US3175705A

US3175705A - Article gripping apparatus

Info

Publication number: US3175705A
Application number: US264850A
Authority: US
Inventors: Jr James C Houda
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1963-03-13
Filing date: 1963-03-13
Publication date: 1965-03-30
Anticipated expiration: 1982-03-30

Description

i d States Patent Patented Mar. 30, 1965 3,175,703 BUTTON LOADING MECHANISM FOR SEWING MACHINES Darcy Andrews Young, Jr., Brighton, N.Y., assignor to Rochester Button Company, Rochester, N.Y., a corporation of New York Filed June 20, 1962, Ser. No. 203,918 2 Claims. (Ci. 214-1) The present invention relates to button feeding apparatus for sewing machines, and more particularly to an improved apparatus for delivering buttons to the button gripping jaws of a commercial type sewing machine.

Commercial sewing machines for sewing buttons on fabric are equipped with a button chuck comprising a pair of jaws for holding a button just above the fabric onto which it is to be sewn, and in registry with the sewing machine needle. To speed up the loading of buttons in the button chuck, devices have been developed for automatically delivering buttons from a button supply to the jaws of a button chuck.

One such device is disclosed in the copending US. patent application of Roy H. Hendrickson, Serial No. 820,975, which was filed June 17, 1959, now Patent No. 3,042,254 and assigned to the same assignee as the instant application. The device includes a transfer arm having a plurality of button-centering pins projecting from one face thereof. A button of the type having a plurality of holes therein is fed from a supply onto the transfer arm in such manner that the button-centering pins enter the holes in the button. Thereafter the transfer arm is moved to insert the button into the jaws of a sewing machine button chuck from the back of the chuck, and is then returned for another button.

After a button has been sewn in place on a piece of fabric, such as a mans shirt front, the sewing machine operator pulls the fabric forwardly to dislodge the button from the jaws and to sever the thread, by which the but ton is sewn to the garment, from the bobbin or other supply in the sewing machine. Sometimes the operator is not fast enough and before she has dislodged the button and the fabric, a new button will be brought to the jaws by the transfer arm. In such case, heretofore the new or incoming button had to strike and dislodge the button then in the jaws, together with the fabric to which the latter was sewn, before the new button could enter and be chucked between the jaws. This contact between the buttons, or between the new button and the fabric onto which the preceding button was sewn, has tended to dislodge the new button from the button-centering pins on the transfer arm before it has been properly positioned in the button chuck, thus causing incomplete transfer and interruption of the sewing cycle.

One object of the present invention is to provide improved apparatus for delivering buttons into the jaws of the button chuck of the sewing machine without using the incoming button to dislodge the button then in the jaws of the chuck.

A further object of this invention is to provide apparatus of the type described in which the button transfer arm is provided with means for clearing the button chuck before inserting a new button thereinto.

Another object is to provide an improved button transfer mechanism which will speed up the overall sewing operation, and which will obviate any difficulty if a slow operator fails to dislodge a button in time from the button chuck after it has been sewn on the fabric.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims Which considered in conjunction with the attached drawing.

In the drawing:

FIG. 1 is a fragmentary vertical view of a button feeding apparatus built according to one embodiment of this invention, and showing the button transfer arm in its button receiving position;

FIG. 2 is a plan view of this feeding mechanism, and showing also part of a sewing machine button chuck, and the button transfer arm in dotted lines in the course of its swing from its button receiving position to its button delivery position;

FIG. 3 is a fragmentary view of the button transfer arm at the end of its delivery swing, in a plane parallel to the plane of FIG. 2, and showing the plow on the transfer arm as it engages and forces out of the front of the button chuck, the preceding button and the material to which it has been sewn; and

FIG. 4 is a fragmentary side elevational view of the button carrying end of the transfer arm.

In the illustrated embodiment of the invention, the transfer arm has four locating pins which project upwardly adjacent the free end of the arm to enter the holes of a button and locate the button on the arm. The arm is pivoted about its opposite end to carry individual buttons from a supply chute rearwardly into the spring-tensioned jaws of the conventional button holding clamp or chuck of a commercial sewing machine.

