Thermally actuated device and door latch means utilizing the same or the like

Abstract

A thermally actuated device having a housing provided with a chamber having a thermally responsive medium therein and being defined in part by a motion-transmitting member movable relative to the housing in response to expansion or contraction of the thermally responsive medium that is adapted to be heated by an electrical heater disposed in the chamber, the heater comprising a cylindrical member of electrical insulating material having a conductive coating on the surface thereof that provides substantially a uniform thermal flux to the thermally responsive medium throughout substantially the entire surface area of the heater. Two such actuators are utilized with a door latch member so that when one of the devices is thermally actuated, the same moves the latch member to a locking position thereof and when the other device is thermally actuated, the same moves the latch member to an unlocking position thereof.

Description

This invention relates to an improved thermally actuated device as well as to an improved door latch arrangement utilizing such thermally actuated devices or the like.

It is well known that a thermally actuated device can be provided wherein the same comprises a housing means having a chamber therein filled with a thermally responsive medium, such as Freon, and bein defined in part by a motion-transmitting member movable relative to the housing means in response to expansion or contraction of the thermally responsive medium that is adapted to be heated by an electrical heater disposed in the chamber. For example, see the patent to Harris, U.S. Pat. No. 3,609,635, and the patent to Stropkay, U.S. Pat. No. 3,664,698 which disclose such thermally actuated devices.

It is a feature of this invention to provide an improved thermally actuated device of the above type.

It is another feature of this invention to provide an improved door latching mechanism utilizing such thermally actuated devices or the like.

In particular, one embodiment of this invention provides an improved heater means for such a thermally actuated device or the like, the heater means providing substantially a uniform thermal flux to the thermally responsive medium in the thermally actuated device throughout substantially the entire surface area of the heater means whereby it is believed that no hot spots will be created by the heater means of this invention that might cause a deterioration or break-down of the thermally responsive medium as well as a breakdown of the heater means itself. Such a heater can comprise a tubular cylindrical member of electrical insulating material having a conductive coating on the exterior surface thereof that provide an electrical resistance heater when electrical current passes through the same.

Another embodiment of this invention provides electrical insulating material substantially completely bordering the chamber of the thermally actuated device to effectively electrically insulate the electrical heater from the housing means of the device.

For example, the motion-transmitting member of the thermally actuated device can comprise a flexible diaphragm of the rolling type and be formed of electrical insulating material, the flexible diaphragm closing off a tubular housing member between the opposed ends thereof and having a tubular portion extending along the inside surface of the tubular member to one end thereof. A closure member of electrically insulating material closes off that one end of the tubular member and cooperates with the tubular portion of the diaphragm to seal the closure member to that one end of the tubular member whereby the chamber is substantially completely defined by the diaphragm and the closure member.

Such thermally actuated devices of this invention or other thermally actuated devices can be utilized to form an improved door latch means of this invention, such as a remote control door latch means for a vehicle access door or the like wherein the conventional door locking mechanism thereof comprises a manually operated plunger which when pushed downwardly locks the door and when pulled upwardly unlocks the door.

One embodiment of this invention provides a movable latch member for cooperating with the plunger of the conventional door locking mechanism and a pair of thermally actuated devices respectively and operatively associated with the latch member. One of the thermally actuated devices when thermally actuated causes movement of the latch member to its plunger locking position and the other of the thermally actuated devices when thermally actuated causes movement of the latch member to its plunger unlocking position.

Accordingly, it is an object of this invention to provide an improved thermally actuated device having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide an improved remote controlled door latching arrangment for a vehicle or the like, the latching arrangement having one or more of the novel features set forth above or hereinafter shown or described.

Other objects, uses and advantages of this invention are apparent from a reading of this description, which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIG. 1 is a cross-sectional view schematically illustrating the improved door latching arrangement of this invention, with the improved thermally actuated devices of this invention illustrated being in cross section and with the latch means being in the unlocked position thereof.

FIG. 2 is a view similar to FIG. 1 and illustrates the door latching arrangement in the locking position thereof.

FIG. 3 is an enlarged, fragmentary, cross-sectional view illustrating a joint structure of one of the thermally actuated devices of FIG. 1 in combination with the rolling diaphragm thereof.

FIG. 4 is an exploded, perspective view of the improved heater means for the thermally actuated devices of FIG. 1.

FIG. 5 is a view similar to FIG. 1 and illustrates another embodiment of the thermally actuated device of this invention.

FIG. 6 is a fragmentary view similar to FIG. 5 and illustrates another embodiment of the thermally actuated device of this invention.

FIG. 7 is an exploded, perspective view of certain parts of the device of FIG. 6.

FIG. 8 is a view similar to FIG. 1 and illustrates another embodiment of the improved door latching arrangement of this invention with the improved thermally actuated devices of this invention illustrated in cross section and with the latch member being in the unlocked position thereof.

FIG. 9 is a view similar to FIG. 1 and illustrates one of the thermally actuated devices moving the door latching member to its door locking position.

