Abstract:
A lanced and/or slit seamed housing and method of manufacture having a peripheral rolled and lanced or punched seam between a wrapper and the housing panels. The method of manufacture utilizes similar or dissimilar sheet materials in a variety of material thicknesses and with or without coatings applied prior to formation whereby a housing is formed quickly and safely. The rolling and lancing method manufactures a blower housing with an assured and positive sealed seam between the panels and wrapper of the housing. The lances or slits maintain the integrity of the seam and prevent slippage between the wrapper and panels.

Description:
This application claims priority of U.S. Provisional Patent Application No. 61/124,127, filed Apr. 15, 2008, entitled Lance and Slit Seamed Housing and Method of Manufacture. 
     BACKGROUND OF THE INVENTION 
     The art of the present invention relates to sheet metal housings in general and more particularly to blower fan housing assemblies used in heating ventilating and air conditioning (HVAC) systems. The present art apparatus and method of manufacture continuously forms a rolled, lanced, and/or slit seam which locks the housing sides or panels with a perimeter wrapper sheet. The manufacturing apparatus and method of manufacture uniquely rotates two housing sides or panels and a preformed perimeter wrapper through one or more rollers which form a lanced and/or slit seam at the perimeter interface of the panels and wrapper. 
     Housings of various sizes and configurations are often employed in forced air furnaces and/or air conditioners and typically have a blower mounted therewith. The blower provides the ventilating air flow for heating, ventilating, and air conditioning systems. That is, the ventilating air flow forced through or over a heat exchanger or evaporator provides the desired air heating or cooling. A conventional blower housing is generally manufactured from sheet metal often having a painted, galvanized, or aluminized coating. The housing typically supports the blower (in the form of a powered blower wheel) and comprises two blower sides or panels with a wrapper sheet formed and attached around a perimeter interface. The blower wheel creates the required high volume of air flow. The wrapper sheet is substantially positioned between and formed or wrapped around a substantially parabolic radius contour of the two blower housing panels with a seam or joint peripherally created there between. The seam or joint must secure or lock the panels and wrapper whereby lateral or radial movement there between is prohibited during powered blower operation. The seam or joint must also prohibit any air flow leakage from the housing perimeter or peripheral interface. 
     Prior art seaming or joining of the wrapper to the housing panels varies from manufacturer to manufacturer and includes welding, flanging, or stacking of the panels and wrapper. Many manufacturers form a flange on either the wrapper or the panels and spot weld the combination of panels and wrapper around the perimeter interface. This prior art method of attachment is time consuming, labor intensive, and often represents a health and safety risk to the assembler. It is also prohibits coating of the sheet metal with a non-conductive coating prior to assembly. Other manufacturers utilize one or more discrete stakes, punches, or crimps around the seam. These prior art methods eliminate some of the safety and environmental issues associated with welding but are also time consuming and labor intensive, and often produce a seam which is inferior to the aforementioned welded seam. 
     The prior art housing assembly techniques and equipment are also dedicated or designed to produce only one type, style, diameter, or width of blower housing and utilize a specific thickness of sheet metal. HVAC equipment utilizes many different types, styles, diameters, and widths of blower housings in order to satisfy the air flow requirements of the system and the environment served. Different sizes of blower housings also utilize different thicknesses of sheet metal. Many of the prior art housing assembly techniques and equipment are also dedicated or designed for a specific sheet metal thickness. 
     The present art utilizes a continuous roll and lance (or slit) lock method which produces a superior rolled seam in less time than the prior art welding, punching, staking, or crimping systems. The present art assembly apparatus also allows a manufacturer to produce a wide variety of housing types, styles, diameters, or widths with a minimal setup or changeover adjustment. The present art also accommodates a plurality of sheet metal thicknesses and material types. Although rollforming of seams between flat sheet metal materials is recognized within various industries, simultaneous rollforming and lancing of housings or blower housings has not heretofore been performed. That is, it is difficult to create a uniform rolled and lanced seam on the parabolic peripheral geometry of the housing. 
