GB2569967A

GB2569967A - Mechanic timer element

Info

Publication number: GB2569967A
Application number: GB1800114.9A
Authority: GB
Inventors: Neuber Tobias; Speiser Wolfgang
Original assignee: Linde GmbH
Current assignee: Linde GmbH
Priority date: 2018-01-04
Filing date: 2018-01-04
Publication date: 2019-07-10
Also published as: GB201800114D0

Abstract

A mechanical timer element 100 comprises two torsion springs 110, 120 coaxially wound on a spool 130 and separated from each other by the spool, e.g. via wall 133, wherein each torsion spring 110, 120 is adapted to be twisted inside the spool element 130 from a neutral position in a first rotational direction through a twisting angle and to afterwards twist in a second rotational direction back into the neutral position within a time interval depending on the twisting angle. The torsion springs may have hooks 111,121 which may attach to elements 151 of an outer cover (150, Fig. 2). The timer element may comprise a viscous damping element such as silicon oil. Being preferably free from electronic elements, the device can be used to control a gas flow valve wherein the gas is flammable or explosive such as oxygen.

Description

Mechanic timer element

The present invention relates to mechanic timer element and a control mechanism comprising a mechanic timer element of that kind.

Prior art

Timer elements can be used to measure time intervals to be set. When for example used in explosive or flammable environments, it may not be possible to use electronic timer elements for safety reasons. In these cases it may only be possible to use mechanic timer elements.

It is an object of the present invention to provide an improved precise mechanical timer element.

Disclosure of the invention

According to the present invention a mechanic timer element and a control mechanism with the features of the independent claims are provided. Further advantages and embodiments of the invention will become apparent from the description and the appended figures.

The mechanic timer element comprises two torsion springs wound on a spool element coaxially to each other and separated from each other by the spool element. Each of the two torsion springs is adapted to be twisted or wound up inside the spool element from a neutral position in a first rotational direction through a twisting angle and to afterwards twist or unwind in a second rotational direction back into the neutral position within a time interval depending on the twisting angle. The two torsion springs are particularly mounted such that both torsion springs can be twisted in the same first rotational direction.

The torsion springs are particularly spiral torsion springs, particularly flat spiral springs, i.e. elements defining an essentially two dimensional curve winding in a plane around a centre. The torsion springs can also be helical torsion springs, i.e. helix elements defining a three dimensional curve turning around an axis while moving parallel to the axis. It is also possible to use two different elements as these two torsion springs, e.g. one spiral torsion spring and one helical torsion spring.

The spool element particularly comprises a separation element between the two torsion springs, for example a wall which especially extends in a plane perpendicular to an axis to which the two springs are mounted coaxially. Particularly, the spool element comprises a common spool on which the two springs are wound on. The separation element is particularly attached to this common spring. The spool element is particularly formed as one piece. However, it is also possible that the spool element comprise a separate spool for each torsion springs.

Particularly, an inner end of each torsion spring is attached to the spool element. From this inner end, the torsion springs are wound on the spool element and an outer end lies on top of the spool element. The neutral position particularly refers to a position of this outer end of the corresponding torsion spring. The twisting angle is particularly measured from the neutral position to a position of the corresponding torsion spring's outer end after the twisting in the first rotational direction.

By twisting the torsion springs in the first rotational direction, the timer element can particularly be wound up. The twisting angle especially sets the time interval, which shall be measured by the mechanic timer element. Particularly, the torsion springs can be twisted manually. Alternatively, also an automated twisting can be possible, for example by means of an external actuator.

In order to twist the torsion springs, a torque in the first rotational direction is applied to the torsion springs. Thus, the torsions springs are compressed and/or expanded and store mechanical energy. By means of this stored mechanical energy the twisted torsion springs exert a force or torque in the second rotational direction opposite the first rotational direction. Thus, the twisted torsion springs decompress and/or contract within the time interval.

The present invention provides a mechanic timer element, which can measure time intervals with good precision and which can easily be assembled. Particularly, friction of the torsion springs, particularly of the twisting of in the second rotational direction is reduced. The torsion springs can thus twist in the second rotational direction uninterrupted with low friction losses. Furthermore, a breakdown torque of the torsion springs can be reduced and kept low. Particularly, also relatively short time intervals of e.g. 5 minutes or less can be measured with good precision.