FIG. 10 is a fragmentary view similar to FIG. 9 and illustrates an attempt to move the door latching member form its latching position to its unlocking position while the latching thermally actuated device is still in the actuated condition thereof.

FIG. 11 is a fragmentary cross-sectional view taken on line 11--11 of FIG. 8 and illustrates one lead means for the electrical heater means of the thermally actuated devices of the latching arrangement of FIG. 8.

FIG. 12 is a fragmentary cross-sectional view of another embodiment of the thermally actuated devices of this invention.

While the various features of this invention are hereinafter described and illustrated as being particularly adapted to provide thermally actuated devices for operating a door latch means for a vehicle or the like, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide thermally actuated devices for other uses as desired.

Therefore, this invention is not to be limited to only the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIGS. 1 and 2, one embodiment of the improved door latch arrangment of this invention is generally indicated by the reference numeral 20 and comprises a latch member 21 pivotally mounted by a pivot member 22 intermediate its opposed ends 23 and 24 to a door structure (not shown) with the end 23 having an elongated slot 25 therein for interconnecting the end 23 of the lever 21 to a suitable and conventional up and down vertically moved and normally manually operated vehicle door latch plunger member (not shown) so that when the lever 21 is pivoted in a clockwise directioin to the position illustrated in FIG. 1 in a manner hereinafter described, such door latch plunger is moved to its up position and thus to its door unlocking position and when the lever 21 has the end 23 thereof pivoted downwardly in the manner illustrated in FIG. 2, such door latch plunger member is moved vertically downwardly and thus to its door locking position. The elongated slot 25 in the lever 21 permits such arcuate motion of the end 23 of the lever while causing substantially straight line vertical motion of a cylindrical pin (not shown) passing through the slot 25 and being fixed to the door latch plunger.

The door latch or member 21 is moved between its operating positions by a pair of thermally actuated devices of this invention that are respectively and generally indicated by the reference numerals 26A and 26B with the parts thereof being identical and therefore being indicated by like reference numerals so that the description of one actuator 26A or 26B also applies for the other actuator 26B or 26A.

Each thermally actuated device 26A and 26B comprises a housing means 27 formed of two metallic tubular members 28 and 29 having adjacent ends 30 and 31 crimped or rolled together to secure the same together and to hold an outer peripheral bead or portion 32 of a flexible rolling diaphragm 33 of rubber or other suitable flexible and electrically insulating material therebetween which cooperates with the tubular member 28 and an electrically insulating end closure 34 at the lower end 35 of the tubular housing member 28 to define a chamber 36 therein.

A piston member 37 has a part thereof disposed in the upper tubular member 29 with a piston rod portion 38 thereof passing out through a reduced tubular end 39 of the tubular housing member 29 to be interconnected by a pin means 40 to a lever actuator or bracket 41 for the latch lever 21 in a manner hereinafter described. A reduced lower end 42 of the piston member 37 is adapted to be received in a cup forming portion 43 of the rolling diaphragm 33 when the same is in its natural position as illustrated in FIG. 1, the piston member 37 having a large annular guiding portion 44 between the portions 42 and 38 thereof for sliding against the inside peripheral surface 45 of the tubular member 29 as the piston member 37 moves upwardly and downwardly in the manner illustrated in FIGS. 1 and 2.

The chambers 36 of the thermally actuated devices 26A and 26B are adapted to have a thermally responsive medium 36' disposed therein for expanding and contracting in rerlation to the temperature thereof and thereby causing the diaphragms 33 to roll upwardly or downwardly relative to the housing means 27 in a manner well known in the art. For example, each chamber 36 can be partially or completely filled with liquid Freon which when heated, as described in the aforementioned U.S. Patents, will rapidly vaporize and thereby expand in the chamber 36 to drive the rolling diaphragm 33 upwardly in the manner illustrated by the actuator 26B in FIG. 2 to drive the piston member 37 thereof upwardly therewith for transmitting motion to the lever 21 in a manner hereinafter described.

In order to insure that the rolling diaphragm 33, as it rolls between the positions illustrated in FIGS. 1 and 2 for the actuator 26B, will have many cycles and thereby be long lasting, the housing members 28 and 29 can be so formed in the manner illustrated in FIG. 3 adjacent the ends 30 and 31 thereof that the end 31 provides an arcuate annular portion 46 to trap an annular bead 47 of the rolling diaphragm 33 between the ends 31 and 30 of the members 29 and 28 and permit the rolling diaphragm 33 to have a preformed annular fold 48 adjacent to the piston portion 42 when the diaphragm 33 is in its relaxed position illustrated in FIG. 3. Thus, the diaphragm 33 will begin to roll with the fold 48 up along the peripheral surface 45 of the housing member 29 in the manner illustrated by the diaphragm 33 of the actuator 26B in FIG. 2. Also the cup shape of the portion 43 of the diaphragm has the side wall thereof normally at an angle relative to the piston portion 42 but once pressure is developed in the respective chamber 36, the side wall of the cup portion 43 is deformed against the piston portion 42 in the manner illustrated by the actuated device 26B of FIG. 2.

