Reexamination Certificate
1999-06-15
2001-06-05
Sipos, John (Department: 3721)
C053S331500, C053S318000
Reexamination Certificate
active
06240678
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a screw capping head with a magnetic clutch for applying pre-threaded closures onto threaded containers. More particularly, the invention provides a capping head with torque adjustment features.
BACKGROUND OF THE INVENTION
Capping machines for the application of prethreaded closures onto prethreaded containers have been known for some time. In order to ensure that a prethreaded closure is not applied too tightly, which could possibly result in damage, conventional screw capping machines are provided with a screw capping head often called a “headset” having a torque dependent clutch. The clutch limits the maximum torque which can be transmitted to the prethreaded closure. Clutches of various types have been used. These have included slipping clutches and mechanical torque limiting clutches and also magnetic clutches. One example of a magnetic clutch is shown in U.S. Pat. No. 5,490,369 to Ellis et al., which is assigned to the Aluminum Company of America and which in incorporated herein by reference. Other examples of clutches are disclosed in U.S. Pat. Nos. 4,364,218; 4,492,068; 4,674,264; and 5,197,258. While many prior types of clutches have been generally satisfactory, many have not adapted themselves to ready adjustability, thus resulting in substantial down time when changes in the amount of applied torque are required due to different closures being applied, application forces required, etc. The Ellis et al., U.S. Pat. No. 5,490,369 teaches a capping head with an adjustable magnetic clutch consisting of opposed rings of magnet. One of the rings is disposed in a piston ring assembly that is adjustable relative to the other magnetic ring in order to vary the torque limit of the clutch.
SUMMARY OF THE INVENTION
Briefly, the screw capping head of this invention relates to a head assembly for applying prethreaded closures onto prethreaded containers which provides for readily changing the torque to be applied to the various closures, thus making the capping head adaptable to be used with a variety of different closures and containers.
A capping head incorporating the instant invention includes a first housing assembly adapted to be secured to a rotatable drive spindle. A clutch housing is mounted onto the first housing assembly and adapted for axial movement relative to the housing. The clutch assembly has an upper portion and a lower portion. The upper portion includes a magnetic clutch comprising a first circular ring of magnets secured to the portion of the clutch to which the drive spindle is connected. A clutch lower housing portion is in axial alignment with and mounted for free rotation relative to the clutch housing upper portion. The clutch housing lower portion comprises a second ring of magnets axially spaced from the first ring of magnets, which are mounted in the clutch housing upper portion. Together, the first and second rings of magnets define a magnetic clutch. The gap between these axially spaced sets of magnets determines the torque to be applied to the closure. The clutch is capable of slipping after the application of a prethreaded closure onto a prethreaded container when the desired torque value has been reached or exceeded. Essentially, the mode of operation is that as the chuck engages the cap upon the container to be capped, a top load is provided for cap-to-container sealing and/or for adequate rotary frictional engagement between the chuck and the cap by slight telescoping of the spindle and housing to compress a spring disposed therebetween. The magnetic attraction between the magnetic rings will impart at torque load from the housing which rotates with the drive spindle with the chuck assembly. This torque load permits the chuck assembly to engage and tighten the cap which has previously been threadedly engaged onto a container to a predeterminable tightness beyond which the mechanical resistance to further tightening overcomes the magnetic attraction. When this occurs, the magnetic clutch assembly merely slips as the spindle and associated housing continue to rotate with respect to the clutch lower housing portion.
The magnetic clutch assembly of the instant invention provides a mechanism for the calibration of the magnetic torque load to any number of predetermined set positions. Additionally, once a predetermined set position is established such as after the manufacture of the clutch assembly, the actual torque of the magnetic clutch can be adjusted through a range of values from, for example, a magnetic torque of 7.0 inch pounds to 22.5 inch pounds, by means of a predetermined set of incremental adjustments. These adjustments are possible through the use of an adjusting ring that permits the selected change of the torque value from a first predetermined value to a second (or different) predetermined value. Furthermore, the nature of the adjusting ring permits the return from the second predetermined value to the first predetermined value through a simple incremental movement of the adjustment ring.
Therefore, in summary, a capping head assembly comprises a first housing having a spindle mounting collar means and means for supporting a clutch housing. The clutch housing has an upper portion with a first magnetic ring means and a lower portion with a second magnetic ring. The lower portion is freely rotatable relative to the upper portion of the clutch housing. The lower portion includes means for establishing an adjustable air gap between the first and second magnetic rings. Locking means maintain the means for adjusting an air gap at a selected position.
It is therefore an object of this invention to provide an improved capping head with a magnetic clutch that permits the selection of a torque load.
It is a further object of this invention to provide a capping head with a magnetic clutch that can be calibrated during assembly to compensate for manufacturing tolerances that might cause the magnetically driven torque forces to vary from unit to unit.
It is yet another object of this invention to provide a capping head with a structure that facilitates the wash down or cleaning of the capper head and associated support equipment.
REFERENCES:
patent: 4304611 (1981-12-01), Ellis
patent: 4364218 (1982-12-01), Obrist
patent: 4492068 (1985-01-01), Obrist
patent: 4599846 (1986-07-01), Ellis et al.
patent: 4604853 (1986-08-01), Albrecht et al.
patent: 4633646 (1987-01-01), Ellis et al.
patent: 4674264 (1987-06-01), Ellis et al.
patent: 5197258 (1993-03-01), Johanek
patent: 5284001 (1994-02-01), Ochs
patent: 5313765 (1994-05-01), Martin
patent: 5490369 (1996-02-01), Ellis et al.
patent: 8602917 (1984-11-01), None
Sipos John
Trempus Thomas R.
LandOfFree
Capping head with torque adjustment does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Capping head with torque adjustment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Capping head with torque adjustment will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2464198