WO2008063999A2

WO2008063999A2 - Adaptor device and latch sensor circuit for child safety seat

Info

Publication number: WO2008063999A2
Application number: PCT/US2007/084535
Authority: WO
Inventors: Said Nakhla
Original assignee: Britax Child Safety, Inc.
Priority date: 2006-11-13
Filing date: 2007-11-13
Publication date: 2008-05-29
Also published as: WO2008063999A3

Abstract

A latch sensor for sensing and indicating proper attachment of a child safety seat having at least one releasable attachment latch for attachment to a vehicle seat provided with at least one complementary latch anchor. The latch sensor includes at least one electrical contact carried by the attachment latch of the child safety seat and electrically connected to an indicator, and a latch sleeve having at least one electrical contact and electrically connected to the electrical system of the vehicle, and adapted to be positioned over the attachment latch. In a position with the latch anchor in proper, latched position in the attachment latch of the child safety seat, the electrical contact of the attachment latch of the child safety seat mates with and closes a circuit with the electrical contact of the latch sleeve to provide an indication that the child safety seat is property latched.

Description

ADAPTOR DEVICE AND LATCH SENSOR CIRCUIT FOR CHILD SAFETY SEAT

Cross-Reference to Related Applications

[0001] This application claims the benefit of U.S. Provisional Application No.

60/865,529, filed on November 13, 2006.

Technical Field and Background of Invention

[0002] This invention relates to an adapter device that includes a latch sensor, and that operates to insure an uninterrupted supply of electricity to a child safety seat. Several other related functions, including a wireless embodiment, are also described. Many child safety seats are now equipped to interconnect with various types of electronic systems built into vehicles. Most vehicles now come equipped with latch anchors, such as "Isofix" latch assemblies, that enable the child safety seat to be securely fastened to the vehicle by means other than standard passenger seatbelts. The present invention provides additional security to the child by permitting easy recognition of an improperly latched seat. A wireless sensor for determining the tension on a child safety seat harness is also disclosed.

Summary of the Invention

[0003] Therefore, it is an object of the invention to provide a latch sensor that detects and indicates proper latching of the child safety seat to the vehicle seat. [0004] It is another object of the invention to provide a latch sensor that utilizes the vehicle electrical system to power the latch sensor.

- 3144/118PCT Page 1 - [0005] It is another object to provide a tension sensor that determines that proper tension on the harness of a child safety seat has been achieved. [0006] It is another object to provide a tension indicator that operates wirelessly utilizing battery power carried within the child safety seat itself. [0007] These and other objects and advantages of the invention are achieved by providing a latch sensor for sensing and indicating proper attachment of a child safety seat having at least one releasable attachment latch for attachment to a vehicle seat provided with at least one complementary latch anchor. The latch sensor comprises at least one electrical contact carried by the attachment latch of the child safety seat and electrically connected to an indicator, and a latch sleeve having at least one electrical contact and electrically connected to the electrical system of the vehicle, and adapted to be positioned over the attachment latch. In a first position with the latch anchor in proper, latched position in the attachment latch of the child safety seat, the electrical contact of the attachment latch of the child safety seat mates with and closes a circuit with the electrical contact of the latch sleeve to provide an indication that the child safety seat is property latched. In a second position with the latch anchor not in proper, latched position in the attachment latch of the child safety seat, the electrical contact of the attachment latch of the child safety seat does not mate with and close a circuit with the electrical contact of the latch sleeve to provide an indication that the child safety seat is not property latched.

[0008] In accordance with another embodiment of the invention, the child safety seat includes first and second laterally spaced-apart attachment latches for attachment to the latch anchor of the vehicle.

- 3144/118PCT Page 2 - [0009] In accordance with yet another embodiment of the invention, the child safety seat includes first and second laterally spaced-apart attachment latches, and the at least one latch anchor of the vehicle comprises first and second laterally spaced- apart latch anchors for receiving respective ones of the first and second spaced-apart attachment latches.

[0010] In accordance with another embodiment of the invention, a cigarette lighter-type electrical connector is provided for connecting the latch sensor to the electrical system of the vehicle.

