Heat sensitive actuator device

Patent metadata

Field	Value
Publication number	US-2017276122-A1
Application number	US-201515509289-A
Country	US
Kind code	A1
Filing date	Sep 8, 2015
Priority date	Sep 15, 2014
Publication date	Sep 28, 2017
Grant date	—

Abstract

A heat sensitive actuator uses a shape memory material layer which is thermally stimulated to change shape, in response to a rise in temperature, from a first shape at a first temperature to a second shape at a second temperature. A layer stack is associated with the shape memory material layer, and it can adopt the first shape at the first temperature. In this way, the layer stack is used to return the shape memory material to its original shape after cooling.

First claim

1 . An actuator device having an actuator member, the actuator member being configured to define at least a first actuation state of the actuator device and a second state of the actuation device, the second state being different from the first state, the actuator member comprising:
a layer stack comprising a first layer and a second layer attached to each other for operating like a bimetallic strip upon heating and cooling of the actuator device, the first and second layers having different coefficients of thermal expansion, and a shape memory material layer comprising one of the layers of the layer stack or a separate layer, and comprising or consisting of one or more shape memory materials, the shape memory material layer being configured to change shape from a first shape at a first temperature to a second shape at a second temperature higher than the first temperature, the first shape being associated with the first actuation state and the second shape being associated with the second actuation state, wherein the layer stack is configured, through the thermal contraction of the layers of the layer stack excluding any shape memory material layer, to return the shape memory material layer from the second shape to the first shape upon a temperature change of the actuator device from the second temperature to the first temperature.

2 . An actuator device as claimed in claim 1 , wherein the first temperature is below the phase change temperature of at least one of the at least one shape memory materials and the second temperature is above the phase change temperature of the at least one of the at least one shape memory material.

3 . An actuator device as claimed in claim 1 , wherein the second layer comprises or consists of the shape memory material layer.

4 . An actuator device as claimed in claim 1 , wherein the shape memory material layer is a layer different from the first layer and the second layer.

5 . An actuator device as claimed in claim 4 , wherein the shape memory material layer is directly attached to only the second layer and not directly attached to the first layer.

6 . An actuator device as claimed in claim 4 , wherein the shape memory material layer is sandwiched between the first layer and the second layer.

7 . An actuator as claimed in claim 4 , wherein the first shape and/or the second shape are bent shapes in a stack direction of the layer stack and either
the first shape is a less bent shape than the second shape, the first layer is at the outer side of the second shape and the first layer has a higher coefficient of thermal expansion than the second layer, or the first shape is a more bent shape than the second shape, the first layer is at the inner side of the first shape memory material layer and the first layer has a higher coefficient of thermal expansion than the second layer.

8 . An actuator as claimed in claim 1 , further comprising a heater device for heating at least the shape memory material layer and/or a cooling device for cooling at least the shape memory material layer.

9 . An actuator as claimed in claim 1 , wherein the first shape and the second shape each comprise coiled spring shapes with different degrees of spring expansion.

10 . An apparatus comprising an actuator device as claimed in claim 1 , wherein at least part of the apparatus is controlled by the actuator device.

11 . An apparatus as claimed in claim 10 , wherein the apparatus comprises a circuit including the actuator device, wherein the actuator device operates as a switch.

12 . An apparatus as claimed in claim 10 , wherein the apparatus is a lighting device.

13 . An apparatus as claimed in claim 10 , wherein the apparatus is a part of, or is a motor, wherein the actuator device is part of a valve for control of fluid used with the motor when in operation.

14 . Use of an actuation device as claimed in claim 1 to control flow of electricity, liquid or gas based on temperature or heat change.

15 . An actuation method, comprising:
providing a shape memory material layer comprising or consisting of at least one shape memory material; providing a layer stack comprising a first layer and a second layer attached to each other for operating like a bimetallic strip upon heating and cooling, the first and second layers having different coefficients of thermal expansion; heating the actuator device to thereby change the temperature of at least the shape memory material layer from a first temperature to a second temperature higher than the first temperature to thereby change the shape of the shape memory material layer from a first shape to a second shape, the first shape being associated with a first actuation state of the actuation device and the second shape being associated with a second actuation state of the actuation device; cooling the actuator to thereby change the temperature of at least the layer stack from the second temperature to the first temperature to cause the layer stack return the shape memory material layer from the second shape to the first shape, through the thermal contraction of the layers of the layer stack excluding any shape memory material layer.

Assignees

• Koninklijke Philips Nv

Inventors

• Van Den Aker Karel Johannes Adrianus

Classifications

• F03G7/06145 Primary

  Springs · CPC title

• F03G7/065 Primary

  using a shape memory element · CPC title

• F03G7/0613

  using layers of different materials joined together, e.g. bimetals · CPC title

• F03G7/0614 Primary

  using shape memory elements · CPC title