Patent Application
20170038231
Sensors commonly comprise a base portion that is fixed joined to a body having a parameter thereof to be measured. For example, the base portion can be secured to a port in a hydraulic circuit or device, where the base forms a fluid tight seal with the body. The sensor further includes a cover member that together with the base portion form a complete enclosure or protective housing for components such as sensor electronics and the like, thereby protecting the components from the outside environment.
Some cover members are secured to their respective base portions in a manner allowing the cover member to be joined in a single known position with respect to the base portion. A disadvantage of such a sensor is that in order to obtain a desired orientation of the cover member when mounted to the body, the base portion must be mounted in a certain position such that the cover member when secured to the base portion achieves the desired orientation. Although there exist other sensors that allow the cover member to be secured to the base portion at a desired orientation after mounting of the base portion, or irrespective of the mounting position of the base portion, the components used to mount the cover member to the base portion can increase complexity of the union formed between the cover member and the base portion, thereby increasing the costs, and/or increasing the overall dimension(s) (e.g. height or width) of the sensor housing.
This Summary and the Abstract herein are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary and the Abstract are not intended to identify key features or essential features of the claimed subject matter, nor are they in-tended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the Background.
A sensor housing includes a base portion having an annular recess bounded by a peripheral flange and concentrically oriented with respect to a longitudinal axis. A cover member is secured to the base portion to form an enclosure. The cover member has an annular rim received in the annular recess, while the annular rim has an upwardly facing surface. The cover member is rotatable relative to the base portion with the annular rim at least partially in the annular recess. A coupling mechanism includes one or more fixing elements secured to the peripheral flange. The fixing element directly or indirectly engages the upwardly facing surface to inhibit removal of the annular rim away from the annular recess and fix the rotational position of the cover member relative to the base portion and about the longitudinal axis.
The fixing element can comprise at least one set screw at an angle that is oblique with respect to the longitudinal axis, and preferably a plurality of set screws spaced apart from each other about the longitudinal axis, each set screw at an angle that is oblique with respect to the longitudinal axis.
The coupling mechanism can also comprise one or a plurality of intermediate bearing members engaging the upwardly facing surface, the fixing element engaging the intermediate bearing member(s) on a side remote from the upwardly facing surface. The intermediate bearing member can comprises spherical ball(s) or a ring at least substantially, or completely, encircling and disposed on the annular rim. The fixing element can comprise a fastening ring disposed on the annular rim or one or more spaced apart set screws. Each set screw can be parallel or oblique to the longitudinal axis.
The fixing element can also comprise a spring biased pin engaging the annular rim, while the annular rim includes a plurality of spaced apart recesses about the annular rim, each recess having a lower surface comprising the upwardly facing surface. In a further embodiment, the recesses are disposed in an annular groove.
A first embodiment of a sensor 10 is illustrated in
The rotatable housing can be used for any unit having a base portion 14 that is mounted in a fixed position. In a particular advantageous embodiment, the base portion 14 is mounted to a hydraulic or other fluid circuit or component to form a fluid tight seal with the body 22 using a threaded portion 23. In the embodiment illustrated, the base portion 14 includes a flange 30 and an elongated member or rod 32 that forms an elongated cavity that is isolated from the fluid by a remote end surface 36 and a peripheral wall 35. In one illustrative embodiment, the sensor can be a magnetostrictive sensor having an elongated waveguide disposed in the cavity. A position magnet, not shown, moves axially with respect to the waveguide and the elongated member 32. Inside the sensor a torsional strain pulse is induced in the waveguide by momentary interaction of two magnetic fields. The strain pulse is detected by the electronics in the housing of the sensor. One magnetic field is produced by a moving position magnet, which travels along the elongated member 32 with the waveguide inside. The other magnetic field is generated by a current pulse applied to the waveguide. The position of the moving magnet is determined precisely by measuring the time elapsed between the application of the current pulse and the arrival of the strain pulse at the sensor housing. The result is a reliable position measurement with high accuracy and repeatability.
