Abstract:
A briquetting machine for compacting metal chips into briquettes with a movable die that provides plural die cavities. After metal chips are loaded into a loading chamber from a hopper, a chip compacting ram pushes the chips at a high speed and low pressure into one of several bores, disposed within a sliding die gate, and against an endplate. The bore and endplate together constitute a die and define at least two die cavities. After the ram reaches a predetermined low pressure, the ram then proceeds at a relatively low speed and relatively high pressure to compress the chips within the die into a briquette. Upon reaching a predetermined compaction pressure, the ram retracts from the bore. After such time, the die gate is moved to a location where one bore lies before an ejector cylinder. The ejector cylinder then extends into the bore, expelling the briquette from the bore.

Description:
TECHNICAL FIELD OF THE INVENTION 
     This invention relates to briquetting machines; more specifically to machines for compacting a charge of metal chips into a briquette. 
     BACKGROUND OF THE INVENTION 
     Metal chips accumulate during the machining of metal workpieces. Because machining processes typically utilize a cutting fluid to lubricate and cool the workpiece during a given operation, the machining processes inevitably generate metal chips permeated with cutting fluid. To minimize production costs, it is economically desirable to use a compactor to separate the cutting fluid from the metal chips to facilitate a re-use of the cutting fluid during subsequent machining processes. 
     Furthermore, it is economically desirable to salvage the metal chips themselves to allow for their recycle and re-use. Compaction of the metal chips into dense briquettes thus facilitates an improved handling and transportation of the metal chips during the recycling process. 
     Briquetting machines for compacting metal chips have been proposed and constructed in the past. Such machines essentially comprise a feed hopper that introduces the metal chips into a feed chamber, with a compaction chamber, or die, located downstream for compressing with a ram the metal chips into a briquette. A typical prior briquette compactor utilizes a single die during the compaction process. The inner diameter of the die is sized to accept the insertion of the ram. 
     During the compaction process, frictional forces necessarily develop between the chips and the inner wall of the die. These frictional forces cause wear on the inner diameter of the die, thus causing a loss of the close tolerance desired between the die and the ram outer diameter. Because a single die subject to repeated compaction cycles is subject to wear, an operator must incur added costs for replacing worn dies. 
     Prior art briquetting machines fail to provide a compaction process that prolongs die life by reducing the wear of a given die. Thus, there continues to be a need for a method and apparatus for compacting metal charges efficiently while reducing the costs of die replacement. The present invention meets these desires. 
     SUMMARY OF THE INVENTION 
     The present invention provides a novel and improved briquetting machine which provides advantages in construction, mode of operation, efficiency and use. 
     To achieve the foregoing, the present briquetting machine includes a ram that co-acts with a die gate that provides plural die cavities. The die gate is carried on an elongate frame aligned along a horizontal axis. The die gate is movably mounted on the frame so as to be shifted from a first position to a second position. In a preferred embodiment of the invention, the die gate has two through bores disposed therein. The two bores are located side-by-side across the face of the gate and are movable along an axis transverse to that of the frame to positions in registry with the ram. 
     An endplate is fixably mounted to the frame, adjacent to the back side of the movable die gate and co-acts therewith to define a die cavity. The endplate is of a size less than that of the die gate and is juxtaposed relative to only one of the bores. The die gate, together with the endplate, define a die cavity sized to receive the ram when juxtaposed relative to one another. 
     The ram is also mounted to the frame, oriented substantially parallel to the longitudinal frame axis, and is proximal to the front face of the die gate. The ram is slidably receivable into one of the two bores and against the endplate when the die gate is in the first of two positions, and is slidably receivable into the other of the two bores and against the endplate when the die gate is in the second of two positions. 
     A loader for metal chips to be compacted is affixed to the frame. The loader is adapted to dispense a charge of metal chips at a location between the ram and the die gate. The ram, when actuated, compresses the dispensed charge of metal chips into a die in registry therewith to form a briquette. 
