GB2148179A

GB2148179A - Determining spinweld quality in spinwelder

Info

Publication number: GB2148179A
Application number: GB8430766A
Authority: GB
Inventors: Laughlin Donald Mac; Vincent Fortuna
Original assignee: Cosden Technology Inc
Current assignee: Cosden Technology Inc
Priority date: 1982-01-06
Filing date: 1984-12-05
Publication date: 1985-05-30
Also published as: BR8300008A; DE3248583A1; NL8205028A; FR2519291A1; GB2148179B; ES518808A0; GB8430766D0; ES8400925A1; GB2114506B; GB2114506A; IT1159811B; GB8300107D0; IT8319017A0; AU1003383A

Abstract

A method and apparatus is for determining the quality of a spinweld bond produced on a single or multiple spindle production spinwelder. The invention also provides a method and apparatus for alarming and/or ejecting products containing defective welds. The method and apparatus utilizes a detector means to determine the condition of a tool or spindle (i.e., if it is still "live" rotating at a point when it should be at rest) and a timing means to actuate an indicator when a live tool is detected. This is also disclosed means to detect a spinweld station with an actuated indicator and to eject the product thereon, and a device for automatically shutting down a spinwelder which produces an excess of defective products. <IMAGE>

Description

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SPECIFICATION

Braking apparatus and live-tool inspection system for spinwelding machinery

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The present invention relates to a braking device and to a method and apparatus for controlling thermoplastic friction welding machines. More particularly, the present invention relates to an electromechanic-10 al apparatus for determining the quality of a spin-welded bond produced by a single or multiple spindle production spinwelder and further to a method and apparatus for alarming and/or ejecting products containing defective welds. The invention 15 also relates to an integral braking means for braking a live spindle.

In the art of joining thermoplastic articles by friction welding, a device may be used which spinwelds thermoplastic axially mating sections. 20 The sections are driven in rotation relative to each other and then axially abutted in mating relationship. In a device, such as that disclosed in United States Patent No. RE 29,448, one of the two mating sections is chucked to an initial number which is 25 brought up to speed by a rotary drive. The rotary drive is uncoupled as the sections are moved into axial abutment and the breaking of the inertia member by the axial abutment of the sections is transformed into frictional heat which welds the 30 thermoplastics seams to each other.

The apparatus described above may typically be a part of a larger apparatus such as that disclosed in United States Patent No. 3,800,376 for performing a plurality of successive operations with individual 35 container sections.

Obviously, the present invention may also be useful in connection with other devices similar to those disclosed above.

In general, during the spinwelding process, welds 40 are produced by the storage of kinetic energy in the driving tool. When the two functional surfaces to be welded are brought into intimate contact, the kinetic energy is dissipated in the form of heat, thus resulting in fusion or welding of the surfaces 45 brought together.

For purposes of the description which follows, a defective weld is defined as a failure to create a bond of adequate strength, usually due to a failure of either a loss of one of the surfaces to be welded 50 through, for instance, a missing component or an improper fit; or a mechanical failure of a driving tool or the driven position of one of the components to be welded.

When such a failure occurs and the tool or spindle 55 continues to rotate, it becomes difficult to load another component onto the spindle. The moving spindle should be at rest when the component is loaded to prevent the likelihood of its flying off the rotating tool surface which may be rotating as fast as 60 2000 rpm. The prior art lacks a device for the integral braking of the spindle ortool on which the containers are carried in order to stop the rotation of the spindle so that the new container section may be loaded onto the spindle while it is at rest. The live 65 tool inspection aspect of the present invention is designed to detect excess rotation of a driving tool at a point in the spinweld process where the tool should be at rest.

In connection with known spinwelding devices, a 70 need exists for accurately and instantly determining when a container weld is defective or when an accomplished container weld has fractured. In addition, there is a need to identify and remove any defective product such as a container so that it will 75 not be utilized and its intended contents wasted. It is desirable to perform this operation accurately and automatically to maximize the production output of the overall system. In addition, it is both necessary and desirable to identify any particular piece of 80 equipment wherein a large amount of defective containers are being produced to allow for remedial or protective action.

