Abstract: Method and system for controlling the operation of a motorized wheelchair where the motors have discrete predetermined speeds thus requiring little user intervention to operate and the motors may be controlled to act as generators to provide dynamic braking of the wheelchair.

Abstract: In an electronically controlled sewing machine which has the capability of accepting plug-in modules consisting of read only memories, a method is provided for checking the integrity of the module memory and the means for coupling the memory to the sewing machine controller. The controller reads the first two locations in the memory to check for the presence of alternating patterns of ones and zeros which indicate that shorted or open data lines are unlikely. Another location in the memory contains the number referred to as a checksum. The controller adds the contents of all the other locations of the module memory to this checksum. If the module is undamaged, this sum will be zero. If the sum is not zero, the controller recognizes that a faulty module has been inserted and advises the operator accordingly.

Abstract: An electronically controlled household sewing machine includes an arrangement for needle positioning. The machine responds to a tap of the foot controller for stopping the sewing machine at the next change of state of the armshaft timing signal.

Abstract: An arrangement for changing the condition of an electrical circuit path when the presser bar lifter is pivoted to lift the presser bar uses a modified thread tension release cam which pivots with the presser bar lifter and a contact strip which is adapted to contact the cam when the presser bar is raised.

Abstract: A buttonhole presser device includes electrical switch contact members which cooperate with adjustable contact closing members to close an electrical circuit path. The switch contact members are carried by the shank of the presser device and are arranged so that when the presser device is installed on the presser bar one of the switch contact members is in electrical contact with the presser bar and the other switch contact member is in electrical contact with a conductor. The presser bar and the conductor are electrically connected to an electrical control circuit within the sewing machine.

Abstract: An electronically controlled sewing machine includes an arrangement for operating the machine in a diagnostic mode, wherein several tests for checking the functioning of the sewing machine can be performed. In a first test, all of the light emitting diodes on the panel of the sewing machine are sequentially energized. This verifies proper operation of the display panel. In a second test, a particular light emitting diode responds to the armshaft sensor such that it is dark when the needle is up and is illuminated when the needle is down. The motor speed function is monitored by a test which lights particular light emitting diodes in 100 stitches per minute increments of motor speed. Proper overall operation of the sewing machine, including the actuators, is monitored by running several test patterns. To isolate a possible fault in the sewing machine foot controller, the sewing machine may be run at a preset speed without depressing the foot controller.

Abstract: An elevator system including a plurality of elevator cars capable of individual, independent control, and a system processor which places the plurality of elevator cars under group control. A monitor responsive to the calls for elevator service, and the resetting thereof when a call has been served, removes the elevator cars from group control to allow them to operate upon independent control, when a call for elevator service exists for a predetermined period of time during which no call resets were generated.

Abstract: A monitoring system for off-site monitoring, traffic study and/or trouble shooting of elevator installations. Communication between the remote monitoring site and a selected elevator installation is established via a direct dial telephone link. The remote monitoring site includes visual display means for displaying the operation of the selected elevator installation in real time, means for storing and analyzing status signals from the elevator installation, as well as for printing out the results of such an analysis, and control means for entering commands to be executed by the elevator system.