The present invention relates to a device for preventing unscrewing of a closure cap, which can be mounted on a stationary stub of a container, in particular a motor vehicle radiator, as generically defined by the preamble to claim 1.
In one such unscrewing prevention device, known from European Patent Disclosure EP 0 760 789 B1, a control bolt of the twist preventer is acted upon, counter to the action of a compression spring, by a so-called memory spring, which expands at a suitably high temperature. The control bolt is disposed in an axial blind bore of a thickened portion of the stub that is provided with the counterpart closure element. In this disposition of the twist preventer, it is difficult to bring the heat, which exists concretely in the container, to the heat-variable memory spring without major temperature losses.
The object of the present invention is therefore to create an unscrewing prevention device of the type defined at the outset whose twist preventer is disposed in an optimal way for the delivery of operating data.
For attaining this object, in an unscrewing prevention device of this type, the characteristics recited in claim 1 are provided.
By the provisions according to the invention, depending on the type of drive mechanism intended for the twist preventer, an optimal position of the drive mechanism with a view to delivering the operating data to be employed is attainable.
In one embodiment, the characteristics of claim 2 are provided, which means that the housing that receives the drive mechanism is disposed in an optimal way at the place where the pressure or temperature are directly present. Moreover, the housing is accommodated in a space-saving way. In this respect, the characteristics of claim 3 and/or claim 4 may advantageously be provided.
In another exemplary embodiment having the characteristics of claim 5, the housing is mounted on the outside of the container whenever the operating data have been taken from the operating status of the engine. This moreover has the advantage that the container itself needs to change only insignificantly. In this respect it may be expedient to provide the characteristics of claim 6.
Advantageous structural features in terms of the twist preventer are obtained from the characteristics of one or more of claims 7 through 10.
Various ways of triggering the drive mechanism are advantageously apparent from the characteristics of claims 11, 12, 13, and 14.
Advantageous structural features in terms of the housing and the diaphragm will become apparent from the characteristics of one or more of claims 15 through 18.
Further details of the invention can be learned from the ensuing description, in which the invention is described and explained in further detail in terms of the exemplary embodiments shown in the drawing.
Shown are:
FIG. 1, in a schematic longitudinal section, a closure cap mounted on a motor vehicle radiator, with a pressure-controlled twist preventer, in a first exemplary embodiment of the present invention, the half-sections on the right and left of the twist preventer each representing one of the two terminal positions;
FIG. 2, a view corresponding to FIG. 1, but with a temperature-controlled twist preventer in a second exemplary embodiment of the present invention;
FIG. 3, a view corresponding to FIG. 1, but with an electromagnetically controlled twist preventer in a third exemplary embodiment of the present invention;
FIG. 4, a view corresponding to FIG. 1, but with a negative-pressure controlled twist preventer in a fourth exemplary embodiment of the present invention; and
FIG. 5, a view corresponding to FIG. 1 of a pressure-controlled twist preventer, but in a fifth exemplary embodiment of the present invention.
The device 10, 110, 210, 310, 410 for preventing unscrewing of a cap or the like shown in a plurality of exemplary embodiments in the drawing is used for operationally controlled prevention of unscrewing of a closure cap 11, 111, 211, 311, 411 from the closure element 12, 112, 212, 312, 412 of a container 13, 113, 213, 313, 413, for instance a motor vehicle radiator, whenever, because of the operating state of the container (increased pressure or temperature), unscrewing the closure cap from the container stub can be dangerous to the user.
The closure cap 11, 111, 211, 311, 411 has an outer part 14, 114, 214, 314, 414 with a grip element 16, 116, 216, 316, 416, which is integrally provided with a closure element 17, 117, 217, 317, 417, which here serves a female thread 18, 118, 218, 318, 418 for screwing the closure cap onto and unscrewing it from the opening of the stub 12, 112, 212, 312, 412, which has a male thread 19, 119, 219, 319, 419, of the motor vehicle radiator 13, 113, 213, 313, 413 or other container. It is understood that the closure element 17, 117, 217, 317, 417, instead of having a thread, may be provided with a bayonet mount element, which can be connected to a corresponding bayonet mount element on the stub. An inner part 21, 121, 221, 321, 421 of the cap is disposed in suspended fashion, concentrically with the closure element 17, 117, 217, 317, 417, on the inside of the grip element 16, 116, 216, 316, 416. The inner part 21, 121, 221, 321, 421 of the cap is rotatable relative to the grip element 16, 116, 216, 316, 416 of the outer part 14, 114, 214, 314, 414 of the cap but is axially held firmly. The inner part 21, 121, 221, 321, 421 of the cap is embodied as a valve pot and receives an overpressure/negative-pressure valve assembly 22, 122, 222, 322, 422, shown only schematically in dashed lines, whose overpressure valve is triggerable in one or two stages.
