Method of and apparatus for locking a powered movable furniture item

[0002] This application claims the benefit of prior filed co-pending U.S. provisional patent application No. 60/203,168, filed on May 8, 2000.

[0003] The invention relates to a method of and apparatus for locking a feature of a powered furniture item, and particularly to an electric lockout for selectively preventing actuation of one or more features of the furniture item.

[0004] It is known to provide furniture items with various electrically powered features or apparatus. Examples of such powered apparatus include, but are not limited to:

[0005] 1) one or more motors, or a hydraulic system connected to a stationary lift and/or recline chair, dental or medical chair, sofa, love seat, bed, futon, etc;

[0006] 2) one or more heater elements (either temporarily or permanently) connected to a stationary lift and/or recline chair, dental or medical chair, sofa, love seat, bed, futon, etc;

[0007] 3) one or more vibrating elements (either temporarily or permanently) connected to a stationary lift and/or recline chair, dental or medical chair, sofa, love seat, bed, futon, etc; or

[0008] 4) an air bladder system connected to a stationary lift and/or recline chair, dental or medical chair, sofa, love seat, bed, futon, etc;

[0009] An example of a system having one or more vibrating elements is shown in U.S. Pat. No. 5,730,707, entitled POWER SUPPLY FOR VIBRATING FURNITURE, which is incorporated herein by reference. An example of a system having a hydraulic lift system and at least one motor is shown in U.S. Pat. No. 5,467,002, entitled ADJUSTABLE CHAIR HAVING PROGRAMMABLE CONTROL SWITCHES, which is incorporated herein by reference.

[0010] One example of a furniture item with a powered apparatus is a power-lift chair. Power-lift chairs help elderly, disabled or similarly situated individuals get into and out of the lift chair. For example, when the user wishes to sit in the lift chair, the user operates a controller to raise and rotate (hereinafter, referred to as “raise”) the lift chair from a “normal” state. The term “normal” state refers to the normal resting position, i.e., the lift chair is not in the raised position. The user raises the lift chair to the desired height and rotation position thereby allowing the user to readily sit in the lift chair. By raising the lift chair, the user is allowed easier access to the chair. After the user sits in the lift chair, the user operates the controller to return the chair to the normal state. That is, the lift chair lowers and reverses the direction of rotation (hereinafter, referred to as “lowering”) until it returns to the normal state. Similarly, if the user is sitting in the chair while the chair is in the normal state, the user can raise the lift chair thereby allowing the user to easily get out of the lift chair. The lift chair uses one or more electrical motors to raise and lower the chair.

[0011] Another example of a furniture item with a powered apparatus is a power-recline chair. Power-recline chairs allow a user to controllably recline the power-recline chair. As compared with a manual recline chair, the power-recline chair allows greater control and stability of the chair while reclining the chair. For example, the user operates a controller such that the power-recline chair moves to a desired reclined position. If the user is already in a reclined position, the user operates the controller until the chair returns to the upright position. Power-recline chairs utilize one or more electrical motors to move the chair between the recline and upright positions.

[0012] The functional utility of power-lift chairs and power-recline chairs can be combined into the same chair. That is, a lift and power-recline chair combines the features of the lift chair and the power-recline chair.

[0013] In some circumstances, it is desirable to prevent unauthorized use of the powered apparatus of the furniture item. For example, children should not be allowed to operate such items without proper supervision and/or training.

[0014] Accordingly, the invention provides a powered furniture item having an electronic lockout for preventing unauthorized use of the item. The powered furniture item has an unlocked state and a locked state. In the unlocked state, the item responds to user initiated commands generated by a controller. In the locked state, either the item does not respond to commands generated by the controller, or the controller is precluded from generating such commands.

[0015] In one embodiment, the invention provides a powered movable chair including a frame, a powered apparatus mounted to the frame to power the movable chair, and a controller including a control circuit coupled to the powered apparatus. The control circuit includes at least two switches for selectively controlling a change of the status of the powered apparatus between a locked state and an unlocked state. The control circuit is operable to generate an output signal allowing control of the powered apparatus in the unlocked state and preventing control of the powered apparatus in the locked state. The control circuit is further operable to change from the unlocked state to the locked state when a user operates only a first switch of the at least two switches, and to change from the locked state to the unlocked state when a user operates two switches of the at least two switches.

