Radial offset monitor
A stripper assembly for a can bodymaker is configured to remove a can body from a punch mounted on a ram of the can bodymaker. The stripper assembly comprises a stripper housing defining an internal bore through which the punch passes and a radial offset monitor. The radial offset monitor comprises one or more eddy current sensors located within the stripper housing or attached thereto. The radial offset monitor is configured to detect misalignment of a ram and/or a punch, or a can body held on the punch, within the bore. A method of detecting axial misalignment of a ram and/or a punch of a can bodymaker, or of a can body held on the punch is also described. The method comprises providing a stripper housing defining an internal bore through which the punch passes; obtaining electrical output signals from one or more eddy current sensors within the housing or attached thereto, and processing the signal(s) to detect any axial misalignment.
1 . A stripper assembly for a can bodymaker and being configured to remove a can body from a punch mounted on a ram of the can bodymaker, the stripper assembly comprising:
a stripper housing defining an internal bore through which the punch passes; and
a radial offset monitor comprising one or more eddy current sensors, the one or more eddy current sensors being located within the stripper housing and being capable of detecting the misalignment of a can body held on a punch moving axially through the bore while the bodymaker is in operation and can bodies are being fed in, relative to an axis of the can body.
2 . The stripper assembly according to claim 1 , wherein the radial offset monitor is integrated into the stripper housing.
3 . The stripper assembly according to claim 1 , comprising a sensor housing co-located with the stripper housing, wherein the sensor housing defines an internal bore and the one or more eddy current sensors are located within the sensor housing.
4 . The stripper assembly according to claim 1 , comprising a stripper provided with stripping fingers.
5 . The stripper assembly according to claim 1 , comprising at least two eddy current sensors angularly spaced apart from one another about an axis along which the punch travels.
6 . The stripper assembly according to claim 5 , wherein the radial offset monitor comprises four eddy current sensors equiangularly spaced apart from one another about said axis.
7 . The stripper assembly according to claim 1 , wherein each of the one or more eddy current sensors is adjustable in a direction orthogonal to an axis along which the punch travels.
8 . The stripper assembly according to claim 1 , wherein said bore is cylindrical.
9 . A can bodymaker comprising:
a toolpack; and
the stripper assembly according to claim 1 .
10 . The can bodymaker according to claim 9 and comprising a controller having:
an input for receiving sensor data from the radial offset monitor; and
a processor configured to compute one or more of ram position, ram trajectory, punch position, punch trajectory, can body presence, and can body sidewall thickness.
11 . The can bodymaker according to claim 9 and comprising a screw adjustment mechanism to automatically adjust one or more components of the bodymaker in response to detection by the radial offset monitor of a misalignment of the ram and/or punch and/or can body in order to achieve realignment.
12 . The can bodymaker according to claim 11 , wherein the one or more components is or include the ram, the punch, a domer, and the adjustment is a radial adjustment.
13 . A can bodymaker comprising a radial offset monitor, said radial offset monitor comprising:
a stripper including a housing;
a body located in the stripper housing and defining an internal bore; and
one or more eddy current sensors positioned within the body, spaced around the bore and capable of detecting the misalignment of a can body held on a punch moving axially through the bore while the bodymaker is in operation and can bodies are being fed in, relative to an axis of the can body.
14 . A method of detecting axial misalignment of a ram and/or a punch, or of a can body held on the punch in a can bodymaker, the method comprising:
providing a stripper housing defining an internal bore through which the punch passes;
obtaining electrical output signals from one or more eddy current sensors within the stripper housing; and
processing the signal(s) to detect any axial misalignment,
whereby the steps of obtaining electrical output signals and processing the signal(s) occur while the punch moves axially through the internal bore while the bodymaker is in operation and can bodies are being fed in, relative to an axis of the can body.
15 . The method according to claim 14 and comprising processing the sensor data to compute one or more of ram position, ram trajectory, punch position, punch trajectory, can body presence, can body sidewall thickness.
16 . The method according to claim 14 , and comprising using a screw adjustment mechanism to automatically adjust one or more components of the bodymaker in order to correct the misalignment.
17 . The method according to claim 14 , the method being carried out while the bodymaker is producing can bodies.
18 . A stripper assembly for a can bodymaker and being configured to remove a can body from a punch mounted on a ram of the can bodymaker, the stripper assembly comprising:
a stripper housing defining an internal bore through which the punch passes; and
a radial offset monitor comprising one or more eddy current sensors, the one or more eddy current sensors being located within the stripper housing or attached thereto,
wherein the radial offset monitor is configured to detect misalignment of the ram and/or the punch, or of a can body held on the punch, within said bore while the punch moves axially through the internal bore while the bodymaker is in operation and can bodies are being fed in, relative to an axis of the can body.