Magnetic apparatus

• US 10,347,407 B2
• Filed: 09/28/2016
• Issued: 07/09/2019
• Est. Priority Date: 10/01/2015
• Status: Active Grant

• Current Assignee: SPD S.p.a (Ludwig Schunk Stiftung E.V.)
• Original Assignee: SPD S.p.a (Ludwig Schunk Stiftung E.V.)
• Inventors: Filosa, Giuseppe, Cipolla, Matteo, Cosmai, Giovanni, Conti, Claudio, Amboni, Roberto
• Primary Examiner(s): Barrera, Ramon M
• Application Number:
  US15/765,414
• Publication Number:
  US 20180301262A1
• Time in Patent Office: 1,014 Days
• CPC Class Codes: B23Q 17/00 Arrangements for observing, indicating or measuring on machine tools for automatic control or regulation of feed movement, cutting velocity or position of tool or work B23Q15/00
• CPC Class Codes: B23Q 17/005 by measuring a force, a pressure or a deformation
• CPC Class Codes: B23Q 2717/00 Arrangements for indicating or measuring
• CPC Class Codes: B23Q 3/1543 using electromagnets
• CPC Class Codes: B23Q 3/1546 using permanent magnets
• CPC Class Codes: B25B 11/002 Magnetic work holders
• CPC Class Codes: H01F 2007/208 combined with permanent magnets
• CPC Class Codes: H01F 7/0252 PM holding devices H01F7/021, H01F7/0215, H01F7/0226 take precedence
• CPC Class Codes: H01F 7/0257 Lifting, pick-up magnetic objects
• CPC Class Codes: H01F 7/04 Means for releasing the attractive force
• CPC Class Codes: H01F 7/206 Electromagnets for lifting, handling or transporting of magnetic pieces or material electromagnets for guidance of vehicles, workpieces B65G21/2009; for magnetic suspension or levitation H02N15/00

Abstract

A magnetic apparatus (1) comprising a magnetizable surface (2) configured to anchor a one or more ferromagnetic elements in a removable manner and a plurality of magnetic poles (3), each provided with a free surface (4) thereof, the magnetizable surface (2) being at least partially defined by the free surfaces (4) of said plurality of magnetic poles (3) placed side by side; one part of said magnetic poles (3) has at least two measuring areas (5) on the free surface thereof, each measuring area (5) being associated with at least one sensor (6) adapted to detect a magnetic flux exiting from said area.

Claims

1. A magnetic apparatus (1) comprising a magnetizable surface (2) configured to anchor a ferromagnetic element in a removable manner and a plurality of magnetic poles (3), each provided with a free surface (4) thereof, the magnetizable surface (2) being at least partially defined by the free surfaces (4) of said plurality of magnetic poles (3) placed side by side, characterized in that on the magnetizable surface (2) at least a part of the magnetic poles (3) is arranged in a group, each free surface (4) of each magnetic pole (3) of the group having at least two measuring areas (5), each measuring area (5) being associated with at least one sensor (6) adapted to detect a magnetic flux exiting from said area.

2. A magnetic apparatus (1) according to claim 1, wherein the sensor element comprises at least one coil (6) adapted to detect a magnetic flux which crosses said measuring area (5) during at least one activation transient of the magnetizable surface.

3. A magnetic apparatus (1) according to claim 2, wherein at least one part of the perimeter of the measuring area (5) is delimited by a channel (7) made in the magnetic pole (3) which houses at least one part of the coil (6), the channel (7) being open on said free surface (4) of the magnetic pole (3).

4. A magnetic apparatus (1) according to claim 3, wherein the channel (7) is defined by a groove made on the free surface of the magnetic pole.

5. A magnetic apparatus according to claim 4, wherein the groove is cross-shaped and divides the free surface (4) of the magnetic pole (3) into four measuring areas (5).

6. A magnetic apparatus (1) according to claim 3, wherein the channel (7) is obtained between the peripheral surface of a hole (9) made in the magnetic pole and the peripheral surface of a ferromagnetic core (10) housed in the hole and/or wherein the ferromagnetic core (10) is screwed in said hole (9) and/or wherein the coil (6) is wound about the ferromagnetic core (10) at a surface recess (11) thereof and/or wherein the head (12) of the ferromagnetic core is aligned with the free surface (4) of said pole and/or wherein the ferromagnetic core (10) is positioned at a barycenter of a sector of the magnetic pole (3).

7. A magnetic apparatus (1) according to claim 3, wherein an insulating resin (13) is arranged inside the channel.

8. A magnetic apparatus (1) according to claim 1, wherein each of said magnetic poles (3) comprises a core (3A) associated with at least one reversible magnet (15) coupled to a reversion coil (16) and at least one permanent magnet (18) also associated with said core (3A) and/or wherein the magnetic field generated by the at least one reversible magnet (15) is substantially equal to the magnetic field generated by the at least one permanent magnet (18).

9. An apparatus according to claim 1 wherein each of said magnetic poles (3) comprises a core associated with a magnetizing coil and/or wherein each of said magnetic poles (3) is associated with a permanent magnet and a mechanical system adapted to modify the combination between a ferromagnetic material and a permanent magnet at said magnetizable surface.

10. A method for detecting the anchoring force exerted on a ferromagnetic element by a magnetizable surface (2) at least partially defined by the free surfaces (4) of a plurality of magnetic poles (3), at least a part of the magnetic poles (3) being arranged in a group, comprising the step of detecting a magnetic flux exiting from at least two distinct measuring areas (5) formed on each single free surface (4) of each magnetic pole (3) of the group, and associating a value of the force exerted by the magnetizable surface (2) on the ferromagnetic element with said flux.

11. A method according to claim 10, wherein said anchoring force is detected by reading a signal obtained from a plurality of coils (6), each associated with one of said measuring areas (5) and/or wherein the signal deriving from each coil (6) is separately amplified (AI, An), filtered (FI, Fn) and converted to digital (CAD) before being processed by a computer (MC) and/or wherein the signal of all coils (6) is added (S), amplified (A), filtered (F) and converted to digital (CAD) before being processed by a computer (MC).