Abstract: A capacitive sensing apparatus for a vehicle seat includes a deflectable dielectric mat and a flexible printed circuit that wraps around the major surfaces of the dielectric mat to define upper and lower conductor strips that overlap in a direction perpendicular to the dielectric mat. Overlapping regions of the conductor strips define an array of capacitive load cells distributed over the seating surface. A connector stub depending from the flexible printed circuit couples the conductor strips to an external circuit that measures the capacitance of the various load cells to determine occupant weight and weight distribution.

Abstract: Portable scale devices, apparatus and methods for use with stretchers so that emergency medical service (EMS) personal can accurately measure a patient's weight in the field so that proper medication treatment and dosage can be administered. A head plate member can be pivotably attached to a middle plate, and a foot plate member can also be pivotably attached to the middle plate. The head and foot plate members can be inclined to form a V configuration relative the middle plate. A scale can be attached beneath the middle plate so that the pivotable head and foot plate members on the middle member with the scale can be easily inserted between a mattress and a stretcher. The portable scale devices, apparatus and methods can be used in the field as soon as a patient is placed on the stretcher, as well as when the stretcher is being physically moved and handled in the field, and additionally when the stretcher is being placed and/or moved by a vehicle such as an ambulance.

Abstract: An occupant load sensor (10) is fixed to a bracket (48) via a sleeve (60a) of a collar (60) arranged in an outer periphery of a thread (32) of a bolt portion (30), and a bush (62) interposed between the sleeve (60a) and a through hole (48a) of the bracket (48). Accordingly, a slight movement is allowed between the bolt portion (30) and the bracket (48) on the basis of gaps formed between the thread (32) and the sleeve (60a) and between the sleeve (60a) and the bush (62), and it is possible to cancel a force applied from the other directions than a vertical direction. Therefore, a load from the seat side is applied in the vertical direction and it is possible to accurately detect.

Abstract: A vehicle seat for receiving an occupant is placed on a slider so as to move along a guide rail. A pair of belt anchor brackets for anchoring each end of a lap belt at each side of the seat is provided under the guide rail, and a weight sensor for sensing weight variation of the seat is provided under the belt anchor bracket. The tension of a seat belt (lap belt) does not affect the weight sensing functionality of the weight sensor and the state of the seat can accurately be determined.

Abstract: A capacitive load cell includes upper and lower capacitor plates and an intermediate dielectric comprising two or more layers of compressible material with diverse compressibility characteristics. The most easily compressed dielectric layer provides sensitivity to low occupant weight, while the less easily compressed dielectric layer(s) provide sensitivity to medium and high occupant weight.

Abstract: A load cell apparatus has a load cell adapted to couple to a first structure. The load cell comprises a load cell body and a sensor. The sensor provides an output signal indicative of an amount of weight applied to the load cell. A stud extends away from the load cell body. The load cell apparatus has a stud receiver including a space in which a portion of the stud is received. A set of rollers are coupled to one of the stud receiver and a second structure and contact the other of the stud receiver and the second structure.

Abstract: A seat weight measuring apparatus capable of securely withstanding large force due to large load, such as force in the event of a vehicle collision, applied to a vehicle seat. Normally, a small force is applied to a rear pin bracket and the sleeves through which a pivot bolt is inserted do not substantially collide with the inner peripheries of holes. As a large force is applied to the rear pin bracket, a stopper bolt collides with a base frame and the rear pin bracket collides with the pivot bolt. The large force exerted on the rear pin bracket is shared and borne by portions of the frame thereby reducing the localized stresses in the frame.

Abstract: The present invention involves a vehicle for passengers having a passenger safety system. The system has a crash sensor, a vehicle seat with a weight sensor assembly, an air bag and an air bag controller. The crash sensor is capable of providing a signal when the vehicle experiences an impact force of a predetermined magnitude. The vehicle seat is capable of supporting a vehicle occupant, with a seat frame member attached to a vehicle floor pan. The seat frame member has a rigid end and a resiliently flexible end, the resiliently flexible end able to resiliently deflect with respect to the vehicle floor pan upon experiencing a force due to the weight of the vehicle occupant. The sensor assembly has a cantilevered beam, a fulcrum, and a sensing device.

