Setup-setback thermostat having a simple setup-setback visual indicator

Abstract: A thermostat (5) has a simple to see and use setup-setback visual indicator (22,23). One temperature control (10) is used to set temperature while a second temperature control (15) is used to activate the setup or setback. The second temperature control (15) is offset from the body (25) of the thermostat in the setup or setback mode to provide simple visual indication of the setup or setback.

Description: This invention relates generally to building temperature controls and more specifically to setback thermostats. In homes with non-automatic setback thermostats, it is normal for the homeowner to set the temperature down at night and up again in the morning. This is done by altering the setpoint of the device. The repeatability of the actual temperature set depends upon the persons visual acuity and manual dexterity. In addition, no indication of the setback is readily apparent. CH-A 665 705 corresponding to FR-A 25 75 843 shows a temperature controller comprising the features of the preamble of claim 1. First temperature setting means in the form of a potentiometer is used for selecting a desired temperature and second temperature setting means is a mode selector for switching between three modes of operation, namely clock-controlled operation, permanent heating, and setback operation. Both temperature setting means are provided at the front surface of the controller housing together with an indicator of a temperature sensor. US-A 4 355 347 describes a temperature control device including thermostatic control means for automatically controlling the temperature of a location. Means for setting a predetermined temperature includes an elongated temperature scale and a setpoint. The scale and setpoint are movable with respect to each other. A single temperature scale is provided with different colors for facilitating reading by persons with impaired vision who cannot readily observe numbers on a temperature scale. It is an object of the present invention to provide a thermostat having a simple setback and setup indication. This object is achieved by the invention as characterized in claim 1. Preferred embodiments and details are described in the dependent claims. A slide for setting a desired temperature is formed within an assembly used for putting the thermostat into the setup or setback mode. A flange adjacent to the assembly and hidden by the assembly when the thermostat is in a normal operating mode, can be colored to contrast with the assembly to provide a visual indication of setup or setback when the assembly is moved. In a first embodiment, two potentiometers are adjusted by the slide and assembly upon movement of the slide and assembly to adjust the temperature setpoint. In a second embodiment, two ramps are placed between a temperature sensitive element and a switch. One ramp is continuous while the other ramp has at least two flat regions along one side. By arranging the ramps, the temperature sensitive element and the switch in a desired way, movement of the ramps affects the temperature at which the switch is actuated. BRIEF DESCRIPTION OF THE DRAWING Figure 1A is a front perspective view of the exterior of the thermostat in a normal operating mode. Figure 1B is a perspective view of the thermostat in a setback mode. Figure 1C is a perspective view of the thermostat in a setup mode. Figure 2A is a partial internal view of the first and second temperature setting and adjusting means in an electronic embodiment of the thermostat. Figure 2B is a block diagram of the electronic embodiment of the thermostat. Figure 3A is a partial internal view of the first and second temperature setting and adjusting means of a mechanical embodiment of the present invention. Figures 3B, 3C and 3D are top views of the mechanical embodiment excluding the temperature setting means. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to Figure 1A, thereshown is the exterior of thermostat 5 of the present invention. The thermostat includes a first temperature setting means 10, second temperature setting means 15, flange 20 and cover 25. The cover may include a temperature scale, setpoint indicator 26 and temperature indicator 27. The thermostat is capable of turning on a heating or cooling system when the setpoint of the thermostat does not match the temperature sensed by the thermostat in a manner well known in the art. The setpoint is adjusted by moving first temperature setting means 10, which in this case is a slide, in the channel 16 formed in the second temperature setting means 15 until setpoint indicator 26 indicates a desired temperature. More on the operation of the thermostat will be described below. As was stated before, at night or when the controlled space is to be unoccupied for a long period, it is desirable to reduce the energy used to maintain space temperature. This may be accomplished by lowering the setpoint when in a heating mode (setback) or raising the temperature when in a cooling mode (setup). The present invention provides a simple to make and simple to use setback or setup indication means as shown in Figures 1B and 1C. Second temperature setting means 15 is movable with respect to cover 25 and flange 20 to put the thermostat into either setback or setup mode. As an example, the position of second temperature setting means in Figure 1B could be indicative of the thermostat being in setback mode. Then, Figure 1C would be indicative of setup mode. It is obvious however, that these positions could also be reversed. Flange 20 may be modified at regions 22 and 23 so that these regions when exposed due to movement of second temperature setting means 15 easily indicate whether the thermostat is in setback or setup mode. For example, region 22 could be colored blue to indicate setback while region 23 could be colored red to indicate setup. While the exterior of the inventive thermostat 5 has been described, more details of the internal operation of the thermostat is provided with reference to Figures 2A through 3D. In Figures 2A and 2B, and electronic version of the inventive thermostat is shown. First temperature setting means 10, also known as a slide, moves in channel 16. Slide 10 contacts first temperature adjustment means 30, which in this case is a potentiometer. Movement of the slide causes a change in the resistance of the potentiometer. In this case, serrated edge 12 of slide 10 contacts gear wheel 35 to change the resistance. A linear potentiometer could be used equally as well with some modification to slide 10. Second temperature setting means 15, also known as an assembly, is connected to second temperature adjustment means 40. The second temperature adjustment means may be a potentiometer. The assembly has a serrated portion 17 which contacts a gear wheel 45 to modify the resistance of the second potentiometer. Again, a linear potentiometer could be used in place of the shown potentiometer with some modifications to assembly 15. In Figure 2B, the electrical circuit of the electronic embodiment is shown. A temperature sensing means 50 produces an electrical signal proportional to a sensed temperature and is connected to comparators 60, 65. The two potentiometers are connected in series and then joined to the comparators. Switch 55 determines whether the thermostat is in a heating or cooling mode. The comparators produce a signal depending upon relative signal levels to operate either the furnace or the air conditioner. Turning now to Figure 3A, thereshown is a portion of a mechanical embodiment of the present invention in a front perspective view. First temperature setting means (slide) 10' and second temperature setting means (assembly) 15' are the same as in the first embodiment. The slide is connected via first rod 66 to first temperature adjustment means 30', also known as a first ramp. The first ramp 30' has a sloped region 31 extending from first end 32 to second end 33. Movement of slide 10 causes movement of first ramp 30. Assembly 15' is connected via second rod 65 to second temperature adjustment means 40', also known as second ramp. Second ramp 40' has three flat regions 42, 43 and 44 separated by sloped regions 46 and 47. Movement of assembly 15' causes movement of second ramp 40'. Note that the three level second ramp 40' is necessary if a setup and setback are both desired in the same thermostat. Otherwise, only two levels are necessary. Looking now at Figures 3B, 3C and 3D, thereshown is a top view of the second embodiment without the first and second temperature setting means and connecting rods. Wall 8 contains all of the pieces of the thermostat. Temperature sensing means 70 is connected to wall 8 and expands as the temperature rises while contracting when the temperature falls. Temperature sensing means 70 may be a bimetal or a filled element and is connected to second ramp 40' by rod 71. Next, first ramp 30' is slidably connected to second ramp 40'. Lastly, rod 72 connects first ramp 30' to switch 80. Switch 80 is operated by moving actuator 81 axially. In Figure 3D, the thermostat is shown in normal operation. Note that second ramp 40' is positioned so that rod 71 rests on the middle level 43 of the second ramp. In Figure 3B, the thermostat is in setback mode with the second ramp being positioned to be in contact with rod 71 at high level 44. Lastly, in Figure 3C second ramp 40' is positioned to be in a setup mode with the second ramp contacting rod 71 at low level 42.