Also projecting above the free end of the transfer arm is a further pin, or plow, which is positioned in front of the button-holding pins, to enter the button chuck jaws in advance of the button-holding pins during delivery of a button into the chuck jaws. The plow urges from the jaws the button which is then in them, and also pushes away from the jaws the fabric to which this latter button has been sewed. Thus the device of the present invention insures proper chucking of successive buttons in the jaws and speeds up the overall sewing operation.

Referring now to the drawing by numerals of reference, 11 designates a base plate which is adapted to be secured on a table or stand at one side of a sewing machine proper. Mounted to overlie the table is one end of a chute 12 forming part of button feeding apparatus of the type disclosed in the above-noted copending application. Chute 12 has an opening or hole 13 through which buttons B from a hopper supply drop onto four buttoncentering pins 15 that project upwardly from the free end of a pivotal transfer or swing arm 16 disposed in button receiving position beneath the hole. The pins 15, which are spaced from one another in correspondence with the holes in the buttons being fed, are adapted to pass through the holes in a button B to hold it for transfer to the jaws of a button chuck. All four pins 15 are spaced rearwardly of a circular pin or plow 17 which also projects upwardly from arm 16 at its free end for a purpose to be described below.

The transfer arm 16 is secured to a shaft 18 that is oscillatably and reciprocably mounted in a pedestal 19 that is secured to or is integral with the base 11 of the apparatus. The shaft 18 is mounted at its lower end in a bushing 21 that is carried in pedestal 19, and is formed intermediate its ends with a collar 22 which is adapted to slide and oscillate in a bearing 23 formed integral with pedestal 19 or with a plate 37 that is secured thereto.

Swinging motion of the shaft 18 to swing the button carrying pins 15 from a position of registry with the hole 13 to a position between the conventional clamping jaws 25 (FIGS. 2 and 3) of an adjacent sewing machine is effected by operation of a cam 26. This cam has a cam path 27 formed in one side face thereof in which there engages a roller or follower 28. This roller or follower is mounted upon a slide 29 (FIGS. 1 and 2) which has rack teeth formed integral therewith at its forward end.

March 30, 1965 J. c. HOUDA, JR

ARTICLE GRIPPING APPARATUS 3 Sheets-Sheet 2 Filed March 13, 1963 INVENTOE March 30, 1965 c. U JR 3,175,705

ARTICLE GRIPPING APPARATUS Filed March 15, 1963 3 Sheets-sheet 5 \NVENTOE tude within the article gripping jaws.

3,175,765 ARTIQLE GRHPHNG APPARATUS James Q Honda, 312, Downers Grove, IlL, assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filed Mar. 13, 1%3, Ser. No. 264,85tl 8 Claims. (Cl. 214-l) This invention relates to article gripping apparatus, and more particularly to article gripping apparatus which positively locks about an article gripped thereby. It is an object of this invention to provide an improved apparatus of such a character.

In large automated assembly machines, it is frequently desired that an article be presented to each of a series of work stations in a prescribed attitude. One suitable manner of accomplishing this article positioning is by positively locking the article within article gripping apparatus, thereby insuring that the article is in a prescribed attitude with respect to the gripping apparatus. It is a relatively simple matter to align the article gripping apparatus with respect to the work station, thereby providing for the alignment of the article with respect to the work station. The present invention is well suited for use in such an application.

In accordance with one embodiment of this invention two pivotable article gripping jaws are connected by a toggle linkage, the knee joint of the toggle linkage being biased toward a normal position wherein the jaws are in a non-gripping position. When the knee joint of the toggle linkage is advanced to an over-center position, the jaws are pivoted to an article gripping position, and they exert a counter force against the toggle links sutlicient to hold the toggle links in the over-center position against the normal biasing force, thereby eifectively locking and positioning the article in a prescribed atti- If no article is gripped by the jaws, when the knee joint is moved to the over-center position, the jaws Will be collapsed to the nongripping position as there is no counter force applied to the knee joint. The return of the jaws to the non-article engaging position is sensed by appropriate devices and a signal thereby derived is effective to deactuate the various operational stations to which the article is presented by the jaws. Deactuation of the various stations avoids the possibility of damaging the jaws at an operational station wherein welding or a similar type operation takes place.

it is another object of this invention to provide article gripping apparatus which upon achieving an article gripping position remains in that position if an article is gripped therein even though a force is exerted thereon which tends to collapse the apparatus to a normal nonarticle gripping position.