     The present art blower housing and method of manufacture incorporates a continuous lance and/or slit rolled seam at the housing peripheral interface which closes and interlocks the edge flanges of the wrapper and panels together. For the preferred embodiment, the preformed housing side panels are inserted into preformed wrapper edge flanges and the resultant edge flange/panel sandwich is fed through one or more specially formed rollers which peripherally lance/slit, and roll the edge seams (i.e. a sandwich) with a single and continuous operation. That is, both sides are locked and seamed simultaneously as the lance and slit rollers follow around the outer perimeter or periphery of the housing. This configuration simultaneously locks the panels and wrapper together to form a seam without a lateral or radial movement between the wrapper and panels. The locking and seaming technique allows the housing to withstand blower loads and vibrations without failure and prohibits any gap between the panels and wrapper through which air leakage could occur. 
     The present art method of manufacture allows the blower housing to be constructed from different types and thickness of sheet materials and further allows the sheet materials to be coated, i.e. painted, galvanized, aluminized, or of dissimilar metals prior to assembly. No primary indexing cycles or secondary welding, punching, staking, or flanging operations are required. The rollers and holding fixture or chuck height and width is fully adjustable for any type of housing style, diameter, width, or material thickness. 
     Accordingly, it is an object of the present invention to provide a lance/slit seamed housing and method of manufacture which provides a secure rolled and lanced/slit seam between the housing side panels and the peripheral wrapper in a quick, easy, and safe manner. 
     Another object of the present invention is to provide a lance/slit seamed housing and method of manufacture which provides a continuously rolled seam without gaps and does not require primary indexing or secondary punching, crimping, or staking operations. 
     A further object of the present invention is to provide a lance/slit seamed housing and method of manufacture which may utilize pre painted or coated materials having a plurality of thicknesses and compositions. 
     A still further object of the present invention is to provide a lance/slit seamed housing and method of manufacture which is quickly and easily capable of formation into a plurality of blower housing styles, types, diameters, or widths. 
     A yet further object of the present invention is to provide a blower housing and method of manufacture which is easy and economical to manufacture in a variety of sizes with the same assembly machines. 
     A yet further object of the present invention is to provide a blower housing and method of manufacture having locking lances or slits and which provides a substantially smooth seam. 
     SUMMARY OF THE INVENTION 
     The art of the present invention comprises a lance and/or slit seamed housing and method of manufacture. The assembly apparatus is designed to simultaneously form the blower housing wrapper around two blower housing sides or panels and peripherally lock seam them together to produce a complete blower housing unit. As the wrapper is formed around the blower housing sides one or more rollers join and interlock the wrapper and panel periphery in order to form a continuous peripheral lanced seam. In the preferred embodiment, rollers having integral lance and slit punches form the continuous peripheral seam which joins the panels and wrapper. That is, the rollers have one or more lancing extensions or protrusions which perform the lancing as the peripheral seam is rolled. In the preferred embodiment, both sides of the housing are lanced and seamed simultaneously as the housing is rotated approximately 180 to 210 degrees during a feed cycle. 
     The preferred embodiment of the assembly apparatus first consists of two opposed rotary actuator assemblies and two sets of rotary lance and slit punch roller assemblies. The rotary actuator assemblies and lance and slit roller assemblies are preferably adjustably positioned on a table, frame, or structure for easy user access. An embodiment of the assembly apparatus fixes a first rotary actuator assembly and a first lance and slit roll assembly onto a frame or weldment. The second rotary actuator assembly and second lance and slit roller assembly are mounted on horizontal slides whereby adjustment for a wider range of housing depths or wrapper widths is provided. Front and rear guides or seats are positioned onto said table, frame, structure, or weldment or integral with the roller assemblies and guide the panels and wrapper and assist in the seam forming process. 
     Each rotary actuator assembly has a fixture which is sized to mate with or at the venturi opening of a respective side panel. The fixture can further be described as a clamp plate, a mandrel, a chuck, a faceplate, a center, a fixture plate, or a spindle. In a preferred embodiment, the fixtures fit within or at each venturi opening and hold each left and right side panel in place throughout a seaming feed cycle. That is, the fixtures maintain alignment of the panels with the rollers and wrapper as rotation is imparted to the housing and the lance and/or slit rolled seam is formed. The aforesaid fixtures may further be shaped to accommodate other variations of housings which do not have the conventional venturi opening. 