Claims: A thermostat for controlling room temperature comprising: a) a thermostat housing (25); b) first temperature setting means (10, 10') movable along a first plane parallel to the mounting surface of said housing, for selecting a first desired temperature; c) second temperature setting means (15, 15') movable parallel to the mounting surface of said housing between first and second extreme positions and having a third intermediate position, for modifying said desired temperature by a predetermined amount; d) temperature adjusting means (30, 40; 30', 40') connected to said first and second temperature setting means (10, 10'; 15, 15'); e) temperature sensing means (50, 70) connected to said temperature adjusting means (30, 40; 30', 40'), said temperature sensing means producing a first signal if the room temperature is greater than said desired temperature and a second signal otherwise; characterized in that f) said thermostat housing (25) is carried by a mounting flange (20) extending parallel to the front surface of said housing; g) said second temperature setting means (15, 15') is movable with respect to said first temperature setting means (10, 10') and with respect to the top surface of said housing (25) in a second plane extending substantially in parallel to said top surface; and h) said second temperature setting means (15, 15') is movable in relation to said flange (20) such that it covers said flange when in its intermediate position, but parts (23, 22) of said flange (20) become visible at its left or right side, when said second temperature setting means (15, 15') is in its first or second extreme position, respectively. The thermostat of claim 1, characterized in that a) said second temperature setting means (15) has a first color; and b) said flange (20) is of a second color different than said first color at a position visible when said second temperature setting means (15) is at said first extreme position. The thermostat of claim 2, characterized in that said flange (20) is of a third color different than said first and second colors at a position visible when said second temperature setting means (15) is at said second extreme position. The thermostat of claim 1, 2 or 3, characterized in that said temperature adjustment means comprises: a) a first variable impedance (30) connected to said first temperature setting means (10) and electrically connected to said temperature sensing means (50), said first variable impedance varying in response to movement of said first temperature setting means (10); b) a second variable impedance (40) connected to said second temperature setting means (15) and electrically connected to said first variable impedance (30) and said temperature sensing means (50), said second variable impedance varying in response to movement of said second temperature setting means (15); whereat c) said temperature adjusting means (30) adjusts said second desired temperature in response to changes in impedance in said first (30) and second (40) variable impedances. The thermostat of claim 4, characterized in that said first and second variable impedances (30,40) are first and second potentiometers, said first potentiometer having a greater range of resistance than said second potentiometer. The thermostat of claim 1, 2 or 3, characterized in that a) said temperature sensing means is a thermally expansive element, (70) which expands due to a temperature change in a first direction and contracts due to a temperature change in a second direction; b) said first temperature adjusting means is comprised of a continuous ramp (30'); c) said second temperature adjusting means is comprised of a ramp (40') having first and second ends (32,33) and a flat region formed at said second end, said second temperature setting means (15) being connected to said first temperature setting means (10); d) said temperature adjustment means is comprised of a rod (71) connected to said first and second temperature adjustment means and said temperature sensing means (70); and e) said thermostat further comprises a pair of spaced electrical contacts, one of said contacts being movable and one of said contacts being fixed, said movable contact being connected to said temperature adjustment means and said temperature sensing element, said movable contact being moved by expansion and contraction of said temperature sensing element and by movement of said first and second temperature setting means (30',40'). The thermostat of claim 6, characterized by a) a first lever (66) connecting said first temperature setting means (10) to said continous ramp (30'); and b) a second lever (65) connecting said second temperature setting means (15) to said stepped ramp (40'), such that both ramps can be adjusted independently.

Inventors: BRUETON STEPHEN J, BRUETON, STEPHEN J.
Applicants: HONEYWELL LIMITED HONEYWELL LI, HONEYWELL LIMITED-HONEYWELL LIMITEE
Application year: 1992
Main classification: G05D23
IPC codes: H01H37, G05D23