Apparatus for mounting electronic module assembly in a sensor

• Main Authors: Wilkie, Brian J, McBride, Timothy M
• Format: Patent
• Language: English; French; German
• Published: 19.07.2017
• Subjects: MEASURING; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; PHYSICS; TESTING; WEIGHING

An occupant weight sensor (1) for placement between a frame (7) fixed to the chassis of a vehicle and a second frame (8) supporting a vehicle seat has a sense element having a first body (12, 22, 28, 34, 50, 62, 64, 68, 84) formed with a planar sense surface on which are mounted piezoresistors electrically connected in a Wheatstone bridge configuration. A post (12a, 22c, 28c, 34e, 50b, 62a, 64a, 68b, 84g) extends outwardly from the first body for attachment to the first frame. A second body is formed with a force transfer portion (14a, 24g, 30d, 36b, 52a, 70a, 94a) permanently attached to the first body along an outer periphery circumscribing the sense surface. The piezoresistors are electrically connected to conditioning electronics received in a chamber formed between the two bodies. The effects of parasitic loads on the sense element are minimized by selected placement of the piezoresistors on the sense surface. In one embodiment, attachment stresses of an electronic module assembly (88) are isolated from the sense surface by attaching the assembly to a support ring end wall (86a) welded to a portion of the first body removed from the sense surface and providing a control gap between the support ring and the sense surface. Several variations are disclosed for attaching the sensor to the first and second frames and both longitudinally and laterally extending electrical connectors are shown.