Percussive drill with safety interlock for reversing gear
AssigneeScintilla AG
InventorPeter Holzer
Life of this patent
Estimating the term…
Abstract
A reversing switch, controlling the direction of rotation of the working spindle of a combination motor-driven hand tool, displaces a rack rod in a direction parallel to the axis of the spindle to provide an interlock both with a percussion boring feature and with provisions for seating attachments on the chuck sleeve of the tool, such as a circular saw. When the percussion boring feature is put into operative position, the rack rod is caused to prevent moving the reversing switch from right-hand rotation to left-hand rotation. When the switch is set for left-hand rotation, the seating surface of the chuck sleeve locks to prevent mounting an attachment and, at the same time, the percussion boring mechanism is blocked in an out-of-service position.
Claims23
A motor-driven combination rotary tool having a casing, a motor therein, a working spindle mounted thereon carrying a bit-holding chuck, manually settable drive-reversing means for causing said spindle to be driven by said motor either in normal right-hand rotation or in the opposite left-hand rotation, and equipped or designed to power optionally usable means for operating detachable auxiliary tools which are compatible only with right-hand rotation of said spindle and also comprising the improvement which consists in that:
- a mechanical interlock device is provided which is mechanically coupled with said drive reversing means independently of the application of rotary force to said spindle for blocking and thereby rendering inoperative said optionally usable auxiliary tool operating means when said drive-reversing means are set for left-hand rotation of said spindle and for blocking, and thereby preventing left-hand rotation of said spindle, so long as said optionally usable auxiliary tool operating means are mechanically coupled to said spindle.
A motor-driven combination rotary tool having a casing, a motor therein, a working spindle mounted thereon carrying a bit-holding chuck manually settable drive-reversing means for causing said spindle to be driven by said motor either in normal right-hand rotation or in the opposite left-hand rotation, and equipped or designed to power optionally usable auxiliary tool operating means compatible only with right-hand rotation of said spindle and also comprising the improvement which consists in that:
- a mechanical interlock device is provided for blocking and thereby rendering inoperable said optionally usable auxiliary tool operating means when said drive-reversing means are set for left-hand rotation of said spindle so long as said optionally usable tool operating means are mechanically coupled to said spindle, said interlock device comprising a manually operable control setting selector member (18) and at least one longitudinally displaceable rod (31, 45;
- 53) mechanically coupled to said selector member (18) and disposed for engagement with blocking means (29, 30) of said auxiliary tool operating means, and includes on at least one said rod a cam surface (32, 50) and a catch surface (33, 51) for at least one blocking member (35, 49) of said blocking means (29, 30).
Dependencies are inferred from the claim text.