[0011] In accordance with another embodiment of the invention, the attachment latch comprises a mount for mounting the attachment latch for movement between a latch anchor receiving position and a latch anchor locking position, wherein the electrical contacts of the attachment latch and the latch sleeve are not in electrical contacts when the attachment latch is in the latch anchor receiving position and are in electrical contact when the attachment latch is in the latch anchor locking position. [0012] In accordance with another embodiment of the invention, the attachment latch is mounted for rotational movement between the latch anchor receiving position and the latch anchor locking position.

[0013] In accordance with another embodiment of the invention, the latch sleeve has at least one electrical contact and electrically connected to the electrical system of the vehicle through the vehicle wiring harness and fuse box. [0014] In accordance with another embodiment of the invention, a latch sensor for sensing and indicating proper attachment of a child safety seat is provided. The latch sensor has at least one releasable attachment latch for attachment to a vehicle seat provided with at least one complementary latch anchor, comprising at least one

- 3144/118PCT Page 3 - electrical contact carried by the attachment latch of the child safety seat and electrically connected to an indicator, and latch means having at least one electrical contact electrically connected to the electrical system of the vehicle. The latch means is adapted to cooperate with the attachment latch, whereby, when the latch anchor is in a proper, latched position in the attachment latch of the child safety seat, the electrical contact of the attachment latch of the child safety seat mates with and closes a circuit with the electrical contact of the latch means to provide an indication that the child safety seat is property latched.

[0015] In accordance with another embodiment of the invention, a sensor carried by a child safety seat for sensing and indicating proper harness tension on the seat occupant is provided, and comprises an electronic resonator tuned to an RF frequency and an install timer switch for completing a wireless circuit with a transponder mounted on the child safety seat and tuned to the RF frequency for being interrogated by a transceiver mounted on the child safety seat. A programmed microprocessor controls the operation of the latch sensor, and a harness tension indicator switch indicates proper harness attachment connected through the microprocessor to the transceiver. [0016] In accordance with another embodiment of the invention, a crash indicator circuit indicates an incident involving more than a predetermined g-force.

Brief Description of the Drawings

[0017] Figure 1 is a fragmentary view showing a child safety seat with a latch and

6 mm latch anchor according to an embodiment of the invention;

[0018] Figure 2 is a perspective view showing a seat base and an attachment method according to an embodiment of the invention;

- 3144/118PCT Page 4 - [0019] Figure 3 is a fragmentary enlarged view of a latch assembly according to an embodiment of the invention;

[0020] Figures 4 and 5 are fragmentary, enlarged cross-sections of a latch assembly that illustrate one proposed means of engagement of the sleeve and latch portions of the latch assembly; and

[0021] Figure 6 is a circuit diagram of wireless system that determines whether a child safety seat has been properly installed.

Detailed Description of the Embodiments of the Invention

[0022] Referring now specifically to Figures 1 and 2 of the drawings, one preferred embodiment of the invention is shown, and includes a child safety seat 10 that includes a base 12 having a pair of latch assemblies 14, 16 for securing the seat 10 to a vehicle seat "S". The description will proceed with reference to latch assembly 14, it being understood that latch assembly 16 and its operation are the same. Both latch assemblies 14 and 16 must be properly attached for the system to function as intended. [0023] By continued reference to Figures 1 and 2, latch assembly 14 includes a latch 18 having a pair of electrically-conductive contacts 20, 22. A latch sleeve 24, which preferably has been previously installed on a latch anchor 34 mounted on the vehicle, is adapted to slide over and fit onto the latch 18, and includes a funnel-shaped notch 26 and a pair of electrically-conductive contacts 28, 30 connected by an electrical cable 31 to an adapter 32. The adaptor shown in Figures 1 and 2 is by way of example a cigarette lighter adapter that is inserted into an electrical port of the vehicle in which the seat 10 is installed. The funnel-shaped notch 26 aides in guiding the latch anchor 34 mounted on the vehicle into the latch 14.

- 3144/118PCT Page 5 - [0024] When the child safety seat 10 is installed, the latch 14 is fitted into the sleeve 24. If the latch 14 is correctly fitted into the sleeve 24, the contacts 20, 22 and 28, 30 mate, and the seat 10 is "powered up", providing an indication that the seat 10 is properly installed.

[0025] Figure 3 shows the latch sleeve 24 properly mounted on the latch 14, with the respective electrical contacts 20, 22 and 28, 30 properly engaged. [0026] For a more permanent installation, the cable 31 can be wired to the vehicle battery through the wiring harness through the vehicle fuse box (not shown) in a conventional manner.

[0027] Referring now to Figures 4 and 5, one preferred embodiment of the latch assembly 14 is shown. In this particular embodiment, the latch 18 of the latch assembly 14 is rotatably-mounted on a pin 40. The latch 18 includes first and second latch fingers 18A, 18B defining between them a latch opening 18C shaped and sized to receive the latch anchor 34. As shown in Figure 4, in the unlatched position the latch finger 18A interferes with the notch 26 so that the latch anchor 34 must engage and move the latch finger 18A rearwardly in order to be fully-inserted into the notch 26. [0028] Note also in Figure 4 the position of the electrical contacts 22 and 30 on the latch 14 and latch sleeve 24, respectively. In this position the contact is "broken", indicating improper installation of the child safety seat 10. Rearward movement of the latch finger 18B by the latch anchor 34 rotates the latch 18 around the pin 40. The clockwise movement shown by comparing Figure 4 with Figure 5 indicates that the rotational movement brings into mating engagement the contacts 22 and 30, closing the circuit and providing an indication that the latch anchor 34 is properly seated in the latch 18. This is one illustrative example of the principle of operation, there being other

-- 3144/118PCT Page 6 - iterations that will likewise provide the same or equivalent functions. As mentioned above, the explanation with regard to the latch assembly 14 applies, as well, to the latch assembly 16.

[0029] As is shown in Figure 6, another embodiment of the invention comprises a wireless system 50 that senses the proper installation of the child seat 10 as well as the proper securing of the child into the child seat. The physical elements of the system

50 are mounted between the three bar slide of the child seat 10 and the child safety seat shell. The wireless system can detect the proper closure of the latch as described above.

[0030] This disclosure is a continuation of an embodiment wherein a sensor is adapted to sense the crotch strap tension as an indication that the child is properly positioned and restrained in the seat. In this earlier embodiment, the sensor is housed in a component sandwiched between the child seat shell and the 3-bar slide on the end of the crotch strap(s).

[0031 ] An LC circuit 52, which acts as an electronic resonator, is tuned to an RF frequency. Switch closure on the circuit 52 completes a circuit with a transponder 54 tuned to a particular radio frequency. The transponder can now be interrogated by a transceiver 56 mounted on the child seat 10. This eliminates the need for any wiring harness, reducing the complexity and cost, and increasing the reliability of the system.

The transponder 54 can also be mounted in the same part as the component between the 3-bar slide and the shell.

[0032] The system 50 is controlled by a programmed microprocessor 58. A harness tension indicator switch 60 indicating proper harness attachment and a crash

- 3144/118PCT Page 7 - indicator 62 indicating an incident involving more than a predetermined g-force is also provided and is controlled by the microprocessor 58. [0033] The detailed operation is as follows:

1. An install switch 64 is provided that, when activated, turns on the power for 1-10 minutes and allows for installation of the seat 10 by monitoring the sensors and providing feedback to the installer once propertension has been reached.

2. The system 50 will turn on as soon as tension is placed on the crotch strap in order to preserve battery life.

3. As soon as the system 50 is turned on, it interrogates the transponder 54 sensing proper tension in the installation.

4. The harness tension indicator switch 60 will be turned off once proper harness tension is achieved.

5. The system continuously interrogates the sensor status while turned on by transmitting a signal every second. The same "off status must be maintained for some predetermined period, such as 5-15 seconds, before an alarm is sounded.

6. The install and operate switch can be combined together to save cost.

7. Means can also be provided for prompting the installer to pull on the crotch strap to turn the system "on."

8. To avoid interference between child seats 10 mounted near each other in the same vehicle, different master frequencies will be used with identifiable tags. Each transponder 54 will have a different resonance frequency to be identified by the transceiver 56.