By providing two torsion springs significant advantages can be yielded compared to conventional timer elements with only one spring. It is particularly possible to use two springs, such that the system of these two springs in combination has a lower spring constant than a single spring used in conventional timer elements. Thus, the sum of the forces needed to twist both torsion springs in the first rotational direction through the twisting angle is particularly lower than a force needed to twist only one single spring through the same angle in conventional timer elements. Thus, a lower effort is needed in order to wind up the mechanic timer element according to the present invention than to wind up a conventional timer element with only one spring.

Moreover, by proving two torsion springs, a rather symmetric distribution of forces in the mechanic timer element can be provided. Asymmetric forces, which can appear in conventional timer elements with only one spring, can be reduced or even prevented. Thus, stresses of the mechanic timer element can be reduced, potential damages can be prevented and a lifetime can be increased. Particularly, a rather constant run time of the mechanic timer element can be provided during its lifetime, i.e. particularly measurement of time intervals with constantly good precision during the lifetime of the mechanic timer element can be provided.

The two torsion springs separated from each other are not in contact with each other and do not interfere with each other. Thus, friction can be reduced, low friction twisting in the second rotational direction springs can be provided, and precision of the mechanic timer element can be increased. Moreover, a space saving design of the mechanic timer element is provided.

Furthermore, the mechanic timer element can easily be assembled. It is particularly not necessary to elaborately prestress a spring and to mount a prestressed spring inside a housing. Each of the two torsion springs can be easily be wound on the spool element, especially such that the torsion spring has a predetermined stress.

Advantageously, the spool element comprises at least one slot, to which an inner end of each torsion spring is attached. Particularly, two slots are provided, one slot for each torsion spring. The corresponding inner end of the torsion springs can especially be attached force-fitted to the respective slot and can e.g. be clamped or plugged into this slot. Alternatively or additionally a bonded connecting between the inner ends and the respective slot is possible e.g. by adhesive means. Thus, an easy assembly of the mechanic timer element can be provided. After attaching the inner ends of the torsion spring to the slot, the torsion springs can easily be wound on the spool element.

Preferably, each of the two torsion springs comprises a hook element, particularly at its outer end. Particularly, the outer end of each torsion spring can be folded or bent in order to form the corresponding hook element. By means of these hook elements, the torsion springs can especially be twisted in the first direction.

Advantageously, the mechanic timer element further comprises an outer cover mounted at least partially around the spool element. The two torsion springs are preferably attached to the outer cover, preferably with their outer end. Thus, by rotating this outer cover, both springs are twisted in the first rotational direction through the same twisting angle at the same time and the mechanic timer element can be wound up. The outer ends of the torsion springs can be attached force-fitted to the outer cover and/or by means of a bonded connection.

The spool element especially comprises a mounting element in order to mount the spool element at a predetermined position and/or in a predetermined orientation in the outer convert. For example the spool element can comprise a notch and/or a rib as this mounting element. The outer cover can e.g. comprise a corresponding element adapted to engage and mechanically connect with this mounting element.

Particularly advantageously, the two torsion springs are attached to the outer cover by means of the hook elements. These hook elements especially engage with a corresponding counterpart arranged on this outer cover.

Advantageously, the two torsion springs are separated from each other by a low friction wall of the spool element. This low friction wall extends especially in a plane perpendicular to the axis to which the two springs are mounted coaxially. Friction can thus further be reduced. For example the low friction wall as well as the spool element can be made of polyoxymethylene (POM) and/or can be coated e.g. with a layer of Teflon.

Particularly, the spool element further comprises a wall beside each of the two torsion springs i.e. at a side of each torsion spring, which is not adjacent to the other one of the two torsion springs. These walls are particularly parallel to each other and especially parallel to the separation element separating the two torsion springs form each other, particularly to the low friction wall. Thus, these walls especially extend in planes perpendicular to the axis to which the two springs are mounted coaxially. Particularly, these two walls can also be provided as low friction walls.