     During the method of manufacture, the rotary actuator assemblies simultaneously rotate the blower housing sides or panels (or allow the rollers to perform the rotation) and thereby feed the panel edges into the wrapper edge flanges or pockets while the lance and slit rollers continuously seam, pinch, and lance the peripheral interface. An alternative embodiment utilizes one or more punches to punch the periphery of the housing panels periphery or wrapper perimeter edge flanges. As the housing panels rotate, the fixtures may approach or retract from the slit and punch rollers, each preferably via a riser cylinder or vertical positioner, in order to follow the peripheral curvature (generally parabolic) of the blower housing sides. The camming action of the housing may also serve to raise or lower fixtures without assistance from a riser cylinder or vertical positioner with the riser cylinder or vertical positioner utilized to initially position the fixtures. Each assembly apparatus utilizes a set of preprogrammed positioning data points for each side panel form which assures a positive insertion of the panel edges into the wrapper edge flanges or pockets as the rollers lance, slit, and seam the periphery of the wrapper and side panels together. 
     During operation, the lance and slit roller assemblies are positioned and aligned with the blower housing sides and the edges of the wrapper. As many housings have at least a portion of the periphery which is a substantially straight edge, the lance and slit rollers are moveable in an axis substantially parallel with the wrapper periphery. This allows the rollers to engage and seam any housing peripheral edge portion which is substantially straight or linear. During this substantially linear seaming operation, the blower housing sides or panels may be held in a substantially fixed position and the rollers traverse the linear portion of the wrapper flange. After the straight flange is formed, the center axis of the rollers are substantially aligned in a vertical axis which intersects or parallels the center axis of the rotary actuators. The housing is then rotated via the rotary actuator assemblies or via the action of the rollers to seam and lance lock the curved portion of the wrapper periphery. 
     During operation, the operator loads both the left and right blower panels or sides onto the respective rotary actuator fixtures. The pre-rollformed wrapper is set into the guides or onto the seats and the edge flanges are aligned with the blower housing sides and the lance, slit, and punch roller sets. The operator then starts the automatic cycle. Each blower panel or side is lowered into the wrapper edge flanges, the lance, slit, and punch rollers feed around the perimeter of the blower housing assembly and form a completed blower housing in a single feed form cycle. 
     The lance and slit seamed housing is typically manufactured from sheet metal, preferably sheet metal which is either inherently corrosion resistant or coated to provide corrosion resistant properties. Typical sheet metals include but are not limited to stainless steel, aluminum, and coated steel products, such as pre-painted steel, galvanized steel, Galvalume® steel, aluminized steel or other painted or coated steels. The sheet metal would typically have a thickness range of 16-26 gauge, as conventionally measured within the sheet metal industry but may have other thicknesses as well. The art of the present invention may also be utilized with non-metallic sheet materials such as polymers and composites. The assembly apparatus may be manufactured from a plurality of materials as recognized by one of ordinary skill when taken in conjunction with the description of each element of the apparatus. In the preferred embodiment, the rollers, rotary actuator assemblies, fixtures, and frame(s) are manufactured from a steel material. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Numerous other objects, features and advantages of the invention should now become apparent upon a reading of the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a right front diagrammatical perspective view of the preferred embodiment of the apparatus for manufacturing the lance and slit seamed housing. 
         FIG. 2  is a right front diagrammatical perspective view thereof with housing panels and a wrapper inserted. 
         FIG. 3  is a front plan view of the embodiment shown in  FIG. 1 . 
         FIG. 4  is a rear plan view thereof. 
         FIG. 5  is a front plan view of the embodiment shown in  FIG. 2 . 
         FIG. 6  is an inside detail view of a preferred embodiment housing wrapper edge flange having the present art lance and slit rolled seam. 
         FIG. 7  is an outside detail view of a preferred embodiment housing wrapper edge flange having the present art lance and slit rolled seam. 
         FIG. 8  is a detail front view of the  FIG. 5  embodiment showing the mating portions of the lance and slit punch and rollers prior to seaming. 
