Structure for load detection element in vehicle seat

• US 6,695,379 B1
• Filed: 04/14/2003
• Issued: 02/24/2004
• Est. Priority Date: 04/14/2003
• Status: Expired due to Fees

• Current Assignee: Tachi-S Company Limited
• Original Assignee: Tachi-S Company Limited
• Inventors: Ishida, Toshiaki
• Primary Examiner(s): PATEL, KIRAN B
• Application Number:
  US10/412,422
• Time in Patent Office: 316 Days
• Field of Search: 296/65.14, 296/65.13, 280/735, 180/273, 177/211, 737/95, 738/49, 738/626.21, 297/217.1
• US Class Current: 296/65.14
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60N 2/0031 mounted on the frame
• CPC Class Codes: B60N 2/0715 C or U-shaped
• CPC Class Codes: B60N 2210/42 Strain gauges

Abstract

Structure for securing a load detection element under a vehicle seat in combination with a support leg element having a hole formed in one end portion thereof, wherein the load detection element is pivotally connected with the support leg element, while being fixedly secured by first and second securing pins to the vehicle seat. The first pin has an end riveted to a bottom side of the vehicle seat and an end portion extending through the hole of support leg element. Such another end portion has a head larger in diameter than that hole and is disposed outwardly under the support leg member, with one space given between the head and support leg member. The second pin has a end fused and fixed in the bottom side of vehicle seat and a head disposed beneath the load detection element, with another space given between the head and support leg member.

Claims

1. In combination with a floor of vehicle and a vehicle seat, a structure for securing a load detection means under a bottom side of said vehicle seat and in a support leg means for supporting said vehicle seat upon said floor of vehicle, said support leg means including;

a bottom wall;

one end facing to a side forwardly of said vehicle seat; and

another end facing to a side backwardly of said vehicle seat,

wherein said load detection means is adapted to detect a load applied from an occupant on said vehicle seat and comprises;

a resiliently deflectable strain means having an elongated body extending along a fore-and-aft direction of said vehicle seat;

an upper side facing to said bottom side of said vehicle seat;

a lower side facing to said bottom wall of said support leg means;

a securing end portion;

a pivotal end portion; and

a deflectable portion defined between said securing and pivotal end portions; and

a strain gauge means fixedly attached to said deflectable portion,

wherein said resiliently deflectable strain means is rotatably journalled at the pivotal end portion thereof by a pivot pin within said support leg means, such that said securing end portion of said resiliently deflectable strain means is disposed adjacent to either of said one and another ends of said support leg means, whereas said pivotal end portion of said resiliently deformable means is oriented to a center of said support leg means,

wherein a hole is formed in the bottom wall of said support leg means at a point adjacent to either of said one and another ends of said support leg means,

wherein a first securing pin is provided in said securing end portion of said resiliently deflectable strain means at a point near to said either of said one and another ends of said support leg means, said first securing pin having an end fixedly connected with said bottom side of said vehicle seat,

wherein a second securing pin of a fusible property having a head portion and an end is provided in said securing end portion of said resiliently deflectable strain means at a point distant from said either of said one and another ends of said support leg means, such that said end of the second securing pin is fused in said bottom side of said vehicle seat, while said head portion of the second securing pin is disposed on the lower side of said resiliently deformable means, with one predetermined space given between said head portion of the second securing pin and said bottom wall of said support leg means, and

wherein, when a normal downward load is applied to the vehicle seat, a downward deflection of said deflectable portion of said resiliently deflectable strain means is caused, in response to which, said strain gauge means detects an amount of the downward deflection and emits a corresponding value indicative of an amount of said load, and wherein, when an excessive great downward load is applied to the vehicle seat, causing the resiliently deflectable strain means to deflect downwardly to a level in excess of said one predetermined space, said head portion of said second securing pin is brought to contact with said bottom wall of said support leg means, thereby protecting said deflectable portion against a deflection in excess of a tolerable range in which the strain gauge means works for detection of the amount of deflection.

2. The structure as claimed in claim 1, wherein, said bottom wall of said support leg means has an inner surface and an outer surface, wherein said first securing pin is of a rivet-type pin having:

a large-diameter portion smaller in diameter than said hole of said support leg means;

a small-diameter portion having said end which can be riveted; and

a head portion formed on said large-diameter portion, said head portion being larger in diameter than said hole of said support leg means, wherein said end of said small-diameter portion extends upwardly through said securing end portion of said resiliently deflectable strain means and is riveted to said bottom side of said vehicle seat, wherein said large-diameter portion extends downwardly through said hole of said support leg means, wherein said head portion of the first securing pin is normally positioned outwardly of said bottom wall of said support leg means, such that another predetermined space is given between said first securing pin head portion and said outer surface of said bottom wall of said support leg means, and wherein said head portion of said second securing pin is normally positioned inwardly of said support leg means, such that said one predetermined space is given between said second securing pin head portion and said inner surface of said bottom wall of said support leg means, whereby, when an excessive great upward load is applied to the vehicle seat, causing the resiliently deflectable strain means to deflect upwardly to a level in excess of said another predetermined space, said head portion of said first securing pin is brought to contact with said outer surface of said bottom wall of said support leg means, thereby protecting said deflectable portion of said resiliently deflectable strain means against a deflection in excess of said tolerable range.

