The present invention relates to method and apparatus for trimming and/or cleaning flashing on plastic frames, for example, which forms when plastic members are fused together. More particularly, the present invention relates to method and apparatus for substantially simultaneously joining and trimming flashing and cleaning internal and external surfaces of plastic frames without the need for removing the joined members from the joining equipment and transporting the members to a remote cleaning/trimming/polishing station.
High speed automatic equipment for joining frame components which have been cut to size and supplied to such equipment for fabricating a frame or a frame-like structure, are well known in the art.
The typical operation is to provide plastic frame members which have been processed preparatory to the joining operation to form a frame, for example. Although machines of this nature are capable of simultaneously joining substantially all four corners of a frame structure, a description will be given herein of the manner in which two frame members forming one corner of the frame structure are joined, it being understood that the remaining three corners are formed in a substantially identical manner and are also performed substantially simultaneously with the corner joining operation described hereunder.
The frame members, which have previously been precision mitred to form a corner, are placed in the machine, typically referred to as a conventional 4-point welder structure, are positioned within clamping devices and are moved towards one another so that the surfaces to be joined engage a locator plate which typically provides a gap of the order of one quarter inch (0.25″) between the surfaces to be joined. The clamping devices clamp the frame members in place so that the surfaces to be joined extend a given distance beyond their clamping devices in a direction toward the opposite clamping device.
The clamping devices are then moved apart by an amount sufficient to enable the locator plate to be withdrawn. After the locator plate is withdrawn, a heated plate is placed in the gap region between the surfaces to be joined. The clamping devices then move the frame members towards one another causing the surfaces to be joined to engage opposing surfaces of the heated plate which heats the surfaces to be joined to a level sufficient to heat a marginal end portion of each frame member to a softened or molten state. This is accomplished by adjusting/controlling the temperature of the heated plate and the time interval during which the engaging surfaces of the frame member are in contact with the heated plate to achieve the desired softened/molten state.
Thereafter, the clamping assemblies are moved to separate the frame members to enable the heated plate to be withdrawn. After the heated plate has been removed from the region between the heated, softened surfaces, the clamping members are moved to bring the softened molten, surfaces of the cooperating frame members into intimate engagement. This action causes the heated surfaces to fuse together as they undergo cooling. In addition, the bringing together of the frame members causes some of the softened material to be squeezed out from the region between the joined ends of the engaged frame members, whereby the softened material squeezed out from between the joined surfaces, forms an undesirable flashing. The flashing may extend outwardly from the external surfaces and inwardly from the interior surfaces.
After the frame members have cooled sufficiently, the frame is removed from the clamping assemblies.
The frame assembly is removed to a separate location from the four-point welding equipment to undergo trimming and polishing, necessitating: removal of the completed frame; transportation to a trimming/polishing station; clamping of the frame at the trimming/polishing station; and performing the trimming/polishing operations. In addition, the techniques presently used for trimming/polishing the flashing typically require a large amount of manual labor to obtain frames having the desired clean, aesthetic appearance, especially in the regions of the joined corners.
The present invention is characterized by comprising method and apparatus for performing both an exterior and an interior trimming and/or cleaning operation which takes place at the welding station and during the welding cycles, thereby significantly reducing both the time and the amount of handling required in the employment of conventional techniques while totally eliminating the need to transport frame assemblies requiring trimming and/or cleaning operations to a second location for performance thereof. In addition the present invention is characterized by comprising method and apparatus for performing trimming operations which provide a frame having a clean, aesthetically pleasing appearance in the external regions of the mitred corners as well as cleaning the interior region of the welded seams while eliminating the need for the labor intensive activities which are necessary when employing conventional techniques.
The present invention is characterized by comprising method and apparatus for mounting the trimming assembly directly upon an automated welder system, which may be a single point, two (2) point or four (4) point welder for joining frame members whose center lines are perpendicular as well as joining members whose longitudinal center lines are parallel or form any angle therebetween, enabling the trimming operation, as well as other operations, to be performed while the joined members of the frame are still mounted in the automated welder, thereby totally eliminating the need for removal of the frame from the automated welder and transporting and mounting the frame upon separate trimming/polishing equipment.
More specifically, the apparatus of the present invention comprises guide blocks joined to the clamping assemblies of the welder equipment. The trimming apparatus comprises a pair of guide members which serve to guide reciprocally mounted trimming blade assemblies. Actuators are provided for each of the trimming blade assembles for selective extension and retraction thereof. In addition thereto, a latching assembly is provided for selectively latching the guide blocks to one another to prevent their movement during the operation of the trimming blade(s), thereby assuring clean, effective trimming of the flashing which avoids the need for additional finishing/polishing after removal of the frame from the welding apparatus. Latching activators are provided separately and independently of the trimming blade assembly activators for selectively latching and delatching the guide blocks.