         FIG. 9  is a detail front view of the  FIG. 5  embodiment showing the mating portions of the lance and slit punch and rollers during seaming. 
         FIG. 10  is a perspective view of a preferred embodiment of the housing panels and wrapper prior to assembly. 
         FIG. 11  is a perspective view of a preferred embodiment of the housing panels and wrapper at initiation of assembly utilizing the manufacturing apparatus of  FIG. 5  and showing the relative movement of the form roller assemblies at a linear or straight portion of the housing. 
         FIG. 12  is a perspective view of a preferred embodiment of the housing panels and wrapper approximately midway through assembly utilizing the manufacturing apparatus of  FIG. 5 . 
         FIG. 13  is a perspective view of a preferred embodiment of the housing panels and wrapper substantially at the completion of housing assembly with the manufacturing apparatus of  FIG. 5  and showing the relative movement of the form roller or roll assemblies at a linear or straight portion of the housing. 
         FIG. 14  is a detailed perspective view of a preferred embodiment of the left fixture showing the panel plate and venturi mandrel which is substantially symmetric with a right fixture. 
         FIG. 15  is a front perspective view of a preferred embodiment of a form roller showing the integral protrusions or punches. 
         FIG. 16  is a side plan view of a preferred embodiment of a form roller showing the integral protrusions or punches. 
         FIG. 17  is a top plan view of a preferred embodiment of a form roller showing the integral protrusions or punches. 
         FIG. 18  is a right front detailed perspective view of the preferred embodiment of the apparatus for manufacturing the lance and slit seamed housing together with the housing panels and a wrapper. 
         FIG. 19  is a left front detailed perspective view thereof. 
         FIG. 20  is a bottom front detailed perspective view thereof. 
         FIG. 21  is a front detailed plan view thereof. 
         FIG. 22  is a rear detailed plan view thereof. 
         FIG. 23  is a left detailed plan view thereof. 
         FIG. 24  is a bottom detailed plan view thereof. 
         FIG. 25  is a front detailed plan view of the preferred embodiment of the apparatus for manufacturing the lance and slit seamed housing without the housing panels and a wrapper. 
         FIG. 26  is a front detailed plan view of the left rollers and a left housing panel and a wrapper during the seaming process. 
         FIG. 27  is a front detailed plan view of the right rollers and a right housing panel and a wrapper during the seaming process. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, there is shown in  FIGS. 1-5  diagrammatical views of the preferred embodiment for the method of manufacture, in  FIGS. 6-13  detailed views of the preferred embodiment housing panels and wrapper having the lanced and slit seams, and in  FIGS. 14-27  detailed views of the preferred embodiment of the improved lance and slit seam housing and method of manufacture  10 . The housing  10  and assembly apparatus  28  provide a quick, convenient, and structurally secure method of manufacturing a housing of virtually any size, shape, or style from a plurality of coated and uncoated materials and from materials of different thicknesses or compositions. 
     The lance and slit seam housing  10  comprises at least one (preferably two) housing panel(s)  12  and a wrapper  20 , each having a periphery  16 . The peripheries  16  of the wrapper  20  and housing panel  12  are rolled together and lanced and/or slit to form a lanced or slit seam  14 . In a preferred embodiment, the wrapper has one or more edge flanges  22  (preferably two) or pockets into which a periphery  16  of a housing panel  12  seats or inserts and together with which is seamed and lanced and/or slit. The edge flanges  22  or pockets of the preferred embodiment are of an at least partially “U” form cross section with a separation between the legs of the “U” sufficient to insert said panel  12 . Also in the preferred embodiment, the panels  12  of the housing  10  have a venturi opening  18  into which at least a portion of the pivotal or rotatable fixtures  56 ,  130  of the assembly apparatus  28  fit or mate. For the preferred embodiment, the peripheral  16  portions are rolled via one or more rollers  80 ,  150  which have one or more integral punches or protrusions  166  positioned at or near a roller circumferential edge. The punches or protrusions  166  perform a lancing or slitting operation on the rolled seam  14 . Alternative embodiments may utilize individual punches  94 ,  166  which provide a punching operation upon the periphery  16  of the housing panels  12  or wrapper  20 . 