The unscrewing prevention device 10, 110, 210, 310, 410 has a twist preventer 25, 125, 225, 325, 425, which has a drive mechanism 27, 127, 227, 327, 427, disposed in a housing 26, 126, 226, 326, 426 provided inside or outside the container 13, 113, 213, 313, 413, and this drive mechanism actuates a locking bolt 28, 128, 228, 328, 428 in order to cause it to engage or disengage a detent opening 29, 129, 229, 329, 429 in the grip element 16, 116, 216, 316, 416 of the closure cap 11, 111, 211, 311, 411. In the various exemplary embodiments, the drive mechanism 27, 127, 227, 327, 427 is triggerable in accordance with various specifications.
In the exemplary embodiment of FIG. 1, the drive mechanism 27 is triggerable by the internal pressure existing in the container 13. To that end, the housing 26 that receives the drive mechanism 27 is disposed in a region inside the container 13 and below the male thread 19 of the stub 12 and opposite an outer region of the grip element 16 of the closure cap 11. The housing 26 has a cylindrical part 31, which protrudes inward integrally from the inner wall of the container 13 and is closed by a cap part 32 that is provided with a plurality of evenly distributed connecting openings 39. An insert 33 is disposed inside the cylindrical part 31 and is clamped in the cylindrical part 31 by the cap part 32 and serves as a guide element for the locking bolt 28. The locking bolt 28, disposed axially movably inside the housing 26, penetrates the container wall that forms the housing bottom, and in this region the locking bolt is for instance round in the manner of a pin. Inside the housing 26, the locking bolt 28 has a widened portion with an annular groove 34, in which a compression spring 36 surrounding the pinlike bolt region is received, which spring is braced at one end on the bottom of the annular groove 34 and on the other on the insert 33. This compression spring 36 presses the locking bolt 28 against a diaphragm 40, which is acted upon by the pressure in the container interior and is fastened in pressuretight fashion on its outer circumference between the cap part 32 and the insert 33. As can be seen from the two half-sections in FIG. 1, the diaphragm 40, in its middle region 37 against which the locking bolt 28 is pressed, can be deflected counter to the action of the compression spring 36 whenever the pressure in the interior of the container 13 exceeds a certain value. Opposite the end of the locking bolt 28 protruding out of the container 13, the grip element 16 is provided with an axial through opening 38, which the locking bolt 28 can engage when the diaphragm 40 has been deflected and can thus prevent relative rotation between the grip element 16 and the container stub 12. The through opening 38 in the grip element 16 is continuous here, or in other words is accessible from the outside, so that professionals will still be able to unlock and accordingly open the closure cap 11 intentionally.
The exemplary embodiment shown in FIG. 2 is similar to that shown in FIG. 1, with the distinction that the drive mechanism 127 in the housing 126 is tg and driven as a function of the temperature that occurs in the interior of the container 113. While the locking bolt 128, compression spring 136, insert 133, and cylindrical part 131 are structurally essentially identically embodied and disposed in terms of position, the drive mechanism 127 has a thermocapsule 140, which contains an expanding material that expands under the influence of heat if the temperature increases. The thermocapsule 140 is braced on the inside of the cap part 132. Located on the thermocapsule 140 is a sealing diaphragm 141, whose middle region is disposed between the top side of the thermocapsule 140 and the opposed underside of the widened region of the locking bolt 128. The circumferential region of the sealing diaphragm 141 is clamped or fastened between the cap part 132 and the insert 133. For direct transmission of the heat from the container interior to the thermocapsule 140, or its expanding material, the cap part 132, just like the cap part 32 in the pressure-controlled tv 27 or 40, is provided with connecting openings 139 distributed preferably evenly over the circumference. The through opening 130, opposite the housing 126 or the locking bolt 128, in the grip element 116 is also embodied approximately in the same way.
In the exemplary embodiment shown in FIG. 3, the drive mechanism 227 is formed an electromagnet 245, which is provided in a housing 226 that once again has a cylindrical part 231, suspended integrally inward into the container on the inside of one region of the container wall. The cylindrical part 231 is likewise covered by a cap part 232, and the cap part 232, with contact and fixation ribs 246, serves to receive the electromagnet 245 and retain it. The electromagnet 245 has a coil 248, inside which a locking bolt 228, as an armature, is axially movable. The locking bolt 228 penetrates an opening in the container wall and protrudes out of the container 213, opposite a corresponding detent bore 238 in the grip element 216. Inside the housing 226, in the container wall, a moisture-proof duct 249 is provided, through which a connection cable 251 is carried to the electromagnet 245. The connection cable 251 leads to a controller, not shown, which detects the operating state of the engine of the motor vehicle.
