Abstract:
Capping head assemblies that are useful for applying pre-threaded closures onto containers with improved sensitivity. 
     The novel features of the devices are a simple and novel means of adjusting the torque in a magnetic clutch assembly. In addition, the advantage of preventing contamination by water and other liquids during the filling and capping of liquid containers, and further, have the capability of being greased without having to disassemble the device. In addition, these can be accomplished without changing the capability of being able to read the adjustment scales on the outside surface of the magnetic clutch assembly and the adjustment scales on the outside surface of the upper spring assembly for adjusting the tension in the spring.

Description:
The invention claimed and disclosed herein deals with devices that are useful for applying pre-threaded closures onto threaded containers with improved sensitivity. 
   BACKGROUND OF THE INVENTION 
   It is known in the art to use capping devices for applying threaded caps to pre-threaded containers. Such devices utilize a clutch to control the amount of torque applied to the cap so that the container is properly closed but prevents too much torque from being applied that could strip the threads of the container and the cap. Also, it is desired to prevent the over tightening of the cap. 
   This has been accomplished by using rings of concentric magnets with some form of control to control the axial position of the magnets. Various devices have also incorporated rings of magnets of alternating polarity. Even though such devices have been available, they have tended to be complex and costly, and not very reliable with regard to retaining a pre-set torque, and thus many capping devices utilizing spring loaded mechanical and friction clutches are still in use but a need still exists for a device incorporating a reliable and simplified but effective clutch mechanism. 
   One prior art device can be found in U.S. Pat. No. 5,197,258, issued Mar. 30, 1993 to Johanek in which a clutch is adapted for use in a capping device to apply a pre-selected amount of torque to the driven component having a pair of axially aligned circular cylinders of equal diameter each having a generally smooth engaging surface facing the other clutch cylinder. Each of the cylinders has cavities in the rear side for containing magnets. The magnets are secured in the cavities by means of a cured polymeric resin. The maximum torque provided by the clutch is controlled by using removable spacer disks of varying thicknesses and having a diameter equal to that of the cylinder positioned between the engaging surfaces. 
   The device disclosed in U.S. Pat. No. 5,437,139, issued on Aug. 1, 1995 to Martin deals with a cylindrical magnet ring in the body of the head surrounding a cap chuck driving element in a low friction bearing in the head, each having an array of permanent magnets, distributed around the periphery. The chuck-driving element rotates with the magnet ring until the resistance of a cap being threaded on the container exceeds a predetermined torque limit, after which the magnet ring rotates relative to the stationary chuck-driving element. The spring for urging the chuck downward is fully contained within the head. 
   Yet another device is that found in U.S. Pat. No. 5,809,742, that issued on Sep. 22, 1998 to Takakusaki, et al in which a plurality of permanent magnets are embedded around the entire outer periphery at the upper end of a spindle with adjacent permanent magnets presenting magnetic poles of different polarities. As the capping head moves through a threadable engaging zone, co action between the permanent magnets causes the capping head to rotate clockwise causing a cap to be threadably engaged with a container. 
   U.S. Pat. No. 5,714,820, that issued on Feb. 3, 1998 to Mitsuhashi, et al deals with magnetic coupling that includes a cylindrical housing, a spindle, an adjusting plate, two pairs of permanent magnet discs, two hysteresis material discs, and a screw member. 
   The spindle is rotatably supported at its axial position by the housing. The adjusting plate is rotatably supported by the spindle to partition as interior of the housing into two sections in a direction of the spindle. The two pairs of permanent magnets are provided in the two corresponding section to respectively oppose each other. One of each pair of permanent magnet discs is fixed in the housing and the other thereof is fixed to the adjusting plate. Each permanent magnet disc has magnetic poles with polarities that alternate in a circumferential direction. The hysteresis material discs are fixed to the spindle and arranged between the corresponding pairs of permanent magnet discs at a predetermined gap. The screw member fixes the adjusting plate to the housing. When the adjusting plate is released and pivoted, the mutual positional relationships between the respective opposing magnetic poles of the two pairs of permanent magnet discs are adjusted simultaneously. 
   U.S. Pat. No. 6,240,678 that issued Jun. 5, 2001 to Spether deals with a capping head assembly that has a first housing with a spindle-mounting collar and supports a clutch housing. The clutch housing has an upper portion with a first magnetic ring and a lower portion with a second magnetic ring. The lower portion is freely rotatable relative to the upper portion and permits the adjustment of the air gap between the first and second magnetic rings. A locking mechanism maintains the adjusted air gap at a selected value that represents a definable torque level in the magnetic clutch. The capping head also includes a post assembly calibration system that establishes a known reference point that compensates for manufacturing tolerances between individual capping heads. 
