EP0383464A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Pumps
Assignee: Hozelock Ltd
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Filing: 1990-02-02
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Granted: —
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Expires: 2010-02-02
Abstract
Abstract A pump for pumping a fluid, eg for pumping water for a garden fountain or waterfall, comprises an electric motor (12) driving an impeller (32) in a pump chamber. The motor is an A.C. synchronous motor and on start up may rotate in either direction of rotation, only one of which is the direction in which the impeller (32) is designed to rotate. A sprag (46) pivotally mounted in the pump chamber is urged to a projecting position (Figure 3) by fluid flow if the motor starts in the undesired direction (48), and the impeller blades engage the projecting sprag, causing the impeller to recoil and thence to rotate in the desired direction of rotation (40), in which fluid flow maintains the sprag (46) against the wall of the pump chamber.
Inventors
- 👤 Kevin Ian Michael Marston
- 👤 Peter Lawrence Watt
- 👤 Philip Andrew Stephen Burrell
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:00
CPC Classifications
H; H02; H02K; H02K7/00; H02K7/10; H02K7/118; H02K7/1185; F; F04; F04D; F04D13/00; F04D13/02; F04D13/06; F04D15/00; F04D15/0077
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
A pump for pumping fluid, comprising an AC synchronous electric motor having a rotor and a stator, a housing defining a pump chamber accommodating an impeller rotatably driven by the rotor, the impeller having a desired direction of rotation, and a brake member movable so that if on start up of the motor the rotor drives the impeller in the undesired rotational direction, the resulting fluid flow or pressure urges the brake member towards an operative position in which the brake member impedes further rotation of the impeller in the undesired direction and thereby causes the rotor to reverse its direction of rotation and to drive the impeller in the desired direction.
Claim 2
Dependent Claim
112 words
A pump for pumping fluid, comprising an AC synchronous electric motor having a rotor and a stator, a housing defining a pump chamber accommodating an impeller rotatably driven by the rotor, the impeller having a desired direction of rotation, and a brake member movable so that if on start up of the motor the rotor drives the impeller in the undesired rotational direction, the resulting fluid flow or pressure urges the brake member towards an operative position in which the brake member impedes further rotation of the impeller in the undesired direction and thereby causes the rotor to reverse its direction of rotation and to drive the impeller in the desired direction.
Claim 3
Dependent Claim
31 words
A pump according to claim 1, wherein the brake member is movably mounted on the impeller and in its operative position engages the housing to provide the braking or blocking effect.
Claim 4
Dependent Claim
20 words
A pump according to claim 3, wherein the brake member is movably mounted on the housing and engages the impeller.
Claim 5
Dependent Claim
24 words
A pump according to claim 3, wherein the brake member engages blades of the impeller when the brake member is in its operative position.
Claim 6
Dependent Claim
83 words
A pump according to claim 3 or 4, wherein the brake member is in the form of a sprag pivotally mounted in the wall of the pump chamber which is shaped so as to cause fluid pressure to lift the sprag and move the latter to its operative position when the impeller rotates in the undesired direction, fluid pressure biassing the sprag to an inoperative retracted position against the wall of the pump chamber when the impeller rotates in the desired rotational direction.
Claim 7
Dependent Claim
41 words
A pump according to any of the preceding claims, wherein the motor is a two pole permanent magnet rotor synchronous motor the rotor of which (on switch off) will come to rest in either of two positions relative to the stator.
Claim 8
Dependent Claim
54 words
A pump according to claim 6, wherein the impeller has two oppositely projecting blades only, the two blades being positioned, in relation to the rest positions of the rotor, to allow the latter at least a certain amplitude of rotation in the undesired direction before one of the impeller blades engages the brake member.
References Cited (Backward Citations)
No citation records indexed.
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