According to a particularly advantageous embodiment, the mechanic timer element further comprises a viscous damping element adapted to damp at least the twisting of the two torsion springs in the second rotational direction. This viscous damping element is particularly a fluid, especially a liquid with a predetermined viscosity and is particularly applied to the torsion springs inside the spool element. Preferably, the viscous dampening element is oil, for example a mineral oil or a silicon oil. The viscous damping element is particularly embedded in a viscous fluid. The viscous damping element especially only damps the twisting of the torsion springs in the second rotational direction, but particularly not the twisting in the first rotational direction, thus enabling an easy winding of the timer element. However, it is also possible that viscous damping element also damps the twisting of the torsion springs in the first rotational direction.

By means of the viscous damping element, friction of the torsion springs, especially when twisting in the second rotational direction, can further be reduced. Particularly, a specific behaviour of the twisting in the second rotational direction can be provided by means of the viscous damping element, especially in dependence of its viscosity. It can particularly be provided that each the torsion spring twists uniformly in the second rotational direction. A relationship between the twisting angle and the time interval can especially be influenced or adjusted by means of the specific viscous damping element used.

According to a particularly advantageous embodiment, the mechanic timer element does not comprise any electronic elements. The mechanic timer element preferably only comprises mechanic elements. Thus, the mechanic timer element can particularly be used in environments where the use of electronic elements is dangerous or even prohibited, for example in environments with explosion protection.

Particularly advantageous, the mechanic timer element is adapted to actuate a control element when the two torsion springs have twisted back into the neutral position after the time interval has expired. The mechanic timer element is therefore advantageously used in a control mechanism adapted to actuate an element. For this purpose, the mechanic timer mechanically interacts with the corresponding control element. For example, a direct mechanic connection can be established between the mechanic timer and the element to be actuated. It is e.g. also possible to provide an indirect connection between the element and the mechanic timer by means of a third element. Since the mechanic timer element particularly does not comprise any electronic elements, it can particularly advantageously be used in an environment where use of an electronic actuation of elements is dangerous or prohibited for safety reasons, e.g. for reasons of explosion protection.

Advantageously, the mechanic timer element is adapted to actuate a valve, i.e. the control element is or comprises a valve. The mechanic timer element is thus preferably used in a flow control mechanism. After winding up mechanic timer and after the time interval has expired, this valve can especially be entirely closed or entirely opened or only partially opened to a predetermined percentage. Thus by actuating the valve, the mechanic timer element is preferably adapted to control a flow of a fluid, particularly through a pipe or tube or the like. Depending on the way the valve is actuated by means of the mechanic timer element, the flow of the fluid can e.g. be started or stopped or increase or reduced. Thus, the mechanic timer element can particularly be used to control flows of fluids, e.g. explosive or flammable fluids, wherein the use of electronic timer elements or electronic actuators is dangerous or even prohibited, e.g. for reasons of explosion protection. Particularly advantageously, the mechanic timer element is adapted to control a flow of oxygen.

The present invention further relates to a control mechanism comprising a preferred embodiment of a mechanic timer element according to the invention. Advantages and embodiments of this control mechanism according to the invention arise from the above description of the mechanic timer element according to the invention in an analogous manner.

It should be noted that the previously mentioned features and the features to be further described in the following are usable not only in the respectively indicated combination, but also in further combinations or taken alone, without departing from the scope of the present invention.

The present invention will now be described further, by way of example, with reference to the accompanying drawings, in which

Fig. 1 schematically shows a part of a preferred embodiment of a mechanic timer element according to the invention in a perspective view,

Fig. 2 schematically shows a preferred embodiment of a mechanic timer element according to the invention in a side view, and

Fig. 3 schematically shows a control mechanism adapted to control a valve comprising a preferred embodiment of a mechanic timer element according to the invention as a block diagram.

Detailed description

Identical reference numerals in the Figs, refer to equal or equivalent elements.

Fig. 1 schematically shows a part of a preferred embodiment of a mechanic timer element 100 according to the invention in a perspective view.

Two torsion springs 110, 120 are wound on a spool element 130 coaxially to each other. The spool element 130 comprises a spool 134, on which these two torsion springs 110, 120 are wound.

