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US5419006A Expired / Lapsed US ⏱️ 0.0 years remaining

Exhauster fan systems

Assignee: JOHNSTON ENGINEERING Ltd
•
Filing: 1993-12-08
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Granted: 1995-05-30
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Expires: 2013-12-08
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Abstract

Abstract An exhauster fan system for a road sweeping machine comprises a rotatable fan, a drive, and a hydrostatic transmission system coupled between the drive and a spindle on which the fan is mounted. The output of the transmission system is controlled to apply a constant torque to the fan spindle. The transmission system comprises a variable displacement pump coupled to drive a fixed displacement motor. A pressure control is associated with the pump to control hydraulic oil flow in the pump to sustain a set pressure in the motor. The pressure control is selectively operable to provide different set pressures to the motor for different operating conditions. The fan is used in the environment of a road sweeping vehicle comprising a chassis, an airtight container mounted on the chassis, at least one suction conduit connected to the container and, positioned within the container, the described exhauster fan system in which the fan creates a high velocity air flow within the suction conduit.

Inventors

  • 👤 Anthony J. Duthie

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 19:07
CPC Classifications
E; E01; E01H; E01H1/00; E01H1/08; E01H1/0827; F; F04; F04D; F04D25/00; F04D25/02; F04D25/04

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 50 words
An exhauster fan system for a road sweeping machine comprising a rotatable fan, drive means, a hydrostatic transmission system coupled between the drive means and a spindle on which the fan is mounted, the output of which transmission system is controlled to apply a constant torque to the fan spindle.
Claim 2
Dependent Claim 50 words
An exhauster fan system for a road sweeping machine comprising a rotatable fan, drive means, a hydrostatic transmission system coupled between the drive means and a spindle on which the fan is mounted, the output of which transmission system is controlled to apply a constant torque to the fan spindle.
Claim 3
Dependent Claim 26 words
An exhauster fan system as claimed in claim 1 in which the transmission system comprises a variable displacement pump coupled to drive a fixed displacement motor.
Claim 4
Dependent Claim 32 words
An exhauster fan as claimed in claim 2 further comprising pressure control means associated the pump to control hydraulic oil flow in the pump to sustain a set pressure in the motor.
Claim 5
Dependent Claim 30 words
An exhauster fan system as claimed in claim 3 in which the pressure control means are selectively operable to provide different set pressures to the motor for different operating conditions.
Claim 6
Dependent Claim 51 words
A road sweeping vehicle comprising a chassis, an air-tight container mounted on the chassis, at least one suction conduit connected to the container and, positioned within the container, an exhauster fan system as claimed in claim 1 in which the fan creates a high velocity air flow within the suction conduit.

References Cited (Backward Citations)

GB580983A Cited
GB1079857A Cited
US4356589A Cited
US4370776A Cited
US4399585A Cited
US4555826A Cited
US4773119A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-05-29 1998-11-28 1999-05-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-05-29 2002-11-28 2003-05-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-05-29 2006-11-28 2007-05-30 $7700.00 Window Closed / Lapsed

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