Abstract:
A takeout jaw for handling glass bottles includes a holder for both fixed and floating inserts. This design allows an insert to be in a fixed position when the insert is provided with a nominal thickness. When a floating insert of a lesser thickness is installed, the spring clip does not engage the floating insert, which allows the floating insert to move vertically or float. The takeout holder contains either type of insert within the pocket with retaining clips that engage chamfers formed on the inserts.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates in general to a fixture for glassmaking and, in particular, to an improved system, method, and apparatus for lifting hot glass bottles from molds in which they are formed with a nonmetallic material that is capable of being both fixed and floating relative to a fixture. 
     2. Description of the Related Art 
     Hot glass, especially when formed into various shapes in the manufacture of glass containers (e.g., bottles), is susceptible to being damaged by contact with glass processing equipment. Most of the equipment that contacts the hot glass in the hot end process area during the manufacture of glass bottles is fabricated from metallic materials (e.g., stainless steel and other alloys). However, in certain areas of the hot end processing of glass bottles, it has been found desirable to utilize non-metallic materials such as graphite, asbestos, plastics or carbon fibers. 
     One such application is in fixtures used to lift hot, newly formed bottles from the mold in which they are formed and set them down on an air pad for cooling before being conveyed to an annealing furnace. These fixtures are called takeout jaws or tongs. Since metallic takeout jaws may cause scratching or checking by contact with the hot formed bottles, takeout jaws are frequently fabricated with a non-metallic insert for contacting the hot glass. Checking is the formation of imperceptible cracks due to sudden localized heat transfer or thermal shock. Non-metallic inserts can significantly reduce checking and scratching. This is particularly important in the current production of light weight, fragile bottles that require gentler handling. 
     Of the materials which have been used as inserts for takeout jaws, the most satisfactory to date has proven to be graphite. Although other non-metallic materials have been used, most of such non-metallic materials are not completely suitable for use in lifting the hot containers from the molds. Asbestos, which was used at one time, has proven to be undesirable for safety and environmental reasons. Plastics suitable for use at the high temperatures encountered in the hot end process area must be specially formulated and also have a relatively short service life. In contrast, graphite possesses properties that are particularly well suited for contacting hot glass containers. Graphite properties include high strength, resistance to oxidation, non-abrasive surface integrity, heat resistance, low porosity, and long service life. 
     One of the disadvantages of conventional takeout jaws was the frequent need to replace parts that were worn out from routine use in the bottle-forming machine. This wear was caused largely by the movement of takeout jaw inserts within the jaw. Inserts were commonly held in position by steel detent balls positioned in holes in the takeout jaws. Detent balls were subject to wear and fouling due to the accumulation of grease, oil, and other foreign matter. The detent balls tended to hang up in their holes and permit the insert to fall out, causing loss of the insert and loss of production. Detent balls seldom provided sufficient fit for the insert to render the insert immovable within the jaw. Therefore, a limited amount of vertical movement or “float” between the insert and jaw was almost always present. 
     Coupled with the fact that jaws having close tolerances could not be readily fabricated from cast bronze, the form of takeout jaws conventionally manufactured, the play between the jaw and insert resulted in wear of the insert and necessitates frequent replacement. Because of the lack of close tolerances in the takeout jaws, replacement of both inserts from a pair of takeout jaws was typically necessary. p In U.S. Pat. No. Re. 34,953, the inserts for the takeout jaws are “fixed” and do not permit float. That patent discloses takeout jaws that reduce the wear on inserts and in which the inserts can be readily replaced in the event of wear or damage without having to replace parts of the jaws themselves. Thus, bottle makers have had two choices in takeout holders: floating and fixed. The criteria for selecting the type of holder includes, for example, the condition of the bottle making machine, the type of finish required, and the skill level of the workers. 
     Fixed holders hold the insert tightly in the holder&#39;s pocket via a spring clip, while floating holders allow the insert to move vertically. The float is accomplished by reducing the thickness of the insert by 0.020 to 0.050 inches less than the pocket of the holder. The insert is contained in the pocket with ball bearings that protrude into the pocket from both sides and corresponding grooves in the insert. Although these two separate designs are workable, it would be advantageous and desirable to provide a single design that accommodates both fixed and floating takeout insert holders. 