   There is disclosed in U.S. Pat. No. 5,490,369 that issued Feb. 13, 1996, to Ellis, a capping head with magnetic clutch that includes a housing assembly including a magnetic clutch interconnecting a drive spindle and a quill for applying a closure to a container. The magnetic clutch consists of opposed rings of magnets and one of the rings is disposed in a piston ring assembly that is quick and easily adjustable relative to the other to vary the torque limit of the clutch. A simple yet efficient clamping assembly is employed to facilitate ready adjustment and retention of the movable piston ring. 
   There is shown in an Arol Company brochure, not dated, a synchronous magnetic type of head. This device differs from the device herein by the use of straight sided ball bearings as the contact thrust bearing, but more importantly, it uses a synchronous magnetic type of head as opposed to the hysteresis type of head as used in the inventive device herein. 
   Basically, the synchronous clutch utilizes two discs with multiple magnets that are set up to oppose each other. To rotate one of the discs relative to the other disc you must overcome the magnetic attraction from the north pole to the south pole. The torque is a pulsating torque from zero to maximum. The number of magnets located around the disc will determine how many pulsations there will be in one revolution. To change peak torque levels in this type of design you need to adjust the air gap between the magnets. Larger air gaps provide for smaller peak torques. 
   U.S. Pat. No. 7,181,892, that issued on Feb. 27, 2007 to the inventors herein deals with a capping head with a magnetic clutch that is useful for applying pre-threaded closures onto threaded containers with improved sensitivity. The device allows for the adjustment of the torque that is required for capping containers such that variable sized and variable types of containers can be capped. 
   In the instant invention, essential construction and attributes of the devices that are disclosed in the aforementioned &#39;892 patent are also a part of this devices herein, and in addition, the devices of the instant invention are constructed such that they can be cleaned using spray washing without the water affecting any part of the device. 
   In addition, the construction of the instant devices is such that the liquids that are contained in the containers to be capped do not affect the devices of this invention when they splash and wash over the equipment that is used to cap the containers. 
   In addition to the novel cup assemblies that cover the devices, this invention teaches the correct sealing that is needed to provide unaffected devices and further, discloses an inventive method of greasing the components without having to disassemble the devices. 
   None of the devices disclosed in the prior art have the advantages of the devices of the instant invention. None of the devices disclosed in the prior art have the simplicity and novel means of adjusting the torque in the magnetic clutch assembly as does the device of the instant invention. In addition, the devices of this invention have the advantages of preventing contamination by water and other liquids during the filling and capping of liquid containers, and further, have the capability of being greased without having to disassemble the device. In addition, the improvements on the inventive devices can be accomplished without changing the capability of being able to read the adjustment scales on the outside surface of the magnetic clutch assembly, nor the adjustment scales on the outside surface of the upper spring assembly for adjusting the tension in the spring, that are novel features of these devices. 
   THE INVENTION 
   In a first embodiment, the invention disclosed and claimed herein deals with capping head assemblies comprising a combination of a magnetic clutch assembly having an upper portion and a bottom edge and which comprises a first annular drive magnet in a torque ring that is not movable relative to the magnetic clutch assembly. The drive magnet has a multiple pole configuration and there is a second annular drive magnet in the magnetic clutch assembly and it has a multiple pole configuration. There is a moveable hysteresis annular magnet interposed between the drive magnets, said magnets being axially spaced from each other. 
   There is a means for adjusting the position of the torque ring relative to the magnetic clutch assembly, the means comprising a torque adjustment rotating end cap that changes the polarity of the second annular magnet in the magnetic clutch assembly relative to the first annular drive magnet in a predetermined position whereby the flux of the magnets can be changed to vary the torque limit of the magnetic clutch assembly. The torque adjustment rotating end cap is rotatably mounted in the bottom end of the magnetic clutch assembly. 
   There is a means for securing the torque ring relative to the magnetic clutch assembly to retain the torque ring in a fixed position. 
   There is a double row angular contact thrust bearing located in the upper portion of the magnetic clutch assembly and encircling the rotatable drive member, the double row angular contact thrust bearing surmounting the first annular series of magnets. 
   Optionally, there is a top load spring setting scale tooled into the outside surface of the first housing assembly and optionally, an application torque setting scale tooled into the outside surface of the magnetic clutch assembly, near the bottom edge thereof. It is contemplated within the scope of this invention to have a device that contains both a top load spring setting scale tooled into the outside surface of the first housing assembly and an application torque setting scale tooled into the outside surface of the magnetic clutch assembly. 
