US 5,718,544 AGranted

Method for producing a two-part member having rack teeth

AssigneeNihon Velbon Seiki Kogyo Kabushiki Kaisha

InventorKoichiro Nakatani

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Abstract

A base member such as an elevation pipe of a photographic tripod is severed and rack teeth are formed thereon in a single operation while the base member remains clamped in a V-block. The first rack tooth on each side of the location where the base member is severed includes half of a trough portion between adjacent rack teeth. Additional trough portions forming the remainder of the teeth are formed, either in the same severing and shaping operation, or in a later shaping operation. The formation of the inner half trough portions ensures that, when the two severed ends of the base member are brought together, a smooth transition will exist between the two rack portions. In addition, since the two severed ends always include half troughs immediately adjacent thereto, weaknesses and chipping resulting from the presence of partial rack teeth in these locations is avoided.

Claims6

Dependent claims

A method for producing a two-part member having rack teeth comprising:

clamping a base member in a V-block;
the step of clamping including exposing a portion of said base member upon which said rack teeth are to be formed;
forming a transverse groove in said V-block;
forming, as an integral unit, a cutting and shaping assembly which includes a rotary cutting blade and at least a first rotary shaping blade on a first side of said rotary cutting blade, and at least a second rotary shaping blade on a second side of said rotary cutting blade;
said first rotary shaping blade adjacent said rotary cutting blade being shaped to form a first half of a trough portion between adjacent rack teeth;
said second rotary shaping blade adjacent said rotary cutting blade being shaped to form a second half of a trough portion between adjacent rack teeth, whereby, when said first and second trough portions are abutted, a full trough portion between adjacent rack teeth is formed;
engaging said base member with said rotary cutting blade, and moving said cutting and shaping assembly across said base member with said rotary cutting blade aligned with said transverse groove;
continuing the step of engaging until said base member is severed into two separated pieces;
and
continuing the step of engaging while said at least a first rotary shaping blade and said at least a second rotary shaping blade form said half trough portions in said base member.

7 more elements

Apparatus for producing a two-part member having rack teeth comprising:

at least one V-block;
means in said at least one V-block for clamping a base member;
said at least one V-block including means for exposing a portion of said base member clamped therein upon which at least one of cutting and shaping operations is to be performed;
a transverse groove in said V-block;
a cutting and shaping assembly formed as an integral unit;
said cutting and shaping assembly including a rotary cutting blade and at least a first rotary shaping blade on a first side of said rotary cutting blade, and a at least a second rotary shaping blade on a second side of said rotary cutting blade;
said first rotary shaping blade adjacent said rotary cutting blade being shaped to form a first half of a trough portion between adjacent rack teeth;
said second rotary shaping blade adjacent said rotary cutting blade being shaped to form a second half of a trough portion between adjacent rack teeth, whereby, when said first and second trough portions are abutted, a full trough portion between adjacent rack teeth is formed;
said transverse groove being sized to permit said rotary cutting blade to pass therethrough, whereby said base member may be severed while being clamped in said V-block;
and
said transverse groove being further sized to permit said first and second shaping blades to engage said base member, whereby said rack teeth are formed while said base member remains clamped in said V-block.

8 more elements

Dependencies are inferred from the claim text.