It is still another object of this invention to provide article gripping apparatus which upon achieving an article gripping position collapses to a normal non-article gripping position if no article is gripped therein.

It is a further object of this invention to provide article gripping apparatus which after being advanced to an article gripping position collapses to a normal, non-article gripping position if no article is gripped therein such that the article gripping apparatus may deactuate the various operational stations to which the apparatus is advanced.

It is a still further object of this invention to provide article gripping apparatus having the various characteristics prescribed above while being inherently reliable and eflicient in operation, of rugged construction, and economical to manufacture and operate.

This invention together with further objects and advantages thereof will best be understood by reference to the 3,l75,7h5 ?atented Mar. 39, 1965 following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of one embodiment of the invention, showing a single article gripping apparatus at an article loading station;

FIG. 2 is a side elevation view of the apparatus shown in FIG. 1, portions of which are shown in cross section;

FIG. 3 is a partly cross-sectional view taken along the line 3-3 of FIG. 1, and depicting the article gripping jaws in a non-gripping position;

FIG. 4 is a partly cross-sectional view taken along the line 4-4 of FIG. 1, and depicting the article gripping jaws in an article gripping position;

FIG. 5 is a partly cross-sectional view taken along the line 55 of FIG. 4, and depicting the manner in which the toggle mechanism is connected to the article gripping aws;

FIG. 6 is a view of the apparatus wherein the article gripping jaws have been reoriented to a vertical position in order to deliver an article gripped therebetween; and

FIG. 7 is a view taken along the line 77 of FIG. 6.

In the drawings there is illustrated a particular embodiment of the invention which is well adapted to incorporation in a machine wherein it serves to present articles to a succession of operating stations.

As best shown in FIGS. 1 and 2, articles 10 are presented in succession by means of a feed track 11 to a loading station in a large automatic assembly machine. At the loading station an article gripping apparatus 12 grips individual articles for movement through a series of operational stations associated with the assembly machine.

With specific reference to FIGS. 1 and 2, a single article gripping apparatus 12, suitably secured to a rotatable table 13, is shown after it has been indexed to: the loading station. A plurality of gripping apparatuses may be disposed in a circumferentially spaced manner about the rotatable table, but, for the sake of clarity, only one such apparatus is illustrated in the associated drawings. The rotatable table is movable over a lower tooling plate 14 that is suitably supported by a series of frame members 16. The rotatable table is indexed to: the various machine stations by means of a hollow shaft 17 which is secured to the table and intermittently driven by a motor 18 and suitable gears 19.

The operation of the gripping apparatus may be best understood by reference to FIGS. 3 and 4 taken in conjunction with FlGS. 1 and 2. With reference to FIG. 3, the front portion of a base member 21, which is secured to the rotatable table 13, has welded to the radially outer edge thereof a pair of outwardly projecting frame members 22 which have facing L-shaped projections 23 as best shown in FIG. '7. A yoke 24, having a central bore 26, is pivotably mounted between the two frame members 22 by a pair of pivot pins 27. A tubular member 31, which both passes through the opening 26 and is guided within this opening by spline-like projection 32, supports a forward positioning plate 33 and a rear positioning plate 34-. An actuator rod 36 is carried Within the tubular member and passes through suitable openings in the plates 33 and 34-. A ball-locking detent 37, carried within the yoke, cooperates with a recess 38 in the tubular member to effectively lock the tubular member in a suitable position relative to the yoke and thereby to position a plate 330, which is amxed to the plate 33, against the front surface of the yoke.

A forwardly extending support member 39 is attached to the forward positioning plate 33 of the tubular member 31, and a pair of flexible jaw members 41 are attached thereto by pivot pins 40. The jaw members are actuated through a pair of toggle links 42, one end 43 of each of the links being pivotably attached to respective ends 44 of the jaw members by pivot pins 45. The other end 46 of each of the links is pivotably attached to the actuator rod 36 to form a knee joint 54?. This knee joint is biased to a normal position on one side of a centerline through the pivot pins 45 connecting the jaw members and the toggle links by means of a spring 47 which acts between the rear positioning plate 34 and an oblong plate 48 on the rear end of the actuator rod.