     SUMMARY OF THE INVENTION 
     One embodiment of a system, method, and apparatus for handling glass bottles includes a holder for both fixed and floating inserts. This design allows an insert to be in a fixed position while at a first thickness of a fixed insert (e.g., 0.250 inches). When the insert is at or below 0.230 inches thick, the spring clip no longer engages the insert, which allows the insert to move vertically or float. The present invention contains the insert within the pocket with chamfers formed on the parting line of the holder. Retaining clips affixed to the holder are used to retain the insert in the pocket. In addition, an insert blank may be used in conjunction with the inserts. The function of the insert body changes between the fixed and floating configurations by changing the thickness. 
     In the fixed configuration, the takeout jaws hold a piece of non-metallic contact material under spring tension in a manner such that the contact material does not move within the takeout jaws upon contacting a hot glass container. Because the contact material is held securely in position by spring tension, it is possible to lift the hot containers in a manner such that damage to the containers is minimized. Thus, the takeout jaws can be machined to close tolerances enabling the container lifting machine to operate as a precision machine. Because of the resulting gentle handling of the hot containers, it has become feasible to produce lighter weight glass containers and to increase the efficiency and output. 
     One embodiment of a takeout jaw of the present invention comprises a generally arcuate holder for an arcuate piece of nonmetallic contact material, means at the middle of the arc formed by said arcuate holder for holding said arcuate piece immovably within said arcuate holder, and means integral with said holder for attaching the jaw to a support therefor. The takeout jaws of the present invention permit higher bottle yields and decrease the need for replacement of the contact material inserts. 
     The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the present invention, taken in conjunction with the appended claims and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the features and advantages of the invention, as well as others which will become apparent are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the drawings illustrate only an embodiment of the invention and therefore are not to be considered limiting of its scope as the invention may admit to other equally effective embodiments. 
         FIG. 1  is a schematic drawing of the takeout area of a bottle-making machine showing takeout jaws in position over recently formed glass bottles; 
         FIG. 2  is an isometric view of one embodiment of a takeout jaw and insert showing the insert removed from the jaw and is constructed in accordance with the present invention; 
         FIG. 3  is a front view of a takeout jaw of the present invention with the insert removed; 
         FIG. 4  is a partially sectioned side view of a takeout jaw and insert of the present invention showing the insert removed from the jaw; 
         FIG. 5  is a top view of an insert of the present invention; 
         FIG. 6  is an enlarged sectional side view of a portion of a takeout jaw of the present invention show the spring in its untensioned condition; 
         FIG. 7  is an enlarged sectional side view of a portion of a takeout jaw and partially mated insert showing the spring in its fully tensioned condition; 
         FIG. 8  is an enlarged sectional side view of a portion of a takeout jaw and fully mated insert showing the spring in its untensioned condition; and 
         FIG. 9  is a high level flow diagram of one embodiment of a method constructed in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The design of the takeout jaw of the present invention permits machining to close tolerances, thereby ensuring accurate and precise set up for bottle forming machines. The precision machining of the takeout jaws combined with the tightness of the insert in the pocket of the jaw that contains the insert enables the takeout jaws to be accurately located on the bottle in a reproducible manner. This design reduces deformation of the bottle finish at the top of the bottle due to misalignment and, consequently, the number of bottles which must be scrapped. When threaded finishes are required, the inserts contact the threaded finish only at the root and on the underside of the threads to further decrease the likelihood of damage. 
     The machine fabrication of the takeout jaws of the present invention eliminates the high cost of tooling of the cast takeout jaws of the prior art and enables economic production even in relatively small quantities. In the prior art, the cast bronze takeout jaws of the prior art had to be manufactured in quantities of thousands of units to justify the high initial cost of tooling. In contrast, the machined takeout jaws of the present invention can be manufactured economically in quantities as low as hundreds of units. Furthermore, the arcuate or semicircular shape of the takeout jaws of the present invention lends itself to being turned on a lathe. In addition, the number of parts required for the spring clip that retains the insert within a semicircular pocket in the takeout jaw is three, including spring, bolt, and washer, for each takeout jaw compared to eight for the detent ball retainer, which requires two detent ball assemblies per jaw, each consisting of ball, leaf spring retainer, screw and washer. 