In the exemplary embodiment shown in FIG. 4, the drive mechanism 327 is formed by a negative-pressure diaphragm 345, which is inside a housing 326 that is located outside the container 313. The external housing 326 is disposed and retained on one region of the container wall. For that purpose, the container 313 has a circumferential flange 352, which is concentric with the stub 312 that is provided with the male thread 319, and which has a spacing such that on its outer circumference it is approximately aligned with the outermost circumference of the grip element 316. The housing 326 is retained in the flange 352 or in the applicable region 355 of the wall of the container 313, for instance by means of a tongue and groove connection 353 and 354, and remote from the flange 352, it is retained in clamping fashion on its back side by a detent bracket 356 and thus is retained in an optionally replaceable way. The housing 326 is embodied in two parts; the negative-pressure diaphragm 345 is clamped on the outer edge between the two housing parts 357 and 358. The housing part 357 at the back, remote from the closure cap 311, acts as a guide for the locking bolt 328, which is connected to the negative-pressure diaphragm 345 in a manner fixed against relative motion. The housing part 358′ oriented toward the closure cap 311 is provided with a through bore for the locking bolt 328, which bolt simultaneously protrudes into a bore 359 of the flange 352 and can reach into a detent opening 338 of the grip element 316 of the closure cap 311 (as shown in dashed lines). This detent opening 338 may be embodied as an oblong hole or in the form of a slit that is open from the face end. The negative-pressure diaphragm 345 is U-shaped, for instance, specifically in both of its terminal positions. A negative-pressure bore 344 leads into the housing 326 and is connected to the engine in a manner not shown via a negative-pressure hose. Thus the negative-pressure diaphragm 345 can be moved by suction out of one terminal position, shown in solid lines, to its other terminal position (locking position) represented by dashed lines. The negative-pressure diaphragm 345 is prestressed by a compression spring 336, so that it returns to its outset position when the negative pressure has built back up again to normal pressure.
The exemplary embodiment shown in FIG. 5 is once again similar to what is shown in FIG. 1; once again, the drive mechanism 427 in the housing 426 is controlled by the pressure prevailing in the interior of the container 413. However, instead of the diaphragm 40 of FIG. 1, a piston 440 is disposed in the cylindrical part 431 of the housing 426, axially movably counter to the action of a compression spring 436. The piston 440 is guided in pressuretight fashion along the inner wall of the cylindrical part 431 via a sealing ring 442. The piston 440 is integrally provided with a concentric axial locking bolt 428 that is surrounded by the compression spring 436, which is braced at one end on the piston 440 and at the other on an inner annular face of the cylindrical part 431; this annular face surrounds the through bore of the housing 426 through which the locking bolt 428 extends. The locking bolt 428 is pressed, counter to the action of the compression spring 436, into an axial through opening 438 in the grip element 416 whenever the pressure in the interior of the container 413 exceeds a certain value. When the piston 440 has been displaced upward, the locking bolt 428 therefore prevents relative rotation between the grip element 416 and the container stub 412. In this exemplary embodiment as well, the through opening 438 in the grip element 416 is continuous, or in other words accessible from the outside, so that professionals can still intentionally unlock and accordingly open the closure cap 411.
The cylindrical part 431 of the housing 426 is covered on its inner end by a cap 432, which fits over the cylindrical part 431 on the outside in detent-locking fashion. The cap part 432 is provided toward the bottom with a connecting opening 439, which here is concentric in the middle and which makes it possible to transmit the pressure conditions in the interior of the container 413 to the axially movable piston 440.
During engine operation, the coolant in the container 13, 113, 213, 313, 413 will heat up, so that the temperature and pressure will rise there. Because in the exemplary embodiments of FIGS. 1, 2 and 5 the drive mechanism 14, 114 and 414, respectively, is disposed directly in the container interior, then if there is a pressure increase in FIG. 1, in the half-section on the right, or FIG. 5, in the half-section on the left, the diaphragm 40 or the piston 440 will be deflected and moved axially in the direction of the arrow B, counter to the action of the compression spring 36 and 436 acting on the twist preventer 25 and 425, respectively, so that the locking bolt 28 and 428 will engage the detent opening 38 and 438, respectively. In the exemplary embodiment of FIG. 2, in the half-section on the right, the expanding material will be expanded because of the temperature increase, and thus the thermocapsule 140 expands axially in the direction of the arrow B, once again counter to the compression spring 136 acting on the twist preventer, and because of this expanding motion the locking bolt 128 enters the detent opening 138.
The same is correspondingly true for the exemplary embodiment of FIG. 3, in which the temperature and pressure increase in the container 213 is derived indirectly from electrical engine data, for instance upon shutoff of the warm engine. Once again, the locking bolt 228 will engage the detent opening 238.
In the exemplary embodiment of FIG. 4, whenever negative pressure is generated upon shutoff of the engine, the locking action that prevents the unscrewing of the closure cap 311 will occur once the locking bolt 328 has moved into the direction of the arrow C.
It is understood that whenever the operating position (temperature increase or pressure increase), which is picked up directly or indirectly, changes to the normal or outset position, the locking action is undone again, because the locking bolt 28, 128, 228, 328, 428 is returned under the influence of the compression spring 36, 136, 236, 326, 426.
It is understood that in the exemplary embodiments of FIGS. 3 and 4, the location of the drive mechanism housings 226 and 326 can also be provided in some other way (on the outside instead of the inside, or on the inside instead of the outside, respectively). The same is correspondingly true for the location of the locking bolt.
Moreover, in all the exemplary embodiments, it is possible to provide a rockerlike force booster between the drive mechanism 26, 126, 226, 326, 426 and the locking bolt 28, 128, 228, 328, 428 that is deflected away from it.
Patent Application
20050121453