An improved electrical heater maens of this invention for the thermally responsive medium 36' for each actuator 26A and 26B is generally indicated by the reference numeral 50 and comprises a cylindrical tubular member 51 of electrically insulating material, such as a glass tube formed of a glass material having a relatively low coefficient of theremal expansion and a relatively high coefficient of heat conductivity, such as pyrex provided with a conductive coating 52 on the outer peripheral cylindrical surface thereof throughout the entire length of the tubular member 51, the conductive coating 52 being formed of any suitable material which will cause the same to act as a heater means when an electrical current is passed therethrough. For example, such coating can comprise a tin oxide coating.

In order to enhance electrical connection to the conductive coating 52, bands 53 of silver paint can be provided at the opposed ends 55 and 54 of the tubular member 51 on top of the coating 52 so that when electrical connection is made respectively to the bands 53, electrical current is adapted to flow from one band 53 through the coating 52 to the other band 53 and such flow of current through the coating 52 causes the coating 52 to heat up and provide a sufficient temperature to not only vaporize the thermally responsive liquid 36' adjacent the same, but also to be conducted by the tube 51 to the interior surface thereof to vaporize the liquid 36' adjacent the same and thereby cause the rolling diaphragm 33 to be rolled upwardly in the mananer illustrated by the device 26B in FIG. 2 by the thus expending medium 36' in the chamber 36. It is believed that when freon is used for the medium 36' , the same will vaporize adjacent the inside and outside surfaces of the heater 50 in a second or so after the heater 50 is energized and since a uniform surface of the conductive coating 52 and the inside surface of the tube 51 is provided to the medium 36' , it is believed that the energized heater 50 will not have "hot spots" and will thereby provide a uniform thermal flux to the medium 36' through substantially the entire length of the coating 52 and tube 51 to not only not tend to breakdown the freon 36' , but also to not tend to breakdown the heater 50 itself.

For example, it is believed that when a conventional coiled wire electric heater is utilized in the chamber 36 for heating the medium 36' in the manner previously described, "hot spots" are created by such coiled wire heater because of the nonuniformity of the coiled wire heater and it is believed that such "hot spots" not only tend to break down the freon 36' because of the excessive heat being created by such "hot spots" , but also such "hot spots" tend to break down the coiled wire heater itself whereby should the same subsequently break through the deterioration thereof, the broken coiled wire heater has a tendency to spring apart and, thus, against the housing means to cause an adverse short circuiting situation.

However, as previously stated, it is believed that the tubular heater means 50 of this invention will not have such adverse "hot spots" and thereby will not tend to break down the freron 36' or cause a deterioration of itself.

A pair of metal bands 56 are looped in such a manner that the same can be telescoped onto the conductive bands 53 of the tubular member 51 in a press fit manner to provide good electrical contact therebetween so that outwardly extending or projecting ends 57 of the bands 56 can be utilized for lead attaching purposes for each heater means 50.

For example, a pair of wire leads 58 and 59 can be respectively inserted through suitable openings 60 and 61 in the electrical insulating end closure 34 of the respective actuator 26A or 26B with the lead 59 being soldered or otherwise electrically interconnected to the projection 57 of the lower conductive band 56 of the heater means 50 while the other lead 59 is adapted to project through the interior of the tubular member 51 and out of the upper end 55 thereof to be soldered or otherwise attached to the projection 57 of the upper conductive band 56 in the manner illustrated in FIG. 1. With the leads 58 and 59 being appropriately secured and sealed in the openings 60 and 61 of the end closure 54, it can be seen that the leads 58 and 59 not only secure the tubular member 51 thereto, but also the leads 58 and 59 provide electrical connection to the opposed ends 54 and 55 of the conductive coating 52.

As previously stated, it is believed that when electrical current is applied to the conductive coating 52 in a manner hereinafter described, the conductive coating 52 will present a uniform thermal flux to the thermally responsive medium 36' adjacent thereto throughout substantially the entire surface area of the coating 52 so that no "hot spots" will occur and the medium 36' will thereby be uniformally heated and vaporized adjacent the inside and outside surfaces of the heater 50 for the purpose previously described whereby it is believed that the heater 50 will not tend to break down the thermally responsive medium 36' as might be the case when "hot spots" occur in heater means of conventional form.

The devices 26A and 26B previously described respectively have their bracket members 41 provided with pivot pins 62 and 63 that project through elongated openings or slots 64 and 65 in the lever 21 respectively formed on opposite sides of the pivot pin 22 in the manner illustrated in FIGS. 1 and 2 to operate the lever in a manner hereinafter described.

The lever 21 has a conductive flange 66 disposed adjacent a pair of spring biased contact members 67 and 68 respectively carried on conductive rods 69 and 70 disposed for axial movement in tubular insulating members 71 and 72 fixed to the vehicle door or the like and being urged upwardly by compression springs 73 and 74 respectively disposed between the insulating sleeves 71 and 72 and enlarged parts 75 and 76 of the contact members 67 and 68 until enlarged ends 77 and 78 of the rods 69 and 70 engage against the lower ends of the insulating sleeves 71 and 72 to limit further upward movement thereof.