The activators may be electrically operated solenoids, motor driver ball gears or hydraulic or pneumatic devices. In one preferred embodiment, the activators are pneumatically controlled activators forming a part of a pneumatic system for operating the latches at a first pressure level known as “shop psi” for operating the latches and moving the trimming blades in the retraction direction and being provided with a booster regulator for extending the trimming blades at a higher pressure level hereinafter referred to as a “high psi.”
The external and internal trimmings are preferably operated under control of a programmed logic controller (PLC) for automatically controlling the trimming system through a preprogrammed sequence and further automatically initiating operation responsive to control signals from the automated welder system, enabling operation of the trimming system in proper synchronizing and time relationship with the automated, welder equipment.
The guide blocks and cutting blades may be designed to accommodate a variety of different frame structures so as to provide trimming for frames of complex cross-section configurations as well as cross-sections of simple shapes having substantially flat external surfaces at the same time without interfering with or complicating the design and operation of the welder equipment, enabling operation of the welder equipment without any design modifications to accommodate the trimming system.
The cooperating cutting blades may be operated to perform a variety of different combinations of cutting/shearing steps to perform a trimming operation which removes flashing from the joined ends of frames and the like to a degree sufficient to eliminate the need for any further trimming/polishing operations.
The interior cleaning unit is used to clean welded flash materials from the inside corners of welded plastic members. Cleaning is accomplished on the welding machine and is performed during the welding process time, eliminating the need for any further cleaning/processing steps following the welding of the materials.
The inside cleaning unit, in it's simplest form, requires no more than basic logic motion, but may be moved to define a curved path as well as two sequentially performed linear paths. The interior cleaning system may also be controlled utilizing single or multiple-axis controls for programmable positioning, allowing many different shapes and sizes of material processing on the same system without the need for manually changing the cleaning tool. The control may be programmed in a learning phase to accommodate joined frames of different sizes and shapes.
The interior cleaning unit can also be utilized to perform multiple processes such as drilling, milling, grinding, polishing, routing, punching, and the like, merely by mounting the appropriate tool. The interior cleaning system can be used independently or in conjunction with an external cleaning system used for external (i.e., outside corner, top and bottom) profile cleaning.
The invention will be described in detail hereinbelow making reference to the drawings, in which:
a and 3b are perspective views showing the fixtures of
a and 6b respectively show a top plan view and an end view of a boot holding four (4) trimming blades.
a,
7
b and 7c are front, side and top views of blade “1” in
a,
8
b and 8c are front, side and top views of blade “2” in
a,
9
b and 9c are front, side and top views of blade “3” in
a,
10
b and 10c are front, side and top views of blade “4” in
a and 11b are tables showing two possible programmed sequences of the trimming operations obtainable through the programmed logic controller of
a-12d are cross sections of the different profiles of frame members capable of being joined and trimmed employing the system of the present invention.
a-13c are cross sections of other profiles of frame members capable of being trimmed by the system of the present invention, and respectively showing trimming apparatus adapted for use in trimming a single stack, a double stack and a four-high stack of profiles.
a-14k are perspective views showing various stages in the interior cleaning system.
A source 14 provides the desired “shop” pressure, typically of the order of 90 psi, which is coupled through line 16 to a booster regulator 18, and line 16a to 16b and 16c which are respectively coupled to solenoid-operated control valves 18 and 20 for respectively operating the fixture locking cylinder 22 and trimming blade cylinder 24.
The output of booster 18, which is of the order of 170 psi, is coupled to a safety valve 28 through reservoir 26. A pair of one-way valves provided in valve structure 30 prevent the pressure in high pressure line 16d from entering into low pressure line 16b, and vice versa.
The PLC 12 receives a signal from the 4-point welder, as will be more fully described, to initiate the operation of the trimming apparatus.
The cooperating fixtures are shown in
Each locking plate is mounted to pivot about a pivot pin 44, only one of which is shown in
Locking plate 40 of
The upper and lower fixtures 36 and 38 shown in
It should be understood that the upper fixtures 32 and 36 are locked to one another and that the lower fixtures 34 and 38 are locked to one another, the lower locking fixture assembly being substantially identical in design and function to the upper locking fixture description described hereinabove. The locking mechanism prevents the fixtures from moving relative to one another when the trimming blades are operated to prevent the frames being joined from experiencing any movement during trimming of the flashing and also to prevent the cooperating fixture members from moving during the trimming operation, thereby providing a trimming operation which completely removes the flashing, thus avoiding the need for any further trimming and/or polishing operations.
The locking mechanism actuating cylinders 22 are operated to retract the pistons 22a upon completion of the trimming operation to enable separation of the fixtures preparatory to removal of the joined frame members.