The base member 21 has gaging surfaces 49 which cooperate with the rear positioning plate 34 and the tubular member 31 to properly orient the article gripping apparatus 12 with respect to the rotatable table 13. The

exact manner in which these surfaces cooperate is ex-' plained in greater detail in the specification below.

In order to actuate the article gripping apparatus 12 from a non-gripping condition (FIG. 3) to a gripping condition (FIG. 4-), the actuator rod 36 is advanced to move the knee joint 50 of the toggle links 42 to the left of a centerline through the pivot pins 45, thereby pivoting the jaw members 41 into an article engaging position. To accomplish this particular gripping operation, a stationary loading device 51 is utilized at the loading station.

As best illustrated in FIG. 2, the loading device 51 is secured to an upper tooling plate 52 that is supported from above by a plurality of frame members 53. A push rod 54, which is slidably carried by a frame member 56, has a cam follower 57 pinned to its rear portion. The cam follower is biased by a spring 58 into continuous engagement with an elliptical cam 59 such that rotation of the cam 59 imparts reciprocal motion to the push rod. The cam is mounted on a shaft 61 which passes through the hollow shaft 17 and is continuously driven by the motor 18.

In operation of the loading device 51, a portion of the rotation of the cam 59 causes advancement of a pusher plate 62 carried by the push rod 54. The pusher plate engages the oblong plate 48 on the rear portion of the actuator rod 36. As the actuator rod is advanced by this movement, the knee joint 50 of the toggle links 4-2 is moved towards the centerline through the pins 45 and the jaw members 41 are pivoted toward each other about the pivot pins 40. Before the knee joint of the toggle links reaches the centerline, gripping surfaces 63 of the jaw members engage the article 10. Further advancement of the toggle links from this point causes the jaw members to resiliently deflect about their pivot pins 45. This deflection continues and reaches a maximum value when the knee joint of the toggle links is on the centerline. When the knee joint passes appreciably beyond the centerline, the counter force exerted on the links by the jaw members becomes greater than the force exerted on the knee joint by the biasing spring 47 such that the knee joint and jaws are locked in article gripping position as depicted in FIG. 4-. More specifically, when the article gripping apparatus 12 is in an article gripping position, the knee joint has two forces exerted thereon. The force eX- erted by the biasing spring 47 tends to return the knee joint to the position depicted in FIG. 3, while the counter force exerted on the knee joint by the jaw members 41 is sufficient to overcome the normal force exerted by the spring and to maintain the knee joint in its over-center position.

The article gripped between the gripping surfaces 63 of the jaw members 41 is both held securely and properly positioned with respect to the article gripping apparatus 12 as both of the jaw members apply the same gripping pressure on the article. Also, when the jaw members achieve a locking position, the article is precisely oriented with respect to the rotatable table 13, since the article gripping apparatus is accurately positioned with respect to the table 13. Since the table is heavy in construction it is a simple matter to insure that the article gripping apparatus is properly aligned with any operathgllal station to which it is presented by indexing of the ta 2.

From FIG. 2 it should be noticed that the f ed trac l 11 represent the articles 149 to the article gripping apparatus 12 at a position which is slightly below the centerpoint between the two jaw members 41. Thus, the article is picked up from the track when the jaw members are closed and is indexed to the first operational station without engaging the track.

If no article 10 is present for the jaw members 41 to grip, the knee joint 50, after passing over the centerline, is returned by the biasing spring 4-7 to an open position as depicted in FIG. 3 as soon as the pusher plate 62 is withdrawn from engagement with the oblong plate 43 through further rotation of the cam 59. This return movement results from the fact that no counter force is created on the toggle links 42 by deflection of the jaw members to offset the normal biasing force of the spring.

In the illustrated embodiment and application of the invention advantage is taken of this characteristic of the apparatus to prevent operation of a station at which empty jaws are presented. As the open jaw members are advanced to the individual operational stations, the retracted lower jaw member engages individual microswitches 64 secured to the lower tooling plate 14 and, through suitable control circuitry, deactuates the particular operational stations to which the empty article gripping apparaus 12 is presented.

After the article gripping apparatus 12 has been indexed from the loading station it is presented to a series of operational stations disposed in a circumferentially spaced relationship about the table 14. While the exact nature of operational stations may vary with the type of article 10 presented to the stations, it is important to note that the article gripping apparatus of this invention presents the article to each of the stations in a prescribed attitude. Also, if the article gripping apparatus does not present an article to a particular Work station, that station is deactuated.