   There is a first housing assembly having an upper portion and a lower portion, wherein the lower portion has an outside wall and the first housing assembly is shielded by a two-piece cup assembly. 
   The two-piece cup assembly comprises an independent upper cup having an open bottom, a top and a bottom edge. The top has a large central opening through it. The upper cup is mounted over the compression spring and the upper cup is retained in place by the spring retention plate. 
   There is an independent lower cup. The lower cup has a bottom, an open top, and an outside surface and the bottom has a large central opening through it. The lower cup is mounted under the compression spring and the lower cup is retained in place by the adjustment ring while the bottom edge of the upper cup slidably overlaps the outside surface of the lower cup. 
   The upper double row angular contact thrust bearing magnetic clutch housing and the upper end of the lower shaft contains a seal between them to seal the bearings. The first housing assembly housing and the outside edge of the upper double row angular contact thrust bearing magnetic clutch housing also have a seal between them. 
   There is a multiple component grease port assembly contained in the interior of the wall of the lower portion of the first housing assembly housing. The multiple component grease port assembly comprises a first vertical shaft having a predetermined diameter less than the thickness of the wall of the lower portion of the first housing assembly, a top end, a bottom end, an upper segment, and a lower segment. 
   The first vertical shaft has a first opening in the top that is sealed with a removable plug. The lower segment has a diameter less than the diameter of the upper segment and the first vertical shaft has a second opening through the side wall of the first vertical shaft upper segment leading to the upper portion of the first housing assembly. 
   The first vertical shaft has contained in it a resilient spring surmounting a metal ball bearing. The spring and the metal ball bearing are in contact with each other. The metal ball bearing located at and rests at the juncture of the upper segment and the lower segment of the first vertical shaft. 
   The second vertical shaft openly connects to the first vertical shaft. The second vertical shaft has a bottom end, and the bottom end is sealed with a removable plug. There is an angled shaft openly connected to the second vertical shaft and it opens through the outside wall of the lower portion of the first housing assembly housing. 
   In a second embodiment, this invention comprises a capping head assembly comprising a first housing assembly securable to a drive spindle, through a spindle adapter. The first housing assembly has an outside surface and a top portion, a middle portion, and a lower portion. 
   There is a spring retention plate surrounding the first housing assembly, the spring retention plate comprising a combination of a lower jam nut and an upper adjustment ring. 
   There is a compression spring mounted beneath the lower jam nut and it surrounds the first housing assembly. The spring slidably rests on a portion of a magnetic clutch housing. The first housing assembly is shielded by a two-piece cup assembly, the first housing assembly having an upper portion and a lower portion. The lower portion has an outside wall and is shielded by a two-piece cup assembly, the two-piece cup assembly comprising an independent upper cup having an open bottom, a top and a bottom edge. The top has a large central opening through it and the upper cup is mounted over the compression spring, and under the adjustment nut. The upper cup is retained in place by the adjustment nut. 
   There is an independent lower cup. The lower cup has a bottom, an open top, and an outside surface. The bottom has a large central opening through it. The lower cup is mounted under the compression spring and is retained in place by a first upper housing of a magnetic clutch assembly. The bottom edge of the upper cup slidably overlaps the outside surface of the lower cup. The outside surface of the lower cup has multiple circumferential lines having a predetermined spacing between them, tooled into the outside surface. 
   There is a magnetic clutch assembly housing comprising an upper housing containing a metal tube comprised of a lower portion having a top edge, and an upper nut portion having a lower edge and a top, the top edge of the lower portion and the lower edge of the upper nut portion being threaded such that they mate and thread together. The nut has a flange at the top. The flange has a diameter larger than the diameter of the upper housing, the difference in diameter of the upper housing and the flange, provides a stop for any upward movement of the first housing assembly. There is a plastic tube insert fitted on the inside of the metal tube. The upper housing has a bottom end outside edge. 
   The lower housing comprises a container for magnetic components for the capping head assembly. The lower housing has a top, a shouldered portion near the top, an outside wall, and an interior hollow shaft with a bottom portion, and a bottom edge. 
   The shaft has a threaded upper end, and is held in place by a threaded ring nut wherein the threads of the threaded wing nut mate with the threaded upper end of the hollow shaft. 
   The lower housing houses a first annular drive magnet in a torque ring that is not movable relative to the magnetic clutch assembly. It has a multiple pole configuration. The first annular drive magnet is held in place by a first magnet plate. 
   There is a second annular drive magnet in the magnetic clutch assembly that has a multiple pole configuration, the second annular drive magnet is also held in place by a second magnet plate. 