Each of the fixtures 32, 34, 36 and 38 is provided with a reciprocating trimming blade assembly 58, 60 shown in
a is a perspective view showing a portion of the trimming assembly of
b is a perspective view showing the latching assembly portion which cooperates with that shown in
Although
A typical operating sequence will now be described.
Initially, the welding operation takes place prior to the trimming operation. It should be understood that the welding operation may comprise equipment for fusing all four corners of a frame or alternatively for fusing only one corner, it being understood that the present invention may be utilized with equal success and efficiency in either single corner or four corner fusing equipment as well as 2 or 3 corner (i.e., 2 or 3 point) welding units.
The operation of the joining of two frame members at one corner will be described herein for purposes of simplicity, it being understood that the welding and trimming operations that are not shown are substantially identical in design and function.
The frame members F1 and F2 to be joined are respectively placed between the fixture pairs 32-34 and 36-38. Although not shown for purposes of simplicity, it should be understood that suitable clamping means that such as hydraulically or pneumatically operated clamping pistons or electrically operated solenoids urge the cooperating fixtures 32-34 and 36-38 toward one another to suitably clamp the frame member F1 and F2 therebetween.
A locator plate, not shown for purposes of simplicity, is extended into the region between the fixture pairs 32-34 and 36-38 and the fixtures are closed into the locator plate. The members being joined are inserted into the fixtures and the clamping actuators clamp the frame members in place. As is conventional, the processed ends F1a and F2a of the frame members of F1 and F2 are arranged by the locator plate so as to extend slightly beyond the end faces of the fixtures. For example, the mitred end of frame member F1 is arranged to extended preferably about ⅛th of an inch beyond faces 32a and 34a for fixtures 32 and 34. Frame member F2 has its processed surface F2a extending a similar distance beyond the faces 36a and 38a of fixtures 36 and 38. These distances may be modified according to the materials being joined, as well as other factors.
With the frame members in this position and locked in place, the fixtures are moved apart and the locator plate is retracted. The heating plate is then extended into the gap between the mitred end surfaces and the fixtures are moved towards one another causing the end surfaces to make contact with the heated plate in order to melt the end portion of each frame member for a period sufficient to render the plastic material softened or molten. The ends of the frame members F1 and F2 are typically maintained in contact with the heat plate for approximately 20 seconds. The heat plate is typically maintained at a temperature of 450° F. when joining frames formed of PVC, for example, which is used for storm windows and the like. Other materials may require different temperatures and different dwell times according to the material being used. For example, resilient gaskets used in refrigerators for sealing a refrigerator door, require less heat to soften the material sufficient for fusing two joined pieces.
Thereafter, the fixtures are moved apart and the heat plate is retracted from the region between the fixtures. The fixtures are then moved into an engaged position joining the heated, softened, molten ends of the frame members. The members are maintained in this fusion position for about 20 to 25 seconds, allowing the frame members to be fused together and cooled.
In the present invention, the PLC 12 takes the signal from the welder assembly which may be signals provided to 24 volt dc solenoids employed in conventional welder machines.
The trim cycle begins whereby PLC 12, upon receipt of the appropriate signal from the welder, operates the solenoid controlled valves 18 causing the valves to couple the “shop” psi to the line 16e of the locking mechanism actuator cylinder 22 whereupon the piston arms 22a are extended causing the latching plates 40 and 42 to enter into the cooperating slots 50 and 52 in fixtures 36 and 38 (see
Making reference to the table shown in
At step 3 the left trimming knife of each trimming pair, i.e., the trimming knives of assemblies 58 and 60 of fixtures 32 and 34, are retracted. At step 4 the left trimming knives of assemblies 58 and 60 are then extended. At step 5, the right trimming knives i.e. the trimming knives of assemblies 62 and 64 of the upper and lower fixtures 36 and 38 are retracted at the lower psi and then at step 6 they are extended at the higher psi. By retracting and extending the trimming blade assemblies 58-64 through a number of different steps, this assures the complete removal of the flashing. The number of steps typically may vary in accordance with the nature of the members and/or materials being fused. For example, when making gasket frames formed of a resilient compressible material, it has been found that such materials require a lesser number of steps to perform a trimming operation. Thus, according to the material, the program is selected which removes the flashing without the need for further removal by cutting by hand and/or polishing.
In addition to operating the trimming blades so as to open and close simultaneously or so as to hold one blade closed while the other is repeatedly opened and closed, a shearing operation may be performed by holding one of the cooperating blades of each blade pair in a retracted position and repeatedly extending and retracting the other blade of the blade pairs. For example, the right-hand blades 62 and 64 (
The shearing sequence may be alternated whereby the left-hand blades of assemblies 58, 60 perform shearing while the right-hand blades of assemblies 62 and 64 are retracted and the blade assemblies then reverse their operations so that the left-hand blades of assemblies 58 and 60 are retracted while the right-hand blades 62 and 64 perform the shearing operation.
