US 3,940,839 A · High accuracy positive positioning mechanism for an assembly machine

Abstract

An assembly machine having a high accuracy positive positioning mechanism, which engages the assembly table when the indexing system is in a dwell portion of the cycle, not moving the assembly table. A positioning pin, which is mechanically connected to operate in synchronism with the indexer for the assembly table, positively engages and positions, if necessary, the assembly table. The positive positioning mechanism engages the assembly table between indexing steps. An overload clutch is provided between the indexer and the assembly table, to relieve mechanical overloads which may occur and to prevent damage to the assembly machine. The positive positioning mechanism is not driven by the indexer output thus it is unaffected by wear or defects in the indexer, the indexer drive, or the overload clutch mechanism. The dial positioning system utilizes the slack or backlash which is inherent in gears and thus permits moving the assembly table slightly, to a highly accurate position, during the portion of the machine cycle when the indexer is not moving the table. The positive positioning dial locating system utilizes a cam which operates and reciprocates a mechanical linkage to position a locator in time with the indexing unit. The reciprocating locator shaft is down and out of engagement with the assembly table during indexing and up and in engagement with the table during the dwell portion of the machine cycle. The locator shaft moves up due to the action of a spring actuated cam displaced lever and moves positively down due to the action of the cam. Thus the locator shaft is raised due to force applied through the spring and lowered due to the positive force applied by the cam. This arrangement assures positive disengagement of the locator pin, which is disposed at the end of the locator shaft, from the locator bushing which is connected to the assembly table. In the event that the assembly table is out of position the spring action will prevent damage to the locating system components. The locator bushing and the locator pin position the assembly table independent of wear in the indexer or overload mechanism thus overcoming a common problem in assembly machines.

Claims23

Dependent claims

An assembly machine for use in manufacturing an article comprising:

a rotatable assembly table on which at least a portion of the article is positioned at a selected position;
a plurality of work stops located at predetermined positions around said rotatable assembly table;
indexing means connected to said rotatable assembly table for rotating said rotatable assembly table a predetermined distance at repeatable intervals;
positive locating means for engaging and positively positioning said rotatable assembly table between the repeatable intervals when said indexing means is not rotating said rotatable assembly table so that the article is accurately aligned with the associated work stop;
drive means connected to and driving said indexing means, wherein said positive locating means is connected to and driven by said drive means independent of said indexing means and comprises;
a cam driven by said drive means;
a cam follower following the motion of said cam;
a locator shaft linked to said cam follower to be driven in accordance with the movement of said cam follower;
a locator pin disposed at one end of said locator shaft for engaging and positioning said rotatable assembly table when said indexing means is not rotating;
and,
said cam being constructed to force said locator pin out of engagement with said assembly table when said assembly table is being rotated by said index means.

8 more elements

An assembly machine comprising:

drive means;
a main center support column;
an annular assembly table disposed around said main center support column and being supported for relative rotary movement around said main center support column;
indexing means having an input driven by said drive means and an output connected to said annular assembly table which rotates said annular assembly table through a predetermined angle at discrete spaced apart intervals;
assembly table positioning means driven by said drive means for engaging and accurately positioning said annular assembly table between the discrete spaced apart intervals when said indexing means rotates said annular assembly table;
an upper tooling mount located above said annular assembly table disposed around and supported from said main center support column;
a lower tooling mount located beneath said annular assembly table disposed around said main center support column;
a main center drive shaft disposed within said main center support column and being driven by said drive means;
an upper tooling actuating means disposed around and supported from said main center support column and being driven by said main center drive shaft for supplying power to tooling which can be attached to said upper tooling mount;
and,
a lower tooling actuating means disposed around and supported from said main center support column and being driven by said main center drive shaft for supplying power to tooling which can be supported from said lower tooling mount.

8 more elements

Dependencies are inferred from the claim text.

High accuracy positive positioning mechanism for an assembly machine

Life of this patent

High accuracy positive positioning mechanism for an assembly machine

Life of this patent

Abstract

Claims23