   There is a moveable hysteresis annular magnet interposed between the first and second annular drive magnets, the magnets being axially spaced from each other, and each drive magnet being potted in a potting compound. 
   There is means for adjusting the position of the torque ring relative to the magnetic clutch assembly, the means comprising a torque adjustment rotating end cap that changes the polarity of the second annular magnet in the magnetic clutch assembly relative to the first annular drive magnet in a predetermined position whereby the flux of the magnets can be changed to vary the torque limit of said magnetic clutch assembly. The torque adjustment rotating end cap is rotatably mounted in the bottom end of the magnetic clutch assembly. 
   Further, there is a means for securing the torque ring relative to the magnetic clutch assembly to retain the torque ring in a fixed position and there is a first radial ball bearing located supra to the first annular drive magnet and it encircles the rotatable drive member. 
   There is a second radial ball bearing located infra to the second annular drive magnet and it encircles the rotatable drive member as well. 
   The threaded ring nut and the upper portion of the shouldered second lower housing contain a seal between them to seal the bearings and the upper housing bottom end outside edge and the lower housing shouldered portion near the top having a seal between them as well. 
   There is a seal between the torque adjustment rotating end cap and the bottom portion of the interior hollow shaft and a seal between the second magnet plate and the lower edge of the lower housing of the magnetic clutch assembly. 
   A further embodiment of this invention is a capping head assembly as set forth Supra wherein the first housing assembly has a multiple component grease port assembly contained in the interior of the wall of the first housing. The multiple component grease port assembly comprises a first opening in the first housing assembly wall that contains a grease zerk in it. 
   It also contains a first vertical shaft. The first vertical shaft has a predetermined diameter less than the thickness of the wall, a top end, a bottom end and a first opening in the top end that opens to the grease zerk. 
   The second vertical shaft has a diameter greater than the first vertical shaft, but less than the thickness of the wall, the second vertical shaft having an upper opening and a lower opening, the upper opening aligning with the bottom end of the first vertical shaft and the bottom end having an opening passing through the wall and into the lower housing. 
   The capping head assemblies of this invention have several other improvements over prior art devices that provide additional advantages, namely, there are more radial holes in the clutch body for machines having little space. This makes it easier to install and remove headsets. 
   In addition, there are more radial holes in the top load spring adjustment rings. This makes it easier to adjust the top load on the machine. Further, the devices of this invention have reduced inertia output nuts that reduce the torque variation with changes in bottling speed. 
   The devices of this invention also have reduced inertia internal magnets that reduce the torque variation with changes in bottling speed and as will be note infra, there are spring covers with adjustment height guides tooled into them to provide instant visual settings to adjust the turret height of the capping machine. 
   Still other improvements are color coded high and low force springs that provide quick visual reference for which spring is in the headset and there are new seals in conjunction with the use of the spring covers that provide protection in steam, water, and hot fill applications. This combination provides longer life in these kind of applications. 
   Finally, the devices of this invention have a changed greasing situation in that improved grease distribution assemblies and improved grease retention are provided in the top load assembly. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a full front view of one device of this invention. 
       FIG. 2  is a full top of the device of  FIG. 1 . 
       FIG. 3  is a full cross sectional front view of a device of this invention through the line A-A of  FIG. 2 . 
       FIG. 4  is a full cross sectional side view of a device of this invention through the line B-B of  FIG. 2  wherein the device has been revolved about 90°. 
       FIG. 5  is an enlarged view of the area H of  FIG. 3  showing the details of the grease assembly. 
       FIG. 6  is a full side view of another embodiment of this invention. 
       FIG. 7  is a full top view of the device of  FIG. 6 . 
       FIG. 8  is a full cross sectional top view taken through line C-C of  FIG. 7 . 
       FIG. 9  is a full cross sectional side view of  FIG. 6  taken through line D-D of  FIG. 7 . 
       FIG. 10  is a full cross sectional side view of  FIG. 6  taken through line E-E of  FIG. 7 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Thus, the invention disclosed and claimed herein deals with a capping head assembly  1  for capping containers. Turning now to  FIG. 1 , there is shown a full front view of the device  1  of this invention. There is shown a first housing assembly  2  that is securable to a drive spindle, not shown, and a magnetic clutch assembly  3 . 
   With reference to  FIG. 4 , there is shown the first housing assembly  2  that has a top portion  4  and a lower portion  5 , wherein the lower portion  5  has an upper segment  6 . The first housing assembly  2  has a compression spring  7  surrounding it. 