The spool element 130 further comprises two slots 135, to which the torsion springs 110, 120 are attached. Particularly, an inner end 112, 122 of each torsion spring 110, 120 is attached to one of these two slots 135 and can e.g. be plugged into the respective slot 135. In Fig. 1, only the inner end 112 of the first torsion spring 110 is visible. Inner end 122 of the second torsion spring 120 is visible in Figure 2. After attaching the respective inner end 112, 122 to the corresponding slot 135, the respective torsion spring 110, 120 can easily be wound on the spool 134.

The spool element further comprises a separation element 133 separating the two torsion spring 110, 120 from each other. Especially a low friction wall is provided as this separation element 133. The low friction wall 133 particularly extends form the spool 134 in a plane perpendicular to the axis according to which the two torsion spring 110, 120 are mounted coaxially.

Furthermore, the spool element 130 comprises a first wall 131 beside the first torsion spring 110 and a second wall 132 beside the second torsion spring 120. These walls 131, 132 are especially also low friction walls. In each of the walls 131, 132 a mounting window 131a, 132a is provided for an easy winding of the corresponding torsion spring 110 120.

The spool element 130, particularly the walls 131, 132, 133 and the spool 134 are especially formed as one piece and are e.g. made of polyoxymethylene.

Moreover, a viscous damping element 140 is provided in form of a liquid, especially a mineral or silicon oil, with a predetermined viscosity. This viscous damping element 140 is especially embedded in a viscous fluid.

An outer end 111, 121 of each torsion spring 110, 120 is bent and forms a hook element. By means of these bent outer ends or hook elements 111, 121 the torsion springs 110, 120 can be attached to an outer cover of the mechanic timer element 100. Moreover, a mounting element 136 e.g. in the form of a notch is provided in order to arrange the spool element 130 at this outer cover at a predetermined position and orientation, as will hereafter be explained in reference to Fig. 2, which shows a preferred embodiment of a mechanic timer element according to the invention in a schematic side view.

As shown in Fig. 2, the mechanic timer element 100 further comprises an outer cover 150, which at least partially covers the spool element 130. On the outer cover 150, counterparts 151 are provided with which the hook elements 111, 121 of the torsion springs 110,120 can engage. By means of these counterparts 151 the torsion springs 110, 120 are attached to the outer cover 150. The mounting element in form of notch 136 can engage with a corresponding counterpart 152 arranged on the outer cover 150.

In Fig. 1 and 2 the torsion springs 110, 120 are shown in a respective neutral position.

In order to measure a time interval, the torsion springs 110, 120 can be deflected from this neutral position, as will be explained hereafter.

By means of the outer cover 150, the mechanic timer element 100 can be wound up in order to measure a timer interval. By rotating the outer cover 150 in a first direction through a specific twisting angle, in the example of Fig. 1 and 2 counter clockwise, both torsion springs 110, 120 are twisted from the neutral position in this first direction through this twisting angle. By this twisting angle the specific time interval to be measured is set. After being twisted, the torsion springs 110, 120 twist in a second rotational direction, in the example of Fig. 1 and 2 clockwise, back into the neutral position within this set time interval.

By means of the specific design of the mechanic timer element 100, especially by means of the low friction walls 131, 132, 133, the separation of the two torsion springs 110,120 in the spool element 130 and the viscous damping element 140, friction can be kept low, such that the torsion springs 110, 120 can twist in the second rotational direction with low friction. The specific oil used as viscous damping element 140 is particularly chosen in order to damp at least the twisting of the two torsion springs 11, 120 in this second rotational direction.

The mechanic timer element 100 advantageously does not comprise any electronic elements, but only mechanic elements and can thus particularly preferably be used in environments where the use of electronic elements is dangerous or even prohibited, for example in environments with explosion protection.

Moreover, the mechanic timer element 100 is advantageously adapted to actuate elements, particularly mechanically and not electronically. The mechanic timer element 100 is therefore according to a particularly preferred embodiment of the invention used in control mechanism to actuate elements. A preferred embodiment of a control mechanism 200 of that kind according to the invention is shown in Fig. 3 in a schematic block diagram. The control mechanism 200 is embodied as a flow control mechanism comprising a valve 210 arranged in a pipe 220. By means of the valve 210 a flow 221 of a fluid, in this particular example gaseous oxygen, can be controlled.

