Control device for a hand-operated electric power tool

• US 4,636,961 A
• Filed: 07/23/1984
• Issued: 01/13/1987
• Est. Priority Date: 08/19/1983
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Bauer, Hans-Peter
• Primary Examiner(s): RUGGIERO, JOSEPH F
• Application Number:
  US06/633,572
• Time in Patent Office: 904 Days
• Field of Search: 364/474, 364/475, 364/140-147, 364/174, 364/188-193, 408/9, 408/16, 318/305, 318/490
• US Class Current: 700/168
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: H02P 25/14 Universal motors H02P25/12 takes precedence
• CPC Class Codes: Y10S 388/917 Thyristor or scr
• CPC Class Codes: Y10S 388/937 Hand tool

Abstract

An adjustment circuit for a hand-operated electric power tool includes a data input device for entering information concerning the kind of material to be treated and other information relevant to the operation of the tool. The selected binary coded address word is applied to addressing inputs of a read only memory storing control words for a controlling device for a motor of the tool. Part of the bits of a control word outputted from the ROM are applied to a display device which displays the desired or actual rotary speeds of the tool and/or other data selected by the input device.

Claims

1. A hand-operated electric power tool comprising means for controlling the operation of the tool;

a device for storing binary control words each including a first group of bits for controlling a predetermined mode of operation of said tool and a second group of bits indicative of a rotary speed preset for a particular mode of operation;

said storing device having addressing inputs for receiving a selected binary address word and data outputs for outputting a stored control word assigned to a selected address word;

a data input device connected in parallel to said addressing inputs to apply a selected word thereto;

a data display device connected in parallel to one part of said data outputs pertaining to said second group of bits to display a preset rotary speed value; and

said means for controlling the operation of the tool being connected to another part of said data outputs pertaining to said first group of bits.

2. A hand-operated electric power tool as defined in claim 1 wherein from the other part of the data outputs of the storage device limit the maximum rotary speed of the tool in response to the actuation of the input device.

3. A hand-operated electric power tool as defined in claim 1 further comprising an analog switch controlled by signals from the other part of output signals of the storage device, the analog switch being coupled to said means for controlling the operation of the tool to fix the rotary speed in response to an actuation of the data input device.

4. A hand-operated electric power tool as defined in claim 1 wherein signals from the one part of data outputs of the storage device activate the display device to indicate the desired rotary speed of the tool.

5. A hand-operated electric power tool as defined in claim 1 wherein said data input device includes pushbuttons for delivering binary coded address word to the addressing inputs of the storage device.

6. A hand-operated electric power tool as defined in claim 1 wherein the data input device includes a rotary knob provided with switching contacts for delivering a binary coded address word to the addressing inputs of the storage device.

7. A hand-operated electric power tool as defined in claim 1 wherein the data input device includes at least one pushbutton cooperating with an electronic circuit for generating a succession of binary data in response to repeated depressions of the pushbutton.

8. A hand-operated electric power tool as defined in claim 7 wherein said electronic circuit includes a shift register connected between the data input device and the addressing inputs of the storage device.