   The compression spring  7  is mounted beneath a spring retention plate  13  and held in place around the first housing assembly  2  by the spring retention plate  13  and the spring retention plate  13  is held in place by a retainer ring  10 . The compression spring  7  slidably rests on a moveable spring pre-load adjustment ring  8  that is threadedly mounted around the middle portion  9  of the first housing assembly  2  and said moveable spring pre-load adjustment ring  8  works in conjunction with a jam nut  11  to provide an adjustment for the compression spring  7  in a vertical movement, and the jam nut  11  prevents the adjustment ring  8  from moving in either direction. This assembly allows one to control the amount of compression that is used in the assembly. 
   Threaded onto the bottom of the first housing assembly  2  is a magnetic clutch assembly  3 , said magnetic clutch assembly  3  has an upper portion  12  and a bottom edge  14 . Shown at the bottom edge  14  is a torque adjustment rotating end cap  15  which is used to adjust the internal magnets, discussed infra, and, a magnetic assembly clamping nut  16 . 
   Shown on the outside surface  17  of the first housing assembly  2  is a spring pre-load setting index  18  that is tooled into the outside surface  17 . Also shown is a torque setting index  19 , that is located near the bottom edge  14  of the magnetic clutch assembly  3  and this index  19  is also tooled into the outside surface  21  of the magnetic clutch assembly  3 , just above the torque adjustment rotating end cap  15 . 
   With regard to  FIG. 4 , there is shown a full cross sectional side view of the device  1  of this invention, taken through line B-B of  FIG. 2 . 
   There is shown a mounting shaft opening  20 . Also shown is the spring retention plate  13 , the retainer ring  10 , compression spring  7 , moveable spring pre-load adjustment ring  8  and jam nut  11 . In addition, there is shown the magnetic assembly clamping nut  16  and the torque adjustment rotating end cap  15 . 
   The wall  22  of the top portion  4  of the first housing assembly  2  has semi-cylindrical indentions  23  located therein, typically about four such indentions. The indentions  23  are circumferentially located about the first housing assembly  2  and each holds a metal pin  24 , which acts as a device to transmit torque from the drive spindle, thru wall  22  to the bottom portion  5  of the first housing assembly  2 . Typically there are four such metal pins  24  in each first housing assembly  2  and it is preferred that these pins are manufactured out of stainless steel to prolong the life of such pins. The torque from the drive shaft is transmitted to the first housing assembly  2  through the metal pins  24 . This permits the upper portion  4  of the first housing assembly to move relative to the entire first housing assembly  2  against the action of the compression spring  7  during which action the metal pins  24  will move in the semi-cylindrical indentions  23 . The metal pins  24  provide a positive connection between the first housing assembly  2  and the lower portion  5  of the first housing assembly  2 . 
   The lower portion  5  of the first housing assembly  2  has a threaded connection between the first housing assembly  2  and the upper portion of  12  of lower assembly  3 . 
   A novel feature of these inventive devices is that the first housing assembly  2  is shielded by a cup assembly  25 , that is comprised of two cups, a lower cup  26  and an upper cup  27 , both of which are independently mounted on and around the first housing assembly  2 . The upper cup  27  has an open bottom  28 , a top  29 , and a bottom edge  30 . The top  29  has a large center opening  31 . The large center opening  31  is needed to accommodate the mounting of the upper cup  27  over the first housing assembly  2 , in that the upper cup  27  is mounted over the compression spring  7  and is retained in place by the spring retention plate  13 . 
   The lower cup  26  has a bottom  32 , an open top  33 , and an outside surface  34 . The bottom  32  has a large central opening  35  through it to accommodate the first housing assembly  2 . The lower cup  26  is mounted under the compression spring  7  and is retained in place by the adjustment ring  8 . The bottom edge  30  of the upper cup  27  slidably overlaps the outside surface  34  of the lower cup  26 . 
   The combination of the lower cup  26  and the upper cup  27  prevents liquids from entering the first housing assembly  2 , and this is in combination with certain seals that will be discussed infra. 
   Because of the this cup arrangement, there is no ready access to the interior of the first housing assembly  2  to enable one to grease the interior, especially the pins  24  and the sliding surfaces adjacent thereto. For this reason, the first housing assembly  2  has a novel assembly to enable one to grease the interior of the first housing assembly  2 . 
