Abstract:
A part removal tool for removing a resilient molded tubular part from a mold core first clamps the molded part on a cup removal tool at one end of the part and then inflates the part to separate the part from a mold core. The part removal tool includes a protective housing having spaced protective side plates that protect interior switches, conduits and actuators, while providing easy connections with exterior quick release fittings. The tool employs replaceable clamps and part removal cups so that the tool can be used for a variety of parts of different sizes and shapes. An extendable part ejector rod can be used to facilitate removal of a part from a mold core.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]    This is a continuing non-provisional application based on and claiming the filing priority of co-pending provisional patent application Serial. No. 60/186,766, filed Mar. 3, 2000. 
     
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not Applicable.  
         BACKGROUND OF THE INVENTION  
         [0003]    Large diameter flexible tubes having convolutions in the tubes are used for a number of applications in automotive and other fields. These are typically formed by injection molding wherein a core is positioned between severable halves of a mold and molten rubber is injected between the core and the mold halves.  
           [0004]    A problem with molding products in this manner is that it is difficult to remove the finished product from the mold core after the product is formed. A part removal tool can be used for this purpose. A part removal tool includes a cup that fits closely over the mold core in between the part and the mold core, and a clamp that clamps the part on the cup. Air is then injected into the cup and this inflates the part so that the part becomes dislodged from the convolutions in the mold. The cup part is then pulled off the mold by withdrawing the cup and clamped edge of the part away from the mold core.  
           [0005]    A problem with prior part removal tools is that a separate tool had to be manufactured for each mold core size. Further, the part removal tools had exposed electrical cable and pneumatic tubes, and these were subject to damage during use. Prior product removal tools also were complicated, made of a number of parts, and structurally weak. An object of the present invention is to provide an improved part removal tool that is simple, strong, encloses the pneumatic hoses and electrical cables and, most importantly, accommodates a number of different sizes of part removal cups for different sizes of mold cores.  
         SUMMARY OF THE INVENTION  
         [0006]    In accordance with the present invention, a part removal tool for removing a molded elastic tubular part from a mold core comprises a housing having protective side plates spaced on each side of an open interior. The housing has an open front end. A handle is mounted to the plates at a rear end of the tool. An enlarged recess in the side plates adjacent the front end of the tool makes it possible to install a number of different part removal cups having substantially different outer dimensions in the tool. A part removal cup manifold is mounted between the plates at a rear end of the recess, the manifold having an inlet for pressurized gas and one or more outlets for pressurized gas. A part removal cup is removably mounted in the housing in the enlarged recess between the plates, the cup having an open front end facing outwardly from an open interior toward the open front end of the housing. The part removal cup has relatively thin peripheral sidewalls surrounding the open front end such that the sidewalls conform with and fit closely over a specified mold core. The part removal cup has a rear end mounted in the housing in sealed relationship with the manifold outlet, the rear end having one or more openings therein that provide sealed communication between the manifold outlet and the open interior of the cup. A clamp is movably and removably mounted in the housing adjacent the open end of the part removal cup for movement between an open position, wherein the clamp is spaced away from the cup sufficiently that the cup can be inserted between a molded product and a mold core, and a closed position, wherein the clamp clamps an end of the product on the cup after the cup has been inserted on the mold core the clamp having a clamping surface compatible with the adjacent exterior surface of the part removal cup. A clamp actuator opens and closes the clamp. A cup air actuator injects pressurized gas through the manifold to the cup to separate a clamped part from a mold core.  
           [0007]    The tool housing and its protective side plates protect switches, conduits, and actuators mounted in the housing, while quick release fittings exterior to the housing facilitate removal and installation of electrical and pneumatic lines from the tool.  
           [0008]    The part removal cup is bolted in the housing to the manifold and is removable and replaceable with a different cup for a different molding application. The clamp has clamping elements that also are easily removable for installing different clamping elements that are compatible with different part removal cups.  
           [0009]    The tool can also include an extendable part ejection rod that extends outwardly through the cup to push the mold core away from the molded part clamped to the end of the part removal cup.  
           [0010]    These and other features of the present invention are apparent from the preferred embodiment of the invention described below and shown in the appended drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a perspective view of a tube molding press employing the part removal tool of the present invention.  