3. The structure as claimed in claim 1, wherein said resiliently deflectable means comprises at least two strain elements, wherein one of said at least two strain elements is disposed at a point near to said one end of said support leg means, while another of said at least two strain elements is disposed at a point near to said another end of said support leg means, and wherein each of said at least two strain elements has said elongated body, said upper side, said lower side, said securing end portion, said pivotal end portion, and said deflectable portion, and wherein said deflectable portion is smaller in thickness than said securing end portion and said pivotal end portion.

4. In combination with a floor of vehicle and a vehicle seat, a structure for securing a load detection means under a bottom side of said vehicle seat and in a support leg means for supporting said vehicle seat upon said floor of vehicle, said support leg means including:

a bottom wall having an inner surface and an outer surface;

one end facing to a side forwardly of said vehicle seat; and

another end facing to a side backwardly of said vehicle seat, wherein said upper rail is fixed to said bottom side of said vehicle seat,

wherein a slide rail device is provided between said load detection means and said bottom side of said vehicle seat, said slide rail device comprising;

a lower rail fixed to said bottom side of said vehicle seat, said lower rail having a flat bottom surface and one end; and

an upper rail slidably fitted via a plurality of rollers in said lower rail, said plurality of rollers being movably interposed between said flat bottom surface of said lower rail and said upper rail,

wherein said load detection means is adapted to detect a load applied from an occupant on said vehicle seat and comprising;

a resiliently deflectable strain means having an elongated body extending along a fore-and-aft direction of said vehicle seat;

an upper side facing to said bottom side of said vehicle seat;

a lower side facing to said bottom wall of said support leg means, a securing end portion;

a pivotal end portion; and

a deflectable portion defined between said securing and pivotal end portions; and

a strain gauge means fixedly attached to said deflectable portion,

wherein said resiliently deflectable strain means is rotatably journalled at the pivotal end portion thereof by a pivot pin within said support leg means, such that said securing end portion of said resiliently deflectable strain means is disposed adjacent to either of said one and another ends of said support leg means, whereas said pivotal end portion of said resiliently deformable means is oriented to a center of said support leg means,

wherein a first hole is formed in said flat bottom surface of said lower rail at a point near to said either of said one and another ends of said support leg means;

wherein a second hole is formed in said flat bottom surface of said lower rail at a point distant from said either of said one and another ends of said support leg means;

wherein a hole formed in said bottom wall of said support leg means in alignment with said first hole;

wherein a first securing pin of rivet type is provided, which has;

a large-diameter portion smaller in diameter than said hole of said support leg means;

a small-diameter portion having one end which can be riveted; and

a head portion formed on said large-diameter portion, said head portion being larger in diameter than said hole of said support leg means,

wherein said first securing pin is fixed in said securing end portion of said resiliently deformable strain means at a point near to said one end of said support leg means, such that said end of said small-diameter portion extends upwardly through said securing end portion of said resiliently deformable strain means and is riveted to said bottom side of said vehicle seat, while said large-diameter portion extends downwardly through said hole of said support leg means, and that said head portion is normally positioned outwardly of said bottom wall of said support leg means, such that a first predetermined space is given between said head portion and said outer surface of said bottom wall of said support leg means;

wherein a second securing pin of a fusible property having a head portion and an end is fixedly provided in said securing end portion of said resiliently deformable strain means at a point distant from said one end of said support leg means, such that said end of the second securing pin is fused and fixed in said second hole so as to be flush with said flat bottom surface of said lower rail, while said head portion of the second securing pin is disposed on the lower side of said resiliently deformable strain means, with a second predetermined space given between said head portion of the second securing pin and said inner surface of said bottom wall of said support leg means; and

wherein, when a normal downward load is applied to the vehicle seat, a deflection of said deflectable portion of said resiliently deflectable strain means is caused, in response to which, said strain gauge means detects an amount of the deflection and emits a corresponding value indicative of an amount of said load, and wherein, when an excessive great downward load is applied to the vehicle seat, causing the resiliently deflectable strain means to deflect downwardly to a level in excess of said second predetermined space, said head portion of said second securing pin is brought to contact with said inner surface of said bottom wall of said support leg means, and by contrast, when an excessive great upward load is applied to the vehicles seat, causing the resiliently deflectable strain means to deflect upwardly to a level in excess of said first predetermined space, said head portion of said first securing pin is brought to contact with said outer surface of said bottom wall of said support leg means, so that said deflectable portion of said resiliently deflectable strain means is protected against a deflection in excess of a tolerable range in which the strain gauge means works for detection of the amount of deflection.