   Turning now to  FIG. 3 , which is a cross sectional full side view of the device of  FIG. 1 , taken through line B-B of  FIG. 2  and  FIG. 5 , which is an enlarged grease assembly taken from area H of  FIG. 3 , this novel grease assembly is contained in the wall of the lower portion  5  of the first housing assembly  2  and is comprised of a first vertical shaft  36  within the upper segment  6  of the wall  22 . This first vertical shaft  36  has a predetermined diameter of less than the thickness of the wall  22 . The first vertical shaft  36  has a top end  37 , a bottom end  38 , an upper segment  39 , and a lower segment  40 . The first vertical shaft  36  has a first opening  41  in the top end  37  that is sealed with a removable plug  42 . The lower segment  40  has a diameter less than the diameter of the upper segment  39 . The first vertical shaft  36  has a second opening  51  through the sidewall of the first vertical shaft upper segment  39  that leads to the upper portion  5  of the first housing assembly  2 . 
   The first vertical shaft  36  has contained in it, a resilient spring  43  surmounting a metal ball bearing  44  and the metal ball bearing  44  and the resilient spring  43  contact each other. The metal ball bearing  44  is located at the juncture  45  of the upper segment  39  and the lower segment  40  in the first vertical shaft  36 . 
   There is a second vertical shaft  46  openly connected to the first vertical shaft  36  and the second vertical shaft  46  has a bottom end  47  that is sealed with a removable plug  48 . 
   Finally, the novel grease assembly has an angled shaft  49  that is openly connected to the second vertical shaft  46  and this angled shaft  49  opens through the outside wall  50  of the lower portion  5  of the first housing assembly housing  2 . 
   When grease is applied to the angled shaft  49  at the opening in the outside wall  50 , the grease advances through the second vertical shaft  46  to the first vertical shaft  36  and then through the second opening  51  and into the interior of the first housing assembly  2  thereby allowing for the capability of greasing the interior of the first housing assembly  2  without having to disassemble the first housing assembly  2 . 
   Further with regard to  FIG. 3 , there is shown the magnetic clutch assembly  3 . There is an upper portion  52  and a bottom edge  14 . The magnetic clutch assembly  3  comprises a first annular drive magnet  56  in a torque ring  54  that is not movable relative to the magnetic clutch assembly  3 . The first annular drive magnet  56  has a multiple configuration. There is a second annular drive magnet  55  in the magnetic clutch assembly  3  and this magnet has a multiple pole configuration. There is a means for adjusting the position of the torque ring  54  relative to said magnetic clutch assembly  3  and this means comprises a torque adjustment rotating end cap  15  that changes the polarity of the second annular magnet  55  in the magnetic clutch assembly  3  relative to the first annular drive magnet  56  in a predetermined position whereby the flux of the magnets through the hysteresis magnet  62  can be changed to vary the torque limit of the magnetic clutch assembly  3 . The torque adjustment rotating end cap  15  is rotatably mounted in the bottom end  14  of the magnetic clutch assembly  3 . 
   Located within an upper double row angular contact thrust bearing magnetic clutch housing  57  is a annular double row angular contact bearing  58 , which bearing has not been used in this type of assembly to the patentee&#39;s knowledge. The contact bearing  58  surrounds the lower shaft  71  and rests on a magnet mounting plate  54 , and just beneath the magnet mounting plate  54  is a non-moveable annular first drive magnet  56 . Directly seated beneath the non-moveable annular first drive magnet  56  is an annular hysteresis magnet  62 , and just directly beneath the hysteresis magnet  62  is a moveable annular second drive magnet  55 . The moveable annular second drive magnet  55  is held in place and attached to the torque adjustment rotating end cap  15  by screw or bolt  64 . 
   It should be noted that the combination of the lower shaft  71 , a spacer  65 , the contact bearing  58  and the hysteresis magnet  62  are all held in place by the shaft nut  16 . The moveable annular second drive magnet  55  is attached to the torque adjustment rotating end cap  15 . By turning the torque adjustment rotating end cap  15 , the moveable annular second drive magnet  55  can be moved in a circular motion. 
   Both of the annular drive magnets  56  and  55 , are magnetized in a multiple pole configuration. If one envisions a pie that has been sliced into multiple pieces, each individual piece would represent a different pole. The hysteresis magnet  62  is located between the drive magnets  56  and  55 . When the drive magnets  56  and  55  have poles of North and South that are directly lined up opposite each other, the magnetic flux goes straight through the center of the hysteresis magnet  62 . This is the minimum torque position of this apparatus. When the poles of the drive magnets  56  and  55  line up North and North directly opposite each other, the flux goes into the center hysteresis magnet  62 , travels circumferentially around the magnet, and then exits to a south pole. Because the flux travels so far within the hysteresis magnet  62 , this is the maximum torque position of the magnets. Thus, in this invention, the torque is adjusted by changing the relative angular positions of the magnetic poles of the drive magnets  56  and  55  to each other, and the torque is not adjusted or influenced by the air gaps between the magnets as in the prior art devices. 
