US 6,148,985 AGranted

Safety device on metal-forming machine tools

AssigneeTelegaertner Geraetebau GmbH

InventorsIngo Wagner, Horst Wolf

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Abstract

The invention concerns a safety device on metal-forming machine tools, in particular on pneumatic pressing machines, used in the execution of short-stroke pressing processes, for preventing intervention in the danger zone during the tool working movement and unintentional closure movements. The machine essentially comprises a machine housing, a power-generating system, a control system and a tool arrangement with a fixed part and a movable part, and the actual metal-forming tool connected thereto. The object of the invention is the highly reliable prevention of injuries owing to inattentiveness in spite of hands' being left in the immediate danger zone. To that end, the safety device (8) consists of a lever-like part (9) which is disposed between a guide part (15) and a counter bearing (14), is connected both to the power-generating system (2) and to the movable part (4) of the tool (3), slides along the guide part (15) and co-operates with the counter bearing (14) such that each working stroke of the movable part (4) occurs in two stages, first as a stroke for moving into a predetermined position (20) and then as a power stroke for carrying out the forming process, which occurs only when there is no obstacle (25) in the space between the movable part (4) and the workpiece.

Claims41

Dependent claims

A safety device for press machines including a machine housing, a power-generating device for imparting motion to a force member which moves along a first travel path starting at an initial position, the safety device comprising:

a pressing part having a tool portion for accepting a forming tool, said pressing part being slidably mounted in said machine housing so as to be movable along a second travel path;
a guide member disposed parallel said first travel path;
an abutment member disposed parallel said second travel path and having a first surface portion parallel said guide member and disposed a first distance from said guide member;
a lever part disposed between said guide member and said abutment member and having a first lever end and a second lever end disposed apart a second distance greater than said first distance, and an engagement surface proximate said second lever end;
said lever part having a movable connection to said pressing part such that said second lever end is contactable with said first surface portion of said abutment member;
said lever part having a movable connection to said force member such that said first lever end is contactable along said guide member;
said lever part having said movable connections to said pressing part and said force member such that said force member and said lever part supports a weight of said pressing part when said lever part extends from said force member at a first angle so that up and down movement of said force member allows up and down movement of said pressing part, wherein downward force of said pressing part is substantially limited to the weight of said pressing part, and interruption of the downward movement of the pressing part by an object, in combination with continued downward movement of said force member, before said pressing part reaches a predetermined position, displaces said lever part from said first angle orientation relative to said force member to move said first lever end and said second lever end respectively into contact said guide member and said abutment member to jam said lever part therebetween thereby preventing further movement of said pressing part;
and
said abutment member having a second surface portion below said first surface portion and said abutment member being disposed such that, when said pressing part is move to said predetermined position, said second lever end is below said first surface portion and interruption of downward motion of the pressing part by a workpiece in combination with continued downward travel of said force member displaces into said engagement surface of said lever part into pivotal contact with said second surface portion of said abutment member to effect a pivot action whereby said lever part transmits force of said downwardly traveling force member to downwardly displace said pressing part to press said workpiece.

6 more elements

A press machine including a machine housing, a power-generating device for imparting substantially vertical motion to a force member which moves from a force member initial position along a first travel path, the press machine comprising:

a pressing member having a tool portion for accepting a forming tool for forming a workpiece, said pressing member being slidably mounted in said machine housing so as to be substantially vertically movable along a second travel path through a work stroke including:
a motion stroke extending from a pressing member initial position down to a predetermined position whereat the forming tool is situated at the workpiece;
and
a power stroke extending from said predetermined position down to a final position whereat said workpiece is formed;
a lever member having first and second lever ends, first and second lever end portions respectively including said first and second ends, and an intermediate portion between said first and second lever end portions;
said intermediate portion being moveably connected to said pressing member so as to vertically support said pressing member;
said first lever end portion being moveably connected to said force member so as to rest at a rest position, relative said force member, extended from said force member at a downward incline and be freely pivotable in an upwards direction relative said force member from said rest position such that said force member and said lever member are deflectable upwards relative said force member when encountering an obstruction imparting sufficient force to overcome weight of said lever member, said pressing member and said forming tool during downward movement of said force member effecting said motion stroke;
and
a pivot engagement surface adjustably disposed in said machine housing at a position aligned with said second lever end portion of said lever member when said pressing member is at said predetermined position with said forming tool at the workpiece such that further downward motion of said force member results in upward deflection of said lever member relative to said force member and said second lever end portion of said lever member being displaced into pivotal engagement with said pivot engagement surface whereby said lever member imparts force to said pressing member at said moveable connection during further downward motion of said force member until said pressing member is at said final position.

6 more elements

A press safety mechanism for advancing a forming tool to a workpiece in a press machine which includes a machine housing, a power-generating device for imparting substantially vertical motion to a force member which moves from a force member initial position along a first travel path, the press machine comprising:

a pressing member having a tool portion for accepting the forming tool for forming a work piece, said pressing member being slidably mounted in said machine housing so as to be substantially vertically movable along a second travel path through a work stroke including a motion stroke extending from an initial pressing member position down to a predetermined position whereat the forming tool is situated at the workpiece;
a lever member having first and second lever ends, first and second lever end portions respectively including said first and second ends, and an intermediate portion between said first and second lever end portions;
said intermediate portion being moveably connected to said pressing member so as to vertically support said pressing member;
and
said first lever end portion being moveably connected to said force member so as to rest at a rest position, relative said force member, extended from said force member at a downward incline and be freely pivotable in an upwards direction relative said force member from said rest position such that said force member and said lever member are deflectable upwards relative said force member when encountering an obstruction imparting sufficient force to overcome weight of said lever member, said pressing member and the forming tool during downward movement of said force member effecting said motion stroke.

2 more elements

Dependencies are inferred from the claim text.