US 7004042 B2
A sensor arrangement includes a sensor having a sensor body, a lockable arm on the sensor body, where the lockable arm is flexible, and an encoding element on the lockable arm. The arrangement includes a housing that has a bore with two sides, one of which has a recess. The sensor is inside the bore such that the encoding element is inside the recess and such that the lockable arm locks to an edge of the housing.
1. A sensor for insertion into a bore of a housing, the sensor comprising:
a sensor body;
a lockable arm on the sensor body, the lockable arm being flexible; and
an encoding element on the lockable arm.
2. The sensor of
3. The sensor of
4. The sensor of
5. The sensor of
6. The sensor of
7. The sensor according to
8. The sensor of
9. The sensor of
10. The sensor of
a second lockable arm on a side of the sensor body that is opposite to a side of the sensor body having the lockable arm.
11. The sensor of
12. The sensor of
13. The sensor of
an end stop on the sensor body that limits a range of flexibility of the lockable arm.
14. The sensor of
15. The sensor of
16. The sensor of
17. The sensor of
a sensor element at a front end of the sensor body, the front end being a part of the sensor that is inserted first into the housing; and
a contacting device for connecting to cables, the contacting device being at a back end of the sensor body, the back end being inserted into the housing after the front end;
wherein the sensor element is electrically connected to the contacting device.
18. The sensor of
a flange between the lockable arm and the contacting device.
19. A sensor arrangement, comprising:
a sensor comprising:
a sensor body;
a lockable arm on the sensor body, the lockable arm being flexible; and
an encoding element on the lockable arm; and
a housing that has a bore with two sides, one of the sides having a recess, the sensor being inside the bore such that the encoding element is inside the recess and such that the lockable arm locks to an edge of the housing.
20. A method for manufacturing a sensor comprised of a sensor body, a lockable arm on the sensor body, the lockable arm being flexible, and an encoding element on the lockable arm, the method comprising:
injecting plastic into a mold comprised of two halves, the mold having a projection integrated into at least one of the two halves that forms a space between the lockable arm and the sensor body.
The invention relates to a sensor having a sensor body, on which a lockable arm is arranged, and having an encoding element for defining the insertion direction. The invention also relates to a method for manufacturing the sensor, as well as a sensor arrangement in a housing.
Sensors, as mentioned above, are known from the state of the art, in which the lockable arms are arranged in a plane. An encoding element is arranged in a plane that is perpendicular to that plane. Such sensors may be inserted in housing bores with encoding and may be locked there. Also, the housing bore features an additional recess that serves for encoding, thus for defining the insertion direction of the sensor in the housing. The sensor may be inserted into the housing only if the code on the sensor body is in the same place as the code on the housing bore.
Such sensors are used, for example, as temperature sensors. Temperature sensors have an NTC temperature sensor element at one end of the sensor body. At the other end of the sensor, a contacting device is provided, which connects cables leading from the outside to the sensor with the sensor element in an electrically conductive manner. Such sensors can, for example, be inserted from the outside into air conditioners housings, where they are then used for measuring the temperature in the air conditioner.
The lockable arms serve to secure the sensor in the housing.
The known sensors have the disadvantage that the manufacture of the sensor body by inexpensive injection molding is possible only in a relatively complicated manner, because of the arrangement of the lockable arm and the encoding. The sensors must be designed in two parts in the form of the so-called “hinged sensors”. In the process, the upper half and the lower half of the sensor are manufactured as if folded open. The two halves are connected to each other by an integral hinge and are assembled as one sensor body by folding them together.
The task of the present invention is therefore to describe an insertable sensor that is easy and inexpensive to manufacture.
This aim is achieved by an insertable sensor according to claim 1. Advantageous embodiments of the sensor as well as a sensor arrangement in a housing are shown in the remaining claims.
A sensor suitable for being inserted in the bore of a housing and having a sensor body is indicated. A flexible lockable arm is arranged on the sensor. The sensor also has an encoding element arranged on the lockable arm.
By arranging the encoding element on the lockable arm of the sensor, it becomes possible to manufacture the sensor simply and inexpensively in one piece, by injection molding. Such manufacture may, for example, be in the form of a mold formed by two halves. The mold parting line is in the plane in which the lockable arm flexes. The use of slide valves, as are necessary for molding the special cavities in the known sensors, can be dispensed with. Rather, it becomes possible to manufacture cavities or free spaces under the flexible lockable arm in the form of integrated projections. The two halves forming the mold can be easily parted after injection molding.
The lockable arm may be arranged on the narrow side of the sensor. This has the advantage that the encoding element is also located on the narrow side of the sensor. This makes it easy to comply with the customer specifications required recently, because according to these specifications, the code in the housing is often located on the narrow side of the housing bore.