To unload the article gripping apparatus 12, special unloading devices are provided. A first device, as best illustrated in FIGS. 1 and 2, is provided to pivot the article gripping apparatus between horizontal and vertical positions. A second device 66, as best illustrated in FIGS. 6 and 7, is provided both to advance and retract the jaw members 41 while in the vertical position and to open the jaw members while in their advanced vertical position to deliver the article 1d at the unloading station.

The unloading station of the assembly machine is provided between the last operational station and the loading station. Between these last two mentioned stations, the lower tooling plate 14 is cut away to permit the article gripping apparatus to assume the vertical position. 7

The pivoting mechanism as referred to above (FIGS. 2 and 3) is controlled by means of a cam groove 67 on the underside of the upper stationary tooling plate 52. This cam groove, while having an exact radius with respect to the shaft 61 over most of its length, has an elliptical portion which corresponds in arc length to the arcuate spacing of the last operational station and the loading station. As the article gripping apparatus 12 is indexed from the last operational station to the unloading station, a cam follower 68, which rides within the cam groove, is moved laterally towards the center of the shaft 61. The cam follower 68 is attached to a first shaft 69 and a suitable spring connection '71 is made between the first shaft and a second shaft 72 such that a constant pulling force is exerted between the shafts 69 and '72 as lateral movement is impared to the cam follower during its movement toward the center of the shaft 61.

A portion of eachof the two shafts 69 and 72 is guided in a slide block '73 which is secured to the rotatable table 13. The facing end portions of the two shafts 69 and '72 have corresponding recesses 74 (FIG. 2) which slidably receive a small plate '76 therein. In their normal position, for example at the loading station as depicted in FIG. 2, the small plate abuts the ends of the recesses in r each of the shafts. However, as the first shaft 69 is moved backward, through lateral movement of the cam follower 68 in the cam groove 67, a constant pulling force is exerted on the second shaft 72 through the spring connection 71 and the shafts 69 and 72 are separated thereby causing movement of the small plate 76 out of engagement with the ends of the recesses 74.

As best shown in FIGS. 3 and 4, the front of the second shaft 72 is pivotably connected to a link 77. The other end of the link is pivotably attached to the yoke 24 such that when a rearwardly directed force on the second shaft is applied to the yoke at this point, it will cause the yoke to rotate counterclockwise about its pivotable connection 27 to the outwardly projecting members 22. Thus, the article gripping apparatus 12. is pivoted to the vertical position as depicted in FIG. 6.

To insure that the article gripping apparatus 12 is precisely aligned in the vertical plane, a constant rearwardly directed force is exerted on the second shaft 72 at the unloading station, thereby causing a gaging surface 7 S on the yoke 24 to be drawn into and held at a point of positive engagement with a gaging surface 79 on the front portion of the base member 21.

The vertical positioning is accomplished just previous to the point at which the article gripping apparatus 12 reaches the unloading station so that the article gripping apparatus may be rotated into the unloading device 66.

As best depicted in FIGS. 6 and 7, the unloading device 66 has an :air cylinder 81, suitably supported from above, which imparts reciprocal movement to a shaft 82. A pair of recessed members 83 are suitably secured to the forward end of the shaft 82. As the article gripping apparatus 12 is rotated the last portion of its travel to the unloading station, the rear positioning plate 34 of the tubular member 31 is rotated into recesses 34 of the recessed members. if an article is presented to this particular station by the article gripping apparatus, the air cylinder 81 is actuated to advance the shaft 82 downwardly. The back surface of the recesses 84 engage the plate 34 and thereby moves the tubular member out of engagement with the locking detent 37. As the shaft 82 is advanced downwardly from this point the tubular member 31 is advanced until the oblong plate 48, secured to the actuator rod 36, engages the facing L-shaped projections 23 of the forwardly projecting members 22. With such adavncement in the downward direction, the article 10, gripped between the jaw members 31, is directed precisely into a container 86 which has been advanced by another suitable apparatus to receive the article.