In addition, it is necessary to design a control system for an apparatus as noted above that can be 85 retrofitted into existing equipment or incorporated in new units and which therefore uses a lower voltage power source.

Accordingly, it is an object of the present invention to provide an integral braking device for stopping a 90 tool or spindle in which a product such as a container section is to be placed prior to placing the product thereon.

It is a further object of the invention to provide a method and apparatus for determining when a 95 thermoplastic weld is defective and for removing or ejecting products with defective welds.

It is still a further object of the present invention to provide a method and apparatus for determining when a particular unit is producing an excessive 100 number of defective products and then identifying the equipment problem or automatically shutting the unit off.

In addition, it is still a further object of the present invention to provide a control device which may be 105 retrofitted onto existing equipment.

In accordance with the present invention, there is provided a spinwelding device having a braking apparatus for stopping a rotating tool, comprising.

a) a brake arm mount for mounting said braking 110 apparatus;

b) a brake arm, pivotingly supported in said brake mount on a pivot pin;

c) a brake shoe means pivotingly carried by said brake arm and having thereon a brake shoe for

115 engaging a rubbing surface of said rotating tool;

d) brake activating means resiliently spaced from said brake shoe when said braking device is inactive and operable to periodically engage said brake shoe means to brake said rotating tool.

120 The invention may comprise a braking device for single or multiple spindle spinweld machines having a brake means associated with each spindle. Where there is a top and bottom spindle, the invention will preferably provide a braking means for each one. 125 The brake means of the invention is preferably cam-operated to time the braking action to occur prior to the loading of a product or a component onto the spindle.

The braking means may preferably consist of a 130 cam-actuated, spring-loaded brake adapted to bear

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against a wear-resistant braking surface and which is self-adjusting and adjustable and which will not jam the spindles.

The inspection method and apparatus of this 5 invention may comprise either a single spindle system in which the invention would preferably operate on a time basis following weld initiation, or a multiple spindle application wherein the system would preferably scan the product at a fixed point in 10 the machine's rotation position and then alarm and/or reject any defective product.

The more complex multiple spindle embodiment would, in accordance with the present invention, comprise a means for detecting if a tool or spindle is 15 live, i.e. turning at a position after a weld should have been accomplished and the spindle be at rest, this indicates a defective weld has occurred. When a live spindle is detected, a mechanical "flag", a light or an alarm may be used to identify the station 20 having the defective product.

Preferably, a mechanical flag is used which can also preferably be used to actuate the defective product eject mechanism which senses the presence of the flag and energizes an eject mechanism. 25 Preferably the sustem will also include a means for determining the number of defective products attributable to each piece of equipment and if the number of defective welds becomes excessive, an automatic maintenance notice and/or system shut-30 down is effected.

The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which

Figure 7 is a perspective view of a machine for 35 dispensing upper and lower plastic container halves from nested stacks thereof which may be used with the system of the invention, joining these container halves together to make containers, filling the containers, and affixing caps onto the tops of the 40 containers.

Figure 2 is a somewhat diagrammatic plan view of the machine of Figure 1;

Figure 3 is a vertical cross-sectional view through the spinwelding unit of the machine of Figures 1 and 45 2.

Figure 4 is a vertical cross-section of top tooling subassembly of Figure 3 showing the brake means in cross-section.

Figure 5 is a cross-section across section line A-A 50 of Figure 4;

Figure 6 is a block diagram of the live spindle inspection system in accordance with the present invention.

Figure 7 is a block diagram of the defective 55 product rejection system in accordance with the present invention;

Figure Sis a block diagram of the live spindle detection of Figure 6;

Figure 9 is a block diagram of the flag set timer of 60 Figure 6;

Figure 10 is a timing chart of the system of Figures 6 and 7.

It will be helpful at the outset to describe generally the overall construction and operation of a spinweld-65 ing machine with which the present invention may be used. It should be understood that the details of the spinwelding machine described below are exemplary only and that the braking and detection/ ejection systems of the present invention may be used with other machines as well. One such machine is illustrated in Figures 1,2 and 3. This machine assembles plastic containers with bulk supplies of nested container halves, fills the containers, and caps and seals the open tops of the filled containers.

The containers are assembled from separately fabricated container top havles 4 and container bottom halves 6, with the two halves of each container being frictionally welded together at the middle of the container.

The machine is in the form of a base or table structure 3 carrying hereon a control panel 10, a series of processing units and means for transferring the container portions to and from the various processing units. The processing units and the transfer means are driven by intermeshing gears corresponding in location to the configuration shown in Figure 2. Preferably, a single drive unit may be employed to impart rotational movement to each drive gear and to each corresponding processing unit and transfer means. Also, the pitch line circles of the intermeshing gear drives preferably are in alignment with the circles formed by joining the centerlines of the container halves and the containers as they travel throughout the system. The processing units are all rotatable units, and transfers between units are accomplished through rotating star wheels, permitting the compact and efficient arrangement indicated in Figure 1 of the drawings.

The upper and lower container halves 4 and 6, respectively, are delivered from the star wheel device 18 into alignment with the center lines of an upper cylindrical mandrel 150 and a lower cylindrical mandrel 152. The mandrels are mounted for movement in a circular path about the central axis of the spin welder 32 (Figure 3). The transfer takes place at an angular zone where thestarwheel periphery moves into a position of tangency to the path followed by the several upper and lower mandrels. This transfer is assisted by conventional stationary guide rails 154 as illustrated in Figure 2. The end portions of the guide rails 154 intersect the path of the container halves on the star wheel 18 and cause the container halves to move onto the mandrels rather than permitting them to continue to move about the axis of the star wheel.

The star wheel device 18 includes upper and lower generally circular plates 156 having general semicircular, even circumferentially spaced cutouts 118 at their peripheries for engaging the outer peripheries of the container halves 4 and 6. The cutout portions of the upper and lower plates are superposed and the pairs of superposed cutout zones comprise carrier stations of the star wheel device 18. The plates 156 are carried by a shaft 158 extending through a stationary cylindrical member 160 and being connected at its lower end portion to a drive gear 39. This shaft 158 is jouralled within bearing means carried by the frame or table 8 and indicated generally at 161 in Figure 3.

The spin welder drive gear 43 is attached to a

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hollow drive shaft 166 extending upwardly about the center of the spin welder unit 32. This hollow shaft is rotatable about bearing means 168,170 and 172 which are located between a stationary vertical shaft 5 174 and the hollow drive shaft 166.

At its upper end the center stationary shaft 174 supports a stationary vacuum supply means generally indicated at 176 and an annular cam track 178. The platform 8 also has a part thereof a vacuum 10 supply shown generally at 180 and an annular cam track 182.

It would be helpful at this point to describe generally the spin welding operation to form a basis for the detailed description which follows. The 15 container halves, once aligned with the center lines of the upper and lower spindles or mandrels 150 and 152, are surrounded by the spindles for subsequent spinning. The spindles rotate about the central axis of the spin welder 32 and also move vertically 20 toward each other when surrounding the container halves. The lower spindle 152 which surrounds the bottom half additionally rotates about its own axis during the spinning operation. Once the container halves are frictionally welded, the spindles are 25 caused to separate and free the surrounded joined container.

Each of the spindles is moved vertically on a shaft which is stationary with respect to its own axis but which revolves about the central axis of the spin 30 welder unit 32. The shafts for the upper mandrels 150 are designated 184 and the shafts for the lower spindles 152 are designated 186. Each upper spindle shaft 184 extends downwardly from a support member 188, and each lower spindle shaft 186 35 extends upwardly from a support member 190.

These support members 188 and 190 are carried by main rotating shaft 166 at the center of the spin welder, so that the spindle shafts 184 and 186 revolve about the central axis of the spin welder 32. 40 The rotational movement of the shafts 184 and 186 about the spin welder central axis causes the spindles 150 and 152 to rotate therewith.

Vertical movements of the spindles with respect to their shafts 184 and 186 are achieved by means of 45 connecting rods 192 and 194 operatively connected to the spindles 150 and 152, respectively. These connecting rods have cam followers cooperating with the previously mentioned stationary cam tracks to vertically position the upper and lower spindles as 50 they rotate about the central axis of the spin welder 32. The upper connecting rod 192 has cam follower 196 thereon for travelling within the stationary upper cam track 178. The lower connecting rod 194 also has a cam follower 198 associated therewith for 55 movement within the lower cam track 182.

Each lower spindle 152 is additionally capable of spinning about the axis of its shaft 186 when a pulley area 200 thereof is brought into contact with the spin welder driving belt 34 (Figure 2) during a predeter-60 mined number of degrees of the rotation of the mandrel about the central axis of the spin welder 32. For this purpose, bearing means (not shown) are interposed between each spindle 152 and its shaft 186.

65 The upper vacuum supply indicated generally at

176 is suitably connected to a vacuum port which feeds to the periphery of a central opening (not shown) within the upper mandrel. The shape of this opening conforms generally to the shape of the 70 upper container half 4. The vauum is applied about the outer periphery of the container half 4 when it is being surrounded by the upper spindle 150.

Turning now to Figures 4 and 5, there is depicted a vertical and top cross-section, respectively, of the 75 braking device of the present invention in connection with a top tooling or spindle subassembly such as that of Figure 3. It should be understood that a similar assembly can be used to break the lower tooling or spindle assembly 152 of Figure 3 and that 80 a braking assembly can be provided for each rotating tool on the spinwelding machine.

The top tooling or spindle 150 of Figure 4 may be driven by a single belt as shown in Figure 3 or by a plurality of belts that engage belt grooves 223 of 85 Figure 4. It should be understood that if no load or breaking is applied to the spindle ortool 202, it will continue to rotate making it difficult to load a component on it. The component will have a tendency to "fly" off of a rotating spindle. In orderto 90 properly load the spindle, it should be at rest.

In orderto equip the spindle' 150 with a breaking assembly, a flat surface 203 is provided on the side of a stationary surface associated with the spindle. This may be done by machine or other similar 95 method. The numeral 202 denotes the spindle shell in which is provided with a stainless steel or other wear-resistant band or rubbing strip 204 against which a break shoe 231 will bear. The wear-resistant material 204 is provided since preferably the spindle 100 is made of aluminium which will not tolerate the wear it would experience as a braking surface.

The brake assembly is mounted by a brake mount

206 which is bolted or otherwise attached to the surface 203 by means of bolts or other fasteners 221.

105 Pivotingly supported by pivot pin 211 within the brake mount 206 is the brake arm 207. The brake arm

207 is urged against set screw 219 and locknut 220 by return spring 217. The position of brake arm 207 is adjusted by means of the set screw 219 and

110 locknut 220 so as to adjust the clearance 224

between the rubbing strip 204 and the brake shoe 231.

The brake is activated by a timing cam 230 which contacts the cam roller 214 which in turn is fixedly 115 attached to the brake block 208. The brake block 208 is slidingly supported on the guild rod 209 which extends from the brake shoe holder 210. A clearance 222 is maintained between the brake block 208 and the brake shoe holder 210 by means of a compress-120 ion spring 218, whose force must be overcome before any braking force will be applied by the brake shoe 231 against the rubbing strip 204. In this way, potential jamming of the brake against the spindle is obviated. The brake shoe holder 210 pivots about 125 brake shoe holder pivot 212 to ensure that the brake shoe always presents a flat surface of the spindle and more particularly to the rubbing strip 204. This double pivot arrangement permits the brake shoe to move to the left (as viewed in Figure 4) while 130 preventing the brake shoe from rotating clockwise

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and only contacting the spindle with its bottom surface. Roller pin 213 is provided for the cam roller 214 and is journalled between bearing surfaces provided in the brake block 208. Retaining ring 225 is 5 provided to prevent the brake block 208, which slides on guild rod 209, from escaping. In addition, a bushing 228 is provided in the brake block 208 through which the guild rod 209 fits. Another bushing 229 is provided for pivot pin 211 in the brake 10 mount 206.

The brake shoe is attached to the brake shoe holder by an appropriate cement or other suitable means.

In operation, the cam will rotate into position to 15 apply the brake priorto the time the spindle is to be loaded. The cam contacts the cam roller 214 which is secured to the brake block 208 by means of the cam roller pin 213. Under the influence of the cam 230, the brake block 208 moves to the left along guild rod 20 209 until it overcomes the force of the compression spring 218 and travels the distance of the gap 224. At that point, the brake body 208 contacts the brake shoe holder 210 which is pivotingly supported on brake arm 207 by means of pivot pin 211. The brake 25 arm 207 is also pivotingly supported on pivot pin 211 so that the entire assembly can pivot to the left with the brake shoe 210 remaining square to the braking surface 204 of the spindle 150.

The clearance 224 between the brake shoe 210 and 30 the braking surface 204 can be adjusted by means of set screw 219 and locknut 220 to ensure proper braking action.

Turning now to Figure 6, there is depicted a block diagram of the live tool inspection system of the 35 present invention. Each driving spindle, for instance 152 in Figure 3, is equipped with an optical can bar 324 positioned around its circumference. This scan bar consists of a series of reflective and non-reflective bars that produce a series of reflective 40 impulses when the spindle or mandrel 152 is rotated. In addition, a proximity probe 301, such as that available from Peico Electric Eye, Model No. RLS, is used to sense the proximity of a timing marker on a multiple spindle machine. The probe may be a Hall 45 effect type device and will emit a single pulse of for instance 5 -10 ms duration each time the shaft 166 (Figure 3) rotates, see Figure 10, time chart A. It functions as a logic probe to turn on the system in sequence with the arrival of the first container at the 50 scan point. Thus, previous empty tools or spindles are ignored. Once probe 301 turns the system on, the reflective electric eye 320 scans each passing tool to determine if it is rotating. An excess of rotation, determined as described hereinbelow, causes elec-55 trie eye 302 to emit an output pulse for each scan bar 322 that rotates past its field of view.

An electric eye 302, such as that available from Peico Electric Eye, Model PDR may be used for this purpose. The emitter/detector system will preferably 60 consist of a frequency modulated infrared emitter/ detector system (319,320) to prevent less crosstalk with other electric eyes in the system. In any event, the emitter/detector system must have a very fast response time.

65 A live spindle detector, 303 receives the pulses from the electric eye 302, shown in Figure 10, time chart B, and compares the total number of pulses received with a preset digital register. If the number of pulses received is below a preset register set point, no output is generated by detector 303. If the number of pulses exceeds a predetermined set point, the detector 303 will emit a single pulse of relatively short duration, for example on the order of 10 ms, see Figure 10, time chart C.

A detector 303, such as that available from Vercon, Inc., Model NO. DK-128, may be used for this purpose. As best seen in Figure 8, the detector may preferably consist of a trigger latch circuit 324, a decade counter 325 and a one shot 326. The trigger latch circuit 324 functions in a manner similar to an SCR. Upon receipt of the initial trigger signal from 301, the trigger/latch circuit 324 will energize the control system (which is powered from a 12 v DC bus) and also automatically clearthe decade counter 325 so that it starts each spindle rotation count at zero.

With regard to the decade counter 325, it is programmed so that if its pulse count from electric eye 302 exceeds a predetermined level, for instance on the order of approximately six, it will generate an output. The reason a threshold level is used before an output will be generated is to provide for the typical situation of a spindle or tool going past the field of view of the emitter/detector system 320 wherein typically, several reflective surfaces, 322,

will be in the field of view of the emitter/detector 320. A predetermined count on the order of about six is chosen to discriminate between the situation where the tool is live (is rotating) and where it is at rest but the reflecting surface 322 are transmitting to the emitter/detector as they move into its field of vision.

If the pulse count in the decade counter 325 from electric eye 302 exceeds the threshold level, it therefore means that for some reason the tool or spindle is not at rest and that the weld is defective or has otherwise not been accomplished. A defect or malfunction signal is thereby generated by the one shot 326 which may be a Quad 2 logic chip with an RCtiming network. The one shot 326 on receiving a signal from the decade counter 325 that the threshold pulse count has been exceeded emits a pulse of approximately 10 ms duration indicating a "live" tool or spindle condition (i.e. defective weld).