The conductive flange 66 of the lever 22 can be interconnected to ground by an electrical lead 79 as illustrated in FIG. 1.

The rod 69 of the contact member 67 is interconnected by the lead 80 to the lead 59 of the thermally actuated device 26A while the rod 70 of the contact member 68 is interconnected by the lead 81 to the lead 58 of the device 26B.

The electrical power soure or battery for the vehicle containing the door latching arrangement 20 of this invention is generally indicated by the reference numeral 82 and has one side 83 interconnected to ground by a lead 84 and the other side 85 thereof interconnected to a power source lead 86 for the door latching arrangement 20. Normally open "unlock" and "lock" switches, that are generally indicated by the reference numeral 87 and 88 in FIG. 1, have one side or contact 89 and 90 thereof interconnected to the power source lead 86 while the other side or contact 91 of the switch 87 is interconnected by a lead 92 to the lead 58 of the device 26A and the other side or contact 93 of the switch 88 is interconnected by a lead 94 to the lead 59 of the device 26B. The switches 87 and 88 respectively have movable switch blade means 95 and 96 for bridging the contact points 89, 91 and 90, 93 thereof for respectively closing the switches 87 and 88, but automatically return to the open position thereof when manually released.

The operation of the door latching arrangement 20 of this invention will not be described.

Assuming that the door latching arrangement 20 is in the position illustrated in FIG. 1 wherein the end 23 of the lever 21 is in the up position thereof so that the manually operated plunger of the vehicle door latching mechanism is in its up and thus unlocked position and it is desired to move the same to its door locking position, the operator merely closes the lock switch 88 whereby the switch blade 96 bridges the contacts 90 and 93 and thus permits electrical current to flow from the power source lead 86 and lead 59 of the device 26B through the conductive coating 52 of the heater means 50, lead 58, lead 81 and contact 68 to ground through the conductive flange 66 and lead 79 of the lever 21 so that the electrical heater 50 for the device 26B is energized to cause the freon 36' therein adjacent the heater 50 to vaporize almost instantaneously and thereby expand and drive the rolling diaphragm 33 upwardly in the manner illustrated in FIG. 2 whereby the lever 21 pivots in a counterclockwise direction on the pilot pin 22 thereof so that the end 23 of the lever moves to the door lock position as illustrated in FIG. 2.

As the lever 21 is pivoting in a counterclockwise direction about the pivot pin 22 from the position illustrated in FIG. 1 to the position illustrated in FIG. 2, it can be seen that the flange 66 of the lever 21 eventually pivots away from the contact 68 as the end 78 of the rod 70 thereof bottoms out against the conductive sleeve 72 to thereby break the flow of current through the heater 50 of the actuator 26B whereby the device 26B cannot be actuated by the switch 88 when the lever 21 is in the door locking position of FIG. 2. Also, this feature of terminating current flow to the heater 50 before the stroke of the actuated device 26B is completed eliminates the need for circuit breakers for the system 20. Thus, the switch 88 is only operable for moving the lever 21 to its door locking position of FIG. 2. Likewise, when the lever 21 is in its door unlcoked position of FIG. 1, the device 26A cannot be actuated by the door unlock switch 87 since the contact button 67 is away from the conductive flange 66 of the level 21 whereby no current can flow through the heater 50 of the device 26A unless the lever 21 is in its door locked position as FIG. 2.

Thus, when it is desired to unlock the door from the door locked position of FIG. 2 to the door unlocked condition of FIG. 1, the unlock switch 87 is moved to its closed position to thereby permit electrical current to flow through the electrical heater 50 of the device 26a since the contact member 67 is in engagement with the conductive flange 66 of the lever 21, whereby the heater 50 of the device 26A is energized and thereby vaporizes the freon 36' adjacent the same to cause the rolling diaphragm 33 of the device 26A to move upwardly and therby drive the piston member 37 thereof upwardly to pivot the lever 21 in a clockwise direction about the pivot pin 22 from the position illustrated in FIG. 2 to the position illustrated in FIG. 1. Thus, the door lock plunger is moved to its unlocked position and as the lever 21 is moving to the unlocked position illustrated in FIG. 1, the conductive flange 66 of the lever 21 moves out of contact with the contact 67 to break the electrical circuit to the heater means 50 of the device 26A so that the device 26A cannot be again acutated until the lever 21 is in its door locked position of FIG. 2.

Since the door latching member 21 is held in the unlocked position of FIG. 1 or the locked position of FIG. 2 by the conventional detent means of the door latching mechanism, and since the pistons 37 of the devices 26A and 26B are directly interconnected to the latch member 21, stops need not be provided to prevent the piston members 37 from bearing against the diaphragms 33 when the diaphragms 33 are in their down and at rest positions as illustrated in FIG. 1 so that such piston members 37 will not unduly stress such diaphragms 33 in their relaxed or deactuated condition.