The unlocking of the jaw members 41 is caused by the engagement of the oblong plate 43, of the actuator rod 36, with the facing L-shaped projections 23 on the outwardly projecting members 22;. When the oblong plate first contacts the L-shaped projections, the article ll) is still locked between the jaw members. However, a slight additional advancement of the shaft 82 from this point causes a relative advancement of the tubular member 31 with respect to the actuator rod 36 which results in the knee joint 5b of the toggle links 42 being forcefully returned from the over-center position to the normal position, thereby releasing the article gripped between the jaw members.

After the article it is delivered to the container 86, the shaft 82 is moved upwardly by means of the air cylinder 81. The front surfaces of the recesses $4, in the recessed members 83, engage the rear positioning plate 34 and thereby return the tubular member 31 to a locking engagement with the locking detent 37. it should be noted that if no article is gripped by the article gripping apparatus 12 when it is originally rotated to the unloading station, the air cylinder 31 is deactuated and rendered ineffectual for initiating the unloading operation.

The article gripping apparatus is returned to its horizontal position in a manner similar to the method in which it is pivoted to the vertical posit-ion. The cam groove '57, in the upper tooling plate 52, is directed outwardly from the unloading station to the loading station. Thus, when the article gripping apparatus 12 is indexed from the unloading station to the loading station, the cam follower 63 is moved laterally away from the center of the shaft 61 and a positive outwardly directed force is transmitted from the first shaft 69 to the second shaft 72 through the small plate 76 which is now contacting the ends of both of the recesses 74 in the shafts 69 and 72. The forwardly directed force, when applied to the point of pivotal connection between the link 77 and the yoke 24 causes the yoke to pivot clockwise around the pivot pins 27.

The positive forwardly directed force is constantly applied to the yoke 24- while the article gripping apparatus 12 is in its horizontal position. Application of such a force allows for exact horizontal positioning of the gripping apparatus as the aforedescribed gaging surfaces 49 on the base member 21 are positively driven into engagement with the tubular member 31 and the rear positioning plate 34.

The present invention has been described as embodied in article gripping apparatus which, after achieving an article gripping position, remains locked in that position provided that an article is present and gripped therein. However, if no article is gripped by the apparatus when it is in the article gripping position an applied force developed within the apparatus collapses the apparatus to its normal non-article gripping position. The return of the article gripping apparatus to its normal position may be sensed by appropriate devices, and a signal thereby derived is effective to deactuate the various operational stations to which the article is presented by the article gripping apparatus.

While a preferred embodiment of this invention has been illustrated and described, many other embodiments thereof will be apparent. For example, the article gripping jaws may be of non-flexible material if they grip a flexible article. Also if non-flexible jaws are used to grip non-flexible articles, flexibility may be built into the apparatus in various ways such as by the use of floating springloaded pivot points. It is also apparent that the teachings of this invention may be utilized in constructing gripping apparatus which grips articles by engaging internal surfaces thereof. It s intended that the invention be interpreted as including all the modifications which fall within the true spirit and concept thereof.

What is claimed is:

l. in article gripping apparatus for gripping an article at a loading station and for presenting the article to a plurality of successive operational stations in an assembly machine:

a support member;

a pair of jaw members having article gripping surfaces on corresponding portions thereof, said jaw members being pivotably attached to said support member at first pivot points spaced from the gripping surfaces such that the gripping surfaces are movable between a relative non-gripping and a gripping position;

a pair of toggle links having one end of each pivotally interconnected to form a pivotable knee joint, the other end of each of said links being pivotally connected to a respective one of said jaw members at a second pivot point spaced from the corresponding first pivot point such that movement of the knee joint toward a centerline connecting the second pivot points causes the gripping surfaces to pivot about the first pivot points toward the relative article gripping position and movement of the knee joint across such centerline to an over-center position with the gripping surfaces gripping an article causes the knee joint to lock in its over-center position and said jaw members to lock in their article gripping position;

means at the loading station of the assembly machine for advancing the knee joint over the centerline between a normal position corresponding to the relative non-gripping position of said jaw members and its over-center position corresponding to the relative article gripping position of said jaw members;

biasing means effective to move the knee joint from its over-center position to its normal position upon retraction of said advancing means in the event that no article is present and gripped by the gripping surfaces;

means for moving said support member through the successive operational stations such that said jaw members presents the article carried thereby to each station; and

means rendered operable by the return of the knee joint to its normal position to deactuate the successive operational stations to which said moving means presents jaw members which are in their relative nongripping position.