     Two ejectors are mounted to the frame, each aligned para-axial with the frame and the ram. One of the two ejectors is adapted for insertion into one of the two bores when the die gate is in its first of two positions, expelling a formed briquette from the respective bore. The other of the two ejectors is adapted for insertion into the other of the two bores when the die gate is in its second of two positions, expelling a formed briquette from the other respective bore. 
     Because the die gate defines a pair of die cavities disposed therein, each die cavity is subject to only half of the compression cycles of a die of a single-die, prior art compactor. Thus, production efficiencies are increased and the costs for replacing dies in the present invention due to wear are reduced. Other advantages and features of the present invention will be more readily apparent from the following detailed description of a preferred embodiment of the invention, the drawings, and the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings, 
     FIG. 1 is a schematic perspective view of a briquetting machine embodying the present invention; 
     FIG. 2 is a front elevational view of a die end of the briquetting machine embodying the present invention; 
     FIG. 3 is a side elevational view of the briquetting machine shown in FIG. 2; 
     FIG. 4 is a plan view of the briquetting machine shown in FIGS. 2 and 3; 
     FIG. 5 is a schematic cross-sectional view illustrating selected components of a die assembly of a briquetting machine embodying the present invention; 
     FIG. 6 is a schematic cross-sectional view illustrating the die assembly components of FIG. 6 with the die gate in a second, alternate position; and 
     FIG. 7 is a simplified hydraulic circuit diagram for operating a briquetting machine embodying the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The invention disclosed herein is, of course, susceptible of embodiment in many different forms. Shown in the drawings and described hereinbelow in detail are preferred embodiments of the invention. It is to be understood, however, that the present disclosure is an exemplification of the principles of the invention and does not limit the invention to the illustrated embodiments. 
     Embodiments of the contemplated apparatus illustrated in the FIGURES show details of mechanical elements that are known in the art and that will be recognized by those skilled in the art as such. The detailed descriptions of such elements are not necessary to an understanding of the invention. Accordingly, such elements are herein represented only to the degree necessary to aid an understanding of the features of the present invention. 
     For ease of description, a machine embodying the present invention is described hereinbelow in its usual assembled position as shown in the accompanying drawings, and terms such as upper, lower, horizontal, longitudinal, etc., may be used herein with reference to this usual position. However, the machine may be manufactured, transported, sold, or used in orientations other than that described and shown herein. 
     Referring to FIGS. 1 and 2, a dual die chip compactor  10  embodying the present invention includes an elongate frame  12 , a ram assembly  14 , a dual die assembly  16  and a chip loader  22 . Frame  12  includes an upstanding end member  24  situated at the actuator end of compactor  10 , an endplate  26  situated opposite end member  24 , and their supporting base  28 . Also conveniently grouped with the components of frame  12  are four tie rods  30  which interconnect upstanding end member  24  to endplate  26 . 
     With further reference to FIGS. 3 and 4, hydraulic ram assembly  14  includes a cylinder subframe, a main hydraulic cylinder  32 , a chip compactor ram  40 , and a ram chuck  42  therebetween for removably mounting ram  40  to the piston (not shown) of cylinder  32 . The cylinder subframe secures cylinder  32  to upstanding member  24  and is formed by a plate  44  and four interconnecting tie rods  46 . Ram chuck  42  includes a chuck locking bolt  43  and provides a mechanism for replacing and substituting rams. 
     Situated opposite main cylinder  32  and adjacent endplate  26  is dual die assembly  16 . Here, a sliding die gate  48  is mounted between endplate  26  and an opposing die chamber support plate  50 . Die gate  48  defines a pair of through bores  58  and  60  (FIG. 5) situated horizontally side-by-side. Each bore has a diameter to accommodate a relatively close insertion of the chip compactor ram  40 . 
     Die assembly  16  also includes a pair of ejector cylinders  62  and  63 , which can be hydraulically or pneumatically actuated as desired. Cylinders  62  and  63  are secured to frame  12  by and between support plate  50  and an ejector support plate  64 . The two ejector cylinders (or ejectors) are positioned one on each side of ram  40  such that each ejector cylinder is substantially para-axial to the path of ram  40 . Each ejector cylinder  62  and  63  is positioned such that their respective piston rods  65  and  66  are in axial alignment with a pair of ejection openings ( 68  and  70 ) defined by endplate  26 . 
