WO2012174417A1

WO2012174417A1 - Hitch ball angle sensor

Info

Publication number: WO2012174417A1
Application number: PCT/US2012/042731
Authority: WO
Inventors: Douglas R. MOTTS; Chandrakumar Kulkarni; Fred Brickley
Original assignee: Cequent Performance Products, Inc.
Priority date: 2011-06-17
Filing date: 2012-06-15
Publication date: 2012-12-20

Abstract

A hitch ball sensor assembly is provided. The hitch ball sensor assembly includes a hitch ball positioned on a housing and rotatable with respect to the housing. A shaft may be connected to the hitch ball and extend within a bore within the housing. An angle sensor is configured to sense the rotation of the shaft. The hitch ball may include a deformable material positioned about a portion of the hitch ball. The deformable material may be in the shape of a ring and may be any deformable material, such as rubber.

Description

TITLE

HITCH BALL ANGLE SENSOR

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 61/498,335 entitled "HITCH BALL ANGLE SENSOR," filed on June 17, 201 1, and further claims priority to Provisional Patent Application No. 61/508,166 entitled "HITCH BALL ANGLE SENSOR," filed on July 15, 201 1, each of which are hereby incorporated by reference in their entirety.

FIELD OF INVENTION

[0002] The present invention generally relates to a sensor for determining the angle of a towed vehicle with respect to a towing vehicle.

BACKGROUND

[0003] The use of a ball joint trailer coupling comprising a hitch ball and cooperating socket assembly to tow a trailer behind a towing vehicle is generally known. Such ball joint couplings often comprise a hitch ball and corresponding hitch ball receiver. The ball joint coupling provides the necessary freedom of movement to allow a trailer to track smoothly behind the towing vehicle while also providing a dependable connection. One example of a hitch ball design is set forth in U.S. Patent No. 6,983,950 to McCoy et al., which is hereby incorporated by reference in its entirety. [0004] Towed vehicles, such as trailers, may experience turbulence and other forces that cause them to sway, fishtail or otherwise veer from the route directed from the towing vehicle. In particular, hitches such as ball joint hitches allow a large degree of travel and lateral movement of the towed vehicle with respect to the direction of the towing vehicle. Too much sway, however, may have dangerous and even catastrophic effects. For example, a fishtailing towed vehicle may tip or roll over.

[0005] To prevent such undesired effect it may be useful to monitor the direction of travel of the towed vehicle with respect to the towing vehicle. Accordingly, a sensor designed to monitor the angular direction of travel of a towed vehicle is needed.

SUMMARY

[0006] A hitch ball sensor assembly is provided. The hitch ball sensor assembly includes a hitch ball positioned on a housing and rotatable with respect to the housing. A shaft may be connected to the hitch ball and extend within a bore within the housing. An angle sensor is configured to sense the rotation of the shaft. The hitch ball may include a deformable material positioned about a portion of the hitch ball. The deformable material may be in the shape of a ring and may be any deformable material, such as rubber.

[0007] In an embodiment, the angle sensor of the hitch ball assembly may be positioned on the side of the housing. The housing may include an opening, approximately perpendicular with the bore, to provide communication between the angle sensor and the shaft. The shaft may include one or more magnets to interface with the sensor. [0008] In an embodiment, the sensor may be a non-contact sensor, such as a magneto- resistive sensor. The sensor may have a resolution of at least 0.05 degrees. The sensor output may be utilized by components of a towing vehicle or towed vehicle to prevent unwanted conditions for the towing or towed vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The operation of the invention may be better understood by reference to the detailed description taken in connection with the following illustrations, wherein:

[0010] FIG. 1 is an embodiment of a hitch ball angle sensor;

[0011] FIG. 2 is an embodiment of a hitch ball angle sensor;

[0012] FIG. 3 is a perspective view of a hitch ball angle sensor;

[0013] FIG. 4 is a labeled side view of a hitch ball angle sensor;

[0014] FIG. 5 is a hitch ball design;

[0015] FIG. 6 is a perspective view of a hitch ball assembly having an angle sensor; [0016] FIG. 7 is a side view of a hitch ball assembly having an angle sensor; [0017] FIG. 8 is a cutaway view of a hitch ball assembly having an angle sensor; [0018] FIG. 9 illustrates a hitch ball with an off-center locator pin hole; and [0019] FIG. 10 illustrates various hitch ball attachment feature designs. DETAILED DESCRIPTION

[0020] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized and structural and functional changes may be made without departing from the respective scope of the invention. Moreover, features of the various embodiments may be combined or altered without departing from the scope of the invention. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments and still be within the spirit and scope of the invention.

[0021] A hitch ball assembly 10 having an angle sensor is generally provided, as illustrated in FIGS. 1-3. The hitch ball assembly 10 may include a hitch ball 12. The hitch ball 12 may be any appropriate size and shape, such as generally spherical. The hitch ball assembly 10 may be connected to a towing vehicle (not shown). For example, the hitch ball 12 may be directly or indirectly connected to a hitch bar 14, such as connected to a ball mount 16 that is carried on the hitch bar 14. The hitch bar 14 may be designed to connect to a hitch receiver on the towing vehicle.

[0022] The hitch ball 12 may be configured to engage a hitch ball coupler (not shown) on a towed vehicle to generally form a ball joint coupling between the towing vehicle and the towed vehicle. The coupler may include a generally spherically shaped opening to receive a similarly shaped hitch ball 12.

[0023] The hitch ball 12 may include a ring 18 positioned about at least a portion of the hitch ball 12. The ring 18 may be composed of a deformable material such as foam rubber or other similar materials. The deformable ring 18 may prevent slipping between the hitch ball 12 and corresponding coupler, thereby allowing the hitch ball to move or rotate with movement or rotation of the coupler, as is further described below. Alternatively, the hitch ball may include a frictional covering or surface treatment to prevent slipping between the coupler and the hitch ball 12. By utilizing a deformable ring 18, the hitch ball assembly may eliminate the need for additional parts, such as a key, that are designed to secure the engagement between the hitch ball and the coupler.

[0024] The hitch ball 12 may be supported by a ball shank or ball housing 20. The housing 20 may be any appropriate size and shape, such as generally conical, as illustrated in FIG. 1, or having a squared base and tapered upper portion, as illustrated in FIG. 2. The housing 20 may be connected to the ball mount 16. For example, the housing 20 may include a threaded bolt 22. The bolt 22 may be integrally formed with and extend from the bottom surface of the housing 20. The threaded portion may engage a similarly sized and threaded opening 24 in the ball mount 16. It will be appreciated, however, that the housing 20 may be connected to the ball mount 16 by any means known in the art.

[0025] The housing 20 may be configured to receive the hitch ball 12. For example, housing 20 may include a bore 26 positioned near the center of the housing 20. The bore 26 may extend through at least a portion of the housing 20. Alternatively, the bore 26 may extend completely through the housing 20. The hitch ball 12 may include or a shaft 28. The shaft 28 may be integrally formed with the hitch ball 12 or otherwise connected thereto, as described in further detail below. The shaft 28 may extend into the bore 26 as shown in FIGS. 1 and 2. The bore 26 may be sized and shaped to allow the shaft 28 to freely rotate therein. Accordingly, the housing may support the hitch ball 12 and shaft 28 and allow the hitch ball 12 and connected shaft 28 to rotate with respect to the housing 20 and bore 26.

[0026] The hitch ball assembly 10 may retain the shaft 28 within the bore 26 and prevent the ball from being removed from the housing 20. For example, as disclosed in U.S. Patent No. 6,983,950 to McCoy et al, the housing may include one or more ball bearings positioned to engage a cavity in the shaft 28, thereby preventing removal of the shaft 28 from the bore 26 while still allowing rotation of the shaft 28 within the bore 26. The ball bearings may be spring loaded or otherwise biased to allow the hitch ball 12 and shaft 28 to be removed and interchanged as necessary and allow different hitch ball sizes to be selected. It will be appreciated, however, that the shaft 28 may be held within the bore 26 by any means known in the art.

[0027] The hitch ball assembly 10 may include a sensor 30 configured to measure the rotation of the hitch ball 12. The sensor 30 may be configured to monitor the rotational position of the shaft 28 or hitch ball 12 relative to a fixed position, such as relative to the housing 20, or may monitor the absolute rotational position of the shaft 28 or hitch ball 12. The sensor 30 may utilize any appropriate sensing elements, such as mechanical, magnetic, magneto-resistive, torsional, optical, capacitive or inductive sensing elements, or any other sensing elements known in the art.

[0028] In an embodiment the sensor 30 may utilize non-contact fixed sensing elements with a rotating actuator. The rotating actuator may be tied to the shaft 28 or other accompanying rotating parts of the sensor 30. The fixed sensing elements may be fixed to any non-rotating part of the hitch ball assembly 10, such as a portion underneath the housing 20 or connected to the housing 20. Alternatively, the sensor 30 may utilize non-contact rotating sensing elements with a fixed actuator. Further, the sensor may employ contacting sensing elements, such as contacting resistive elements with a rotating wiper or fixed wiper.

[0029] In an embodiment, the sensor 30 may be a magneto-resistive sensor, such as a KMA200 magneto-resistive sensor. The sensor may comprise an array of magneto- resistive sensing arrays to provide a resolution of 0.05 degrees or better. The high resolution sensor may eliminate the need for additional components in the hitch ball assembly 10. For example, alternative designs utilize lower resolution sensing means that require additional components, such as a gear train, to increase the sensing resolution. By utilizing a high resolution non-contact sensor, the hitch ball assembly eliminates the need for such components.

[0030] The sensor 30 may monitor the rotational position of the shaft 28 or hitch ball 12 based on the sensing elements and emit an output signal based on the rotational position. To that end, the sensor 30 may include electronic circuitry to measure, adapt, condition and calibrate the output from the sensing element. The output signal may communicate data, information or values based on voltage, pulse width modulation (PWM), duty cycle, or over network protocols such as CAN, LIN, SPI, I2C BUS Data Link, or using other means of communication.

[0031] The sensor 30 may be in communication with components of a towing vehicle or a towed vehicle, such as the vehicle communication bus on the towing vehicle or vehicle communication bus on the towed vehicle, anti-lock braking (ABS) module, engine controller, brake controller, transmission control, or other various components of the towing or towed vehicle. The sensor output signal may be used to sense various conditions of a towed vehicle, such as sway or a jackknife condition. The components of the towing or towed vehicle may then modify and adjust vehicle towing or trailer systems to avoid the unwanted conditions. For example, the towing or towed vehicle may modify the engine or transmission output to alter the speed of the vehicle or gearing, brakes of the towing vehicle or trailer, lights, or any other vehicle systems in response to the input from the sensor 30. In an embodiment, a towing vehicle may include a trailer brake controller configured to receive an input signal from the angle sensor 30. The trailer brake controller may modify the brakes of the trailer based on the angle sensor input signal to reduce unwanted conditions such as sway of the trailer. The angle sensor 30 may also be used to modify other vehicle systems such as back-up assist, park assist and stability control.

[0032] In an embodiment, the sensor may be positioned near the bottom of the hitch ball assembly 10, as shown in FIG. 1. For example, the bolt 22 may extend through the threaded opening 24. The sensor 30 may be coupled to the bolt 22 by a threaded nut 32, and may be positioned below the nut 32.

[0033] The sensor 30 may comprise a collar 34 and a fixed portion 36. The collar 34 may be connected to the shaft 28 to rotate therewith. For example, the shaft 28 may be keyed 38 to engage a keyed opening 40 in the collar 34. Alternatively, the shaft 28 and collar 34 may be integrally formed. As described above, the collar may include sensing elements 42, such as magnets or the like, to facilitate sensing of rotational position of the shaft 28. The magnets may be positioned within a cavity in the collar 34 an arranged to be 180 degrees apart from one another. The fixed portion 36 may connect to the nut 32 and extend within the collar 34. The fixed portion 36 may include sensing elements and pickups, as well as other electrical circuitry as described above. The hitch ball assembly 10 may further include wires and other components to provide power and communication to and from the sensor 30.

[0034] The size and geometry of the ball mount 16 may be configured to provide protection for the sensor 30. For example, as illustrated in FIG. 1, the sensor 30 may protrude below the ball mount 16. The ball mount 16 may include a skirt or guard (not shown) to protect the sensor 30 from any unwanted collisions. The ball mount 16 may further include harnessing or connection points for wires and cables (not shown) to interface with the sensor 30.

[0035] In an embodiment illustrated in FIG. 2, the sensor 30 may be mounted above the ball mount 16. For example, the sensor 30 may be a fixed position sensor positioned above the ball mount 16 and inserted within the housing, as shown in FIGS. 2 and 3. The sensor may extend into the bore 26 and below the shaft 28. The sensor may include sensing elements, such as pick ups 44, aligned with a portion of the shaft 28. The sensing elements 44 may interface with a magnet 42 or other sensing elements located on the bottom of the shaft 28.

[0036] In use, the hitch ball 12 may be coupled to a trailer hitch coupler. The deformable ring 18 or frictional surface of the hitch ball 12 may allow the ball to rotate with respect to the housing 20 as the trailer coupler rotates. A sensor 30 mounted to the housing 20 may read the rotational position of the shaft 28 or hitch ball 12. The sensor 30 may be mounted under the ball mount 16 and include a rotating collar 34 that interfaces with a fixed portion 36 to read the rotational position. Alternatively, the sensor 30 may be mounted above the ball mount 16 and positioned within the housing 20. The sensor 30 may interface with magnets 42 or other sensing elements positioned at the bottom of the shaft 28. The sensor may read the rotational position of the shaft 28 and emit an output signal based on the position.

[0037] In an embodiment, the sensor 30 may be arranged to engage the side of the housing 20 as shown in FIGS. 8-11. The shaft 28 may include a magnet 42 embedded in or mounted on the shaft 28 to interface with the sensor 30. As seen in the cutaway view of FIG. 8, the shaft 28 may extend through only a portion of the hitch ball 12. The shaft 28 may include a shaft collar 46 or other attachment feature to facilitate engagement with the ball. The attachment feature 46 may allow the hitch ball 12 to be removably attached to the shaft 28 to provide interchangeability of the hitch ball 12. The housing 20 may include an opening 48 to allow the sensor 30 to interface with the shaft 28, such as the side of the shaft. In an embodiment, the opening 48 may be approximately perpendicular to the bore 26 to provide communication between the sensor 30 mounted on the side of the housing 20 and the magnet 42 on the shaft 28. The assembly 10 may further include a mounting pin to connect the hitch ball 12 to the assembly 10. The hitch ball 12 may therefore include a mounting pin hole 50 to receive the mounting pin. As shown in FIG. 9, the mounting pin hole 50 may be located off-center to prevent the mounting pin from interfering with the shaft 28.

[0038] The hitch ball 12 may include attachment features in addition to the ring 18 to enhance the connection between the hitch ball 12 and the trailer coupler. For example, as illustrated in FIG. 10, the hitch ball 12 may include one or two rings 18 positioned about the generally spherical hitch ball 12. In an embodiment, a first ring 18 may be positioned about the upper hemisphere of the hitch ball 12 and a second ring 18 may be positioned about the lower hemisphere of the hitch ball 12. This arrangement may improve contact between the rings 18 and the trailer coupler and ensure contact between at least one ring 18 and the coupler at all times. In another embodiment, the hitch ball 12 may include a pattern of deformable material 52 embedded or positioned on the surface of the hitch ball 12. For example, the hitch ball may include a plurality of deformable material spots, a plurality of deformable material line segments, or any other arrangement of deformable material about the surface of the hitch ball 12 to enhance connection between the hitch ball 12 and the trailer coupler.

[0039] It will be appreciated that the deformable material 52 may be inserted or molded as convex circular protrusions or similar vertical stripes over either the top or both hemispheres of the hitch ball 12. The protrusions may thus be minimized to avoid snagging the coupler upon removal from the hitch ball engagement.

[0040] Although the embodiments of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be understood that the present invention is not to be limited to just the embodiments disclosed, but that the invention described herein is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the claims hereafter. The claims as follows are intended to include all modifications and alterations insofar as they come within the scope of the claims or the equivalent thereof.

Claims

CLAIMS Having thus described the invention, we claim:

1. A hitch ball sensor assembly comprising:

a housing;

a hitch ball positioned on the housing and rotatable with respect to the housing;

a shaft connected to the hitch ball and extending within a bore in the housing; an angle sensor configured to sense the rotation of the shaft; and

a deformable material positioned about a portion of the hitch ball.

2. The hitch ball sensor assembly of claim I, wherein the angle sensor is a non- contact sensor.

3. The hitch ball sensor assembly of claim 1, wherein the deformable material comprises a ring positioned about a portion of the hitch ball.

4. The hitch ball sensor assembly of claim 1, wherein the deformable material comprises a plurality of linear segments of deformable material positioned about the hitch ball.

5. The hitch ball sensor assembly of claim 1, wherein the deformable material is rubber.

6. The hitch ball sensor assembly of claim 1, wherein the hitch ball is removably connected to the shaft.

7. A hitch ball sensor assembly comprising:

a housing having a bore therein;

a hitch ball positioned on the housing and rotatable with respect to the housing; a shaft connected to the hitch ball and positioned within the bore in the housing; and

an angle sensor connected to the housing and configured to sense the rotation of the shaft.

8. The hitch ball sensor assembly of claim 7, wherein the housing includes an opening in communication with the bore arranged approximately perpendicular to the bore.

9. The hitch ball sensor of claim 8, wherein the angle sensor is positioned in communication with the opening.

10. The hitch ball sensor of claim 7 further comprising one or more magnets positioned on the shaft to interface with the angle sensor.

11. The hitch ball sensor assembly of claim 7, wherein the angle sensor is a non- contact sensor.

12. The hitch ball sensor assembly of claim 7, further comprising a threaded bolt extending from the housing and connected to a ball mount.

13. The hitch ball sensor assembly of claim 7, wherein the shaft is retained within the bore by one or more ball bearings.

14. The hitch ball sensor assembly of claim 7, further comprising a deformable material positioned about a portion of the hitch ball.

15. A hitch ball sensor assembly comprising:

a housing;

a hitch ball supported by the housing and rotatable with respect to the housing; a shaft connected to the hitch ball and extending within a bore in the housing; and an angle sensor configured to sense the rotation of the shaft, wherein the angle sensor comprises a magneto-resistive sensing element.

16. The hitch ball sensor assembly of claim 15, wherein the resolution of the angle sensor is at least 0.05 degrees.

17. The hitch ball sensor assembly of claim 15, wherein the magneto-resistive sensing element includes an array of magneto-resistive sensing bridges.

18. The hitch ball sensor assembly of claim 15, wherein the angle sensor is configured to provide an input signal to one or more components of a towing vehicle.

19. The hitch ball sensor assembly of claim 18, wherein the towing vehicle is configured to modify at least one of a braking output, an engine control output or an engine transmission output based on the angle sensor signal.

20. The hitch ball sensor assembly of claim 18, wherein the one or more components of a towing vehicle includes a trailer brake controller configured to modify a trailer brake signal based on the angle sensor signal to reduce the sway of a trailer.