There is also a free space between the lockable arm and the sensor body, for flexing the lockable arm toward the inside. This has the advantage that the lockable arm can be flexed easily toward the inside, without impediment by the sensor body. This flexing toward the inside is necessary if the sensor is to be inserted into the bore of a housing, together with the lockable arm. The lockable arm must be flexible toward the inside, in order to be able to lock into place.
It is also an advantage if the lockable arm has an outer edge running toward the inside at a slant to the insertion direction. With such an outer edge, the lockable arm can be pushed along the edge of a housing bore. The slant means that the inside force exerted on the lockable arm towards the inside increases slowly, making for an insertion process that can be easily controlled.
The sensor may be manufactured by injecting a plastic into a mold made of two halves. In this process the mold parting line between the two halves may run in the plane in which the lockable arm flexes, enabling the two advantages described above to come into play.
The encoding element may extend parallel to the plane of the mold parting line. In another embodiment of the sensor, the encoding element may also extend in the plane of the mold parting line. This increases the flexibility in the use of the sensor.
In an advantageous embodiment of the sensor, the encoding element may be located on the exterior of the lockable arm, making it simple to mold the encoding element in such a way that it protrudes above the outline of the sensor body, and thus can fulfill its encoding function.
In another embodiment of the sensor, a second lockable arm can be provided on the side of the sensor body opposite the lockable arm, yielding an essentially symmetrical design of the sensor that is locked into the bore of a housing by lockable arms after insertion, and is therefore mechanically more stable.
Moreover, the encoding element may be a projection protruding beyond the outline of the sensor, as seen counter to the insertion direction. This projection may, for example, have the shape of a rib.
Furthermore, the encoding element may have a border at its front end, as seen from the insertion direction, running perpendicular to the insertion direction and in the flex direction of the lockable arm. Such a border running in the flex direction has the advantage that a deterioration of the encoding through flexing back the lockable arm, and insertion into a housing in an unplanned direction can be avoided. The border running perpendicular to the insertion direction and in the flex direction also means that there is no starting incline in the encoding element, thereby preventing insertion of the sensor in the wrong orientation, with a great degree of certainty.
Furthermore, an end stop can be provided on the sensor body, to limit the flex range of the lockable arm. The limitation of the flex range of the lockable arm has the advantage of preventing the encoding element from being pushed completely inside when the lockable arm flexes in, and thereby no longer fulfilling its encoding function.
In the process, it is of advantage if the encoding element is designed in such a way that it protrudes beyond the outline of the sensor body even if the lockable arm is pushed toward the inside up to the end stop, as seen counter to the insertion direction. In this way, it retains its encoding function even if the lockable arm is completely pushed in.
A recess may be provided at the back end of the lockable arm, as seen from the insertion direction, which is suitable to accommodate an edge of a housing, ensuring a secure lock of the sensor body with the housing.
The lockable arm may extend from the sensor body counter to the insertion direction, ensuring a secure lock of the lockable arm with the housing.
Furthermore, a sensor is indicated in which a sensor element is located at the front end of the sensor body as seen from the insertion direction, and in which also a contacting device for cables is provided at the back end of the sensor body as seen from the insertion direction. The sensor element is connected with the contacting device in an electrically conductive manner.
Such a sensor has the advantage that it can be contacted electrically from the outside via a plug or via a terminal connection, after installation of the sensor in a housing with the sensor elements integrated in the front end of the sensor. The electrical contact serves, in this connection, to read the sensor signals supplied by the sensor element.
Furthermore, a flange may be arranged between the lockable arm and the contacting device, which flange helps to better seal the connection between the sensor body and the housing.
Furthermore, a sensor arrangement is indicated, in which a housing is provided in addition to the sensor described above, which housing has a bore with two narrow sides. The housing also has an additional encoding recess arranged on one of the narrow sides. The sensor is inserted through the encoding recess with its encoding element, and the lockable arm interlocks with an edge of the housing.
Such a sensor arrangement has the advantage that a sensor that can be manufactured in one piece by simple injection molding can be inserted into the housing securely and correctly.
Furthermore, a method for manufacturing a sensor is indicated, whereby the sensor is manufactured in two halves by injection molding of a plastic. The two halves have projections protruding toward the interior of the mold forming the free space(s) necessary for flexing the lockable arms. The projections may be made of metal, in particular steel.
In the following, the invention is explained in more detail by way of exemplary embodiments and the respective illustrations.
The sensor of
The positioning of the encoding recess 21 corresponds to the positioning of the encoding element 5 of
The invention described here is not limited to temperature sensors or to sensor bodies manufactured by injection molding, but can be used for any type of sensors.