US3035337A - Automatic machine for applying threaded closure caps to collapsible tubes and the like - Google Patents

Description

M y 22, 1962 F. R. MEIERHOFER 3,035,337

AUTOMATIC MACHINE FOR APPLYING THREADED CLOSURE CAPS TO COLLAPSIBLE TUBES AND THE LIKE Filed March 12, 1957 3,035,337 AUTOMATIC MAC FOR APPLYENG THREAD- El) CLOSURE CAPS T CGLLAFSKBLE TUBES AND THE LIKE Friedrich Robert Mcierhofcr, Wanlrdorfieldstrasse 105, Bern, Switzerland Filed Mar. 12, 1957, Ser. No. 645,58d Claims priority, application Switzerland Mar. 15, W56 8 Claims. (Cl. 29-24tl) The present invention relates to an automatic machine for applying threaded closure caps to collapsible tubes of the type used for dispensing semi-fluid substances such as toothpaste, creams and the like and tightening each cap on the threaded shank of its associated collapsible tube prior to filling the tube.

The automatic machine of the present invention performs the operation of securely screwing a threaded cap on each collapsible tube before the tube is forwarded to the filling machine. At this stage, the large end of each tube is open thereby permitting it to be mounted on a rotary mandrel while the closure cap is applied.

The cap mounting machine comprises a turntable carrying a series of mandrels. Three stations are provided. At the first, or oiling station, the threaded shank of each tube is daubed with a lubricant. At the second station, or cap pickup station, the lubricated shank of the tube is loosely threaded into a waiting cap held by suitable cap feeding mechanism, but the cap is not tightened. At the third or wrench station, a stationary wrench socket is provided and the loosely threaded cap is inserted in the wrench socket and fully tightened. The maximum torque of the final tightening operation is limited by a slip clutch connected to permit rotation of the otherwise stationary wrench socket.

A main power operated camshaft is provided which synchronizes the operations of the several instrumentalities of the automatic machine and also causes or controls intermittent angular displacement of the turntable whereby each tube is advanced successively from the lubrieating station to the pickup or threading station and from the cap pickup station to the tightening station. The amount of angular displacement of the turntable each time that it is advanced is equal to the angular spacing between adjacent mandrels and the three stations are spaced for simultaneous cooperation with three separate tubes supported on three different mandrels.

An object of the invention is to avoid breakage of the caps, which are ordinarily formed of inexpensive and brittle plastic material, this being effected by the provision of resilient cushioning means and slip clutches so that excessive forces cannot be exerted on the closure cap at any time.

Another object of the invention is the provision of interchangeable socket wrench members for receiving closure caps of different sizes and shapes.

Various additional objects, features and advantages of the invention will become apparent upon reading the folllowing specification together with the accompanying drawing forming a part hereof.

Referring to the drawing:

FIGURE 1 is a diagrammatic view of a complete automatic cap applying machine shown in side elevation, the machine being partly broken away and shown in axial section to illustrate details of construction.

FIGURE 2 is an enlarged fragmentary front elevational view showing the lower or terminal end of the cap feeding mechanism.

FIGURE 3 is an enlarged front elevational View of the stationary wrench socket.

The machine which is illustratively disclosed comprises a stationary supporting bracket 1 which carries 3,35,337 Patented May 22, 11962 conventional orienting and feeding means for continuously supplying threaded closure caps 2. The orienting portion of the cap feeding means is conventional and is diagrammatically shown as a storage cylinder 3 including suitable power operated means for gathering individual caps 2 and feeding them With their interiorly threaded end portions all oriented in the same direction. Each cap 2 comprises an interiorly threaded shank portion 2a which is to be applied to the exteriorly threaded integrally formed shank portion of a collapsible tube as described below. In conventional manner, the shank portion of each collapsible tube has an open-ended axially extending aperture formed therein. This aperture is not visible in the drawing. The inner end of the axial aperture communicates directly with the interior of the tube. The outer end of the aperture is normally closed by the threaded cap. When the cap is removed, the contents of the tube may be discharged through the open-ended axial aperture. The cap 2 also comprises an enlarged octagonal head portion 2b having a slightly rounded crest. The heads 2b are longitudinally slidably disposed in a cap feeding chute 4 with the interiorly threaded cylindrical shank portions 2a of the caps projecting outwardly between spaced parallel guide members of the chute 4-. The chute 4 extends horizontally from the top of the storage and orienting device 3 and thence downwardly, terminating in a vertical portion disposed above a horizontally reciprocable cap holder 7. The cap holder 7 is secured to a vertically extending horizontally reciprocable bar 8 by a nut 7a.

Above the nut 7a, the bar 8 is slidably mounted on a guide stud Eta. At its lower end, the bar is has a boss 9 formed thereon which is fixed to the right hand end of a horizontally reciprocable slide rod Ill. At its left hand end, the slide rod 10 carries axially spaced collars liia and 10b. The collars Ma and 10b are engaged by the free end of the upwardly extending arm of a bellcrank lever 13. The bell-crank lever 13 is pivoted at 13a to a fixed supporting bracket 1312.

A main cam shaft 11, driven at constant speed by a suitable motor or other means (not shown), carries a circular cam 12 which engages a cam follower roller 14 mounted at the free end of the laterally extending arm of the bell-crank lever 13. When the cam follower roller 14 is engaged by the raised portion 12a of cam 12, the slide rod 10 and vertical bar 3 are displaced toward the left and held in the position shown in FIG. 1. When the roller 14 engages the depressed portion 12b of cam 12, suitable springs or other means (not shown) urge the slide rod 14) and vertical bar 3 toward the right.

A further cam 15 is fixed to the main camshaft 11 and comprises a raised portion 15a and a depressed portion 155. A plurality of lever members 16 are provided. Each lever member 16 is pivoted intermediate its ends at 16:: to a fixed supporting bracket 1611. As shown in the drawing, the lower one or" the levers 16 is provided with a cam follower roller 1'7 which engages the cam 15. The corresponding cam follower roller of the upper lever member 16 has been omitted fromthe drawing for simplicity of illustration. It is to vbe understood, however, that both lever members 16 oscillate in unison on their respective pivots lea, suitable means such as a further cam 15 being provided for the actuation of the upper lever member 16.

Thrust bearings 18 are mounted on axially displaceable lower and upper spindles 18a and 1811. Each thrust bearing 13 is pivotally connected to the upper end of one of the lever members 16 by a pin 19. The machine comprises a series of leftwardly spring pressed axially movable drive rods 21} each provided with a rubber tip 21. Upon movement toward the right of the thrust bearings 18, the spindles 18a and 18b are displaced toward the right and the axially displaceable drive rods are simultaneously forced toward the right and placed in driving connection with the spindles 18a and 181: by engagement of serrated clutch members of the clutches 22. The collapsible tubes 23, which are axially slidably mounted on freely rotatable mandrels 24 journaled in ball bearings 24a, are thereupon forced toward the right and are caused to rotate by frictional engagement with the mandrels 24 and with the rubber tips 21 of the drive rods 20, the drive rods 20 being slidably keyed or otherwise connected with the mandreis 24 so that each drive rod 20 and its associated mandrel 24 rotate together as a unit. The resilient tips 21 frictionally and yieldingly engage the collapsible tubes 24 at the inner ends of their exteriorly threaded shank portions 23a.

The cap holder 7 comprises a leftwardly spring pressed axially displaceable slide member 25 provided with a leftwardly projecting lower lip 25a for retaining the lowermost one of the caps 2 within the cap feeding chute 4. The slide member 25 carries a leftwardly projecting rubber bumper 26 positioned for central resilient frictional engagement with the rounded outer surface or crest of the head of the lowermost cap 2 within the cap feeding chute 4. The bumper 26 is eccentrically located with respect to the axis of the slide member 25.

The machine is provided with suitably powered drive gears 27 having wide faced teeth. Only peripheral fragments of the drive gears 27 have been shown in section in the drawing. The drive gears 27 mesh with pinions 28 freely rotatably mounted on the spindles 18a and 18b and connected thereto for axial displacement therewith. The pinions 28 are connected to drive their respective spindles 18a and 1811 through friction slip clutches 29 which limit the maximum torque which can be transmitted from either of the spindles 18a or 1812 to the rubber tip 21 of any of the drive rods 20 while the drive rod 20 is connected thereto through the cooperating serrated clutch members of clutches 22.