     One of the major modes of insert failure is chipping of the surface of the insert. More precise mating of the insert with the bottle finish is ensured by close tolerance machining. Such machining is possible because of the semicircular design of the insert of the present invention, which reduces the risk of chipping. The semicircular design of the pocket in which the insert is retained and the semicircular configuration of the insert ensure that maximum surface contact between jaw and insert is realized. Since the insert contacts a large surface area of the pocket in the jaw and since the insert is held immovably within the pocket by the insert retaining spring, which is positioned at the center of the semicircular pocket, there is no play between the insert and takeout jaw. Thus, abrasion of the bottom surface of the insert caused by such play is eliminated. Precise alignment of the takeout jaws and bottles is thereby maintained while reducing damage to bottles and increasing the life of the insert. 
     Referring to the drawings,  FIG. 1  depicts a typical production environment in which the takeout jaws of the present invention are used. The number  10  represents a series of the takeout jaws of the present invention, which are positioned above a series of hot bottles  12 . Takeout jaws  10  are connected to a lifting arm  14 . Bottles  12  have just been removed from a bottle forming mold  16  and are suspended just above air pad  18  by a cushion of air, the source of which is not illustrated. Hot bottles  12 , which were red hot when lifted out of the mold by takeout jaws  10 , are cooled upon air pad  18  and then transferred to a conveyor belt  20  for transport to an annealing furnace, also not illustrated. Cooled bottles  22  are shown upon conveyor belt  20 . 
     Referring to  FIGS. 2 and 3 , one embodiment of a single takeout jaw  24  and mating insert  26  constructed in accordance with the present invention is shown. Takeout jaw  24  has a semicircular body  28  and a yoke  30  for attachment to a lifting arm  14  ( FIG. 1 ). Body  28  has a base  32  and a shelf  34  that form between them a semicircular pocket  36 . Pocket  36  is open at the front and closed at the rear by semicircular back wall  38  of body  28  except for an opening  40  in the center of back wall  38 . A center portion  42  in the lower surface of shelf  34  is cut out to provide clearance for a spring clip  58  ( FIG. 3 ). The spring clip  58  is located in opening  40  at center portion  42 . 
     In the embodiment shown, insert  26  is generally semicircular in form except for a lug  44  formed by cutting notches in the back wall  46  of insert  26 . The upper surface  48  of insert  26  has a depression  50  with a hole  52  in the bottom thereof. Hole  52  is used for locating or fixturing purposes in machining insert  26  to the desired dimensions. The front surface  54  is generally semicircular except for two flat portions  56  at either end of the semicircle. If desired, front surface  54  can be threaded to provide a convenient means for contacting bottles having threaded finishes. 
       FIG. 4  shows the several horizontal surfaces in phantom and also shows that one embodiment of the insert is adapted to be positioned within the pocket in the takeout jaw and that the spring clip and depression in the insert are lined up to be engaged. Spring clip  58  is attached to back wall  38  of takeout jaw  24  by means of a screw  60  and a washer  62 . 
       FIGS. 5 ,  6 ,  7  and  8  illustrate how one embodiment of the insert fits within the takeout jaw. The spring clip  58  is normally untensioned as shown in  FIG. 6 . As the insert  26  is pushed in the direction shown by arrow  64  ( FIG. 7 ), the lug  44  engages spring clip  58  and causes it to become tensioned. Then, when the insert is pushed all the way in ( FIG. 8 ), spring clip  118  is snapped into depression  50  and becomes untensioned as in  FIG. 6 . Removal of insert  26  from takeout jaw  24  requires exertion of a large force to tension spring clip  58  and allow removal of insert  26  from takeout jaw  24 . 