     Unique to the present art is the secure co-attachment of the housing panels  12  and wrapper  20  without the need for welds or secondary assembly operations. The assembly apparatus  28  for performing the method of manufacture uniquely performs the entire assembly operation on a plurality of material types, thicknesses, and sizes, with and without coating, with a minimum of user input or handling. With the user able to minimize handling during the assembly process, user safety is maximized during the assembly process. Alternative embodiments may utilize edge flanges  22  which are of a cross sectional form other than a partially “U” form, including but not limited to “L” forms, pocketed forms, staked forms, pin indexed forms, or clipped forms. 
     For the preferred embodiment, each lance or slit seam  14  represents one or more (preferably a plurality) pressed indentations within the periphery  16  of the wrapper  20  and panels  12  along with the rolled seam  14 . The indentations are pressed into the sandwich of the wrapper edge flanges  22  and the housing panel  12  periphery  16 . The indentations force the wrapper  20  and panels  12  to lock together, thereby preventing undesirable rotation of the panels  12  relative to the wrapper  20 . In addition to the lancing and/or slitting of the periphery  16 , the seam  14  is rolled via one or more rollers  80 ,  150 . For the preferred embodiment, the roller assemblies  74 ,  144  represent a mated pair of rollers  80 ,  150  with a first roller  81 ,  151  having one or more punches or protrusions  94 ,  166  which mate with one or more recesses  167  within a second roller  83 ,  155 . Via a mechanical force between the mated pair of rollers  80 ,  150 , an intimate sandwich is formed between the wrapper  20  and panels  12 . Alternative embodiments of the housing  10  may place the edge flanges  22  or pockets on the housing panels  12  instead of the wrapper  20 . 
     The preferred embodiment assembly apparatus  28  utilizes one or more first rollers  81 ,  151  which seam, rollform, and lance the periphery  16  against one or more second rollers  83 ,  155 . The second rollers  83 ,  155  can be construed as roller seats. For the preferred embodiment, each seam  14  is formed with two rollers which sandwich the periphery  16  there between with one of the rollers acting as the seat. All embodiments may utilize one or more punches or protrusions  94 ,  166  which are integrally formed with one or more of the rollers  80 ,  150 . Alternative embodiments may utilize a separate and adjacent punch  94 ,  166  which lances or slits the seam  14 , the housing panels  12  periphery  16  or the wrapper  20  edge flanges  22 . 
     The assembly apparatus  28  comprises a right base plate assembly  30  and a left base plate assembly  100 , all of which sit upon a table, frame, weldment, or structure  172 . For the preferred embodiment, the right base plate assembly  30  is moveable or slidable in a direction which is substantially perpendicular to the flow axis of the housing  10  wrapper  20  or laterally. The lateral movable or slidable attribute allows adjustment of the apparatus  28  for various widths of housings  10 . The preferred embodiment moves or slides the right base plate assembly  30  on slide rails  24  which are mated with female slides  26  on an underside of the assembly  30 . Alternative embodiments may utilize a plurality of mechanically accepted forms or assemblies to allow said sliding or moving. Although the preferred embodiment allows the right base plate assembly  30  to slide relative to the left base plate assembly  100 , obvious variations such as the left base plate assembly  100  sliding, both base plate assemblies  30 ,  100  sliding, or an intermediate structure allowing lateral movement of portions of the assembly apparatus  28  is contemplated as within the scope of the present art  10 . For the preferred embodiment, the base plate assembly  30  is driven or moves via a base plate horizontal drive assembly  104  having a motor drive  106  and a worm screw  108  mated with a threaded eyelet  34 . 
     Each base plate assembly  30 ,  100  has one or more guides  32 ,  102  (right housing guide  32  and left housing guide  102 ) which may also be a portion of the rollers  80 ,  150 . The guides  32 ,  102  may traverse from the rear to the front of the apparatus  28  or simply be formed as an extension or portion of the rollers  80 ,  150 . The guides  32 ,  102  allow the extending lips  23  which are formed by the very geometric nature of the wrapper edge flanges  22  to be guided during the assembly process. The guides  32 ,  102  may be integrally mounted with the right and left base plate assemblies  30 ,  100  respectively or may be slidable, adjustable, rotatable, or mounted with different portions of the apparatus  28  in alternative embodiments. 