- 3144/118PCT Page 8 - [0034] Another alternative is to use an ID chip on every transponder. As also shown in Figure 6, multiple transponders 54 may be mounted in the seat. [0035] The foregoing has described a latch sensor for a child safety seat. While specific embodiments of the present invention have been described, it will be apparent to those skilled in the art that various modifications thereto can be made without departing from the spirit and scope of the invention. Accordingly, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation.

- 3144/118PCT Page 9 --

Claims

I claim:

1. A latch sensor for sensing and indicating proper attachment of a child safety seat having at least one releasable attachment latch for attachment to a vehicle seat provided with at least one complementary latch anchor, comprising:

(a) at least one electrical contact carried by the attachment latch of the child safety seat and electrically connected to an indicator; and

(b) a latch sleeve having at least one electrical contact and electrically connected to the electrical system of the vehicle, and adapted to be positioned over the attachment latch, whereby, in a first position with the latch anchor in proper, latched position in the attachment latch of the child safety seat, the electrical contact of the attachment latch of the child safety seat mates with and closes a circuit with the electrical contact of the latch sleeve to provide an indication that the child safety seat is property latched, and in a second position with the latch anchor not in proper, latched position in the attachment latch of the child safety seat, the electrical contact of the attachment latch of the child safety seat does not mate with and close a circuit with the electrical contact of the latch sleeve to provide an indication that the child safety seat is not property latched.

2. A latch sensor according to claim 1 , wherein the child safety seat includes first and second laterally spaced-apart attachment latches for attachment to the latch anchor of the vehicle.

- 3144/118PCT Page 10 -

3. A latch sensor according to claim 1 , wherein the child safety seat includes first and second laterally spaced-apart attachment latches, and the at least one latch anchor of the vehicle comprises first and second laterally spaced-apart latch anchors for receiving respective ones of the first and second spaced-apart attachment latches.

4. A latch sensor according to claim 1 , and including a cigarette lighter-type electrical connector for connecting the latch sensor to the electrical system of the vehicle.

5. A latch sensor according to claim 1 , wherein the attachment latch comprises a mount for mounting the attachment latch for movement between a latch anchor receiving position and a latch anchor locking position, wherein the electrical contacts of the attachment latch and the latch sleeve are not in electrical contacts when the attachment latch is in the latch anchor receiving position and are in electrical contact when the attachment latch is in the latch anchor locking position.

6. A latch sensor according to claim 5, wherein the attachment latch is mounted for rotational movement between the latch anchor receiving position and the latch anchor locking position.

~ 3144/118PCT Page 11 -

7. A latch sensor according to claim 1 , wherein the latch sleeve having at least one electrical contact and electrically connected to the electrical system of the vehicle through the vehicle wiring harness and fuse box.

8. A latch sensor for sensing and indicating proper attachment of a child safety seat having at least one releasable attachment latch for attachment to a vehicle seat provided with at least one complementary latch anchor, comprising:

(b) latch means having at least one electrical contact electrically connected to the electrical system of the vehicle, and adapted to cooperate with the attachment latch, whereby, when the latch anchor is in a proper, latched position in the attachment latch of the child safety seat, the electrical contact of the attachment latch of the child safety seat mates with and closes a circuit with the electrical contact of the latch means to provide an indication that the child safety seat is property latched.

9. A sensor carried by a child safety seat for sensing and indicating proper harness tension on the seat occupant, and comprising:

(a) an electronic resonator tuned to an RF frequency;

(b) an install timer switch for completing a wireless circuit with a transponder mounted on the child safety seat and tuned to the RF frequency for being interrogated by a transceiver mounted on the child safety seat;

- 3144/118PCT Page 12 - (c) a programmed microprocessor for controlling the operation of the latch sensor; and

(d) a harness tension indicator switch indicating proper harness attachment connected through the microprocessor to the transceiver.

10. A sensor according to claim 9, and including a crash indicator circuit indicating an incident involving more than a predetermined g-force.

- 3144/118PCT Page 13 -