The control mechanism 200 further comprises a preferred embodiment of a mechanic timer element 100 according to the invention, e.g. analogously to the one shown in Fig. 1 and 2. As explained above, the mechanic timer element 100 can be wound up in order to measure a specific time interval, thus twisting the torsion springs 110, 120 through the corresponding twisting angle. After this time interval has expired, i.e. after the two torsion springs 110, 120 have twisted back into the neutral position, the mechanic timer element 100 actuates the valve 210. By means of this actuation, the valve 210 can e.g. be opened or closed. For this purpose, the mechanic timer element 100 mechanically interacts with the valve 210, indicated by reference numeral 211.

Since the mechanic timer element 100 comprises no electronic elements and actuates the valve 210 mechanically, the mechanic timer element 100 can particularly be used for the flow control of explosive or flammable gases.

List of reference numerals 100 mechanic timer element 110 first torsion spring 111 outer end, hook element of the first torsion spring 112 inner end of the first torsion spring 120 second torsion spring 121 outer end, hook element of the second torsion spring 122 outer end of the second torsion spring 130 spool element 131 first wall of the spool element 131 a mounting window in the first wall 132 second wall of the spool element 132a mounting window in the second wall 133 separation element, low friction wall 134 spool 135 slots 136 mounting element, notch 140 viscous damping element, oil 150 outer cover 151 counterparts for the hook elements 152 counterparts for the mounting element 200 control mechanism, flow control mechanism 210 valve 211 mechanic interaction 220 pipe 221 flow of a fluid, flow of gaseous oxygen

Claims

1. A mechanic timer element (100) comprising two torsion springs (110, 120) wound on a spool element (130) coaxially to each other and separated from each other by the spool element (130), wherein each torsion spring (110, 120) is adapted to be twisted inside the spool element (130) from a neutral position in a first rotational direction through a twisting angle and to afterwards twist in a second rotational direction back into the neutral position within a time interval depending on the twisting angle.

2. The mechanic timer element (100) according to claim 1, wherein the spool element (130) comprises at least one slot (135), to which an inner end (112, 122) of each torsion spring (110, 120) is attached.

3. The mechanic timer element (100) according to claim 1 or 2, wherein each of the two torsion springs (110, 120) comprises a hook element (111, 121) at its outer end.

4. The mechanic timer element (100) according to any one of the preceding claims, further comprising an outer cover (150) mounted at least partially around the spool element (130), wherein the two torsion springs (110, 120) are attached to the outer cover (150), preferably with their outer end (111, 121).

5 The mechanic timer element (100) according to claim 4 and 5, wherein the two torsion springs (110, 120) are attached to the outer cover (150) by means of their hook elements (111, 121).

6. The mechanic timer element (100) according to any one of the preceding claims, wherein the two torsion springs (110, 120) are separated from each other by a low friction wall (133) of the spool element (130).

7. The mechanic timer element (100) according to any one of the preceding claims further comprising a viscous damping element (140), preferably oil, adapted to damp at least the twisting of the two torsion springs (110, 120) in the second rotational direction.

8. The mechanic timer element (100) according to any one of the preceding claims, wherein the mechanic timer element (100) is free of any electronic elements.

9. The mechanic timer element (100) according to any one of the preceding claims adapted to actuate a control element (210) when the two torsion springs (110, 120) have twisted back into the neutral position after the time interval has expired.

10. The mechanic timer element (100) according to claim 9, wherein the control element is or comprises a valve (210).

11. The mechanic timer element (100) according to claim 10, wherein the control element (210) is adapted to control a flow (221) of a fluid, preferably of oxygen.

12. Control mechanism (200) comprising a mechanic timer element (100) according to any one of the preceding claims and a control element (210), wherein the mechanic timer (100) is adapted to actuate the control element (210) when the two torsion springs (110, 120) have twisted back into the neutral position after the time interval has expired.

13. Control mechanism (200) according to claim 12 adapted to actuate a valve (210).

14. Control mechanism (200) according to claim 13 adapted to control a flow (221) of a fluid, preferably of oxygen.