The program of
In the example given, the frame members have a fairly regular and simple shape. It should be understood that the fixture and blade assemblies of the present invention may be provided with any desired configuration so as to conform to the profile of the frame members being joined and trimmed. For example, the frame profiles may be quite simple such as a gasket having substantially flat surfaces or maybe a frame for a window such as a storm window and have a much more complicated frame profile, as shown by the different profiles of
In addition to the trimming apparatus embodiment described hereinabove, the present invention may be adapted for use in trimming joining members, such as, but not limited to, frame members and utilized with heating/fusing/joining apparatus capable of performing heating/fusing/joining operations on a single stack or frame or on multiple stacks of frames, simultaneously.
For example, the embodiment shown in
a shows a somewhat complex “right-hand” profile P arranged in a suitable clamping fixture F to be joined to a “left-hand” profile, not shown for purposes of simplicity. For example, the fixture 32, 34 of
Heating/fusing/joining structures are also available which are capable of simultaneously operating on a stack of two (2) or more members. For example,
a-14g are views of the interior cleaning system 100 which is compatible for use with and synchronized with the heating, fusing, and external trimming apparatus set forth above. The trimming assembly for trimming of the external surfaces shown in
Making reference initially to
a shows the main support plate 110 in the home position.
b shows an enlarged detailed view of a portion of the apparatus 100 and
a shows the tool post 106 in the home position with its interchangeable cleaning head 126 positioned so as to be displaced from the external trimming and the heating and fusing components, shown in detail in
The head of the tool post receives interchangeable tools and may be rotated by a driving device. The head is capable of receiving knives, milling means, drills and other like tools for operating on the interior region of the frame F. The tool may also be an ultrasonic tool or a vibratory tool.
The tool post 106 may be extended in height as shown in
To operate a drill or other tool head which requires that it be rotated, a drive shaft 146 is coupled between a drive motor 144 in lower housing 130 and a rotatable tool head 142, as shown in
When the tool post 106 has been brought to a position where the tool head is clear of the welder heads, actuator 112 is operated to move the main support plate 110 in the upward vertical direction to bring the tool head 126 toward the working height position shown in
Once the tool head reaches the position in
Although in the example given, backward and forward movement of the cleaning tool is described to clean the surfaces F1, F2, F3, the tool may be moved in only one (1) direction or may be moved backward and forward more than once to achieve the desired cleaning operation. The tool head may be fitted with a buffing or grinding tool as an alternative to a trimming blade, or an ultrasonic or vibratory tool for cleaning or other operations. The tool head also may be fitted with a screw driver tip for a inserting a screw or drill for drilling a hole in the frame members.
The tool post is further provided with an air injecting nozzle 128 for blowing air into the corner to effect cooling of the flashing preparatory to cutting. The air nozzle may also be operated subsequent to the cutting operation to blow the debris removed by the cleaning tool away from the frame members F which have just been cleaned, as shown in
After the cleaning operation is complete the vertical actuator 112 drives the tool post 106 horizontally and away from frame F and drives the main support plate 110 vertically downward as shown by arrows D and E in
In applications where it is desired to provide for interior cleaning of first and second stacked frame members, the tool post is provided with a second cleaning tool 126′ and a second air nozzle 128′. The second pair of frame members and the clamping and guiding devices therefore have been omitted from
As is mentioned above, the cleaning head maybe interchanged with other types of heads such as a drilling head, trimming knife or the like. The drill may be utilized to drill holes in the frame. The air nozzles, although not shown for simplicity, have their right-hand ends extending rearwardly from the tool posts for coupling to flexible tubing (not shown) for delivering air under pressure from a suitable pressurized air source (not shown) to the air nozzles 128 and 128′. The pressurized air source may be either the shop pressure or high pressure obtained from source 14 shown in
Single or multiple point welders are not limited to joining and trimming double stacks and may be utilized to join multiple stacks greater in number than two. For example,
It should be understood that the profiles for single, double or quad stacks are held by clamping fixtures similar to those respectively shown in
It can be seen that the present invention provides a novel apparatus and method for trimming and/or cleaning plastic frame members and the like, and which is utilized in conjunction with conventional welding apparatus enabling the trimming operation to be performed while the frame members are retained at the welding apparatus thus eliminating the need for removing the fused frame members and relocating them to a separate independent apparatus. Although the preferred embodiment is directed to joining frame members, it should be understood that the trimming apparatus of the present invention may be used to trim any joined plastic members, regardless of their orientation and may be used to trim members whose center lines are arranged to be parallel, perpendicular or any angle therebetween.
This application is a continuation-in-part of pending application Ser. No. 10/241,901 filed Sep. 25, 2002.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10254901 | Sep 2002 | US |
| Child | 11169489 | Jun 2005 | US |