Also, should an attempt be made to actuate the device 26A while the actuator 26B still has its medium 36' in an actuated or expanded condition thereof, such as illustrated in FIG. 2, even though once the heater means 50 has been deenergized and the heat sink effect of the surrounding mechanism will almost simultaneously cause the medium 36' to cool in a second or so to permit the actuated diaphragm 33 to move down to its at rest position, suitable overrun springs could be provided between the piston parts 38 of the piston members 37 and their associated bracket means 41 to take up such dual actuation forces as will be apparent in connection with the description of the embodiment of the system of FIGS. 8-11 that will be hereinafter described.

Therefore, it can be seen that the door lock arrangement 20 of this invention permits the door latch member 21 to be remotely controlled by the devices 26A and 26B between its locked position of FIG. 2 and its unlocked position of FIG. 1 by utilizing the relatively small theremally actuated devices 26A and 26B in the manner previously described.

However, it is to be understood that the devices 26A and 26B can be utilized for other motion transmitting purposes than the door latching arrangement 20 previously described.

Another thermally actuated device of this invention is generally indicated by the reference numeral 100 in FIG. 5 and parts thereof similar to the devices 26A and 26B previously described are indicated by like reference numerals followed by the reference letter "C".

As illustrated in FIG. 5, the device 100 includes the piston member 37C and heater means 50C previously described but has a different housing means 101 and rolling diaphragm 122 now to be described.

The housing means 101 comprises a one piece tubular member 102 having opposed ends 103 and 104 and the rolling diaphragm 122 has a tubular portion 105 extending down along the internal peripheral surface 106 of the housing member 102 from the fold 107 thereof to be crimped by the end 104 of the housing member 102 around an annular flange 108 of the end closure member 34C of the heater means 50C whereby not only does the tubular portion 105 of the rolling diaphragm 122 fluid seal the housing member 102 to the end closure 34C, but also the tubular portion 105 of the rolling diaphragm 122 together with the end closure 34C completely borders the chamber 36C for the thermally responsive medium 36'C with electrically insulating material except for the leads 58C and 59C so that the lead 59C could be disposed externally to the tubular member 51C as the same would be completely insulated from the casing 102 by the rolling diaphragm 122 and no short circuiting would take place therebetween.

For example, another thermally actuated device of this invention is generally indicated by the reference numeral 110 in FIGS. 6 and 7 and parts thereof similar to the device 100 are indicated by like reference numerals followed by the letter "D".

As illustrated in FIG. 6, the actuator 110 is provided with the tubular portion 105D of the rolling diaphragm 122D extending down along the internal peripheral surface 106D of the one piece tubular housing member 102D in the same manner as provided for the actuator 100 except that the tubular portion 105D of the rolling diaphragm 122D terminates in an outwardly directed annular flange 111 and the lower end of the tubular housing member 102D likewise terminates in an outwardly directed annular flange 112 complimentary thereto. A disc-like end closure member 113 of electrically insulating material cooperates with the flange 111 of the rolling diaphragm 122D to sandwich the leads 58D and 59D therebetween so that the leads 58D and 59D can project outwardly therefrom for lead attachment purposes while being compressed between the flange 111 of the rolling diaphragm 122D and the end closure 113 by a clip member 114 disposed against the end closure 113 and having bent over fingers or annular flange 115 gripping against the flange 112 of the housing member 102C in the manner illustrated in FIG. 6. The flange 115 can have suitable openings passing therethrough through which the leads 58D and 59D can project or the flange 115 can comprise a plurality of fingers between which the leads 58D and 59D can project.

If desired, the annular flange 111 of the rolling diaphragm 122D and the end closure 113 can have suitable grooves 116 and 117 formed therein in the manner illustrated in FIG. 7 to facilitate the assembly of the leads 58D and 59D therebetween if the material for the flange 111 and end closure 113 is not sufficiently resilient to completely capture the leads 58D and 59D therebetween when the clip 114 secures the same together.

While the door latching arrangement 20 previously described is of the two lead type and has the pistons 37 of the thermally actuated devices 26A and 26B directly interconnected to the latch member 21, it is to be understood that the door latching system of this invention could be so constructed and arranged that a one wire or one lead electrical circuit could be provided which would be more compatible for an automobile door latching system and/or the door latching arrangement could be such that the pistons of the thermally actuated devices could merely provide a pushing function on the door latch member without being directly interconnected thereto.

For example, such a door latching system of this invention is generally indicated by the reference numeral 20E in FIGS. 8-10 and parts thereof similar to the system 20 previously described are indicated by like reference numerals followed by the reference letter "E".

As illustrated in FIG. 8, the system 20E includes two like thermally actuated devices 26E and 26E' with the devices 26E and 26E' being identical in structure and thereby having the same reference numeral and letter for like parts thereof.