   In  FIG. 1 , it should be noted that there are two torque adjustment set screws  66  that are inserted through the wall  67  of the magnetic clutch housing  57  to impede the movement of the torque adjustment rotating end cap  15 . When it is desired to adjust the torque, the screws  66  are loosened and the adjustment is made, then the screws  66  are tightened to hold the torque adjustment rotating end cap  15 . 
   Turning now to  FIG. 4 , which is a full cross sectional side view of the device  1  of  FIG. 1 , through lines B-B of  FIG. 1 , there is shown a bolt  68  that holds the magnet mounting plate  59  to the magnetic clutch housing  57  and also there is shown a screw  69  that holds the first, non-moveable drive magnet  56  to the torque ring  54 , so that it cannot move out of position. The terminal end  41  of the magnetic clutch assembly contains a chuck, not shown, that is used to grip the caps that are used for capping containers. 
   In  FIG. 3 , the upper double row angular contact thrust bearing magnetic clutch housing  57  and the upper end  70  of the lower shaft housing  59  contain a seal  72  between them to seal the bearings  58  from the influence of liquids. In addition, the first housing assembly  2  lower portion  5  of the housing and the outside edge  74  of the upper double row angular contact thrust bearing magnetic clutch housing  57  have a seal  73  between them to seal off any influence from liquids. 
   Turning now to one other embodiment of this invention, there is shown in  FIG. 6 , a capping head assembly  75  comprising a first housing assembly  74 , securable to a drive spindle (not shown) through a spindle adapter  76 . The first housing assembly has an outside surface  77  and a top portion  78 , a middle portion  79 , and a lower portion  80 , best viewed in  FIG. 8 . 
   There is a spring retention plate  81  for the compression spring  82 . The spring retention plate  81  surrounds the first housing assembly  74  and is comprised of a combination of an upper jam nut  83  and a lower adjustment ring  84 . 
   The compression spring  82  is mounted beneath the lower adjusting nut  84  and the compression spring  82  surrounds the first housing assembly  74 . The compression spring  82  rests on a lower portion  85  of the magnetic clutch housing  100 , described infra. 
   The upper housing assembly  86  is shielded by a two-piece cup assembly, the two-piece cup assembly comprised of an independent upper cup  27  having an open bottom  28 , a top  29  and a bottom edge  30 , The top  29  has a large central opening  91  through it to accommodate the first housing assembly  74 . 
   The independent upper cup  87  is mounted between the compression spring  82  (beneath it) and the lower adjustment ring  84  (over it), the independent upper cup  87  being retained in place by the adjustment ring  84 . 
   There is an independent lower cup  92  having a bottom  93 , an open top  94 , and an outside surface  95 . The bottom  93  has a large central opening  96  through it. The independent lower cup  92  is mounted under the compression spring  82  and the independent lower cup  92  is retained in place by a first upper housing  86  of the magnetic clutch assembly  100 , the bottom edge  90  of the independent upper cup  87  slightly overlaps the independent lower cup  92 , and slides independently of the independent lower cup  92 . 
   The independent lower cup  92  has tooled into its outside surface  95 , multiple circumferential lines  97  having a predetermined spacing between them that allows for tracking the adjustment of the compression spring  82 . 
   The other major part of the capping head assembly  75  is the magnetic clutch assembly and it is contained in a magnetic clutch assembly housing  100 . The magnetic clutch assembly housing  100  is comprised of an upper housing  86 , and a lower housing  85 . The upper housing  86  contains a metal tube  99  comprised of a lower portion  101  having a top edge  102 , and an upper nut portion  103  having a lower edge  104  and a top  105 . 
   The top edge  102  of the lower portion  101 , and the lower edge  104  of the upper nut portion  103  are threaded such that they mate and thread together. 
   In addition, in the upper portion  86 , there is a another threaded portion consisting of a flanged nut  106 , the flanged nut  106  having a diameter larger than the diameter of the upper housing  86 , the difference in diameter of the upper housing  86  and the flanged nut  106  providing a stop  107  for any upward movement of the first housing assembly  74 . The metal tube  99  has a plastic tube insert  108 . The lower housing  85  has a bottom end outside edge  109  which will be discussed infra. 
   The lower housing  85  comprises a container for the magnetic components of the capping head assembly  75 . The lower housing  85  has a top  110 , a shouldered portion  111  near the top  110 , an outside wall  112 , and an interior metal tube  99 , interior plastic tube  108 , in hollow shaft  113 , with a bottom portion  114 , and a bottom edge  109 . 
   The first assembly  2  has a threaded upper end  149  and the first assembly  2  is held in place by the threaded nut  150 . The threads  151  of the threaded nut  150  mate with the threaded upper end  149  of the first assembly  2 . 