The coupling mechanism 18 between the base portion 14 and the cover member 16 includes at least one and in a further embodiment a plurality of fixing elements 40 mounted in one or more corresponding bores 42 in a peripheral rim or flange 44 in the base portion 14. In the embodiment of
The annular recess 46 is configured to receive an annular rim 50 of the cover member 16. Each of the fixing elements 40 are of sufficient length and mating threads of the fixing elements 40 and bores 42 are arranged such that a remote end of each of the fixing elements 40 directly engages the annular rim 50 of the cover member 16 when the annular rim 50 is disposed in the annular recess 46. In the embodiment illustrated, the annular rim 50 includes an upwardly facing annular bearing surface 58 upon which each of the fixing element(s) 40 can bear against. The upwardly facing annular bearing surface 58 can be configured so as to be substantially orthogonal to the inclination of the bore(s) 42. A seal 60 arranged in an annular recess of the base portion 14 engages an inwardly facing surface 62 of the annular rim 50 to seal the internal chamber formed from the base portion 14 and cover member 16. In a preferred embodiment, the annular rim 50 has the same cross-section about the periphery of the cover member 16, which allows the cover member 16 to be secured in any desired rotational position upon the base portion 14 when the fixing element(s) 40 are fixedly secured in the bores 42 and bear against the annular rim 50.
Unlike the direct coupling of the fixing element(s) 40 to the cover member 16 in
In the embodiment illustrated, the intermediate bearing member(s) 70 are spherical balls, although other shapes can also be used. Each intermediate bearing member 70 is disposed in a recess 72 below the peripheral flange 44′ that guides the intermediate bearing member 70 allowing only linear movement of the intermediate bearing member 70 herein radial movement toward the annular rim 50′ and against upwardly facing annular bearing surface 58 when the fixing element 40′ bears against the intermediate bearing member 70 on a surface remote such as generally opposite a surface of the intermediate bearing member 70 engaging the annular rim 50′. As with the embodiment of
In a further embodiment, each recess 88 is disposed in an annular groove 92 having upper and lower annular walls 94 and 96. The depth of the groove 92 formed by the walls 94 and 96 is configured such that the pin 80 will not exit the groove 92 even when the pin 80 is not aligned with a recess 88. In this manner, the groove 92 and in particular the lower annular wall 96 inhibits removal of the cover member 16 from the base portion 14 while the cover member 16 is rotated relative to the base portion 14 as well as when the pin 80 has engaged a recess 88. Stated another way, each of the recesses 88 and the groove 92 includes a lower, upwardly facing annular bearing surface 58 (lower surface of recess 88 or annular wall 94) that engages pin(s) 80 so as to inhibit removal of the cover member 16 from the base portion 14. In this embodiment, a seal 98 is disposed between the annular rim 50″ and an inner surface of the peripheral flange 44″.
Upon location of the annular rim 50 partially in annular recess 46 outwardly facing threads of the fixing element 40′″ engage inwardly facing threads as indicated at 99 on the base portion 14 in the desired rotational position of the cover member 16 on the base portion 14. Edges 103 formed on the fixing element 40′″ provided by recesses 105 (or projections 107) formed thereon allow the fixing element 40′″ to be turned such that the threads of the fixing element 40′″ more fully engage the threads of the base portion 14 causing the fixing element 40′″ to bear against the intermediate member 102 driving the cover member 16 toward and against the lower surface of the annular recess 46 to fix the position of the cover member 16 on the base portion 14. Since the inner surface 101 of fixing element 40′″ slides upon the outer surface 104 of the cover member 16, the rotational position of the cover member 16 can remain fixed while the cover member 16 is driven toward the lower surface of the annular recess 46. One or more o-rings 112 seal the enclosed space of the cover member 16 and the base portion 14.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/201376, filed Aug. 5, 2015, the content of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62201376 | Aug 2015 | US |