     In order to quickly and easily adjust the relative separation between the right and left base plate assemblies  30 ,  100 , a base plate horizontal drive assembly  104  comprising a motor  106  and worm screw  108  is preferably mounted with the frame  172 . For the preferred embodiment, the worm screw  108  extends through and is threaded with a threaded eyelet  34  mounted with the right base plate assembly  30 . As shown in the preferred embodiment, the aforesaid  104 ,  106 ,  108 , &amp;  34  are mounted below the base plate assemblies  30 ,  100 . As understood within the mechanical arts, the aforesaid  104 ,  106 ,  108 , &amp;  34  may be mounted in a plurality of locations and/or may comprise a plurality of hydraulic, pneumatic, mechanical, or electric actuators which provide quick and convenient base plate assembly  30 ,  100  adjustment. 
     For the preferred embodiment of the assembly apparatus  28 , each base plate  30 ,  100  has a clamp mount  42 ,  116  (right side clamp mount  42  and left side clamp mount  116 ) and a form roller assembly  74 ,  144  (right form roller assembly  74  and left form roller assembly  144 ). Each form roller assembly  74 ,  144  is also movable or slidable in a direction or axis substantially parallel with the flow of the housing  10  wrapper  20  (i.e. linearly, parallel, or peripherally tangent to the peripheral  16  axis) on slide rails  75  via the action of a roller drive assembly  85  or simply via the action of the roller  80 ,  150  rotational force imparted to the wrapper edge flanges  22  and/or panel periphery  16 . The roller drive assembly  85  may utilize a plurality of drive techniques including but not limited to worm screws, hydraulic or pneumatic actuators or pistons, chain drives, stepping motors, or electromagnetic drives. For the preferred embodiment, the roller drive assembly  85  is a motor driven linear actuator as understood within the mechanical arts. 
     The clamp mounts  42 ,  116  further comprise a vertical slide assembly  48 ,  122  (right vertical slide assembly  48  and left vertical slide assembly  122 , respectively) which is moved and driven (or initially positioned for panel  12  loading) by a vertical positioner  44 ,  118  (right vertical positioner  44  and left vertical positioner  118 , respectively). The vertical positioners  44 ,  118  are preferably motor driven linear actuators but may comprise a plurality of actuators such as the pneumatic, hydraulic, electromagnetic, or mechanical actuators in alternative embodiments. In the preferred embodiment, vertical positioning seats limit the vertical movement of each slide assembly  48 ,  122 . 
     For an alternative embodiment, each of the vertical slide assemblies  48 ,  122  may have horizontal slide assemblies (right horizontal slide assembly and left horizontal slide assembly respectively) which are moveable in a substantially horizontal or lateral direction (i.e. substantially perpendicular to the flow of the housing  10  wrapper  20 ) in order to mate the fixtures  56 ,  130  with the housing panels  12 . Each horizontal slide assembly is driven and positioned via a horizontal positioner  50 ,  124  which can be a pneumatic cylinder or a plurality of pneumatic, hydraulic, electromagnetic, or mechanical actuators. 
     Onto each horizontal slide assembly  52 ,  126  for the alternative embodiment or the vertical slide assemblies  48 ,  122  for the preferred embodiment is mounted a rotary motor  54 ,  128  having an extending shaft onto which each fixture  56 ,  130  is pivotally or rotatably mounted. Said rotary motor  54 ,  128  is preferably a pneumatic motor but may also comprise a plurality of pneumatic, hydraulic, electromagnetic, or mechanical rotary drives or actuators or simply be a non driven rotating shaft. As understood by one skilled within the art and as part of the method of manufacture, each motor  54 ,  128  and rotary roller drive assembly  68 ,  168  is controlled by and interfaced to a preprogrammed motion controller in order to optimally position the housing  10  during the assembly process. 
