Patent US4170254A successfully refreshed from Google Patents.
US3749480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mirror rotation correction system
Assignee: WITT D DE
•
Filing: 1971-08-19
•
Granted: 1973-07-31
•
Expires: 1991-08-19
Abstract
Abstract A rear view mirror rotation system compensating for the relative movement of a tractor-trailer combination having a mechanical sensing device adjacent the ''''fifth wheel.'''' The relative mechanical rotation is converted to an analog electrical signal for rotating the appropriate rear view mirror so that the driver can maintain a line of vision to the rear wheels of the trailer. Hook-up and initial alignment of the system is quite simple requiring only the attachment of a sensor and certain adjustments to the electrical circuitry that can be made by the driver of a rig from within the cab of the tractor. No substantial modification or adaptation of the trailer is required other than to provide a simple retainer or fastener for the sensor. Thus, a tractor equipped with the system can be used universally with any trailer.
Inventors
- 👤 Witt D De
- 👤 Witt R De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:33
CPC Classifications
B; B60; B60R; B60R1/00; B60R1/02; B60R1/025
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
178 words
A device for automatically rotating a rear view mirror on a towing vehicle in relation to the relative rotational movement of a towed vehicle comprising: a. electrically operated motor means for rotating a rear view mirror; b. sensing means mounted on the towing vehicle and including a readily attached sensor element operatively engaging the towed vehicle for sensing relative rotation between the towed and the towing vehicles; c. electric signal generating means mounted on the towing vehicle and responsive to the sensing means for generating an input command electric signal representative of the relative rotation; d. means electrically coupling said motor means to said electric signal generating means for rotating a rear view mirror in response to said input command electrical signal; and e. mirror position feedback means operatively coupled to said rear view mirror and to said electric signal generating means for deriving a feedback signal representative of the actual rotational position of the rear view mirror and for supplying the same to said electric signal generating means for use in developing the input command electrical signal.
Claim 2
Independent Claim
178 words
A device for automatically rotating a rear view mirror on a towing vehicle in relation to the relative rotational movement of a towed vehicle comprising: a. electrically operated motor means for rotating a rear view mirror; b. sensing means mounted on the towing vehicle and including a readily attached sensor element operatively engaging the towed vehicle for sensing relative rotation between the towed and the towing vehicles; c. electric signal generating means mounted on the towing vehicle and responsive to the sensing means for generating an input command electric signal representative of the relative rotation; d. means electrically coupling said motor means to said electric signal generating means for rotating a rear view mirror in response to said input command electrical signal; and e. mirror position feedback means operatively coupled to said rear view mirror and to said electric signal generating means for deriving a feedback signal representative of the actual rotational position of the rear view mirror and for supplying the same to said electric signal generating means for use in developing the input command electrical signal.
Claim 3
Dependent Claim
47 words
A device as defined in claim 1 wherein said sensing means is mounted on said towing vehicle at a point closely adjacent the pivotable connection between the towed and towing vehicles whereby it is made insensitive to relative movement between the two vehicles in the vertical direction.
Claim 4
Dependent Claim
40 words
A device as defined in claim 1 wherein said readily attached sensor element comprises a flexible member having one end readily attachable to the towed vehicle and the other end connected to actuate the sensing means on the towing vehicle.
Claim 5
Dependent Claim
58 words
A device as defined in claim 3 wherein the sensing means further includes a rotatable member that is mounted on the towing vehicle and rotatable relative to the towing vehicle, and the remaining end of the flexible member is connected to said rotatable member for turning it a given number of degrees in response to the relative rotation.
Claim 6
Dependent Claim
49 words
A device as defined in claim 4 further including first rotatable electric signal generating means comprising a part of said electric signal generating means and wherein said rotatable member drives said first rotatable electric signal generating means to produce the input command electric signal representative of the relative rotation.
Claim 7
Dependent Claim
88 words
A device as defined in claim 5 wherein said electric signal generating means further includes summing amplifier circuit means, second rotatable electric signal generating means mechanically coupled to and rotatable along with said electrically operated motor means for generating a mirror position feedback electric signal representative of the rotational position of the mirror, and means for supplying said mirror position feedback signal to the summing input of said summing amplifier circuit means along with the input command electric signal produced by the first rotatable electric signal generating means.
Claim 8
Dependent Claim
76 words
A device as defined in claim 6 wherein there are two mirrors provided for the right and left sides of the towing vehicle respectively, there being a respective mirror rotation system for each mirror including a respective mirror rotation motor means and summing amplifier circuit means, and said electric signal generating means further includes selector circuit means for selecting one of two rear view mirror rotation systems tO which the input command electric signal is supplied.
Claim 9
Dependent Claim
46 words
A device as defined in claim 6 further including zero position adjustment means electrically connected to the summing input of the summing amplifier circuit means for adjusting the median position zero-output of the summing amplifier circuit means to compensate for variances in the vehicles being towed.
Claim 10
Dependent Claim
70 words
A device as defined in claim 6 further including variable input signal level adjusting means connected to the respective summing inputs of the summing amplifier circuit means for variably adjusting the relative values of the input command electric signal and the mirror position feedback signal to compensate for variances in the relative values of the signals due to differences in the characteristics of different vehicles being towed and the like.
Claim 11
Dependent Claim
55 words
A device as defined in claim 6 wherein the first rotatable electric signal generating means includes a dead band region straddling the median zero relative rotation position whereby the device is made insensitive to and prevents minimal mirror rotational position adjustments that otherwise might be produced during normal steering corrections occurring during straight-ahead driving conditions.
Claim 12
Dependent Claim
37 words
A device as defined in claim 6 wherein the electric signal generated is an analog signal whereby a continuous linear adjustment is attainable to thereby provide continuous linear adjustment of the degree of rotation of the mirror.
Claim 13
Dependent Claim
98 words
A device as defined in claim 11 wherein said first rotatable electric signal generating means comprises a first variable potentiometer connected to and rotatable along with said rotatable member, said second rotatable electric signal generating means comprises a second variable potentiometer connected to and rotatable along with said mirror rotating motor means, and both of said variable potentiometer means are electrically connected to the summing input of the summing amplifier circuit means with appropriate polarities whereby the output from the summing amplifier circuit means will be driven to zero upon the mirror being rotated to its proper position.
Claim 14
Dependent Claim
109 words
A device as defined in claim 12 further including zero position adjustment means electrically connected to the summing input of the summing amplifier circuit means for adjusting the median position zero output of the summing amplifier circuit means to compensate for variances in the vehicles being towed and variable input signal level adjusting means connected to the respective summing inputs of the summing amplifier circuit means for variably adjusting the relative values of the input command electric signal and the mirror position feedback signal to compensate for variances in the relative values of the signals due to differences in the characteristics of different vehicles being towed and the like.
Claim 15
Dependent Claim
96 words
A device as defined in claim 1 wherein the first rotatable electric signal generating means includes a dead band region straddling the median zero relative rotation position whereby the device is made insensitive to and prevents minimal mirror rotational position adjustments that otherwise might be produced during normal steering corrections occurring during straight-ahead driving conditions and wherein said sensing means is mounted on said towing vehicle at a point closely adjacent the pivotal connection between the towed and towing vehicles whereby it is made insensitive to relative movement between the two vehicles in the vertical direction.
Claim 16
Dependent Claim
74 words
A device as defined in claim 13 wherein there are two mirrors provided for the right and left sides of the towing vehicle respectively, there being a respective mirror rotation system for each mirror including a respective mirror rotation motor means and summing amplifier circuit means, and said electric signal generating means further includes selector circuit means for selecting one of two rear view mirror rotation systems to which the electric signal is supplied.
Claim 17
Dependent Claim
74 words
A device as defined in claim 15 wherein at least the right Rear view mirror is positioned in front of the windshield whereby a line of sight from the driver''s seat in the towing vehicle will pass through the windshield to the mirror and be reflected along the side of the towed vehicle in a manner to minimize the rotational movement of the driver''s eyes away from oncoming traffic while viewing the right mirror.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |