USOO8742281B2
`
`(12) United States Patent
`Kaeseler
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,742,281 B2
`*Jun. 3, 2014
`
`(54) SPOT WELDING CAP CHANGER
`
`(56)
`
`References Cited
`
`(71) Applicant: Joe Ruggiero, Oakville (CA)
`
`U-S- PATENT DOCUMENTS
`
`(72) Inventor: Werner Kaeseler, Baunatal (DE)
`(73) Assignee: 002152706 Ontario Ltd., Oakville,
`Ontario (CA)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U_S_C_ 154(b) by 0 days_
`
`This patent is subject to a terminal dis-
`Claimer_
`
`(21) APPL NO; 13/680,915
`
`(22) Filed:
`
`Nov. 19, 2012
`_
`_
`_
`Pnor PUbhcatlon Data
`US 2013/0240489 A1
`Sep. 19, 2013
`
`(65)
`
`Related US. Application Data
`(63) Continuation of application No. 1 1/997,131, ?led as
`application No. PCT/EP2006/064417 on Jul. 19,2006,
`now Pat. No. 8,314,356.
`
`(30)
`
`Foreign Application Priority Data
`
`Jul. 28, 2005
`
`(DE) ....................... .. 10 2005 035 915
`
`(200601)
`
`(51) Int“ Cl“
`323K 9/26
`(52) U-s- Cl-
`USPC ....................................... .. 219/861; 219/ 86.8
`(58) Field of Classi?cation Search
`None
`See application ?le for complete search history.
`
`$g?gneétaii‘
`2
`gigmum et al‘
`2
`3/1998 Voilmy ct a1.
`5,734,141 A
`4/2008 Nakajima ct a1.
`7,353,578 B2
`8,314,356 B2 * 11/2012 Kaeseler ~~~~~~~~~~~~~~~~~~~~ ~~ 219/861
`
`FOREIGN PATENT DOCUMENTS
`
`10124 243 Cl
`DE
`102 22 248 A1
`DE
`2 760 392 Al
`FR
`2004/035251 A2
`W0
`* cited by examiner
`
`11/2002
`11/2003
`9/l998
`4/2004
`
`Primary Examiner * Kiley Stoner
`(74) Attorney, Agent, or Firm * Browdy and Neimark,
`PLLC
`
`ABSTRACT
`(57)
`The invention relates to a spot welding cap changer (1) with a
`cap puller (2) and two cap magazines (3, 3A), the cap puller
`(2) having a gripper (20) with spring-loaded, pivotable jaws
`(21, 22), which in response to a turning and axial pulling-off
`movement detaches a spot welding cap
`of a pincer spot
`welding head introduced into it from a shaft of the pincer
`welding head in such a way that it is clamped to prevent it
`twisting, and the cap magazines (3, 3A) holding spot welding
`caps respectively in a round cap carrier (31) such that they are
`circularly arranged in a directed and oriented manner and are
`respectively transported individually one after the other into
`an access position against a stop (32) by an advancing force
`(P)~
`
`27 Claims, 5 Drawing Sheets
`
`Ex. C&D 1006, page 1
`
`

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`US. Patent
`U.S. Patent
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`Jun. 3, 2014
`Jun. 3, 2014
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`Sheet 1 0f5
`Sheet 1 of5
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`US 8,742,281 B2
`US 8,742,281 B2
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`Ex. C&D 1006, page 2
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`Ex. C&D 1006, page 2
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`

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`US. Patent
`U.S. Patent
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`Jun. 3, 2014
`Jun. 3, 2014
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`Sheet 2 0f5
`Sheet 2 of5
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`US 8,742,281 B2
`US 8,742,281 B2
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`Ex. C&D 1006, page 3
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`Ex. C&D 1006, page 3
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`

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`US. Patent
`U.S. Patent
`
`Jun. 3, 2014
`Jun. 3, 2014
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`Sheet 3 of5
`Sheet 3 0f 5
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`US 8,742,281 B2
`US 8,742,281 B2
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`Ex. C&D 1006, page 4
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`Ex. C&D 1006, page 4
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`

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`US. Patent
`U.S. Patent
`
`Jun. 3, 2014
`Jun. 3, 2014
`
`Sheet 4 of5
`Sheet 4 0f 5
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`US 8,742,281 B2
`US 8,742,281 B2
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`Ex. C&D 1006, page 5
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`Ex. C&D 1006, page 5
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`

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`US. Patent
`U.S. Patent
`
`Jun. 3, 2014
`Jun. 3, 2014
`
`Sheet 5 0f5
`Sheet 5 of5
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`US 8,742,281 B2
`US 8,742,281 B2
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`Ex. C&D 1006, page 6
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`Ex. C&D 1006, page 6
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`

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`US 8,742,281 B2
`
`1
`SPOT WELDING CAP CHANGER
`
`This application is a continuation of application Ser. No.
`11/997,131, ?led on Jul. 30, 2008, now US. Pat. No. 8,314,
`356.
`The invention relates to a spot welding cap changer with a
`cap extractor and two cap magazines, the cap extractor having
`a gripper with spring-loaded, pivoting jaws, which in
`response to a turning and axial extraction movement detaches
`a spot welding cap of a pincer spot welding head inserted into
`it from a shaft of the pincer welding head in such a way that
`it is clamped to prevent twisting, and the cap magaZines
`holding spot-welding caps in a cap carrier in such a way that
`they are circularly arranged in a directed and oriented manner
`and are one by one transported by an advancing force against
`a stop, into an access position allowing to attach them axially
`to the free shaft of the pincer and to extract them with it.
`Such a mechanical electrode cap changer is known from
`the DE 102 22 248 A1. It has a two-part cap extractor, acces
`sible from both sides, in a body separate from the magaZine.
`Since gravity causes the caps to slide against a cap stop, the
`device can only be operated stationary in the vicinity of a
`mobile welding robot. Changing caps at a stationary pincer
`spot welding head, to which each component is fed by a robot
`for welding, is therefore not possible. The pincer spot welding
`heads/welding installations often have short shafts, which are
`for instance curved, so that the cap extractor, equipped with
`three large jaws and accordingly big, cannot be positioned for
`extraction.
`It is the object of the invention to provide for an automatic
`faster and safer exchange of the spot welding caps both at
`mobile and stationary spot welding installations with a short
`access distance.
`The solution resides in that the cap extractor has two
`opposed grippers, each with jaws that are open at their ends
`and can be rotated towards each other with approximately
`parallel toothed grip surfaces whose distance is slightly
`smaller than a diameter of a spot welding cap, and each cap
`magaZine contains a cap carrier, which, driven by a spring
`box, presses by way of its advancing force one of the caps
`respectively against the stop, and in the access position a rim
`overlap overlaps the cap on one side.
`Advantageous forms of the invention are indicated in the
`subclaims.
`In the new embodiment the cap extractor and the magaZine
`are mounted on a support which preferably is spring
`mounted. In contrast to the known system, the new construc
`tion design gives the possibility not only to be used at welding
`robots, but also at stationary pincer welding heads or welding
`installations.
`Compared with the known clamping system with three
`jaws, the new cap-extraction installation provides for shorter
`clamp and spin travels, therefore much shorter intervals for
`detaching the caps. Moreover, from the smaller design results
`a wider array of application, for instance at non-standard
`pincers or very short, curved shafts.
`The two cap extractors are each open at the ends of the jaws
`and thus accessible to a cap. The jaws grip it directly by way
`of the undersize of their distance and detach the cap, whereby
`a rotation around an angle of about 30-600 su?ices. This way
`a cap change is possible even in extremely narrow con?nes.
`Since the two grippers are oriented in opposite directions,
`respectively one of them is accessible from the various sides
`in a clockwise rotation, so that no turning of the pincer is
`necessary, even if the pincer shafts are screwed on.
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
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`50
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`55
`
`60
`
`65
`
`2
`Furthermore, the round magaZine is much more compact
`than the straight magaZine functioning by gravity of the
`known installation. It can be held and operated in any position
`because of the spring drive.
`Furthermore, the two round magaZines arranged on paral
`lel axes provide in each case for an access with short radial
`travel to the access positions in the access openings. In an
`embodiment with a magaZine cover, this cover is directly
`shifted during access, far enough to let the rim overlap
`uncover the cap frame, so that the detaching is possible. The
`example shows a radial infeed and an axial access of the shafts
`into the magaZine.
`Both partial devices, the cap changer, and the cap maga
`Zine, are mounted on a support close to one another, and thus
`can be set up stationary, or mounted to a robot arm in a ?xed
`or detachable manner. In the ?rst case the welding robot
`changes the caps of its own pincer, and in the second case the
`robot changes the caps at the stationary pincers or installa
`tions respectively by means of the device. The changing
`device at the robot arm is movably mounted, constantly ready
`for operation in a free space next to the gripper of the robot or
`on a guide rail, or it is located in a parking position, where it
`can be picked up and brought to operation by the gripper; this
`is called alternating pincer principle.
`Advantageously, cap sensors are arranged on the device,
`which indicate whether a cap is in place or not. Moreover, the
`charging level of the magaZines is monitored. This way it is
`ensured that after a cap change a cap is in place at the shaft of
`the pincer welding head before the cooling water is switched
`on. Furthermore it can be veri?ed, whether the old cap was
`removed, when it is reported that there is no cap inplace while
`the shaft is approaching.
`The embodiment of the cap magaZine without a cover
`holds the welding caps in an elastic cap carrier in a close ?t,
`axially movable by propulsive or tractive force.
`Advantageous embodiments are represented in the FIGS. 1
`to 6.
`FIG. 1 shows the entire device schematically and in per
`spective;
`FIG. 2 shows a transparent top view of the cap extractor;
`FIG. 2A, 2B show detailed enlargements of the grip sur
`faces;
`FIG. 3 shows a perspective of the cap extractor;
`FIG. 4 shows a cap magaZine in perspective, closed,
`enlarged;
`FIG. 5 shows a cap magaZine in perspective, open,
`enlarged;
`FIG. 6 shows a top view of the magaZine cover.
`FIG. 1 shows a complete spot welding cap changer 1,
`which is movably held on a support rail 5 at a robot arm.
`Alternatively, it is ?rmly mounted with the mounting plate 50.
`The bilaterally equipped cap extractor 2 is bolted at the free
`end of the mounting plate 50, with the two grippers 20 respec
`tively on the sides, their direction opposite to one another.
`Pulled off caps K are depicted between the jaws 21, 22, after
`being detached at the rim of a storage container they drop into
`it.
`
`Offset to the rear from the cap extractor 2 respectively one
`cap magaZine 3, 3A laterally offset to the other is mounted on
`the mounting plate 50, with the magaZine cover 4 respectively
`directed laterally and the access openings 40 oriented axially
`parallel to the extracted welding caps K that are still held by
`the gripper, so that the shafts of the pincer spot welding head
`have to travel only short distances while changing the caps.
`FIG. 2 shows a top view on the cap extractor 2, which
`consists of very few parts. The grippers 20 are composed of
`one ?xed, toothed jaw 21 respectively, and one jaw 22 which
`
`Ex. C&D 1006, page 7
`
`

`
`US 8,742,281 B2
`
`3
`is mounted in such a way that it can be pivoted towards said
`jaw 21. The pivot joint 24 is located behind the ?xed j aw 21 by
`way of a U-shaped structure of the movable jaw arm 25, so
`that a cap K positioned in the gripper 20 will be clamped at a
`twist depending on the direction of rotation.