   Surrounding the interior hollow shaft  113  is a first annular drive magnet  118  set in a torque ring  119  that is not movable relative to the magnetic clutch assembly. This drive magnet  118  has a multiple pole configuration. The first annular drive magnet  118  is held in place by a first magnet plate  120 , wherein the first annular drive magnet  118  is screwed to the first magnet plate  120  by screws  69 . 
   There is a second annular drive magnet  122  in the magnetic clutch assembly that has a multiple pole configuration. The second annular drive magnet  122  is held in place by a second magnet plate  123  using bolts  124 . 
   There is a moveable hysteresis annular magnet  125  interposed between the first annular drive magnet  118  and the second annular magnet  122 , the magnets being axially spaced from each other and each drive magnet being potted in a potting compound  126 . 
   There is a means for adjusting the position of the drive magnet relative to the magnetic clutch assembly. This means comprises a torque adjustment rotating end cap  128  that changes the polarity of the second annular magnet  122  in the magnetic clutch assembly relative to the first annular drive magnet  118  in a predetermined position whereby the flux of the magnets can be changed to vary the torque limit of the magnetic clutch assembly. The torque adjustment rotating end cap  128  is rotatably mounted in the bottom end of the magnetic clutch assembly. There is a means for securing the drive magnet relative to the magnetic clutch assembly to retain the torque ring  119  in a fixed position. 
   In  FIG. 6 , it should be noted that there are two torque adjustment set screws  149  that are inserted through the wall  112  of the magnetic clutch housing  100  to impede the movement of the torque adjustment rotating end cap  128 . When it is desired to adjust the torque, the screws  149  are loosened and the adjustment is made, then the screws  149  are tightened to hold the torque adjustment rotating end cap  128 . 
   There is a first radial ball bearing  129  located supra to the first annular drive magnet  118 . This first radial ball bearing  129  encircles the rotatable drive member. There is a second radial ball bearing  130  located infra to the second annular drive magnet  122 . This second radial ball bearing  130  also encircles the rotatable drive member. 
   There are four seal locations to prevent the entry of liquids, namely, water used in washing the capping head assemblies, and liquids that are being bottled using the capping head assembly. 
   The seals are located between: 
   the threaded ring nut  103  and the upper portion of the shouldered second lower housing  111 , seal  131 ; 
   the upper housing bottom end outside edge  154  and the lower housing shouldered portion near the top  155 , seal  132 ; 
   the torque adjustment rotating end cap  128  and the bottom portion of the interior hollow shaft  111 , seal  133 , and 
   second magnet plate  123  and the lower edge of the lower housing  85  of the magnetic clutch assembly, seal  134 . 
   Turning now to  FIG. 9 , which is a cross sectional view of the device of  FIG. 6 , through line D-D of  FIG. 7 , in the upper portion  86  of the magnetic clutch housing  100 , there is shown the wall  117 . The exterior of the wall  117  has semi-cylindrical indentions  135  located there, typically about four such indentions. The indentions  135  are circumferentially located about the upper portion  86  of the magnetic clutch housing  100 , and each holds a metal pin  136 , which acts as a device to transmit torque from the drive spindle, thru the wall to the magnetic clutch assembly  100 . Typically there are four such metal pins  136  in each wall  117  and it is preferred that these pins are manufactured out of stainless steel to prolong the life of such pins. The torque from the drive shaft is transmitted to the magnetic clutch assembly  100  through the metal pins  136 . 
   Turning now to  FIG. 10 , which is a cross sectional view of the device of  FIG. 6  taken through line E-E of  FIG. 7 , there is shown the lubrication system for the metal pins  136 . The first housing assembly  74  has a multiple component grease port assembly contained in the interior of the wall  137 . The multiple component grease port assembly comprises a first opening  138  in the first housing assembly wall  137  containing a grease zerk  139  therein. 
   There is a first vertical shaft  140 , having a predetermined diameter less than the thickness of the wall  137 , a top end  141 , a bottom end  142 . The first vertical shaft  140  has a first opening  143  in the top end  141  that opens to the grease zerk  139 . 
   There is a second vertical shaft  144  having a diameter greater than the first vertical shaft  140 , but less than the thickness of the wall  137 . The second vertical shaft  144  has an upper opening  145  and a lower opening  146 , the lower opening  146  being plugged with plug  148 , the upper opening  145  aligning with the bottom end  142  of the first vertical shaft  140  and the bottom end  142  having an opening  147  passing through the wall  137  and into the metal pins  136  and indentions  135 .