[0016] The invention further provides a method of controlling a powered movable furniture item (e.g., a chair). The method includes the acts of changing from the unlocked state to the locked state when the user operates only a first switch of the at least two switches, and changing from the locked state to the unlocked state when the user operates two switches of the at least two switches.

[0017] In the prior art, it is known to change a powered furniture item from an unlocked state to a locked state. For example, in U.S. Pat. No. 5,467,002, a user can lock the adjustable chair by actuating multiple switches concurrently. However, the powered furniture item of the invention includes a control circuit operable to change from the unlocked state to the locked state when a user operates a single switch only. By requiring the user to operate one and only one switch to lock the furniture item, the control circuit of the invention is simplified over control circuits of prior art furniture items. The control circuit of the invention reduces the number of parts and has a more simplified software program. In situations where the furniture item needs to lock out quickly, activating one and only one switch is a more effective and simpler method to lock the furniture item. Additionally, by requiring the user to operate two switches to unlock the control circuit, the control circuit of the invention cannot be unlocked haphazardly.

[0018] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.

[0019] FIG. 1ais a perspective view of a power-assist chair capable of raising.

[0020] FIG. 1bis a perspective view of a power-assist chair capable of reclining.

[0021] FIG. 2 is a schematic representation of the controller of the power-assist chair.

[0022] FIGS. 3-9 are top views of controller wands for the power-assist chair.

[0023] Before any embodiments of the invention are explained in full detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including”, “comprising”, “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0024] A power-assist chair 10 of the invention is shown in FIGS. 1aand 1b. Although the description below is for a power-assist chair, other furniture items having a powered apparatus may incorporate the invention. Example furniture items include substantially stationary chairs (e.g., a medical chair, a dental chair, a lift and/or recline chair, a sofa, a love seat, and similar furniture items) or sleeping furniture items (bed, futon, and similar furniture items). The power-assist chair 10 includes a frame 15, one or more powered apparatus mounted to the frame, and a control circuit 20 (FIG. 2). In the embodiment shown, the one or more powered apparatus includes a first motor 25 (FIG. 1a) coupled with a first mechanism (not shown) for raising and lowering the power-assist chair 10 as is known in the art, and a second motor 30 (FIG. 1b) coupled with a second mechanism (not shown) for reclining and returning the power-assist chair 10 as is known in the art. Other power apparatus may be used within the power-assist chair, including a hydraulic system, a heating system, a vibrating element, an air bladder system and similar apparatus.

[0025] As shown in FIG. 2, the control circuit 20 includes a motor-control circuit 35, a visual-display circuit 40, a user-entry circuit 45, a microprocessor 50, and memory 55. The motor-control circuit 35 is mounted to the frame 15, and the visual-display circuit 40, the user-entry circuit 45, the microprocessor 50, and memory 55 are mounted within a hand-held controller. Although the embodiment shown in FIG. 2 includes a microprocessor 50 and memory 55, the control circuit may be implemented with or include any one, all or combination of integrated circuitry, a microprocessor and memory, and/or discrete circuitry. Example hand-held controllers 58 are shown in FIGS. 3-8. Other arrangements are possible including the motor-control circuit 35 being mounted to the frame or the motor-control circuit 35 being mounted within a controller (not shown).

[0026] The motor-control circuit 35 includes circuitry that receives control signals from the microprocessor 50, and activates and/or deactivates the first and second motors 25 and 30. An example motor-control circuit includes two H-bridge circuits. Other motor-control circuits may be used as is known in the art, and other power-apparatus-control circuits may be used depending on the attached power apparatus.

[0027] The visual-display circuit 40 provides a visual interface between the control circuit 20 and the user (not shown). The visual display circuit 40 receives signals from the microprocessor 50 and generates a visual output to the user. For example, the visual display circuit 40 includes a plurality of LEDs (shown in FIGS. 3-8) informing the user that the chair is in a locked state or an unlocked state. Other visual output devices (e.g., incandescent bulbs, LCD screens, etc.) may be used and other information may be conveyed from the control circuit 20 to the user.