     For the preferred embodiment, each fixture  56 ,  130  comprises a panel plate  58 ,  132  and a venturi mandrel  60 ,  134 , each of which are sized to the periphery  16  contour and venturi opening  18  of the housing panels  12 . That is, the panel plate  58 ,  132  is smaller than the periphery  16  of the housing panel  12  in order that the seam  14  may be formed but preferably follows the periphery  16  curvature. The mandrel  60 ,  134  preferably fits closely or mates with the venturi opening  18  whereby the housing panels  12  may be precisely held and guided by the combined movement of the vertical positioners  44 ,  118  and the rotary motors  54 ,  128 . The vertical positioners  44 ,  118  may further allow for initial positioning of said mandrels  60 ,  134  and fixtures  56 ,  130  and allow the camming action of the housing panels  12  to move the fixtures  56 ,  130  in all axis as the housing panels are rotated. Alternative embodiments may utilize fixtures  56 ,  130  having a plurality of sizes, shapes, and forms provided the housing panels  12  may be positioned in a precise fashion. Said fixture  56 ,  130  forms include but are not limited to clamps, pins, magnetic retainers, or suction retainers. One or more horizontal positioners  50 ,  124  are utilized to impart a lateral movement to the fixtures  56 ,  130  in order to engage and disengage the fixtures  56 ,  130  with the housing panels  12  during the seaming operation. 
     Also for the preferred embodiment, each roller assembly  74 ,  144  (right  74  and left  144  respectively) comprises a roller retainer  78 ,  148 . Each roller retainer  78 ,  148  has an attached roller rotary drive assembly  68 ,  168  which actuates or moves the rollers  80 ,  150 , preferably via a gearbox or gear reducer. That is, when the housing panels  12  and wrapper  20  are properly positioned and ready for the lance and/or slit seam  14 , the roller rotary drive assemblies  68 ,  168  rotate the rollers  80 ,  150  and inherently move the roller retainers  78 ,  148  as necessary to form the seam  14 . For the preferred embodiment, the rollers  81 ,  83  are coupled via a pair of meshed gears as are the rollers  151 ,  155 . Also for the preferred embodiment, the rollers  83 ,  155  are slidably positioned relative to the rollers  81 ,  151  and actuated via a roller hydraulic actuator  86 ,  185  or other linear actuator capable of imparting the force necessary to form said seam  14 . A plurality of actuator types may be utilized for the rotary roller drive assemblies  68 ,  168  and the roller actuators  86 ,  185 , including but not limited to hydraulic actuators, mechanical actuators, rotary motors or actuators, or electromagnetic actuators in order to forcibly engage the rollers  80 ,  150  with the periphery  16  and form all or a portion of the seam  14 . In a preferred embodiment, each roller retainer  78 ,  148  further comprises a roller shaft  82 ,  152 , with a center axis  84 ,  153 , onto which the rollers  80 ,  150  are mounted and through which the rotary motion of the roller rotary drive assemblies  68 ,  168  is imparted. As described, the preferred embodiment utilizes rollers  80 ,  150  having integrally and/or periodically mounted protrusions or punches  166  which engage the periphery  16  as rotated in order to form the lance and/or slit  14 . 
     As contemplated by those skilled in the art, all of the aforesaid mechanical, pneumatic, and electrical components are interfaced with and controlled via a motion controller which is pre-programmable for the housing  10  size and shape. For the preferred embodiment, the motion controller is a G&amp;L Digital Motion Controller which is preprogrammed with positioning data points. The controller and interface thereto may take a plurality of forms and technologies, including but not limited to electronic, mechanical, hydraulic, or pneumatic logic. The actuating components are preferably controlled via hydraulic or pneumatic valves which are controlled via the electronic controller. Preferred and alternative embodiments may utilize a plurality of interfacing elements between the controller and the pneumatic and electric components of the drives  54 ,  68 ,  104 ,  128 ,  168  and positioners  44 ,  50 ,  85 ,  86 ,  118 ,  124 ,  185 . Said interfacing elements may be electrical, electromagnetic, pneumatic, hydraulic, mechanical, or combinations thereof as recognized within the art. The program or source code which supports the controller and the interfaces may take a plurality of forms which are recognized by those skilled within the pertinent arts and is therefore described herein by the process and function of the assembly apparatus  28  as a whole. It is further recognized that the controller is programmed to perform an operation for a particular size and shape of housing  10  and that said programming may be scalable and changeable. 