Each actuator 26E and 26E' has the terminal 58E interconnected to the conductive coating 52E of the heater means 50E by conductive clip means 56E previously described. However, the upper end of the conductive coating 52E of each heater 50 is interconnected to the conductive housing means 27E by a conductive cap 150 disposed on the upper end of the tubular member 51E and held thereto by spring fingers 151 of the cap member 150 illustrated in FIGS. 8 and 11, the cap member 150 having a large resilient finger 152 thereof extending outwardly therefrom and bearing against the insdie surface of the housing means 27E to electrically interconnnect the conductive coating 52E to the housing means 27E. In this manner, the housing means 27E is interconnected to ground through the frame structure of the automobile in a conventional manner as the frame structure of the automobile is normally considered as ground for the electrcial system for the automobile, such ground circuit being schematically illustrated by the ground leads 153 in FIG. 8.

The projecting portion 38E of each piston 37E of the devices 26E and 26E' is interconnected to one leg 154 of a U-shaped overrun spring member 155 having the other leg 156 thereof provided with a bumper means 157 for bumping aagainst the latch member 21E to cause the same to pivot about its pivot point 22E for door locking and unlocking means in a manner hereinafter described.

Because the pistons 37E of the actuators 26E and 26E' are not directly interconnected to the door latch member 21E, the same normally are disposed in their down position as illustrated in FIG. 8 and in order to prevent the weight of such piston member 37E from unduly stressing the diaphragms 33E in their relaxed condition, suitable stationary stop means 158 can be carried by the frame structure of the vehicle so that the legs 154 of the overrun springs 155 will bear against the same when the devices 26E and 26E' are in their deactuated condition of FIG. 8 so that the stop means 158 will bear the weight of the piston means 37E and not the diaphragms 33E.

A pair of electrical switches 159 and 160 are carried by the frame means of the vehicle so as to have the respective plungers 161 and 162 thereof engaged by the latch member 21E in such a manner that the plunger 161 of the switch 159 is only the closed position thereof when the latch member 21E is in its door unlatched position of FIG. 8 and only during part of the time that the door latch member 21E is moving from the door unlatched position of FIG. 8 towards the door latching position of FIG. 9. Similarly, the plunger 162 of the switch 160 is only moved to its closed position when the latch member 21E is in its door latched position of FIG. 9 or during part of the travel from the door latched position of FIG. 9 toward the door unlatched position of FIG. 8 for a purpose as will be apparent hereinafter.

The switch 159 when closed by its plunger 161 is adapted to interconnect a lead 163 with a lead 164, the lead 163 being interconnected to the contact 93E of the door latching switch 88E and the lead 164 being interconnected to the terminal 58E of the device 26E. Thus, since the contact 90E of the door latching switch 88E is interconnected by the lead 86E to the side 85E of the vehicle battery 82E, current is adapted to flow through the conductive coating 52E of the heater means 50 of the device 26E only when the switch 88E is moved to its closed position and the switch 159 is in its closed position whereby the flow of current is from the battery 82E, lead 86E, lead 163, lead 164, terminal 58E, conductive coating 52E, end cap 150 and actuator housing 27E to ground by the lead 153 for causing the device 26E to drive the piston 37E upwardly in the manner previously described by vaporizing the freon 36'E adjacent the heater 50E as illustrated in FIG. 9. Thus, the bumper 157 on the U-shaped spring 155 is adapted to engage against the latch member 21E and pivot the same in a counterclockwise direction to move the same from the latching position of FIG. 8 to the door unlatching position of FIG. 9. During such upward movement of the piston 37E, it can be seen that the latch member 21E will move away from the plunger 161 of the switch 159 to thereby terminate the flow of current to the heater means 50E of the actuator 26E before the full stroke of the piston 37E is reached whereby once the actuator 26E has reached the full stroke position of FIG. 9, the heat sink arrangement of the vehicle framing means sufficiently cools the medium 36'E in the chamber 36E to permit the diaphragm 33E to move back downwardly to its deactuated position of FIG. 8 and the piston 37E will follow therewith until the leg 154 of the overrun spring 155 engages against the stop 158 as illustrated in FIG. 8.

With the latch member 21E now in the door latching position of FIG. 9, it can be seen that the door latch member 21E is now engaging the plunger 162 of the switch 160 to interconnect a lead 165 with a lead 166, the lead 165 being interconnected to the contact 91E of the door unlatching switch 87E and the lead 166 being interconnected to the terminal 58E of the actuator 26E'.

Thus, when it is desired to move the latch member 21E from the door latching position of FIG. 9 back to the door unlatching position of FIG. 8, the switch 87E is closed and the heater means 50E of the device 26E' is now energized in the manner previously described to drive the piston 37E thereof upwardly to engage its bumper 157 against the member 21E and pivot the same in a clockwise direction about the pivot 22E to move the same from the latched position of FIG. 9 to the door unlatched position of FIG. 8. During such clockwise movement of the door latch member 21E, the switch 160 is opened so that the medium 36'E therein can again be liquidified through the heat sink arrangement of the door frame means in a matter of a second or so after the termination of the operation of the heater 50E whereby the diaphragm 33E and piston 37E of the actuator 26E' can again return to its relaxed position of FIG. 8 with the overrun spring 155 being held by the stop 158 as illustrated in FIG. 8.