     More specifically, endplate  26  defines a pair of through ejection openings  68  and  70  on opposite sides of the path of ram  40 . 
     Die gate  48  is mounted adjacent endplate  26  and ejection openings  68  and  70  to perform a sliding motion between one of two position. As best illustrated by schematic FIGS. 5 and 6 when viewed together, die gate  48  slides from a first position (FIG. 5) where die gate bore  60  is occluded by endplate  26  and defines a first die cavity to a second position (FIG. 6) where die gate bore  58  is then occluded by endplate  26  forming a second die cavity. Each die cavity is adapted to slidably receive ram  40 . 
     The first position of die gate  48  also results in the alignment of die gate bore  58  with ejection opening  68  such that a briquette ejection passageway is defined for receiving ejection piston  65  and thereby clearing a briquette by expulsion from bore  58 . Likewise, the second position of die gate  48  results in the alignment of die gate bore  60  with ejection opening  70  to form a second ejection passageway for receiving ejection piston  66 . 
     Referring again to FIGS. 1 through 4, the cross-frame sliding motion of die gate  48  is controlled by a gate cylinder  52  with connecting piston  54 . Gate cylinder  52  is affixed to and supported by chamber support plate  50  and endplate  26 . To facilitate a horizontal sliding movement of die gate  48 , gate cylinder  32  is substantially axially aligned with the horizontal path of die gate  48 . 
     Die gate  48  is preferably modular to facilitate selective replacement of components parts and thereby reduce compactor maintenance costs. As shown, die gate  48  includes a main section  72  and collar plates  73 ,  74 ,  75  and  76 . Collar plates  73  and  74  together with main section  72  define bore  58 , while collar plates  75  and  76  together with main section  72  define bore  60 . 
     Endplate  26  is also preferably modular for cost effective operation. Specifically, endplate  26  can be equipped with a replaceable wear guard  78  to protect endplate  26  from excessive wear or damage. Wear guard  78  serves to absorb frictional and crushing forces exerted on it by the metal chips as ram  40  compacts the chips to form a briquette as well as the sliding frictional forces exerted on it by die gate  48 . Wear guard  78  is replaceable, and thus protects endplate  26  from undue wear. Support plate  50  also preferably includes a wear guard  80  to absorb sliding wear from die gate  48  and thereby protect support plate  50 . 
     In operation, metal chips are delivered to die assembly  14  for compaction via a chip loader  22  mounted to frame  12 . Loader  22  is vertically oriented over die assembly  14  and contoured to direct metal chips into a loading chamber  88 . Although various contours and configurations including conveyor-like systems are suitable for loader  22 , a funnel or hopper-like configuration is presently preferred. Loader  22  is preferably equipped with a feed screw (not shown) to move metal chips towards loading chamber  88 . 
     Loading chamber  88  is positioned in the path of ram  40  and is defined by an underlying chip trough  90  mounted to and between ejector support  64  and support plate  50  as best shown in FIGS. 2 and 4. 
     Metal chips are deposited into loader  22  when chip compactor ram  40  is in a retracted position within main cylinder  32 . Loader  22  is contoured to enable a quantity of metal chips to fall into loading chamber  88  under the force of gravity. Alternatively, a feed screw (not shown) can be used within the loader  22  to move the quantity of metal chips into loading chamber  88 . The quantity of metal chips placed within loading chamber  88  is dictated by the loading chamber&#39;s volume. This volume of chips within loading chamber  88  constitutes a charge of metal chips. 
     With a charge of metal chips within loading chamber  88 , chip compactor ram  40  advances at a relatively high speed and a relatively low pressure to move the charge of chips from the loading chamber  88  into bore  60  and against wear surface  71  until a predetermined pressure is achieved to expel entrapped cutting fluid. After such pressure is reached, ram  40  advances at a relatively lower speed and higher pressure within bore  60  to compact the charge of metal chips into a briquette. 
     After yet another, relatively higher predetermined pressure is reached during the compaction of the chip charge within bore  60 , ram  40  retracts from both bore  60  and loading chamber  88  into main cylinder  32 . During this retraction stage of chip compactor ram  40 , another charge of metal chips is deposited in loading chamber  88 . Also during the ram retraction stage, die gate  48  is moved by gate cylinder  52  from a first position, where bore  60  is juxtaposed to wear surface  71 , to an alternate (second) position, where bore  58  is juxtaposed to wear surface  71 . 
     This shift of die gate  48  carries the chip briquette formed in bore  60  into alignment with ejection cylinder  62  and ejection opening  70  of endplate  26 . Ejection cylinder  62  expels the briquette from bore  60  while compactor ram  40  advances through loading chamber  88  and bore  58 . The relative timing of the briquetting action of ram  40  to an ejection action of cylinders  62  and  63  is not critical. Both the compaction and the rejection are completed, however, before die gate  48  is moved to the next position and the compaction cycle repeated. 
     Die gate  48  thus shuttles back and forth between at least two positions to enable the cyclic compression of material within a die gate through bore followed by the expulsion of material from the same die gate bore. The repeating cycle is as follows: (1) chip compactor ram  40  compresses material into bore  60  while ejection piston  65  of cylinder  62  expels compressed material from bore  58 ; (2) after ejection piston  65  and ram  40  retract, die gate  48  is moved into a second position; (3) ram  40  then compresses material into bore  58  while ejection piston  66  of cylinder  63  expels compressed material from bore  60 ; (4) after ejection piston  66  and ram  40  retract, die gate  48  returns to its first piston to repeat this cycle starting at step (1). 
     FIG. 7 is a simplified hydraulic circuit for actuating the hydraulic cylinders  32 ,  52 ,  62  and  63  of the dual die chip compactor  10  in accordance with the operation described above. A series of control valves are employed to activate the hydraulic cylinders by directing pressurized fluid to one selected side of the cylinder while creating a fluid return path to return line  86  from the other side of the cylinder. 
     More specifically, a pair of three-position, four-port control valves  89  and  91  are provided for actuating main cylinder  32 . Either control valve  89  or control valve  91  may independently serve to reversibly actuate cylinder  32 . Two control valves are preferably provided for operational flexibility, load sharing, fault tolerance and increased reliability. 
     As illustrated in FIG. 7, the use of two control valves ( 89  and  91 ) allows for multi-pressure operation of main cylinder  32 . With fluid power source  92  providing relatively higher pressure fluid than fluid power source  94 , the piston of main cylinder  32  can be extended in two stages of increasing pressure. In the first, lower pressure stage, control valve  91  is energized to create a fluid path from fluid power source  94  to the extension chamber of cylinder  32 . In the second stage, control valve  91  returns to center position eliminating the lower pressure path before control valve  89  is energized to create a fluid path from power source  94  to the extension chamber of cylinder  32 . 
     Connecting piston  54  of gate cylinder  52  is extended and retracted via a two-position, four-port control valve  96 . Control valve  98  for activating ejector cylinder  62  and control valve  99  for activating ejector cylinder  63  are both two-position, four port valves which include spring loadings such that their normal position maintains the ejector cylinders in their retracted position. 
     A controller (or controller network)  100  coordinates valve actions to provide the desired sequence of cylinder operation. An optional plug  102  isolates pressurized line  104  into separate line sections  106  and  108 . 
     Additional optional features are contemplated. For example, off-loading chutes  82  and  84  may be mounted to endplate  26  adjacent ejection openings  68  and  70 , respectively, to catch expelled briquettes and direct them to predetermined locations (FIG.  4 ). 
     A wide variety of conventional materials are suitable for making the components of compactors embodying the present invention. These materials include metals, notably steels, and various high-strength composites without limitation that all or any of the elements be made of the same material. For example, wear guards  78  and  80  may be fabricated from specialized wear-resistant materials. 
     The foregoing description and the accompanying drawings are illustrative of the present invention. Still other variations and arrangements of parts are possible without departing from the spirit and scope of this invention.