     The controller operates and controls the assembly apparatus  28  as hereafter described pursuant to the programming. An operator positions a wrapper  20  and two panels  12  within the apparatus  28  whereby the wrapper edge flange  22  extending lips  23  seat with the blower housing guides  32 ,  102  and the respective fixtures  56 ,  130  may engage and hold each panel  12 . The horizontal positioners  50 ,  124  and/or the base plate horizontal drive assembly  104  moves the fixtures  56 ,  130  and/or the right base plate assembly  30  whereby the fixtures  56 ,  130  engage or disengage the panels  12  as preprogrammed within the controller. Preferably the venturi mandrels  60 ,  134  seat within the venturi openings  18  of the housing panels  12 . The controller then actuates the roller hydraulic actuators  86 ,  185  whereby the wrapper edge flanges  22  extending lips  23  are sandwiched with the housing panel  12  peripheries  16 . 
     The controller then actuates the rotary roller drive assemblies  68 ,  168  in order to rotatably engage the sandwich of wrapper edge flanges  22  and panels  12  between the rollers  80 ,  150  and begin the lance and seaming operation. If the lance and/or slit  14  seaming operating is on a substantially straight or linear portion of the housing  10  periphery  16 , the form roller assemblies  74 ,  144  will move substantially linearly on the form roller slide rails  75  via the action of the rotary roller drive assemblies  68 ,  168  as allowed by the pre-programmed controller. The roller drive assembly  85  will simply act as a stop to the movement imparted by the rotary roller drive assemblies  68 ,  168 . 
     Upon completion of a straight or linear portion, the rotary motors  54 ,  128  central axis (also construed as the center rotational axis of the fixtures  56 ) are substantially aligned to an axis which substantially aligns or parallels with the roller shaft  82 ,  152  center axis  84 ,  153  and the rotary motors  54 ,  128  begin a pre-programmed rotation or offer no resistance and allow the rotary roller drive assemblies  68 ,  168  to rotate the rotary motors  54 ,  128  or shafts during the seaming of the curved portion of the periphery  16  or a combination of both as pre-programmed into the controller. The rotation of the rotary motors  54 ,  128  is accompanied by movement of the vertical slide assemblies  48 ,  122  via the action of the vertical positioners  44 ,  118  or simply via the substantially vertical force of the wrapper  20  and housing panels  12  camming action during rotation as pre-programmed with the controller. This contemporaneous movement is often necessary as most housings  10  generally have a parabolic peripheral  16  curvature. (i.e. not a fixed radius) As further sections of the housing periphery  16  are encountered which are substantially straight or linear, the form roller assemblies  74 ,  144  will also move substantially linearly on the form roller slide rails  75 . For substantially straight or linear sections, the clamp mounts  42 ,  116  may also move in lieu of or in addition to said form roller assemblies  74 ,  144 . 
     The fixtures  56 ,  130  and rollers  80 ,  160  are thereafter retracted from the housing  10  via the action of the horizontal positioners  50 ,  124  and roller hydraulic actuators  86 ,  185 , again as pre-programmed into the controller. The result is a completed housing  10  having a lanced and/or slit seam  14  rollformed onto the periphery  16  which may be removed from the apparatus  28 . All of the aforesaid transpires with a minimum of operator interface and a maximum of operator safety. 
     From the foregoing description, those skilled in the art will appreciate that a lance and/or slit seam housing and method of manufacture  10  has been shown and described. The present art  10  quickly and safely forms a structurally strong housing from two or more panels and a wrapper in a safe and quick manner. The present art  10  further provides a housing which may be formed in a plurality of different shapes and from a plurality of different materials, including materials of different thicknesses and materials having various types of coatings. 
     Having described the invention in detail, those skilled in the art will appreciate that all the objects of the present invention are realized and that modifications may be made to the invention without departing from its spirit. Therefore, it is not intended that the scope of the invention be limited to the specific embodiments illustrated and described. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents.