Apparatus and method for trimming a venetian blind assembly

A method for trimming very generally planar slats of standard size and shape preassembled in a standard venetian blind, comprising the following steps, wherein the directions "normal" and "parallel" as recited in any step are taken with respect to the plane of a slat identified in the same step:

• (a) supporting the preassembled blind;
• (b) while the standard blind remains preassembled, providing relative normal alignment between a cutter and a particular one of the slats;
• and then
• (c) while the standard blind remains preassembled, providing relative parallel juxtaposition between the cutter and the particular slat with which the cutter is now normally aligned;
• (d) then while the standard blind remains preassembled, operating the cutter to cut that particular slat to a custom size;
• (e) then while the standard blind remains preassembled, effecting relative parallel motion between the cutter and that particular slat, to provide clearance for relative normal motion of the cutter and that particular slat;
• (f) then while the standard blind remains preassembled, providing relative normal alignment between the cutter and another particular uncut slat;
• (g) then repeating steps (c) through (e) with respect to the just-mentioned other particular uncut slat, thereby cutting that slat to substantially the same custom size;
• (h) then repeating steps (f) and (g) in turn, with respect to slats or a slat remaining uncut before each repetition, until all the slats of the blind have been cut;
• except that after cutting the last slat the repetition of the clearing step (e) may be omitted.

A method for trimming slats of standard size and shape preassembled in a standard venetian blind that has a head rail, comprising the steps of:

• (a) suspending the blind by its head rail with a plurality of the slats depending below the head rail;
• (b) while the standard blind remains preassembled, substantially aligning a cutter vertically with a particular one of the slats;
• and then
• (c) while the standard blind remains preassembled, moving the cutter substantially horizontally into cutting position relative to the slat with which it is now substantially vertically aligned;
• (d) then while the standard blind remains preassembled, operating the cutter to cut that slat to a custom size;
• (e) then while the standard blind remains preassembled, moving the cutter substantially horizontally out of cutting position to clear the cut slat to allow vertical movement of the cutter relative to that slat;
• (f) then while the standard blind remains preassembled, substantially aligning the cutter vertically with another uncut slat;
• (g) then repeating steps (c) through (e), thereby cutting the just-mentioned other slat to substantially the same custom size;
• (h) then repeating steps (f) and (g) in turn, with respect to slats or a slat remaining uncut before each repetition, until all the slats of the blind have been cut;
• except that after cutting the last slat the clearing step (e) may be omitted.

A cutter for custom-trimming very generally planar slats of standard size and shape preassembled in a standard venetian blind, comprising:

• a pair of cutting blades;
• a guideway for defining a path very generally parallel to the plane of a particular such slat, while that particular slat remains preassembled in such a standard blind;
• a carrier that supports the cutting blades and is movably mounted on the guideway for motion along the path, for advancing such blades very generally parallel to the plane of such a slat so that such a slat is between them, while such slat remains preassembled in such a standard blind;
• a blade driver, interposed between the carrier and one of the blades to support that blade, and movably mounted on the carrier for motion very generally perpendicular to the path to advance that blade toward the other blade while such slat is between them and remains preassembled in such a standard blind;
• means for applying force to the carrier to draw the carried along the guideway to advance such blades, while such slat remains preassembled in such a standard blind;
• limit means for engaging the carrier to halt advancement of the carrier along the guideway when the cutting blades have such a slat between them and are properly aligned for cutting such a slat;
• and
• intermediate force-redirecting means disposed on the carrier and arranged to transmit said applied force, with a change in direction, from the carrier to the blade driver after the carrier has engaged the limit means;
• whereby after the force-applying means fully advance the carrier into cutting position the same force-applying means power the blade drive to trim such particular slat.

A length-trimming machine for the slats of an assembled and extended venetian blind that has a head rail and a bottom rail connected by ladder tapes, with salts supported in the ladder tapes;

• said machine comprising:
• a head-rail support;
• head-rail clamping means on the head-rail support;
• a bearing means at each end of the head-rail support;
• two vertical posts respectively engaged in the bearing means;
• first drive means for raising and lowering the head-rail support on the posts;
• slat-trimming means comprising two trimming units, each trimming unit including:
• a blade carriage;
• second drive means, engaged with the carriage, for raising and lowering the carriage,
• a blade assembly comprising a pair of relatively movable slat trimming blades, the blade assembly being mounted on the blade carried for horizontal movement on the blade carriage between a work position, in which the blades are in cutting relationship with the slats of a blind mounted in the machine, and a rest position,
• third drive means for moving the blade pair between the work and rest positions, and
• fourth drive means for moving the blades relative to each other;
• a carriage support for each blade carriage, each carriage support including:
• a vertical track, and
• fifth drive means for moving its associated blade carriage along the vertical track;
• upper and lower horizontal guides, each including a horizontal track;
• the upper and lower ends of the carriage supports being respectively engaged in the tracks of the upper and lower horizontal guides for movement therealong;
• sixth drive means for moving the carriage supports along the upper and lower horizontal guides;
• and
• control means for selectively operating the six drive means.