In the multiple-spindle embodiment, whether or not the decade counter 325 accumulates a pulse count in excess of the threshold value while a particular spindle is before it, a reset signal (see Figure 10, time chart F) is generated by the passing of another spindle into proximity with the electronic eye. This reset signal is generated by detector 304 which issimilarto detector 301 except that it is actuated to each of the weld station spindles or tools. This logic probe or reset probe produces one (approximately 5 ms) pulse atthe conclusion of the scan cycle of each weld station tool. This resets the digital register or decade counter 325 of the live spindle detector 304 to zero. Thus, each weld station spindle is scanned individually. In other words, assuming a multiple spindle embodiment having for example 14 spindles, the detector 304 would gener70

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ate fourteen reset signals for counter/register 325 during each 360° revolution of the machine, while the sensor 301 will only generate a signal pulse during each revolution of the machine. The counter/ 5 register 325 is reset each time a weld station or spindle comes before it, regardless of whether a defect has been sensed.

When the one shot produces a defective weld signal, it is received by the flag set timer 305 which 10 may consist of an electronic time delay circuit,

Circuit Model No. DK-126-A produced by Vercon, Inc. of Michigan, can be used forthis purpose. This circuit is essentially an electronic time delay circuit which is triggered by a flying (i.e. non-clock or 15 random) pulse and which will then execute its preset timing cycle automatically. At the conclusion of its timing cycle the flag set timer automatically resets.

As can best be seen from Figure 9, the flag set timer 305 basically functions as a pulse stretcher and 20 consists of a trigger board 327 and a NOR logic timing delay circuit. A pulse of approximately 10 ms duration is fed into trigger 327 and instantly (less than 8 ms to output) outputs a signal from time delay circuit 328 until the circuit 328 times out, see Figure 25 10, time chart D. The delay circuit 328, once triggered will output a pulse for a preset period of time which is selected depending upon the speed of rotation of the machine and the number of spindles per machine; the time period being generally inversely 30 proportional to the speed of rotation and the number of spindles.

The output from the circuit 328 is used to energize a solenoid 306 of a flag set unit 307, see Figure 10, time chart E. The flag set unit may be either an 35 electromagnetic or pneumatic device used to mechanically raise a flag indicator 309 directly associated with the defective product weld station. The mechanical flag or other optical, electrical, magnetic or audio indicator "informs" the machine 40 of the exact location of the defective product without further consideration of machine speed or container synchronization. Thus, the pneumatic finger 308 or similar element, when actuated will trip a flag member 309 almost instantly and then retract, again 45 almost instantly, so as not to trip the flag associated with the next weld station. It should be noted that when a flag member 309 has been tripped by the actuator 308, an operator looking at the machine will be able to visually determine at the point of exit, for 50 instance the star wheel 40 of Figure 2, the defectively welded products. The flag remains up until reset as described hereinbelow.

There may be attached to the live tool detector 303 a live tool production lockout device 321 which 55 essentially consists of a digitial register or the like that receives any output pulse from the live tool detector 303. Each defective product produced updates the counter 321 by one. When a predetermined level of defects have been reached, the lockout 60 device may automatically suspend further production by the machine and/or initiate a request for maintenance. The lockout counter/register may be Vercon, Inc. Model No. DK-129 which can be connected to the DC logic power source and which will 65 shut down the machine and/or call for maintenance if the accumulated number of rejected products exceeds a predetermined amount.

In order to eject a defective container, the invention provides a flag reader 312-314, an automatic 70 ejection timer 315 and an ejector 316 (see Figure 7).

The flag reader eye may be a beam break device that senses the interruption of a light beam between a light source 312 and an electric eye or light sensor 313. The reader 312-314 is positioned at a point in 75 the rotation of the machine to coincide with the defective product's exit point from the machine (see Figure 3). The flag or similar device breaks the beam of the electric eye or similar device (i.e. magnetic, electrical or other type of optical sensor) thus 80 producing a pulse of about 5 ms output, as shown in Figure 10, time chart G. It should be noted that this type of "time position" arrangement places the system in perfect synchronization with the spin weld machine at all times thereby removing machine 85 production speed as a factor in the overall accuracy of the system.