The mandrels 24, which are eight in number, are carried by a circular turntable 30 which is revoluble about a horizontal axis. The rotational axis of the turntable 30 is parallel to and located directly behind the axis of the upper spindle 18b, as viewed in FIG. 1. The eight mandrels 24 are arranged with their axes at the corners of a regular octagon concentric with the turntable 3%). Suitable mechanism, operated or controlled by or in synchronism with the cam shaft 11 causes the turntable 30 to advance periodically through an angle of 22 /2 in a counterclockwise direction as viewed from the right of FIG. 1. This advance of 22 /2 takes place once for each revolution of the cam shaft 11. The intermittent periodic rotation of the turntable is produced by a ratchet mechanism, a Geneva mechanism, or similar conventional means (not shown) which is operative during a period while both of the cam follower rollers 14 and 17 are in engagement with the depressed portions 12b and 15b of cams 12 and 15, respectively. During this period, all of the cooperating serrated members of the clutches 22 are disengaged and the vertical bar 8 is displaced toward the right from the position shown in FIG. 1 so that the turntable carried clutch members of the clutches 22 and the tubes 23 may pass freely from station to station.

At the wrench station there is an interchangeable socket wrench member 31 which is shown (FIG. 3) having a cap head receiving recess 31a formed therein. The recess 31a is shaped to receive the enlarged octagonal head of the cap 2 in either of two different angular positions of presentation and for this purpose the cap receiving recess 31a is illustratively shown provided with sixteen regularly spaced peripheral indentations for alternate engagement by the eight corners of the cap head 2b. The socket wrench member 31 carries a centrally apertured discshaped stop member 32b for limiting inward movement of the cap head 2b beyond the cap receiving recess 31a. The socket wrench member 31 is secured by a threaded cap 32 to an axially fixed rotatable spindle 32a journaled in a ball bearing 32b. Rotation of wrench spindle 32a during the cap tightening operation is prevented by a friction type torque limiting slip clutch comprising a spring pressed rotatable clutch member 34a axially slidably splined on the wrench spindle 32a and a fixed friction facing 34!) in continuous engagement with the rotatable clutch member 34a. The wrench spindle 32a is hollow and an ejector rod 33 is axially slidably disposed in the spindle 32a. The ejector rod 33 is provided with an enlarged head 33a which is yieldingly urged toward the right by a compression spring 33b surrounding the rod 33. The left hand end of ejector rod 33 may pass freely through the central aperture in the stop member 3211 for ejecting the head 2b of a cap 2 from the wrench recess 31a after completion of the tightening operation.

The ejection action takes place when the vertical bar 8 moves toward the right upon engagement of the cam follower roller 14 with the depressed portion 12b of cam 12. For this purpose, a lever member 35 pivoted at 35a midway between its ends, is mounted on a fixed supporting rod 35b and carries rollers 36 and 37 disposed at its ends. A rod 36a is secured to the vertical bar 8 for horizontal movement therewith and forces the roller 36 to the right as the bar 8 is displaced toward the right in response to rotation of the cam 12. Thereupon, the head 33a of ejector rod 33 is pressed leftwardly by the roller 37 and the cap 2 which wa previously inserted in the socket wrench recess 31a is ejected therefrom and the tube 23 upon which the cap has been tightened is forced back leftwardly upon its mandrel 24 so that the tightened cap may move freely past the wrench station upon the next 22 /2 advance of the turntable 30.

At the cap pickup station, there is cap feed stopping lever 38 (FIGS. 1 and 2) which is pivotally connected by a bolt 38a to a depending ear 25b of the spring pressed slide member 25 of the horizontally reciprocated cap holder 7. At its upper end, the cap feed stopping lever 38 carries a leftwardly projecting rubber friction member 39 for engagement with the rounded crest of the cap 2 in the chute 4 which is disposed immediately above the lowermost cap. The cap feed stopping lever 38 is biased to rotate in a counterclockwise direction as viewed in FIG, 1 by a tension spring 40. The feed stopping lever 38 carries a laterally extending projection 38]; (FIG. 2) which engages a stationary plate 38c when the cap holder 7 moves leftwardly to the position shown in FIG. 1. The projection 38b thus causes clockwise displacement of the stopping lever 38 and retraction of its resilient friction member 39 from engagement with the penultimate cap 2 in the chute 4. When the vertical bar 8 moves to the right after completion of the tightening operation the cap holder '7 likewise moves toward the right and the tension spring 40 rotates the feed stopping lever 38 in a counterclockwise direction so that its friction member 39 presses against the head of the penultimate cap in the chute 4 and prevents downward gravitational feeding of the caps while the lower lip 25a is withdrawn from beneath the cap just picked up by the tube at the cap pickup station.

At the lubricating station, there is a hollow cylinder 41 integrally formed with the vertical bar 8 at its upper end. The cylinder 41 is provided with a large screw plug 42 threaded into its right hand end and which closes the cylinder. The screw plug 42 exerts pressure on a stack of felt discs 43 disposed at the left hand end of the cylinder 41. The left hand end of the cylinder 41 is provided with an inwardly turned lip 41a for retaining the felt discs 43 in the cylinder 41. Lubricant is supplied to the felt discs 43 by an oil cup 44 provided with a lid 45.

As shown, a conical recess 43a is formed in the stack of discs 43 for receiving the threaded shank 23a of the tube 23 and daubing lubricant thereon. This daubing may be accomplished in either of two manners neither one of which is shown in the drawing. One method consists in relocating the entire cylinder 41 and its contents toward the left as viewed in FIG. 1 so that the shank 23a of the tube will be disposed in the conical recess 43a and in engagement with the felt discs 43 with the vertical bar 8 in its leftwardly displaced position which is shown in FIG. 1. Then, when the bar 8 moves toward the right after completion of the cap pickup and tightening operations at the pickup and wrench stations, the lubricated shank 23a will be disposed outside the recess 43a permitting the shank 23a to move freely onwardly to the cap pickup station upon the next 22 /2 displacement of the turntable 30.

Alternatively, a spindle similar to the spindles 18a and 18b may be provided and actuated in unison therewith so that the threaded shank 23a is moved toward the right and into the recess 43a, being rotated therein to pick up a coating of lubricant. If this is done, however, ejection means similar to the ejection rod 33 at the wrench station and operating in unison therewith must be provided to eject the lubricated shank 23a from the recess 43a after the lubricating operation has been completed.

In operation, the cam shaft 11 revolves at constant speed in a counterclockwise direction. Application of lubricant at the lubricating station takes place as described above. The turntable has advanced through 22 /2 degrees of rotation and a different set of tube 23 is presented at each station. At the pickup station, a cap 2 with its head 2b supported at the bottom of the chute 4 is pressed and frictionally engaged by the rubber bumper 26 so that it is resiliently held for starting the thread without breakage. At this stage, the cap is held slightly against rotation but is sufficiently strongly held to permit the cap 2 to be threaded loosely on the previously lubricated shank 23a without being tightened thereon.

At the wrench station, the ejector rod 33 is withdrawn from the wrench recess 31a so that a loosely threaded cap may be received therein.

The cam roller 17 next rides up on the raised portion 15a of cam 15 and the drive rods 24] resiliently press their associated tubes into rotary engagement with the waiting cap at the pickup station and with the wrench recess 31a at the wrench station. A loosely threaded cap is thus picked up at the pickup station and the previously loosely threaded cap is tightened at the wrench station.

Roller 14 then engages the depressed portion 12b of cam 12. Thereupon the vertical bar 8 moves to the right. At the pickup station, the cap holder 7 moves toward the right and the lower lip 25a of slide member 25 is withdrawn from beneath the cap which is then partially or loosely threaded on the shank 23a of the tube. The tube at the pickup station remains displaced toward the right on its mandrel because the picked up cap is still held in the lower end of the chute 4 (FIG. 2). In this displaced or longitudinally advanced position, however, it will be seen that the loosely threaded cap will nevertheless clear the socket wrench 31 and arrive at the wrench station somewhat spaced away from the wrench recess 31a without being pushed back on its mandrel 24. This longitudinally advanced position of the tube is indicated in dotted lines at the wrench station in FIG. 1. In the meantime, during movement to the right of the cap holder 7 and before the next rotational step of the turntable 30, the friction member 39 of the cap feed stopping lever 38 engages the cap immediately above the cap which has just been picked up.

At the wrench station, movement toward the right of the bar 8 causes the tightened cap to be ejected from the wrench recess 31a. Thereafter, with the roller 14 still engaging the depressed portion 12b of cam 12, the roller 17 engages the depressed portion 15b of cam 15 so that the bearings 18 and spindles 18a and 1812 move leftwardly and the clutches 22 are disengaged. During the period beginning after this time and ending before the roller 14 next engages the raised portion 12a of cam 12, the turntable 30 is advanced through 22 /2 This movement of the turntable causes the cap which is in the bottom of the chute 4, then being loosely threaded on the shank 23a of the tube by which it has just been picked up, to move with the tube downwardly out of the bottom of the chute 4 to the wrench station. The cap immediately above the cap which moves downwardly out of the bottom of the chute 4 is held against downward movement by the friction member 39 of the cap feed stopping lever 38. After completion of the 22 /z movement of the turntable 30 and when roller 14 next rides up on the raised portion 12a of cam 12, the bar 8 moves toward the left. The lower lip 25a is then positioned below the bottom of the chute 4 and the friction member 39 is thereafter withdrawn thus permitting downward gravity feed movement of the caps whereby the lowest cap moves downwardly into engagement with the projecting lower lip 25a of slide member 25 and is thus positioned to be threaded on the tube located at the pickup station.

While I have shown what I believe to be a preferred embodiment of my invention, various changes and modifications may be made therein within the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In a machine of the type wherein a series of closure caps are successively threaded individually onto cooperating threaded shank portions of open ended collapsible tubes prior to filling said tubes, said tubes being mounted on a series of mandrels carried by turntable means and advanced step-by-Step whereby each tube is successively brought to and temporarily remains located at each of a plurality of stations, one of said stations being a cap applying station and another station being a cap tightening station, the improvement which consists in the provision of a lubricating station to which each tube is brought prior to being brought to the cap applying station, said lubricating station comprising an absorbent lubricant-impregnated packing adapted for daubing engagement with the end portion of each shank, means operative in synchronism with said turntable means for bringing said packing into and out of engagement with each shank while said tube remains located at said lubricating station between step-by-step advancing movements of said turntable, and means for continuously supplying lubricant to said packing.

2. The improvement according to claim 1, further comprising frictional means at the cap applying station for lightly threading the cap on the lubricant daubed shank of each tube, said threading means including a member which lightly frictionally engages each cap during relative rotation between the cap and the shank in the course of said light threading operation, whereby said cap may slip with respect to said last-named member and damage is prevented if a cap fails to thread properly on a shank.

3. In a machine of the type wherein a series of interiorly threaded closure caps are successively threaded individually onto cooperating externally threaded integrally formed shank portions of open ended collapsible tubes prior to filling said tubes, each shank portion having an open-ended axially extending aperture formed therein the inner end of which communicates directly with the interior of the collapsible tube, the outer end of said aperture being adapted for closure by one of said caps, said tubes being mounted on a series of mandrels carried by turntable means and advanced step-by-step whereby each tube is successively brought to and temporarily remains located at each of a plurality of stations, one of said stations being a cap applying station and another station being a cap tightening station, the improvement which consists in the provision of a rod coaxial with each mandrel and slidably disposed therein, frictional tip means at one end of said rod for engagement with the inner surface of the tube mounted on said mandrel at the inner end of said shank portion, means including a clutch member at the other end of said rod for simultaneously turning said rod and causing axial movement thereof, and means disposed at at least one of said stations and including a clutch member successively engageable with the clutch member on each rod for turning said rod in cap threading direc- I tion, said last-named means being operative in synchronism with said turntable means for causing engagement between said clutch members, said engagement being accompanied by axial displacement of the rod.

4. The improvement according to claim 3, further comprising torque-limiting slip-clutch means interposed between said means for turning said rod and said frictional tip means, said torque limiting means being effective with said clutch members in driving engagement with each other to limit the maximum torque which can be applied in tightening a closure cap on a tube shank.

5. The improvement according to claim 3, further comprising wrench means at said tightening station for receiving and holding a partially threaded cap stationary therein, said cap being urged into said wrench means by said axial movement of said rod and said frictional tip means.

6. The improvement according to claim 4, further comprising ejector means cooperating with said wrench means and connected for operation in symchronism with said turntable means, said ejector means forcing each cap out of said wrench means in a fully tightened condition accompanied by corresponding axial movement of said rod.

7. The improvement according to claim 1, wherein said packing is formed as a body having an aperture formed therein for receiving the outer end of the shank portion of a tube therein during the course of said daubing engagement.

8. The improvement according to claim 1, wherein said packing consists of a stack of felt discs having an outwardly divergent conical recess formed in one end thereof, Said end portion of each shank being received in sa d recess during the course of said daubing engagement.

References Cited in the file of this patent UNITED STATES PATENTS 1,678,463 Davis July 24, 1928 1,871,799 Koenigshofer Aug. 16, 1932 2,016,424 Friden Oct. 8, 1935 2,441,642 McDaniel May 18, 1948 2,550,795 Flaton May 1, 1951 2,583,457 Woodall Jan. 22, 1952 2,700,443 Boice Jan. 25, 1955 2,756,490 Sawdey July 31, 1956 2,762,544 Davis Sept. 11, 1956

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