[0028] The user entry circuit 45 provides an interface between the user and the control circuit 20, and allows the user to enter inputs or commands into the control circuit 20. The user entry circuit 45 includes a plurality of switches (e.g., push-button switches) that are actuated in response to the user pressing respective switches 65, 70, 75, 80 and 85 (best shown in FIGS. 3-11). Actuation of the switches 65, 70, 75, 80 and 85 cause the microprocessor 50 to provide control signals to the one or more power apparatus during the unlocked state. In one embodiment of the invention (see for example FIGS. 4, 5 and 6), the plurality of switches includes a dedicated disable or “lock” switch 70 (also shown in FIGS. 4, 5 and 6) that results in the control circuit 20 changing from an unlocked state to a locked state. In a second embodiment of the invention (see for example FIGS. 3, 7 and 8), the plurality of switches includes a switch 75 (also shown in FIGS. 3, 7 and 8) that may perform multiple functions where one of the functions results in the control circuit 20 changing from the unlocked state to the locked state. For either the first and second embodiments, the switches 70 or 75 include one and only one switch that results in the control circuit changing from an unlocked state to a locked state. The single “lock” switch 70 and the dual function switch 75 may also be referred to as a first select switch. For the embodiments shown in FIGS. 3-8, the plurality of switches includes switches 80 and 85. The switches 80 and 85 may be either dedicated or non-dedicated switches, actuation of which changes the control circuit 20 from a locked state to an unlocked state. The two switches 80 and 85 may be referred to as second and third select switches, respectively.

[0029] Another embodiment of the hand-held controller 58 is shown in FIG. 9. As shown in FIG. 9, the controller 58 includes at least two switches 90 and 95 for selectively controlling a change of the status of the powered apparatus between a locked state and an unlocked state. When a user operates only one 90 of the at least two switches 90 and 95, the control circuit 20 changes from the unlocked state to the locked state. When a user operates two switches 90 and 95 of the at least two switches, the control circuit 20 changes from the locked state to the unlocked state. In a first configuration of FIG. 9, the control circuit 20 changes from the locked state to the unlocked state in response to the user operating the two switches 90 and 95 concurrently. In a second configuration of FIG. 9, the control circuit 20 changes from the locked state to the unlocked state in response to the user operating the two switches 90 and 95 sequentially.

[0030] The control circuit 20 further includes a microprocessor 50 and memory 55 connected to the user entry circuit 45, the motor-control circuit 35 and the visual display circuit 40. The microprocessor 50 interprets and executes instructions stored as one or more software modules in memory 55. Upon executing the software modules, the microprocessor 50 receives inputs from the user entry circuit 45, processes the inputs and generates electrical outputs to the motor-control circuit 35 and/or the visual display circuit 40.

[0031] In operation, when the user manipulates the controller 58 to raise the chair, a signal is generated in the user entry circuit 45. The microprocessor 50 receives and interprets the input signal from the user entry circuit and generates an output to the motor control circuit 35. The motor control circuit 35 receives the generated output signal and controls the motors 25 and 30 accordingly to power the chair 10.

[0032] When the user actuates the single “lock” switch or the dual function switch, the controller locks the chair. More specifically, the microprocessor 50 receives and interprets the input signal from the user entry circuit 45 resulting in the microprocessor 50 changing the state of the chair 10 from the unlocked state to the locked state. The microprocessor also generates an output signal to the visual display circuit 40. The visual display circuit 40 receives the generated output signal and activates a first LED informing the user that the chair 10 is in the locked state. While in the locked state, the microprocessor 50 does not generate an output signal to the motor control circuit 35 until the microprocessor 50 is actively returned to the unlocked state by the user.

[0033] The microprocessor 50 returns to the unlocked state when the user enters the correct input (combination of switches) into the user-entry circuit 45. An input signal is generated in the user entry circuit 45 and is provided to the microprocessor 50. The microprocessor 50 receives and interprets the input signal resulting in the microprocessor 50 changing the state of the chair from the locked state to the unlocked state. The microprocessor 50 also generates an output signal to the visual display circuit.

[0034] Various features and advantages at the invention are set forth in the following claims.