In those extremely rare cases where a person has caused an actuation of the device 26E or 26E' and before the medium 36'E therein has been reliquified, the person causes the other device 26E' or 26E to be actuated so that both devices 26E and 26E' are operating against the lever 21E in a manner to fight against each other, it can be seen that the overrun springs 155 will have the legs 154 and 156 thereof compressed toward each other in the manner illustrated in FIG. 10 to take up such dual expansion of the medium 36'E of the devices 26E and 26E' so that there will be no adverse forces imposed on the devices 26E and 26E' that would harm the same. Thus, when the devices 26E and 26E' are fighting against each other in the manner illustrated in FIG. 10, the door latch member 21E is out of contact with both plungers 161 and 162 of the switches 159 and 160 so that the flow current to the heater means 50E thereof is terminatted whereby the pistons 37E will subsequently move to their deactuated positions and the detent means for the door latching means will cause the door latch member 21E to move to either the latching or unlatching position thereof as the case may be.

Thus, it can be seen that the door latching arrangement 20E of FIGS. 8-11 provides a one wire or one lead electrical system suitable for automobile use and the same readily permits both devices to be actuated without adverse affect on the door latching system, the devices not being directly interconnected to the door latch member 21E, but being operatively associated therewith.

In order to insure that the medium 36'E in the devices 26E and 26E' is readily accessible to the interior of the tubular heater means 50E, the end caps 150 for interconnecting the upper end of the coatings 52E to the housing means 27E can have suitable openings provided therein as illustrated by the reference numeral 167 in FIG. 11 with the openings 167 being formed by the formation of the tang means 151 of the cap 150, if desired.

Further, such caps 150 can be further modified to permit an internal lead to be inteconnected to the upper end of the conductive coating 52E in the manner illustrated in FIG. 12 wherein the internal lead 59E is electrically interconnected by a resilient finger 168 of the end cap 150 bearing against the same with the end cap 150 being resiliently secured on the upper end of the tubular heater 50E by the spring fingers 151 in the manner previously described.

As previously stated, it may be desired to maintain all of the embodiments of the devices 26 of this invention in a substantially vertical position thereof as illustrated in order to insure proper operation thereof because it may be found that the heater means 50 of the devices 26 must remain completely submerged in the medium 36' during heating thereof to prevent the heater means 50 from getting too hot and perhaps burning out. Also, it may be found that it is desired to have the heater means 50 each supported in a raised relation to the bottoms of the respective devices 26 so that the medium 36' is free to flow through the centers of the heater means 50 for better heat transfer to the medium 36' as well as for insuring that the heater means 50 will not become too hot through the improved circulation of the medium 36' relative thereto.

Therefore, it can be seen that not only have improved thermally actuated devices been provided by this invention over the form of the devices set forth in the aforementioned U.S. patents, but also this invention provides an improved remoted controlled door locking arrangement or the like.

While the forms of the invention now preferred have been described and illustrated as required by the patent statute, it is to be understood that other forms can be utilized and still come within the scope of the appended claims.

Claims

What is claimed is:

1. In a thermally actuated device comprising a housing means having a chamber provided with a thermally responsive means and being defined in part by a motion transmitting member movable relative to said housing means in response to expansion or contraction of said thermally responsive means, the improvement of an electrical heater means disposed in said chamber for heating said thermally responsive means when said heater is energized, said heater providing substantially a uniform thermal flux to said thermally responsive means throughout substantially the entire surface area of said heater, said heater comprising a member of electrical insulating material having a conductive coating on the exterior surface thereof that provides an electrical resistance heater means when electrical current passes through the same.

2. In a thermally actuated device comprising a housing means having a chamber provided with a thermally responsive means and being defined in part by a motion transmitting member movable relative to said housing means in response to expansion or contraction of said thermally responsive means, the improvement of an electrical heater means disposed in said chamber for heating said thermally responsive means when said heater is energized, said heater providing substantially a uniform thermal flux to said thermally responsive means throughout substantially the entire surface area of said heater, said heater comprising a cylindrical member of electrical insulating material having a conductive coating on the exterior surface thereof that provides an electrical resistance heater means when electrical current passes through the same.

3. In a thermally actuated device as set forth in claim 2, said cylindrical member being tubular and having opposed ends with said conductive coating extending substantially to said ends.

4. In a thermally actuated device as set forth in claim 3, a pair of electrical leads carried by said housing means and respectively being electrically interconnected to said conductive coating at said ends of said cylindrical member.

5. In a thermally actuated device as set forth in calim 4, one of said leads extending through said tubular member from one end thereof to the other end thereof and being electrically interconnected to its respective end of said conductive coating exterior of the respective end of said tubular member.

