Patent Application
20060054763
This invention concerns a device for positioning and holding a protective sleeve or other elongated item at a predetermined position covering a sensor or other object.
Sensors used in automotive applications, such as oxygen sensors which provide data to control engine operation and performance, are often mounted within the engine compartment of a vehicle where they are subject to a harsh environment including intense radiant heat and constant vibration during vehicle operation. In view of the harsh environment, it is advantageous to cover the relatively delicate sensors with protective sleeving which can damp vibration and reflect radiant heat. Such sleeves often comprise an elongated tube having an inner damping layer of a non-woven material, for example, polyester felt. The inner damping layer is surrounded by a reflective layer comprising, for example, an aluminum foil layer laminated with a reinforcing layer such as a woven scrim of polymer filaments or a polymer sheet material.
Due to the nature of the protective sleeve and its environment, it is difficult to attach the sleeve to the sensor in a manner which will allow the sleeve to be reliably secured in a desired position and also be readily removable for installation and servicing of the sensor. Adhesives, tape and frictional fits are used to effect attachment, but these methods all suffer various disadvantages. Adhesive attachment of the sensor, while generally secure, permanently attaches the sleeve to the sensor. As a result, this method does not allow for easy removal and reuse of the sleeve for servicing of the sensor. Tape and friction fits are unreliable and simply not feasible in view of the heat and vibration encountered by the sensor and its protective sleeve within the engine compartment. Clearly, there is a need for a device that can position and hold a protective sleeve reliably and securely in a desired predetermined position in the face of harsh environmental factors and yet be easily movable to allow for repeated removal and reuse of the sleeve as required for servicing of the sensor.
The invention concerns a positioning device for holding a first elongated member at a predetermined position along a second elongated member. The second elongated member is positioned within a bore extending through the first elongated member. The positioning device comprises a band surrounding a central space. A plurality of flexible, resilient fingers are mounted on the band. Each finger has a first end attached to the band and a second end that extends inwardly into the central space. The second ends are engageable with the second elongated member received within the central space. The band and the fingers are slidably movable along the second elongated member to the predetermined position upon the application of a force to the band directed along the second elongated member. To move the band, the force must be sufficient to overcome the resistance between the fingers and the second elongated member. The fingers forcibly engage the second elongated member and hold the band in the predetermined position in the absence of the force. The band is engageable with the first elongated member for holding it in the predetermined position along the second elongated member.
Preferably, the band is elongated, has a circular perimeter, and may be tapered. The band may be sized so as to interfit within the bore of the first elongated member. A rim is attached to the band and extends outwardly therefrom. The rim is engageable with the first elongated member.
In practical applications, the invention comprises an assembly used to hold a heat shield in position on a sensor connected to a wiring harness. The assembly includes the heat shield, which has a bore for receiving the sensor, an elongated harness sleeve that is positionable to extend outwardly from the sensor and through the bore of the heat shield, (the harness sleeve being positionable to surround and protect the wiring harness), and a positioning device as described above for holding the heat shield at a predetermined position along the harness sleeve.
Sensor 14, for example, an oxygen sensor, is connected to a microprocessor (not shown) via a wiring harness 26 through which it provides data used by the microprocessor to control engine operation and performance. Preferably, the wiring harness 26 is covered by an elongated protective harness sleeve 28 that extends substantially along the length of the harness. Harness sleeve 28 is preferably extruded from a polymer material and has corrugations 30 extending circumferentially to provide radial stiffness and bending flexibility.
Positioning device assembly 10 includes the harness sleeve 28 and a positioning device 32 (described in detail below) that engages both the harness sleeve 28 and the sensor sleeve 12. In use, as shown in a comparison of
A rim 40 is attached to band 34. In this example rim 40 is positioned at the same end of the band as the fingers 38. Rim 40 extends radially outwardly from band 34 and acts as a stop when the positioning device 32 engages the sensor sleeve 12.
Yet another alternate embodiment 52 of the positioning device is depicted in
Positioning devices and positioning assemblies according to the invention provide numerous advantages for securing protective sleeves or other items at a predetermined position along an elongated item such as a wiring harness. They securely fasten the protective sleeve at the desired position to protect a component and yet are easily moved along the elongated item to reposition the sleeve. This allows the sleeve to be quickly removed from the item for component maintenance and then readily repositioned to protect the component without damage to the sleeve, thereby allowing it to be reused. Furthermore, the positioning assembly or device can be part of a sub-assembly that includes the component, wiring harness, harness sleeve and component sleeve. This saves time during integration of the sub-assembly into the vehicle as the steps of assembling the protective sleeve are eliminated.