`The initial pressing force ofthejaws 21, 22 is caused by a
`bracing spring 26, which for example, is formed as a spiral or
`bracing spring with spread ends, each pressing against a jaw
`arm 25.
`On the infeed side the grippers 20 are provided with infeed
`skews 27, 28. From these extend the roughly parallel grip
`surfaces 23, each with a toothing in opposite direction 29A,
`29B, as FIGS. 2A and 2B show in partial view and in detail.
`If there is no cap K inserted in the grippers 20, then the
`distance A of the grip surfaces 23 has a minor undersize
`compared to the cap outside diameter D.
`FIG. 3 shows that the spring 26 and the movable jaws 21, 22
`as well as a jaw plate 62, on which the ?xed jaws 21 are
`formed, are held between two cover plates 60, 61. The jaw
`plate 62 has a corresponding cavity, in which the U-shaped
`jaw arms 22 have free space to move.
`FIG. 4 shows a round cap magaZine 3, which consists of a
`barrel shaped cap carrier 31, closed with a magaZine cover 4,
`whereas a radial section remains free up to the rounded access
`opening 40, in which a welding cap K in the withdrawal
`position is pressed to the edge of a stop 32 at the cover.
`The cover 4 has a small rim overlap 41 of the cap frame in
`the curve of the access opening 40, an induct skew 42 con
`necting to said rim overlap which is cascaded to the top side
`of the cover. At an embodiment with a hinged cover 4, a slot
`43 is formed, through which reaches a bracket 34, bevelled on
`the outside, which keeps the cover shut.
`On the other side of the access opening 40 a hinge 44 with
`a slotted hole 45 is formed in the extension level of the cover,
`the cones 46 of said hinge being held in a hinge support 47.
`FIG. 5 shows the open round magaZine 3 with a hinge and
`equipped with a welding cap K in the drill holes 30 of the cap
`carrier 31, the cap K protruding by a few millimeters. A ?rmly
`mounted spring box 33, schematically depicted, is in the
`centre of the cap carrier 31, said spring box carrying the
`bracket 34 so that it can be radially moved. A preloaded
`spindle or spiral spring is arranged centrally in the spring box
`33, one end of the spring being ?xed to the spring box 33, the
`other to the cap carrier 31, so that the latter is pressed with a
`torsion force P in the direction of the stop 32, which extends
`radially on the magaZine cover.
`The plate-shape bracket 34 extends in a diagonal guiding
`slot on the cover of the spring box 33. In the closed state, as
`shown here, a compression spring arrangement 35, held in the
`cover, extends from the bracket 34 and is supported by means
`of a support pin 36 on the rounded hinge support 47, and
`presses the bracket 34 in the closed position, in which it
`overlaps the cover 4 in the closed state and holds the rim
`overlap 41 in the overlap position, the cone 46 being in the
`rear stop position in the slotted hole 45, as FIG. 1 shows. To
`open the cover 4, the bracket 34 is pushed back manually.
`Alternatively, the round magaZine can be implemented with
`out a hinge for the opening of the cover. In this case the cover
`is only held in a movable manner, so that the shaft of the
`pincer, when inserted, slides the cover by the skew 42 to
`release the rim overlap.
`FIG. 6 shows a top view on the magaZine cover 4, whose
`main outline consists of two semi-circles with shifted centres
`M1, M2, whereby on one side the access opening 40 extends
`in the direction of the centre, and on the opposite side the
`hinge 44 extends on the outside. The slot in the cover 43
`extends 4 in the central area in the direction between the
`
`10
`
`20
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`25
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`30
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`35
`
`40
`
`45
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`50
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`55
`
`60
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`65
`
`4
`access opening 40 and the hinge 44. The bracket 34 in the
`cover and in the ?xed spring box 33 is guided in this direction.