2. Article gripping apparatus as defined in claim 1 wherein said biasing means is a spring urging the knee joint toward its normal position.

3. In article gripping apparatus for gripping an article at a loading station and for presenting the article to a plurality of successive operational stations in an assembly machine:

a support member;

a pair of jaw members having article gripping sur faces on corresponding portions thereof, said jaw members being pivotably attached to said support members at first pivot points spaced from the gripping surfaces such that the gripping surfaces are movable between a relative non-gripping and a gripping position;

an actuator rod pivotally connected to the knee joint of said toggle links;

reciprocating means at the loading station of the assembly machine including a member normally spaced from but advanceable into engagement with said actuator rod to advance said actuator rod such that the knee joint of said toggle links is moved over the centerline between a normal position corresponding to the relative nongripping position of said jaw members and its over-center position corresponding to the relative article gripping position of said jaw members;

biasing means effective to move the knee joint from its over-center position toward its normal position upon retraction of said member of said reciprocating means in the event that no article is present and gripped by the gripping surfaces;

means for moving said support member through the successive operational stations such that said jaw members present the article carried thereby to each station; and

4. Article gripping apparatus as dclined in claim 3 wherein said biasing means is a spring which directly at biases said actuator rod in such a direction as to urge the knee joint toward its normal position.

5. in article gripping apparatus for gripping an article at a loading station and for presenting the article to a plurality of successive operational stations in an assembly machine:

a support member pivotable about a horizontal axis;

a pair of jaw members having article gripping surfaces on corresponding portions thereof, said jaw members being pivotably attached to said support members at first pivot points spaced from the gripping surfaces such that the gripping surfaces are movable between a relative non-gripping and a gripping position;

a pair of toggle links having one end of each pivotally interconnected to form a pivotable knee joint, the other end or" each of said links being pivotally connccted to a respective one of said jaw members at a second pivot point spaced from the correspondin first pivot point such that movement of the knee joint toward a centerline connecting the second pivot points causes the grippinr surfaces to pivot about the first pivot points toward the relative article gripping position and movement of the knee joint across such centerline to an over-center position with the gripping surfaces gripping an article causes the knee joint to lock in its over-center position and said jaw members to lock in their article gripping position;

an actuator rod pivotally connected to the knee joint of said toggle links;

reciprocating means at the loading station of the assembly machine including a member normally spaced from but advanceable into engagement with said actuator rod to advance said actuator rod such that the knee joint of said toggle links is moved over the centerline between a normal position corresponding to the relative non-gripping position of said jaw members and its over-center position corresponding to the relative article gripping position of said jaw members;

spring means biasing said actuator rod in such a direcas to urge the knee joint from its over-center position toward its normal position upon retraction of said member of said reciprocating means in the event that no article is present and gripped by the gripping surfaces;

means for moving said pivotal support member through the successive operational stations such that said jaw members present the article carried thereby to each station;

means rend red operable by the return of the knee joint to its normal position to deactuate the succe sive operational stations to which said moving means presents jaw members which are in their relative non-gripping position; and

means for pivoting said pivotal support member such that said jaw members may be presented to an operational station at a desired attitude.

6. In article gripping apparatus for gripping an article at a loading station and for presenting the article to a plurality of successive operational stations in an assembly machi e:

a support member pivotable about a horizontal axis;

a pair of toggle links having one end of each pivotally interconnected to form a pivotable knee joint, the other end of each of said links being pivotally connected to a respective one of said jaw members at a second pivot point spaced from the corresponding l'll'SlI pivot point such that movement of the knee 9 joint toward a centerline connecting the second pivot points causes the gripping surfaces to pivot about the first pivot points toward the relative article gripping position and movement of the knee joint across such centerline to an over-center position with the 10 a support member; a pair of mutually opposed jaw members pivotally mounted on said support member; first means mechanically coupled to said jaw members to effect at least a partial closure thereof and to gripping surfaces gripping an article causes the knee exert a positive gripping action against an article joint to lock in its over-center position and said jaw when positioned and held therebetween; members to lock in their article gripping position; biasing means to maintain said jaw members in a noran actuator rod pivotally connected to the knee joint mally open position and for opening said jaw memof said toggle links; bers subsequent to at least a partial closure thereof reciprocating means at the loading station of the assemby said first means in the absence of an article havbly machine including a member normally spaced ing been positioned between said jaw members; from but advanceable into engagement with said second means for moving said support member succesactuator rod to advance said actuator rod such that sively to the plurality of operational stations such the knee joint of said toggle links is moved over that said pair of jaw members presents successive the centerline between a normal position correspondarticles carried thereby to each station; and ing to the realtive non-gripping position of said jaw third means responsive to said first means and to the members and its over-center position corresponding operable condition of said jaw members to deactuto the relative article gripping position of said jaw ate the successive stations wherever said second movmembers; ing means presents said jaw members to a station spring means biasing said actuator rod in such a direcwithout an article gripped therebetween.