         [0012]    [0012]FIG. 2 is a perspective view of the part removal tool of the present invention.  
         [0013]    [0013]FIG. 3 is a side-elevational view of the part removal tool of the present invention, partially broken away to show interior components.  
         [0014]    [0014]FIG. 4 is a fragmentary view showing the part clamping mechanism of the present invention.  
         [0015]    [0015]FIG. 5 is a pictorial side-elevational view showing removal of a part by injection of pressurized air between the part and the mold core.  
         [0016]    [0016]FIG. 6 is a perspective view of an alternative embodiment of the present invention employing a core bar to assist the removal of the part from the mold core.  
         [0017]    [0017]FIG. 7 is a side-elevational view of the part removal tool of the present invention, showing the various electrical and pneumatic lines in schematic form.  
         [0018]    [0018]FIG. 8 is a partial plan view of the part removal tool of FIG. 7.  
         [0019]    [0019]FIG. 9 is a side-elevational view of the side plate of the part removal tool of the present invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0020]    Referring to the drawings, a conventional injection molding press  10  for molding flexible tubular members  12  having convolutions  14  is shown in FIG. 1. FIG. 1 illustrates a person  16  employing the part removal tool  18  of the present invention for the purpose of removing part  12  from the mold core  20 .  
         [0021]    Injection molding press  10  comprises a cabinet  22  having an open front side  24 . Upper and lower mold halves  26  and  28  are mounted on columns  30  inside the cabinet. A shuttle mechanism  32  mounted on slides  34  employing cam wheels at the sides of the shuttle mechanism make it possible to slide the mold core  20  into and out of alignment with mold cavities in the upper and lower mold halves or plates. In FIG. 1, the mold core, which is mounted on the end of shaft  36  is shown in an extended position. The mold core can be moved into alignment with mold cavities in the upper and lower mold plates by pushing the mold core inwardly, in a conventional manner.  
         [0022]    Products are molded in the mold core in a conventional manner. Typically these products are rubber when used in automotive applications. Other moldable resins could be employed. When the mold core is moved inwardly into the cabinet in alignment with the mold cavities, the press is closed by raising lower plate  28  upwardly until it engages shuttle mechanism  32 , and then both the lower plate and shuttle mechanism are moved upwardly until they engage the upper plate. At that time, the mold is injected with a moldable resin such as rubber and the part is formed.  
         [0023]    After the part has been formed, the plates are lowered and the mold core extended to the position shown in FIG. 1. At that point, the product is removed from the mold core employing the product removal tool  18  of the present invention.  
         [0024]    Product removal tool  18  is suspended by hook  19  on a cable  38  in a spring wound reel  40  which is in turn mounted on a boom  42  pivotally mounted by a pivot fixture  44  on the top of the cabinet for the press. The boom can be pivoted into operational position shown in FIG. 1 for removal of the part from the mold core. When the mold core is retracted into the press and the part is being formed, the boom is pivoted out of the way to the position shown in phantom FIG. 42′. The spring wound reel exerts enough spring pressure on the cable to neutralize the weight of the part removal tool and thus makes it possible to raise and lower the tool without lifting the weight of the tool.  
         [0025]    Part removal tool  18  is connected to various electrical and pneumatic cables and tubes  46  which are connected by quick disconnect fittings  48  and plugs  50  for quickly connecting and disconnecting the tool from the electrical and pneumatic supply lines. The supply lines are wound around the boom and then eventually extend to a source of electrical power and a source of pressurized air that is available in the plant where the manufacturing operation is taking place.  
         [0026]    The construction of product removal tool  18  is shown in FIGS. 2, 3, and  7 - 9 . Part removal tool  18  comprises an enclosed housing  52  that surrounds and protects the pneumatic and electrical cables and tubes  46  that extend inwardly into the interior of the tool. This protects the cables and tubes from damage during operation of the tool. Housing  52  comprises a pair of spaced plates  54  on opposite sides of the tool. The spaced plates have a vertical center member  56  and inwardly and rearwardly extending upper and lower flanges  58  and  60  at a rear side. A tubular handle  62  is welded to the ends of flanges  58  and  60 . The front portion of plate  56  includes a central enlarged recess  64  in which an air injection cup  66  is mounted. An important feature of recess  64  is that upper and lower edges  68  and  70  are spaced a substantial distance apart so that air injection cups of various sizes will fit in the recess.  