`The cover 4 is about 15 mm high and largely hollow shaped
`and has a stiffening cover rim 48, which passes into the stop
`32 and on the other side into the hinge 44. The cover 4 is
`lowered at the induct skew 42 by about 5 mm to the infeed
`area. Internally, the cover surface drives the caps to the with
`drawal level when turned in the stop position. A chamber 49,
`which contains the compression spring arrangement 35, is
`represented with a dashed outline.
`The compact construction of the cap extractor with the
`magaZines allows for a signi?cant reduction of the changing
`times, for example, from 22 to 17 sec, which corresponds to
`about 23%.
`
`LIST OF REFERENCE SIGNS
`
`1 spot welding cap changer
`2 cap extractor
`20 gripper
`21, 22 jaws
`23 grip surfaces
`24 pivot joint
`25 jaw arm
`26 bracing spring
`27, 28 infeed skews
`29A, 29B toothing
`3, 3A cap magaZine
`30 drill holes
`31 cap carriers
`32 stop
`33 spring box
`34 bracket
`35 compression spring
`36 support pin
`4 magaZine cover
`40 access opening
`41 rim overlap
`42 induct skew on the cover
`43 slot in the cover
`44 hinge
`45 slotted hole in the hinge
`46 cones
`47 hinge support
`48 cover rim
`49 compression spring chamber
`5 support rail
`50 mounting plates
`60, 61 cover plates
`62 jaw plate
`A gripping jaw distance
`D outside diameter of the caps
`K cap
`P advancing force
`M1, M2 semicircle centres
`
`The invention claimed is:
`1. Spot welding cap changer comprising:
`a cap extractor and two cap magaZines, the cap extractor
`having:
`a gripper with spring-loaded, pivoting jaws which in
`response to a turning and axial extraction movement
`detaches a spot welding cap of a pincer spot welding
`head inserted into the pivoting jaws from a shaft of the
`pincer welding head in such a way that the spot welding
`cap is clamped to prevent the spot welding cap from
`twisting,
`
`Ex. C&D 1006, page 8
`
`

`
`US 8,742,281 B2
`
`5
`and the cap magazines holding spot welding caps respec
`tively in a cap carrier in such a way that the spot welding
`caps are circularly arranged in a directed and oriented
`manner and are one by one transported by an advancing
`force against a stop, into an access position allowing the
`spot welding caps to be attached axially to the free shaft
`of the pincer and to extract them with the free shaft of the
`pincer,
`wherein the cap extractor has two opposed grippers, each
`with jaws that are open at their ends and can be rotated
`towards each other with approximately parallel toothed
`grip surfaces whose distance is smaller than a diameter
`of a spot welding cap,
`and each cap magaZine has a cap carrier which, driven by a
`spring box, presses by way an advancing force one of the
`caps respectively against the stop.
`2. Spot welding cap changer according to claim 1, wherein
`respectively one of the jaws of the corresponding gripper is
`?xed at a jaw plate, and the corresponding movable jaw is
`formed at an U-shaped jaw arm, which is supported with a
`pivot joint behind the ?xed jaw.
`3. Spot welding cap changer according to claim 2, wherein
`between the two movable jaw arms, a preloaded bracing
`spring is mounted.
`4. Spot welding cap changer according to claim 1, wherein
`the jaws have infeed skews.
`5. Spot welding cap changer according to claim 4, wherein
`the grip surfaces in each case have an asymmetric toothing,
`which on the two parallel jaws is oriented in opposite direc
`tions.
`6. Spot welding cap changer according to claim 3, wherein
`the jaw arms, the bracing spring and the jaw plate are held
`between cover plates.
`7. Spot welding cap changer according to claim 1, wherein
`the spring box contains a spiral or coil spring, one end of
`which is ?xed at the spring box, and the other end of which is
`?xed at the cap carrier.
