed again. The tensioning mechanism 1 is thereby ready for further tensioning of the pre-loaded spring.

(20) Although the invention has been illustrated and described in detail with preferred exemplary embodiments, the invention is not restricted by the examples disclosed, and other variations may be derived therefrom by the person skilled in the art without leaving the scope of protection of the invention.