6. In a thermally actuated device comprising a housing means having a chamber provided with a thermally responsive means and being defined in part by a motion transmitting member movable relative to said housing means in response to expansion or contraction of said thermally responsive means, the improvement of an electrical heater means disposed in said chamber for heating said thermally responsive means when said heater is energized, said heater providing substantially a uniform thermal flux to said thermally responsive means throughout substantially the entire surface area of said heater, said motion transmitting member comprising a flexible diaphragm of the rolling type, said housing means comprising a tubular member having opposed open ends, said diaphragm closing off said tubular member between said ends thereof and having a tubular portion extending along the inside surface of said tubular member to one end thereof, and a closure member closing said one end of said tubular member and cooperating with said tubular portion of said diaphragm to seal said closure member to said one end of said tubular member whereby said chamber is defined by and substantially completely bordered by said diaphragm and said closure member.

7. In a thermally actuated device comprising a housing meanas having a chamber provided with a thermally responsive means and being defined in part by a motion transmitting member movable relative to said housing means in response to expansion or contraction of said thermally responsive means, the improvement of an electrical heater means disposed in said chamber for heating said thermally responsive means when said heater is energized, said heater providing substantially a uniform thermal flux to said thermally responsive means throughout substantially the entire surface area of said heater, said motion transmitting member comprising a flexible diaphragm of the rolling type, said housing means comprising a tubular member having opposed open ends, said diaphragm closing off said tubular member between said ends thereof and having a tubular portion extending along the inside surface of said tubular member to one end thereof, and a closure member closing said one end of said tubular member and cooperating with said tubular portion of said diaphragm to seal said closure member of said one end of said tubular member whereby said chamber is defined by said diaphragm and said closure member, said closure member and said diaphragm being formed of electrically insulating material whereby said chamber is completely bordered by electrically insulating material.

8. In a thermally actuated device as set forth in claim 7, a piston member disposed in said tubular member and having opposed ends, one end of said piston member being engageable with said diaphragm and the other end thereof projecting out of the other end of said tubular member.

9. In a thermally actuated device as set forth in claim 8, said heater comprising a cylindrical member having a longitudinal axis extending generally in the same direction as the longitudinal axis of said tubular member and said piston member.

10. In a thermally actuated device comprising a housing means having a chamber provided with a thermally responsive means and being defined in part by a motion transmitting member movable relative to said housing means in response to expansion or contraction of said thermally responsive means that is adapted to be heated by an electrical heater means that is disposed in said chamber for heating said thermally responsive means when said heater is energized, the improvement wherein said chamber is substantially completely bordered by solid electrically insulating material the majority of which comprises a rolling diaphragm that comprises said motion transmitting member.

11. In a thermally actuated device comprising a housing means having a chamber provided with a thermally responsive means and being defined in part by a motion transmitting member movable relative to said housing means in response to expansion or contraction of said thermally responsive means that is adapted to be heated by an electrical heater means that is disposed in said chamber for heating said thermally responsive means when said heater is energized, the improvement wherein said chamber is substantially completely bordered by electrically insulating material, said motion transmitting member comprising a flexible diaphragm of the rolling type and formed of electrically insulating material, said housing means comprising a tubular member having opposed open ends, said diaphragm closing off said tubular member between said ends thereof and having a tubular portion extending along the inside surface of said tubular member to one end thereof, and a closure member of electrically insulating material closing said one end of said tubular member and cooperating with said tubular portion of said diaphragm to seal said closure member to said one end of said tubular member whereby said chamber is defined by said diaphragm and said closure member and is thereby substantially completely bordered by electrically insulating material.

12. In a thermally actuated device as set forth in claim 11, a piston member disposed in said tubular member and having opposed ends, one end of said piston member being engageable with said diaphragm and the other end thereof projecting out of the other end of said tubular member.

13. In a thermally actuated device as set forth in claim 12, said heater comprising a cylindrical member having a longitudinal axis extending generally in the same direction as the longitudinal axis of tubular member and said piston member.

14. In a thermally actuated device as set forth in claim 11, said heater means having a pair of leads extending between said tubular portion of said diaphragm and said closure member to the exterior of said housing means for lead attachment purposes.

15. In a remote controlled door latching arrangement for a vehicle and the like wherein a latch member is to be moved between a locking position thereof and unlocking position thereof, the improvement comprising a pair of thermally actuated devices respectively and operatively associated with said latch member, one of said devices when thermally actuated causing movement of said latch member to its locking position, the other of said devices when thermally actuated causing movement of said latch member to its unlocking position, each device comprising a housing means having a chamber provided with a thermally responsive means and being defined in part by a motion transmitting member movable relative to said housing means in response to expansion or contraction of said thermally responsive means that is adapted to be heated by an electrical heater means that is disposed in said chamber for heating said thermally responsive means when said heater is eneragized, said motion transmitting member being operatively associated with said latch member, and an electrical system for said devices, said system having means for permitting only said one device to be thermally actuated by energizing said heater thereof when said latch member is in its unlocking position and said other device to be thermally actuated by energizing said heater thereof when said latch member is in its locking position, said means of said system causing only the energizing of said heater of said one device when said latch member is in its unlocking position and only during part of the movement of said latch member to its locking position and causing only the energizing of said heater of said other device when said latch member is in its locking position and only during part of the movement of said latch member to its unlocking position.