`8. Spot welding cap changer according to claim 1, wherein
`a magaZine cover is held preloaded by a spring in the direction
`of the access opening so that the rim overlap overlaps a cap
`frame in a stop position of the magaZine cover.
`9. Spot welding cap changer according to claim 8, wherein
`a bracket is spring-loaded and movably held at the spring box,
`said bracket reaching through the closed magaZine cover and,
`by overlapping the magaZine cover, holding the magaZine
`cover in place.
`10. Spot welding cap changer according to claim 8,
`wherein the magaZine cover is articulated at a hinge support,
`situated opposite of the access opening.
`11. Spot welding cap changer according to claim 10,
`wherein the magaZine cover is movably guided in a slotted
`hole on the hinge support.
`12. Spot welding cap changer according to claim 1,
`wherein the magaZine cover bears a stiffening cover rim,
`which on one side forms the rim overlap and on the other side
`forms a hinge.
`13. Spot welding cap changer according to claim 1,
`wherein the cap extractor with grippers is mounted on a
`mounting plate, on which with an offset to the rear the cap
`magaZines are mounted.
`
`20
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`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`6
`14. Spot welding cap changer according to claim 13,
`wherein the access openings of the cap magaZines are
`directed towards and salient on different sides of the mount
`ing plate, respectively.
`15. Spot welding cap changer according to claim 13,
`wherein the mounting plate is supported and movably guided
`on a support rail which is mounted on a robot arm or ?rmly
`installed.
`16. Spot welding cap changer according to claim 1,
`wherein sensors are arranged at the cap magaZines, which
`send a signal to a control device when a predetermined
`remaining quantity of spot welding caps is in stock in the
`respective cap carrier.
`17. Spot welding cap changer according to claim 1,
`wherein the magaZine cover bears a stiffening cover rim.
`18. Spot welding cap changer according to claim 1,
`wherein the cap extractor is mounted on a mounting plate.
`19. Spot welding cap changer according to claim 9,
`wherein the magaZine cover is articulated at a hinge support.
`20. Spot welding cap changer according to claim 13,
`wherein the mounting plate is supported on a support rail.
`21. A cap magaZine for use with a cap extractor that
`detaches a spot welding cap of a pincer spot welding head
`inserted into the cap extractor from a shaft of the pincer
`welding head, the cap magaZine comprising:
`a cap carrier sized and shaped to receive a plurality of spot
`welding caps in a circular arrangement; and
`a spring box for driving the spot welding caps within the
`cap carrier, the spring box providing an advancing force
`to advance the caps one by one so that one of the caps
`bears against a stop in the cap magaZine in an access
`position, the access position allowing the spot welding
`caps to be attached axially to the free shaft of the pincer
`welding head and to be extracted from the cap carrier
`with the free shaft of the pincer, and when the cap in the
`access position is extracted from the cap carrier, the
`spring box advances another cap into the access posi
`tion.
`22. The cap magaZine of claim 21, wherein the spring box
`includes a spring, one end of which is ?xed at the spring box,
`and the other end of which is ?xed at the cap carrier.
`23. The cap magaZine of claim 21, wherein a magaZine
`cover is held preloaded by a spring in the direction of the
`access opening so that the rim overlap overlaps a cap frame in
`a stop position of the magaZine cover.
`24. The cap magaZine of claim 23, wherein a bracket is
`spring-loaded and movably held at the spring box, said
`bracket reaching through the closed magaZine cover and, by
`overlapping the magaZine cover, holding the magaZine cover
`in place.
`25. The cap magaZine of claim 23, wherein the magaZine
`cover is articulated at a hinge support, situated opposite of the
`access opening.
`26. Spot welding cap changer according to claim 1,
`wherein in the access position, a rim overlap overlaps the cap
`on one side.
`27. The cap magaZine of claim 21, further comprising a rim
`overlap that overlaps the cap in the access position on one
`side.
`
`Ex. C&D 1006, page 9