     In one embodiment, graphite is used to fabricate the takeout jaw inserts of the present invention. Various grades of graphite are commercially available. A particularly desirable material is a fine particle, high strength, isotropic graphite available from Poco Graphite, Inc., Decatur, Texas, which is sold as GLASSMATE® graphite contact material. 
     In one embodiment, the present invention is ideally suited for providing a takeout jaw assembly  10  comprising a takeout jaw  24  having a pocket  36  that interchangeably accommodates both fixed and floating inserts. The pocket  36  is oriented in a first direction (see arrow  64  in  FIG. 7 ), and defines a second direction (arrow  65 ) perpendicular to the first direction  64 . Fixed retention means (such as a spring clip  58 ) is mounted to the takeout jaw  24  and extends into the pocket  36  in the second direction  65 . A fixed insert  26  has depression  50  and chamfers  70  formed therein for use in a fixed configuration such that the fixed insert  26  is located in the pocket  36  and the spring clip  58  engages the depression  50  to retain the fixed insert  26  in the takeout jaw  24  to prevent motion of the fixed insert  26  in the second direction  65 . 
     A floating insert  26   b  ( FIG. 4 ) also has chamfers  70  formed therein and a floating configuration such that the floating insert  26   b  is located in the pocket  36  and the spring clip  58  is out of contact or free of engagement with the floating insert  26   b  to allow a range of motion (e.g., approximately 0.020 to 0.050 inches) of the floating insert  26   b  in the second direction  65 . 
     The takeout jaw  24  also has retaining clips  72  mounted to sides  74  (e.g., lateral sides) of the takeout jaw adjacent the pocket  36  (e.g., with screws  76 ) for engaging the chamfers  70  of either the fixed insert  26  or the floating insert  26   b  and retaining said either the fixed insert  26  or the floating insert  26   b  in the pocket  36  while in their respective configurations. In one embodiment, the fixed insert  26  has a fixed dimension  78  extending in the second direction  65  and the floating insert  26   b  has a floating dimension  78   b  extending in the second direction  65  that is less than the fixed dimension  78 . In one embodiment, the takeout jaw  24  has a width dimension  80  that is perpendicular to both the first and second directions  64 ,  65 , and the width dimension  80  is less than that of conventional takeout jaws (e.g., approximately 2.0 inches or less). In addition, one embodiment of the takeout jaw  24  has a locating pin  82  and a locating hole  84  that are offset from the pocket  36  in the second direction  65 . 
     In operation, one embodiment of a method of the present invention comprises providing interchangeable fixed and floating inserts for a takeout jaw assembly. As shown in  FIG. 9 , the method starts as indicated at step  90 , and comprises providing a takeout jaw having a pocket oriented in a first direction, and defining a second direction perpendicular to the first direction (step  91 ); mounting a fixed retainer on the takeout jaw (step  92 ); mounting a dual retainer on the takeout jaw (step  93 ); positioning a fixed insert in the pocket in a fixed configuration by engaging the fixed insert with both the fixed retainer and the dual retainer such that motion by the fixed insert is prevented in the second direction (step  94 ); and to reconfigure the takeout jaw: removing the fixed insert from the pocket and positioning a floating insert in the pocket in a floating configuration by engaging the fixed insert with only the dual retainer such that the floating insert has a range of motion in the second direction (step  95 ); before ending as indicated at step  96 . 
     The method also may comprise using retaining clips to engage and retain respective ones of the fixed and floating inserts. In addition, the method may further comprising forming chamfers on the fixed and floating inserts for engagement by the dual retainer; and/or providing the takeout jaw with a locating pin and a locating hole that are offset from the pocket in the second direction. 
     The present invention has several advantages, including the ability to provide one holder for both fixed and floating applications. Users have the option to use the fixed or floating configuration of removing glass bottles from molds without having to change to a different style of holder. This design offers a significant cost saving measure for glass bottle producers. In addition, the takeout jaws of the present invention permit higher bottle yields, are economically producible in small quantities and are characterized by decreased need for replacement of inserts. 
     While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.