tion as to urge the knee joint from its over-center 8. Apparatus in accordance with claim 7 further inposition toward its normal position upon retraction eluding fourth means for orienting said jaw members of said member of said reciprocating mean in the angularly from a first position to a second position; event that no article is present and gripped by the fifth means mechanically coupled to said jaw members gripping surfaces; for moving said members reciprocally along a rectimeans for moving said pivotal support member through linear path while in said second position; and

the successive operational stations such that said sixth means responsive to said last mentioned means jaw members present the article carried thereby to for effecting the opening of said jaw members to reeach station; lease an article gripped thereby when said memmeans rendered operable by the return of the knee bers have been moved to an extended point along joint to its normal position to deactua-te the successaid rectilinear path while oriented in said second sive operational stations to which said moving means position. presents jaw members which are in their relative nong g P T id t l t b h References Cited by the Examiner or pivo mg a pivo a suppor mem er suc that said jaw members may be presented to an opera- UNITED STATES PATENTS tional station at a desired attitude; and 9, 4 8/ 89 James 294- means at the last of the operational station for unlock- 00, 3/11 Lea 294-106 X ing the knee joint of said toggle links by forcefully 1,220,899 /17 sorensen 294- returning the knee joint from its over-center position 71, 3/ 45 Fcdorchak 198-210 to its normal position whereby said jaw members are returned to non-gripping position and the article FOREIGN PATENTS gripped thereby is released. 45 5 6 41 11/94 Sweden- 7. In article gripping apparatus for gripping an article at a loading station and for presenting the article to a plurality of successive operational stations in an assembly machine;

HUGO O. SCHULZ, Primary Examiner.

Claims

7. IN ARTICLE GRIPPING APPARATUS FOR GRIPING AN ARTICLE AT A LOADING STATION AN FOR PRESENTING THE ARTICLE TO A PLURALITY OF OF SUCCESSIVE OPERATIONAL STATIONS IN AN ASSEMBLY MACHINE; A SUPPORT MEMBER; A PAIR OF MUTUALLY OPPOSED JAW MEMBERS PIVOTALLY MOUNTED ON SAID SUPPORT MEMBER; FIRST MEANS MECHANICALLY COUPLED TO SAID JAW MEMBERS TO EFFECT AT LEASTA A PARTIAL CLOSURE THEREOF AND TO EXERT A POSITIVE GRIPPING ACTION AGAINST AN ARTICLE WHEN A POSITIONED AND HELD THEREBETWEEN; BIASING MEANS TO MAINTAIN SAID JAW MEMBERS IN A NORMALLY OPEN POSITION AND FOR OPENING SAID JAW MEMBERS SUBSEQUENT TO AT LEAST A PARTIAL CLOSURE THEREOF BY SAID FIRST MEANS IN THE ABSENCE OF AN ARTICLE HAVING BEEN POSITIONED BETWEEN SAID JAW MEMBERS; SECONDMEANS FOR MOVING SAID SUPPORT MEMBER SUCCESSIVELY TO THE PLURALITY OF OPERATIONAL STATIONS SUCH THAT SAID PAIR OF JAW MEMBERS PRESENTS SUCCESSIVE ARTICLES CARRIED THEREBY TO EACH STATION; AND THIRD MEANS RESPONSIVE TO SAID FIRST MEANS AND TO THE OPERABLE CONDITION OF SAID JAW MEMBERS TO DEACTUATE THE SUCCESSIVE STATIONS WHEREVER SAID SECOND MOVING MEANS PRESENTS SAID JAW MEMBERS TO A STATION WITHOUT AN ARTICLE GRIPPED THEREBETWEEN.