         [0027]    Upper and lower semicircular clamp elements  72  and  74  are positioned adjacent a front open end  76  of the air injection cup. The semicircular clamp elements are mounted for vertical movement on upper and lower drive cylinders  78  and  80 . They ride on nylon or brass guide plates  82  and  84  mounted on flanges  86  and  88  at the mouth  90  of the part removal tool. The clamp elements are removably threaded on the ends of cylinder rods of the drive cylinders. Each clamp element is shaped to fit on a particular cup and mold core, and the clamp elements are changed for each part having a different size or shape, which may or may not be circular in cross section.  
         [0028]    Side plates  52  are formed of a durable metal, preferably aircraft aluminum.  
         [0029]    Plates  52  are spaced apart by spacers in the form of U-shaped channels  92  and  94  at upper and lower sides of the plates. The side plates and upper and lower channels thus provide a protective external housing for a number of delicate pneumatic and electrical components that are mounted in the open interior of the housing. A mounting block  96  is mounted between the plates at an inward end of air injection cup  66  and serves as an additional plate spacer and as a means for mounting a manifold  98  for injecting air through the air injection cup (see FIG. 7). The air injection cup desirably is bolted on the manifold. Preferably, all cups are fabricated with the same size of fitting for mounting the cup on the same manifold.  
         [0030]    The details of the electrical and pneumatic circuitry of the product removal tool of the present invention are shown in FIGS. 3 and 7. The manner in which these components function for removing a part from the mold core  20  is shown in FIG. 5. As shown in FIG. 5, after a part has been molded, end  76  of air injection cup  66  is wedged between an end  100  of part  12  and a distal end of mold core  20 . It should be noted that end  76  of the air injection cup has a beveled forward edge that facilitates wedging the air injection cup between the part and the mold core. Also, a forward part  102  of the air injection cup has a thinner wall than a rearward portion  104  of the air injection cup, thus further facilitating the wedging of the air injection cup between the part and the mold core.  
         [0031]    As shown in FIG. 5, after the air injection cup has been wedged between the part and the mold core, clamps  72  and  74  are actuated so they clamp the end of the product tightly to the walls of the air injection cup in a substantially sealed relationship. At that point pressurized fluid, preferably air, is injected through an inlet tube  106  into manifold  98 . Thereafter, the air enters the open interior of the cup  110  through openings  112  positioned around the peripheral edge of the end of the cup. The pressurized air in the cup is forced between the cup and the mold core into the space  116  between the molded product  12  and the mold core  20 . The product is then, in effect, blown up to the position shown in FIG. 5, wherein convolutions  14  in the part separate from convolutions  118  in the mold core. The part can then be pulled off the mold core by pulling handle  62  in a direction away from the mold core.  
         [0032]    Referring to FIG. 7, the part removal tool is preferably operated by pneumatic air pressure, which is generally available in the plant in which the molding operation takes place. A source of pressurized air  120  is designated schematically in FIG. 7. Air pressure is provided to the air injection cup manifold through an inlet conduit  122 . A fitting  124  provides two inlets into conduit  122 . One inlet  126  is a low pressure inlet that is connected via a pressure regulator  128  to source  120 . The line air pressure available from source  120  varies from plant to plant. For exemplary purposes, a line pressure of approximately 140 pounds per square inch (psi) is typical. In such a situation, pressure regulator  128  may reduce the pressure to low pressure conduit and inlet port  126  to approximately 90 psi.  
         [0033]    An inlet conduit  130  is used for providing extra pressure to the air injection cup manifold when additional inflation pressure is necessary to dislodge the part from the mold core. Conduit  130  does not extend through a pressure regulator and thus receives full line pressure and provides a “turbo” pressure for releasing the product from the mold.  
