Head for the linear dimension checking of mechanical pieces

• US 6,269,546 B1
• Filed: 03/30/1999
• Issued: 08/07/2001
• Est. Priority Date: 11/07/1996
• Status: Expired due to Term

• Current Assignee: Marposs Societa' per Azioni
• Original Assignee: Marposs Societa' per Azioni
• Inventors: Ventura, Luciano
• Primary Examiner(s): Gutierrez, Diego
• Assistant Examiner(s): Guadalupe, Yaritza
• Application Number:
  US09/269,537
• Time in Patent Office: 861 Days
• Field of Search: 337/06, 337/07, 337/08, 337/10, 337/11, 335/42, 335/46, 335/49, 335/50, 337/83, 338/32, 336/13, 336/45, 335/59, 335/56, 335/58, 335/61, 335/44, 335/442
• US Class Current: 33/645
• CPC Class Codes: G01B 7/001 Constructional details of gauge heads G01B7/012 takes precedence
• CPC Class Codes: G01B 7/012 Contact-making feeler heads therefor

Abstract

A gauging or measuring head for the linear dimension checking of mechanical pieces, including a casing (1), an arm (49) carrying a feeler (67) for contacting a piece to be checked, a fulcrum (74), coupled to the casing (1) and the arm (49), for enabling displacements of the arm (49) with respect to the casing (1), a return spring (95) for keeping the feeler (67) in contact with the piece during the checking, a device (98, 100) for retracting the arm (49) and a position transducer providing signals depending on the position of the arm (49) with respect to the casing (1). The fulcrum is made of a deformable element (74) including two coupling blocks (81, 83) and three laminae (75, 77, 79) permanently secured to the blocks (81, 83), and substantially arranged in two different planes of a sheaf of planes.

Claims

1. A head for the linear dimension checking of mechanical pieces including

a support element (1) that defines a longitudinal geometrical axis,

a movable armset with an arm (49), movable with respect to said support element (1), and a feeler (67) coupled to said arm (49),

a fulcrum (74) coupled to said arm (49) and said support element (1), for defining a rotation axis and enabling limited rotational displacements of said arm (49) about said rotation axis with respect to said support element (1), and

a transducer (105,107), coupled to said arm (49) and said support element (1), for providing signals depending on the position of said arm (49) with respect to said support element (1),

characterized in that said fulcrum (74) comprises a deformable element with two blocks (81,83) respectively coupled to said arm (49) and said support element (1) and arranged substantially parallel with respect to each other, the deformable element comprising a first lamina (75) and at least a second lamina (77), each of said first (75) and second (77) lamina being permanently secured to both blocks (81,83) angularly arranged with respect to both said blocks (81,83) and the other of said first (75) and second (77) lamina.

2. The head according to claim 1, wherein said first (75) and second (77) lamina are made of a material that differs from that of said blocks (81,83).

3. The head according to claim 1, including a third lamina (79) permanently secured to both said blocks (81,83) and substantially coplanar to one of said first (75) and second (77) lamina.

4. The head according to claim 3, wherein said first (75), second (77) and third (79) laminae are permanently secured to said blocks (81,83) by die-casting.

5. The head according to claim 4, wherein said first (75), second (77) and third (79) laminae are made of steel and said blocks (81,83) are made of zinc alloy.

6. The head according to claim 1, wherein said support element (1) defines a substantially cylindrical seat (21), and said transducer comprises windings (105) housed in said seat (21), and a core (107) coupled to and movable with said arm (49).

7. The head according to claim 1, including a biasing device located between said arm (49) and said support element (1) and comprising a return spring (95) coupled to said arm (49) and said support element (1).

8. The head according to claim 7, including a device for setting the biasing force of said return spring (95).

9. The head according to claim 1, including two limit stop devices for limiting the displacements of said movable arm (49) in opposite directions.

10. The head according to claim 9, wherein said limit stop devices comprise a screw (85) screwed to said support element (1) for cooperating with said arm (49), and a dowel (91) coupled to said arm (49) for cooperating with said support element (1).

11. The head according to claim 10, comprising devices for setting said limit stop devices (85,91).

12. The head according to claim 1, including a retraction device (98,100,101) for retracting said movable arm to a definite inoperative position.

13. The head according to claim 12, wherein said retraction device includes a pneumatic circuit with a source (92) of compressed air.

14. The head according to claim 13, wherein said retraction device comprises a cylinder (98), a piston (100) and a compression spring (101).

15. The head according to claim 13, wherein said retraction device comprises a bellows (121) having an end fixed to the support element (1) and an opposite free end adapted to cooperate with the movable arm (49) to urge it to said definite inoperative position.

16. The head according to claim 15, wherein said bellows (121) is connected to said pneumatic circuit and is adapted to elongate to bring said free end to cooperate with the movable arm (49).

17. The head according to claim 16, wherein said retraction device further comprises a return spring (135) connected to said bellows (121) and adapted to apply a compression thrust to it.

18. The head according to claim 17, wherein said return spring (135) is inserted in the folds of the external surface of the bellows (121).

19. The head according to claim 15, wherein the bellows (121) is made of plastic.

20. The head according to claim 19, wherein the bellows (121) is made of polyurethan.

21. The head according to claim 15, wherein the bellows (121) is made of metal.

22. The head according to claim 15, wherein the bellows (121) is made of rubber.

23. A head for the linear dimension checking of mechanical pieces including

a support element (1) that defines a longitudinal geometrical axis,

a movable armset with an arm (49), movable with respect to said support element (1), and a feeler (67) coupled to said arm (49),

a fulcrum (74) coupled to said arm (49) and said support element (1), for enabling limited rotational displacements of said arm (49) with respect to said support element (1),

a retraction device (121) coupled to said support element (1) and adapted to cooperate with the movable arm (49) for bringing the arm (49) to a definite inoperative position, and

a transducer (105,107), coupled to said arm (49) and said support element (1), for providing signals depending on the position of said arm (49) with respect to said support element (1),

characterized in that said retraction device comprises a bellows (121) having an end fixed to the support element (1) and an opposite free end adapted to cooperate with the movable arm (49) to urge it to said definite inoperative position.

24. The head according to claim 23, wherein said retraction device includes a pneumatic circuit with a source (93) of compressed air.

25. The head according to claim 24, wherein said bellows (121) is connected to said pneumatic circuit and is adapted to elongate to bring said free end to cooperate with the movable arm (49).

26. The head according to claim 25, wherein said retraction device further comprises a return spring (135) connected to said bellows (121) and adapted to apply a compression thrust to it.

27. The head according to claim 26, wherein said return spring (135) is inserted in the folds of the external surface of the bellows (121).

28. The head according to claim 23, wherein the bellows (121) is made of plastic.

29. The head according to claim 28, wherein the bellows (121) is made of polyurethan.

30. The head according to claim 23, wherein the bellows (121) is made of metal.

31. The head according to claim 23, wherein the bellows (121) is made of rubber.

32. A process for manufacturing a fulcrum (74) to be utilized in a head for the dimension checking, comprising the following steps:

providing at least two laminae (75,77) made of a first material,

obtaining two blocks (81,83) made of a second material, and

permanently securing said laminae (75,77) to said blocks (81,83) for achieving a single deformable element, wherein the laminae (75,77) are angularly arranged with respect to each other and to said blocks (81,83), and the blocks (81,83) are arranged substantially parallel with respect to each other.

33. The process according to claim 32, wherein the step of permanently securing said laminae (75,77) to said blocks (81,83) comprises a die-casting process.

34. The process according to claim 33, wherein said at least two laminae (75,77) are inserted in a die, and both the steps of obtaining said two blocks (81,83) and permanently securing the laminae (75,77) to the blocks (81,83) include melting said second material and injecting the melted second material in said die.

35. The process according to claim 32, wherein said laminae (75, 77) are made of steel and said blocks (81,83) are made of zinc alloy.

36. The process according to claim 32, wherein the step of permanently securing said laminae (77,78) to said blocks (81,83) comprises a welding process.