Abstract: A refrigerator with weighing scale includes a refrigerator and a weighing scale. The refrigerator includes a chamber with top, bottom, front, rear, side surfaces, and a control board, and the weighing scale is attached to the bottom surface of the refrigerator. The weighing scale is retractable from under the bottom surface of the refrigerator. The weighing scale includes a digital scale. The digital scale includes a stepping pad and a display for showing the weight. The display of the digital scale is disposed on the control board of the refrigerator, and the display is electronically connected to the remaining portion of the digital scale. The display on the control board of the refrigerator is turned on by stepping on the stepping pad of the weighing scale, by a control switch provided on the control board, or by being pulled out from under the bottom surface of the refrigerator.

Abstract: An occupant weight detecting device includes plural cells provided on a seat and detecting pressure which is defined by rows in a width direction of the seat and columns in a back-and-forth direction of the seat, a peak row detecting means for calculating the sum of pressure per cells of predetermined number of rows adjoining in the back-and-forth direction and detecting any one row of the predetermined number of rows corresponding to the maximum sum to be defined as a peak row, and a detecting means for detecting a concentrated load position on the seat based on the peak row.

Abstract: In a seat console, weight sensors for measuring the weight of occupants are arranged, which are provided between a top frame and a bottom frame of the console. So that a floating bearing of the top frame in the bottom frame is ensured, the top frame and the bottom frame are held to be supported by the weight sensors. In order to avoid damage or a faulty measurement, the top frame dips into the bottom frame in an open manner.

Abstract: The capacitance of a shielded capacitive load cell is determined so as to minimize the effect of stray or parasitic capacitance between the load cell and other objects including the shield. The load cell conductors are coupled across input and output terminals of an operational amplifier that is tied to a reference voltage. A constant current is applied to the load cell, and the resulting rate of change in voltage at the amplifier output is measured as a representation of the load cell capacitance. In a vehicle seat sensor application including an electromagnetic interference shield between the load cell and the seating surface, the amplifier output is coupled to the load cell electrode furthest from the shield, the amplifier maintains the other load cell electrode at a virtual reference voltage, and the shield is tied to the reference voltage.

Abstract: A compliant interface (14,16) for vehicular seat weight sensors minimizes parasitic stresses affecting sensor output. In one embodiment, an integral compliant interface (14) has an annular flange (14a) attached to a post extending from the sensor body with a first compliant member (14r) disposed between the annular flange and an upper elongated flange (14h) of a mounting bracket (14l) and a second compliant member (14s) disposed between the annular plate and a lower elongated flange (14k) to allow pivotal movement of the sensor limited by a motion stop member (14f) of annular flange (14b) engaging the lower flange. An overload cage (14u) may be placed over the sensor and attached to an additional flange (14l) to contain the sensor in the event of a failure of the mount in a catastrophic high speed crash. According to another preferred embodiment, an interface having upper and lower body members are formed with a sensor post receiving bore (16c) for attachment to the post.

Abstract: A weight-detecting system for detecting the weight of an occupant sitting on a seat includes inner and outer weight-detecting units. The outer weight-detecting unit includes strain resistors mounted on a lower surface of its sensor plate. The inner weight-detecting unit includes strain resistors mounted on an upper surface of its sensor plate. When output voltages from the outer weight-detecting unit are represented by A and B, and output voltages from the inner weight-detecting unit are represented by C and D, the weight of an occupant is detected based on a value A+B+C?+D? provided by adding output voltages C? and D? resulting from the inversion of the output voltages C and D to the output voltages A and B. The weight-detecting units have the same characteristic of change in output voltages with respect to change in temperature. Therefore, when the output voltage (A+B) is added to the output voltage (C?+D?), a detection error due to a change in temperature can be countervailed.

Abstract: In an occupant weight detection system, a pair of weight detection units are mounted along upper faces of base members fixed to a floor of an automobile. A square-frame-shaped linking member made of an iron sheet is interposed between the pair of weight detection units and a pair of seat rails. The pair of weight detection units are integrally linked by the linking member to maintain a positional relationship to each other at a predetermined relationship. Therefore, it is possible to prevent these weight detection means from being mounted in a state in which they are twisted or displaced relative to each other, thereby maintaining the detection accuracy.

Abstract: An apparatus includes a support surface for a human. The support surface has a lower portion and a back portion, with an aperture formed therein. A weight measurement device is coupled with the support surface, such that when a human is supported by the support surface the human's perineum is positioned over the aperture and the human's weight can be measured by the weight measurement device.

Abstract: A therapeutic mattress, inside which are arranged with plurality of sensors which are disposed on the lifting-and-supporting assemblies, and a control system is used to control the lifting-and-supporting assemblies and the sensors, through rise and fall of the lifting-and-supporting assemblies, the therapeutic mattress can be adjusted to support different body parts of the patient. The control system and the sensors can cooperate with each other to provide a precise function of weight-measurement and body-position sensing, and the sensors will cooperate with lifting-and-supporting assemblies to adjust the supporting point of the therapeutic mattress to the patient, thus preventing bedsores.

Abstract: A seat weighing device wherein a load transmitting member for transmitting the seat load to a load sensor is formed without extremely high precision required, thereby enabling simple manufacturing of the load transmitting member. The seat weighing device includes a base having an arm for transmitting the seat load to a load sensor. The arm does not include a V-shaped portion, but includes only a single action portion. The single action portion is mounted to a sensor plate for mounting the load sensor so as to transmit the seat weight from the single action portion to the sensor plate. The arm includes only the single action portion, thereby suppressing irregularities in transmission of the load.

Abstract: A frame-based occupant weight estimation apparatus for a vehicle seat that is supported by two or more floor brackets secured to the vehicle floor spans an open space between the floor brackets to prevent shunting of the occupant weight through a foreign object lying on the floor between the floor brackets. The weight estimation apparatus includes a fluid filled bladder sandwiched between first and second rigid plates, and is held in place between the seat frame and the floor brackets by a set of fasteners. A spring preloads the bladder so that deviations of the bladder fluid pressure from the preload pressure will be indicative of occupant weight. The first plate spans the open space between the floor brackets so that the fluid pressure is indicative of occupant weight even in cases where a portion of the occupant weight is supported by a foreign object disposed between the floor brackets.

Abstract: An occupant classification sense element is provided. The sense element has a body having a center portion, a first attachment portion connected to the center portion by a first flexible beam, and a second attachment portion connected to the center portion by a second flexible beam. First and second strain sensing elements are attached to the first flexible beam and third and fourth strain sensing elements are attached to the second flexible beam. The first, second, third and fourth strain sensing elements cooperate to produce an electrical signal indicative of a force deflecting the first and second flexible beams.

Abstract: A method and apparatus is provided that classifies a seat occupant into one of several different weight classes based on an estimated value of the seat occupant weight. An occupant's measured weight varies when the occupant's seating position changes or when the vehicle travels over adverse road conditions. A plurality of weight sensors are used to measure the weight exerted by a seat occupant against a seat bottom and are used to determine center of gravity for the seat occupant. A seat belt force sensor is also used to assist in classifying the seat occupant. Compensation factors using the seat belt force and center of gravity information are used to generate an estimated weight value. The estimated value of the occupant weight is compared to a series of upper and lower weight thresholds assigned to each of the weight classes to generate an occupant weight sample class. Over a period of time, several estimated weight values are compared to the weight class thresholds.

Abstract: According to a fixing device of the present invention, a screw penetrates through a first fixing hole of a first fixing section and a second fixing hole of a second fixing section to be coupled with a weight measuring machine, and is tightened with a nut, so that the first fixing section is fixed to the second fixing section. In addition, at least one clearance of the first fixing hole and the second fixing hole is configured to be bigger than an assembly tolerance of the two fixing holes. Using this structure, the fixing device, which can accommodate constructive variations of the fixing section of the weight measuring machine and maintain excellent detecting accuracy, and a weight measuring apparatus using the same, can be provided.

Abstract: An occupant weight detecting device includes plural load detecting device and a signal processing device. The plural load detecting device outputs a load signal in response to largeness of load applied to the seat, and the signal processing device sets an occupant load detection range. The signal processing device outputs a variable primary load detection signal based on the load signal in case of the load signal being within the occupant load detection range and a constant secondary load detection signal in case of the load signal being out of the occupant load detection range. The occupant weight detecting device further includes a control device to which the primary load detection signal or the secondary load detection signal is inputted. The control device determines that error is generated on the load detecting device when the signal processing device continues to output the secondary load detection signal during predetermined time.

Abstract: Method and apparatus for identifying and categorizing the weight and characteristics of the occupant currently occupying a vehicle seat. The method for identifying and categorizing the occupant or object involves measuring the deflection of the upper surface of the seat cushion at several points and therefore the weight distribution of the occupant. The system contains multiple weight sensors arrayed for detecting the distribution of the load causing the seat deflection. The system also includes a sensor to measure ambient temperature, preferably for temperature compensation due to the effects extreme temperatures may have on the compression properties of the seat cushion material and the weight sensors. A system processor interprets the data acquired by the sensors, and utilizes an algorithm and weight tables to simulate a neural network in providing an output a control signal indicative of the categorization of the occupant or object.

Abstract: An electronic scale/spreader arm assembly for use with an apparatus includes an axial force transducer, such as a load cell, that is attachable to the apparatus. A spreader bar is configured to receive a support wherein the spreader bar and the load cell are interconnected such that the load cell is pivotally attached to the apparatus and the spreader arm is pivotally attached to the support while the spreader arm and the load cell are attached to one another such that non-axial loads imparted to the spreader arm will not be transmitted to the axial force transducer.

Abstract: There is provided a membrane switch film comprising polyethylene 2, 6-naphthalenedicarboxylate as the major component and having excellent handling properties and durability, and particularly a film which is suitable for a membrane switch to be used in automobile interior devices which are potentially exposed to high temperature. The film is a membrane switch film having a refractive index in the range of 1.770–1.790 on both surfaces in either or both the film processing direction and the widthwise direction and an absolute value of no greater than 0.015 for the difference between the refractive indexes of both surfaces.

Abstract: A device for detecting the weight loaded on a vehicle seat with a sensor (22) and a spring body (24) that connects the vehicle seat to an underbody (18) of a corresponding motor vehicle and is connected, in one fastening area (e.g., 28), with a bottom rail (20) of the vehicle seat on the one hand and, in another fastening area (e.g., 26), to the underbody (18) of the corresponding motor vehicle on the other hand. One of the mounting areas is provided with a bore (38) through which a seat fastening screw (30) is engaged. The sensor (22) is provided with a travel sensor which is disposed parallel to the seat fastening screw (30) between the two fastening areas (26, 28) or to these rigidly connected parts (retaining plate 60 for example) and which measures the distance of these fastening areas (26, 28) parallel to the seat fastening screw (30).

Abstract: A torque-based occupant weight estimation apparatus for a vehicle seat includes front and rear torsion bars through which the seat frame is coupled to a set of floor brackets. The torsion bars are rotatably mounted on the floor brackets, and linkage arms rigidly coupled to opposing ends of each torsion bar are rotatably coupled to the seat frame so as to convert occupant seat weight into torsion bar torque. Torque sensors coupled to the torsion bars provide an indication of occupant weight.

Abstract: This invention describes an occupant size and weight detection device consisting of a combination of force/load sensors (1), a head position sensor (2, 3), a multidirectional acceleration sensor (5), and a seat position sensor (4) used to determine the weight of an occupant based on weight distribution, body angle and foot position. The goal of the invention is to determine the weight of an occupant who is sitting in the front seat of a vehicle that is subjected to the dynamic forces resulting from the vehicle moving. This technology can be used in applications such as automotive occupant weight and position sensing for use with safety devices such as airbags.

Abstract: A frame-based occupant weight estimation apparatus for a vehicle seat includes a compliant linkage assembly that translates vertically applied seat loads to a horizontal plane, where the horizontal forces are measured by a set of force sensors. A compliant member, which may be a spring or a linkage arm, preloads the force sensors to enable off-loading detection, and an overload device securely anchors the seat to the vehicle floor without interfering with normal load measurement.

Abstract: An occupant weight detecting apparatus for detecting an occupant weight on a seat includes a load sensor mounted on the seat to detect a load on the seat and output a load signal. A detected load value is calculated periodically based on the load signal and an average is calculated based on the detected load values calculated during a period in which the detected load value is less than a first predetermined. The average of the detected load values is set to a zero point, and the occupant weight is detected based on the detected load value and the zero point when the detected load value exceeds a second predetermined value.

Abstract: A seat weight sensor for detecting the weight of a seat occupant. The weight sensor has a case mounted between a seat pan and a seat member. One or more strain gauge resistors are mounted in the case. The resistors generate an electrical signal in response to the case being stressed by the weight of the seat occupant. The electrical signal changes as a function of the weight of the occupant. A fastener passes through the seat member, the case, and the seat pan. The fastener secures the sensor between the seat pan and the seat member. The case is adapted to transfer to the strain gage resistor the weight of the occupant up to pre-determined level. The case prevents the strain gage from receiving weight beyond that of the pre-determined level such that the sensor is not damaged by an excessive load. The case also allows the weight sensor to be insensitive to off-axis forces that might otherwise contribute to inaccurate weight readings.

Abstract: Arrangement and method for determining weight of an occupying item in a seat including one or more weight sensors arranged to obtain a measurement of the force applied to the seat, a forcing function determination arrangement for measuring a forcing function of the seat and a processor coupled to the weight sensor(s) and forcing function determination arrangement for receiving the measurement of the force applied to the weight sensor(s) and the measurement of the forcing function from the forcing function measurement system and determining the weight of the occupying item based thereon. The forcing function determination arrangement may include an accelerometer and measures effects on the seat caused by load of a seatbelt associated with the seat and/or effects on the seat of road roughness, steering maneuvers, and a vehicle suspension system.

Abstract: A scale including an event data discrimination and collection system for continuously monitoring a weight of an infant placed on the scale platen, which may be configured as a bed. Load cells are used to continuously monitor infant weight from time placed on the scale platen, so that sudden apparent weight spikes sensed by the load cells but attributable to events involved in patient care may be discarded as artifact, while gradual weight changes reflective of infant physiology are accumulated by the scale controller and used to provide a current weight for the infant.

Abstract: A vehicle seat load measuring apparatus includes a base for bearing a load applied to the seat, an arm supported by the base for receiving the load, a load sensor supported by the arm for detecting the load, and a seat rail for guiding the seat in a longitudinal direction of the vehicle. The base is fixed to the seat rail so that an open face of the base faces in a downward direction. The arm is connected by a stopper pin inserted through holes in the base to a mounting bracket fixed to a vehicle body. The base bracket includes a load bearing portion and is attached to the base and fixed to the seat rail. The load bearing portion of the base bracket is configured to contact the stopper pin when a load exceeding a predetermined value is applied to the seat rail.

Abstract: A method and system for estimating the weight of a seat occupant. In one embodiment, the system includes a linkage having one or more links; an actuator; a pivot driveably coupled between the links and the actuator; and a sensor coupled to the pivot and operable to sense a load at the pivot, where the sensed signal is processed to provide an output signal representative of seat occupant weight. The system provides weight estimation with reduced sensitivity to horizontal loads and may be implemented with seats having a fixed height or a plurality of powered and manual seat height adjustment mechanisms.

Abstract: A seated passenger's weight detection device includes a seat vertical position adjusting means having a front link and a rear link, a weight detection sensor for detecting a weight of a seated passenger on the basis of an input from the front link and an input from the rear link and a backward and forward input cancel means for canceling backward and forward inputs which operate to the front link and the rear link.

Abstract: A patient support including a mattress, a load cell apparatus, and a frame having an intermediate frame and a weigh frame. The load cell apparatus is positioned relative to the intermediate frame and the weigh frame. The load cell apparatus includes a load cell, a mount, and a liner.

Abstract: Automotive load cells having centralized, multi-axis, loose tolerance overload/limit stops provide improved strain gauge response. The modular, integrated stop assemblies magnify sensor substrate deflection by use of opposed concave (Belleville) springs are used in direct contact with the substrate to accommodate ±Z axis deflection and Mx/My moment angular rotation. A flanged guide member on the load stud permits a wide range of geometries. The substrate is thickened around the load stud hole and the outboard support bolt holes. Hollow rivets assist in design modularity. Strain gauges are placed at the yield zones symmetrically with respect to the X axis. The substrate hole Mx/My gap is larger than the stop bracket hole to insure a positive stop for Mx/My moments prior to yield. The inventive multi-axis stop assembly is used in any type load cell, including rectangular, thinned, notched, necked/dogbone, or cantilever substrates with any strain gauge layout configuration.

Abstract: A weight measuring device comprising a base fixed to an object, a strain detection substrate fixed to the base, a fitting pin fixed to the strain detection substrate, an arm rotatably attached to the base by a support pin, and a leaf spring with one end fixed to the arm and the other end supported by the fitting pin. The weight measuring device further comprises a second arm with one end receiving the load of the object to be measured and the other end fixed to the arm through a link pin. By the configuration of the present invention, the load applied to the strain detection substrate is reduced, and a weight measuring device improved in detecting resolution is obtained. Furthermore, the weight measuring device of the present invention is unitized, and the weight measuring device can be easily built into various equipment.

Abstract: In order to develop a vehicle seat with a seat frame for the mounting of a sitting area and with a supporting frame, which keeps the seat frame at a predetermined distance from the vehicle floor and connects the vehicle seat to the vehicle floor, in such a way that the seat supplies information on the weight of the occupants which is substantially uninfluenced in particular by the conditions which are very difficult in terms of measuring technology and the other special ambient conditions within a vehicle, it is proposed that the supporting frame comprises a height-adjusting device, in order to vary the distance of the seat frame from the vehicle floor in a defined way, that at least three load cells which respond to a weight acting on the sitting area and supply a signal corresponding to the weight are disposed at the corner points of an imaginary polygonal area, the signal corresponding to a weight resulting from a distance measurement, and that the load cells respectively have a one-piece force transducer

Abstract: A vehicle weight classification system determines the weight of a seat occupant for controlling airbag deployment. Strain gauge sensors preferably provide signals having a magnitude that is indicative of the weight of the seat occupant. A converting module converts the sensor signals into timing information. A microprocessor, which includes a timer module, receives the timing information and makes a weight determination from the timing information.

Abstract: An infant-support apparatus for an incubator or warmer. The apparatus comprises a frame and an infant supporting deck having a central position relative to the frame. The deck is movable relative to the frame to laterally extended positions away from the central position.

Abstract: A system and method for measuring the weight of patients in a wheelchair are disclosed, including two portable weight measurement devices, wherein the devices measure the weight imposed on two wheels of a four wheel wheelchair, and a receiver that accepts weight measurement data from the portable weight measurement devices. The weight data exchanged between the two portable weight measurement devices and/or with the receiver may be transported over wireless connections.

Abstract: An occupant weight detecting device includes a load detecting means equipped to a seat body for detecting a load applied to the seat body, a calculating means for calculating an initial load value during the seat body under an initial condition based upon a detected load value by the load detecting means and for calculating a value of an occupant load applied to the seat body by subtracting the initial load value from the detected load value, and a filter housed in the calculating means and possessing a cutoff frequency so as to attenuate a fluctuation of the detected load value generated due to an element other than a deterioration inherent to the load detecting means.

Abstract: A weight measurement system is disclosed for measuring the weight of an occupant in a vehicle seat. In a preferred embodiment, a sensor is positioned at the rear portion of the vehicle seat and a load transfer link is used to transfer the weight from the front portion of the vehicle seat to the rear portion, to be measured by the sensor. The transfer link is a selectively compliant beam having a first rigid section and a second rigid section connected to each other via a flexible area. The first and second rigid sections preferably include wing portions for increasing the rigidity of the sections. The flexible area is more compliant than the rigid sections. The load transfer link is configured to transition a load placed on the front portion of the link to the rear portion. In a more preferred embodiment of the invention, the load transfer link is made of a high strength, low alloy steel.

Abstract: The present invention provides a weight sensor device for detecting a weight of an occupant seated on a seat having a seat frame and a cushion. The device has a sensing wire displaced downward in the seat frame as the cushion is deformed due to the weight of the occupant when the occupant is seated on the seat and a variable resistor for converting a displacement of the sensing wire into an electric signal indicative of the weight of the occupant.

Abstract: A seat weight measuring apparatus having enough strength against load in a direction in which a rear side of the vehicle seat is lifted. The seat weight measuring apparatus includes a base frame with a mounting portion at the rear end side of the base frame. The mounting portion includes two stopper bolts as protective mechanisms for transmitting excessive load from a rear rail bracket to the base frame. One stopper bolt is a front (first) stopper bolt, and the other is a rear (second) stopper bolt. Therefore, the mounting portion has higher capability to withstand load than a mounting portion at the front end side of the base frame.

Abstract: A device for measuring a weight of a seat, including the weight of an occupant sitting on the seat.

Abstract: A frame-based occupant weight estimation apparatus for a vehicle seat that is supported by two or more floor brackets secured to the vehicle floor spans an open space between the floor brackets to prevent shunting of the occupant weight through a foreign object lying on the floor between the floor brackets. The weight estimation apparatus includes a fluid filled bladder sandwiched between first and second rigid plates, and is held in place between the seat frame and the floor brackets by a set of fasteners. A spring preloads the bladder so that deviations of the bladder fluid pressure from the preload pressure will be indicative of occupant weight. The first plate spans the open space between the floor brackets so that the fluid pressure is indicative of occupant weight even in cases where a portion of the occupant weight is supported by a foreign object disposed between the floor brackets.