In orderto reset the flag position when mechanical flags are used, a reset unit comprising a roller 310 to contact the flag and a stationary finger 311 are 90 provided. It should be understood that this unit is only exemplary for the mechanical flag embodiment, and other reset devices would be employed for other types of defect indicators and that the indicator is not reset into its original position until 95 after is passes light source 312 and light sensor 313.

The output pulse from the flag reader 314 is received by an auto ejector timer 315 which initiates a preset timing cycle (similarto the manner described hereinabove with regard to the flag set timer 100 305) as depicted in Figure 10, time chart H. At the conclusion of its timing cycle the automatic ejector timer will automatically reset. The automatic ejector timer may be a Vercon, Inc. Model DK-127-A. The "on" time of timer 315 is determined by the position 105 of the defective product at the time its corresponding flag is sensed and by how much time is required to sweep the defective product off of its tool or spindle as described below.

The container ejector is similarto the flag set unit 110 306-308 described hereinabove and may preferably be a solenoid actuated pneumatic device that functions under the direction of the timing cycle of the automatic ejector timer to remove a defective container at the outfeed of the device. The device 115 comprises a solenoid 316, a pneumatic actuator 317 and an element, preferably a pneumatic finger, 318 to eject the container from the machine, and is timed in accordance with the output of timer 315 as depicted in Figure 10, time chart I.

120 The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many 125 modifications and variations are possible in light of the above teaching. For example, the specific means to generate the timing pulses and the timing signals, the indicator means and indicator reset means as well as the specific ejector means may, for example, 130 all be modified within the skill of the art.

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Claims

1. A spinwelding apparatus having means for

5 determining the quality of a spinwelded bond comprising:

a) detection means for sensing the condition of a tool at a spin weld station;

b) processing means connected to said detection

10 meansfor determining the condition of said tool and for generating an output if it is determined that said tool is rotating;

c) indicating means connected to said processing means for receiving said output and producing an

15 indication of the weld station at which said rotating tool is located.

2. A spinwelding apparatus according to Claim 1, further comprising having a brake device, said brake device including:

20 a) a brake arm pivotingly supported at one end;

b) brake shoe means pivotingly supported by said brake arm at the other end of said brake arm;

c) cam follower means resiliently supported in a reset position spaced from said brake shoe means;

25 d) whereby said cam follower means, when actuated, is adapted to engage said brake shoe means and to thereby apply a braking force.

3. A spinwelding apparatus according to Claim 1 or Claim 2, further comprising:

30 a) second detection means responsive to said indication means for detecting the presence of said indication, and producing a detection signal,

b) ejector means connected to said second detection means for removing a defective product associ-

35 ated with said indicated weld station.

4. A spinwelding apparatus according to Claim 1, 2 or 3, wherein said detection means comprises an optical means disposed on said tool for producing pulses when said tool is rotated.

40 5. A spinwelding apparatus according to Claim 4, wherein said optical means comprises an optical scan barcircumferentially disposed on said tool and a frequency modulated infrared emitter and detector.

45 6. A spinwelding apparatus according to Claim 4 or 5, wherein said processing means comprises live tool detector means connected to said means for receiving and counting said pulses and for generating an output pulse when a pulse count exceeds a

50 predetermined count.

7. A spinwelding apparatus according to Claim 6, further including a first probe means forturning on said apparatus in sequence with the arrival of a first loaded weld station at a scan point.

55 8. A spinwelding apparatus according to Claim 6, further including a second probe means for producing a reset pulse at the conclusion of a scan cycle of said tool, and wherein said live tool detector means further comprises a counter and wherein said reset

60 pulse resets said counter.

9. A spinwelding apparatus according to Claim 8, wherein said live tool detector means further includes a threshold detector for preventing an output until said counter exceeds a predetermined count.

65 10. A spinwelding apparatus according to any one of Claims 6 to 9, wherein said processing means further includes a timing means for receiving the output of the live tool detector means and wherein said processing means output is an energizing pulse of predetermined duration generated by said timing means, said pulse duration being dependent at least upon the number of weld stations of a spin weld machine and on the speed of production of said spin weld machine, said timing means being operative at the end of said energizing pulse to automatically reset.