         [0034]    Another pressure line  131  extends to a one quarter inch inlet line  132  that actuates the clamps of the present invention. Line  132  extends through a T connection  134  into a solenoid controlled valve  136 . Solenoid valve is controlled by electrical toggle switch  138 . When toggle switch  138  is in the down position, as shown in FIG. 7, air is directed through outlet fitting  140 . This directs air through conduits  142  and  144  to actuators  78  and  80  and causes the actuators to retract the clamps and hold them in a retracted position. When toggle switch  138  is moved to an upward position, air is redirected to outlet fitting  146 , which causes air to be directed through lines  148  and  150  to fittings  152  and  154  on actuators  80  and  78 . This causes the actuators to bring the clamps together and clamp the product on the air injection cup. Thus, the clamping mechanism positively moves the clamps between their closed and open positions and holds them in the positions.  
         [0035]    Pressurized air flow to the air injection pump cup manifold is controlled by a pneumatic air valve  156  in line  126  and is controlled by an electrical solenoid valve  158  in line  130 . Pneumatic control valve  156  is actuated through air conduit  160 , which is connected to a thumb-operated button  162  on handle  62 . When button  162  is depressed, valve  164  is opened, permitting pressurized air flow from T fitting  136  through conduit  166  and then through conduit  160  to valve  156 . This opens the valve and admits pressurized air through conduit  126  into the air injection cup manifold, which in turn permits pressurized air at the lower pressure (e.g. 90 psi) into the space between the part and the mold core.  
         [0036]    When additional pressure is necessary, an electrical switch in the nature of actuator button  170  actuates electric solenoid  158  through electrical cable  172 . When electrical solenoid is actuated, full line pressure is introduced into air injection pump manifold  98  in addition to the reduced line pressure available through the low pressure inlet. This causes an additional boost of air volume and air pressure in the air injection cup and this provides additional force for removing the part from the mold core.  
         [0037]    It can be seen from the foregoing description that all of the pneumatic and electrical components are housed in a protected fashion in the interior of the part removal tool housing, protecting the parts from accidental injury. This is an important feature of the present invention. The side plates of the housing are formed of durable metal plates, preferably aluminum, which are welded to channels  92  and  94 , mounting block  96 , and handle  62  and are not welded to other components. Welding tends to weaken aluminum, and the present invention structure maximizes the strength of the aluminum.  
         [0038]    Another feature of the invention is the wide mouth employed for the air injection cup. The wide mouth created by the recessed or cutaway portion  64  having lower and upper edges  68  and  70  provides substantial distance between the outer periphery of the air injection cup and the housing. The air injection cup is simply bolted to the housing, so it can be removed and replaced with a larger or smaller cup at will, and there is a wide variety in sizes of cups that can be employed in the large amount of space provided in this housing. In the past, part removal tools have required a separate tool for virtually each mold. With the present invention, one size fits most applications. Indeed, with three different sizes of air injection tools, these tools can accommodate virtually every moldable part that is being made in the fashion described in this invention. This is quite a savings over prior tools.  
         [0039]    An alternative embodiment  200  is shown in FIG. 6. Most of the parts are the same as the prior embodiment, except that the housing is fitted with a pressure cylinder  202  that drives an extendable core bar  204  outwardly and inwardly through the air injection cup. A somewhat different handle assembly  206  is fitted to the housing in order to provide room for cylinder  202 . Handle  206  includes spaced vertical members  208  connected at upper and lower portions by crossbars  210  and  212 . Central vertical members  214  and  216  are connected to the side plates in the same manner as handle  62  of the previous embodiment.  
         [0040]    The core bar feature of this invention provides an extra pulling force for pulling the product off the end of the mold core. A switch  218  actuates pressure cylinder  202  and extends core bar  204  outwardly into contact with an indented portion  220  in the end of mold core  222 . When core bar  204  is extended into contact with the mold core  222 , this forces the mold core away from the product removal tool and tends to pull the product removal tool and attached product away from the mold core. This feature of the invention is useful in molds where product removal is especially difficult.  
         [0041]    It should be understood that the foregoing is merely exemplary of the preferred practice and that various changes and modifications may be made in the arrangements and details of construction of the embodiments disclosed herein without departing from the spirit and scope of the present invention.