11. A spinwelding apparatus according to Claim

10, wherein said indicating means comprises a means for receiving said energizing pulse and actuating a mechanical indicator proximate to the defective weld station.

12. A spinwelding apparatus according to Claim

11, wherein said meansfor receiving said energizing pulse is a solenoid having an associated pneumatically-actuated means for setting said mechanical indicator.

13. A spinwelding apparatus according to Claim

12, wherein said mechanical indicator is a flag member positioned below said weld station and which is actuated into a raised position by said pneumatically-actuated means whereby said flag provides an indication of the location of the defective container without regard to machine speed.

14. A spinwelding apparatus according to any one of Claims 3 to 13, wherein said second detection means is positioned at the exit point of the product from the machine, the apparatus further including a reset means for resetting said indication means.

15. A spinwelding apparatus according to any one of Claims 3 to 14, wherein said ejector means further comprises an ejector timer for receiving the output of said detector means and initiating a preset timed signal, said ejector timer further being operable to automatically reset at the conclusion of said timed signal.

16. A spinwelding apparatus according to Claim 15, wherein said ejector means further includes a solenoid for receiving said timed signals and having an associated pneumatically-actuated meansfor removing defective products at the outfeed exit of the machine.

17. A method for determining the quality of spinwelded bond with a live tool inspection system:

a) scanning a weld station tool equipped with means for producing a rotation signal when said tool is rotated;

b) initiating powerto said system at the arrival of a first weld station tool having a product thereon;

c) receiving said rotation signal with a detector;

d) comparing said rotation signal to a threshold value and generating an output when said rotation signal exceeds said preset value;

e) energizing an indicator means to a set condition with said output whereby the location of a defective product is identified.

18. A method according to Claim 17, further including:

a) detecting the presence of said indicator means in said set condition whereby a detection signal is generated;

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b) energizing an ejector means with said detection signal to remove the defective product from the machine; and c) resetting the detector means at the conclusion 5 of a scan cycle of a tool whereby each tool is scanned individually.

19. A method according to Claim 17 or 18, further including the step of counting the number of occurrences where the step of comparing produces an

10 output and automatically stopping further production of a machine when the number of occurrences counted exceeds a predetermined number.

20. A method according to Claim 19, further including the step of initiating a maintenance signal.

15 21. A method according to any one of Claims 17 to 20, wherein said step of scanning further comprises scanning a series of pulses produced by a reflective scan bar on said weld station tool and said step of receiving further comprising receiving said 20 series of pulses and comparing the number of said pulses with a preset register number and producing said output when said number of pulses exceeds said preset register number.

22. A method according to any one of Claims 17 25 to 21, wherein said step of energizing further includes receiving said output with a timer and initiating a preset timing signal and resetting said timer automatically at the conclusion of said timing signal.

30 23. A method according to Claim 22, wherein the step of energizing further includes activating a solenoid by means of said preset timing signal whereby a mechanical indicator is placed in a set condition.

35 24. A method according to any one of Claims 18 to 23, wherein the step of detecting the presence of said indicator means further comprises sensing with an electric eye the passing of said indicator at a point near the exit of said product from its corresponding 40 weld station tool and producing said detection signal in the form of an output pulse.

25. A method according to any one of Claims 18 to 24, wherein said step of energizing an ejector means further comprises receiving said detection 45 signal with an ejector timer whereby said ejector timer initiates a preset timing signal, resetting said ejector timer automatically at the conclusion of said preset timing signal and activating an ejector solenoid by means of said preset timing signal whereby 50 the defective product is ejected.

26 A spinwelding apparatus according to Claim 1 substantially as hereinbefore described with reference to the accompanying drawings.

27. A method according to Claim 17 substantially 55 as hereinbefore described with reference to the accompanying drawings.

Printed in the UK for HMSO, D8818935,4/85,7102.

Published by The Patent Office, 25 Southampton Buifdings, London,

WC2A1 AY, from which copies may be obtained.