Abstract:
This invention relates generally to a pneumatic and hydraulic rotating, reciprocating cylinder apparatus to be mounted on the proximal end of CNC lathe spindles, vertical or inverted machining centers, hydraulic machining work cells or rotary transfer machines to actuate work holding chucks, work holding fixtures, clamping apparatus or work supports on the distal end of said spindles. More specifically, this invention relates to an actuating system with the capability of boosting the input hydraulic pressure to the holding device by a pre-set multiple up to 5000 psi.

Description:
BACKGROUND 
       [0001]    1. Field of Invention 
         [0002]    This invention relates generally to a pneumatic, hydraulic or other media driver, rotating-reciprocating cylinder apparatus to be mounted on the proximal end of CNC lathe spindles, vertical or inverted machining centers, hydraulic machining work cells or rotary transfer machines to actuate work holding chucks, work holding fixtures, clamping apparatus or work supports on the distal end of said spindles. More specifically, this invention relates to an actuating system with the capability of boosting the input hydraulic pressure to the holding device by a pre-set multiple up to 5000 psi. 
         [0003]    2. Prior Art 
         [0004]    A variety of high speed rotating cylinders exist and are used on many different type of machine tools to activate clamps that turn with the work piece. To achieve high speed operation many complex and costly systems have been produced. It is often the case that sufficient hydraulic pressure to clamp the work piece with sufficient force to withstand these high rotary speeds is not available within the existing system. There are commercially available stationary hydraulic pressure booster systems that work with an internal oscillating pump which boosts inlet pressures by pre-set multipliers but until this invention there was not an efficient apparatus for incorporating such a system with a rotary reciprocating cylinder. 
       SUMMARY 
       [0005]    An objective of the present invention is to provide an apparatus capable of adapting a commercially available hydraulic pressure intensifier, such as the PID Series oil-to-oil intensifier from Enerpac located at 6101 N. Baker Road, Milwaukee, Wis. 53209, into a reciprocating, rotating hydraulic cylinder capable of high speeds (7000 rpms), to increase output pressure (up to 5000 psi) to a holder that rotates with work piece minimizing vibration and satisfying the required application. 
         [0006]    Another objective is to provide an apparatus capable of adapting a commercially available hydraulic pressure intensifier into a reciprocating, rotating hydraulic cylinder capable of high speeds and high clamping pressures that embodies a pneumatic work piece present sensor. 
         [0007]    Another objective is to provide an apparatus capable of adapting a commercially available hydraulic pressure intensifier into a reciprocating, rotating hydraulic cylinder capable of high speeds and high clamping pressures that provides an extra port and piping system that allows the introduction of light viscosity fluid to be introduced to the work piece for cooling or lubrication or activation of another hydraulic or pneumatic device. 
         [0008]    Another objective is to provide an apparatus capable of adapting a commercially available hydraulic pressure intensifier into a reciprocating, rotating hydraulic cylinder capable of high speeds and high clamping pressures that is self contained as an integral part of the clamp cylinder mechanism with no separate add-on parts required. 
         [0009]    These objectives are met by the design as shown and described in the accompanying drawings and specification. 
     
    
     
       DRAWINGS 
         [0010]    In order that the invention may be more fully understood it will now be described by way of example, with reference to the accompanying drawings in which: 
           [0011]      FIG. 1  is a cross-section view of a Rotary Reciprocating Intensified Hydraulic Actuator featuring the hydraulic connections to and through the intensifier to the chuck assembly. 
           [0012]      FIG. 2  is a cross-section view of a Rotary Reciprocating Intensified Hydraulic Actuator featuring the hydraulic connections to and from the clamp cylinder. 
           [0013]      FIG. 3  is a cross-section view of a Rotary Reciprocating Intensified Hydraulic Actuator showing the pneumatic connections to the chuck assembly and the proximity sensor piston stroke control mechanism. 
           [0014]      FIG. 4  is a top view of the intensifier adaptor end cap. 
           [0015]      FIG. 4A  is a section view of the intensifier adaptor end cap showing the mounting screws and the intensifier hydraulic feed connections. 
           [0016]      FIG. 4B  is a section view of the intensifier adaptor end cap showing the clamp cylinder hydraulic feed connections. 
           [0017]      FIG. 4C  is a section view of the intensifier adaptor end cap showing the chuck assembly pneumatic connections. 
           [0018]      FIG. 5  is a bottom view of the intensifier adaptor end cap. 
           [0019]      FIG. 6  is a top view of the intensifier adaptor housing. 
           [0020]      FIG. 6A  is a section view of the intensifier adaptor housing showing the mounting screws and the intensifier hydraulic feed connections. 
           [0021]      FIG. 6B  is a section view of the intensifier adaptor housing showing the clamp cylinder hydraulic feed connections. 
           [0022]      FIG. 6C  is a section view of the intensifier adaptor housing showing the chuck assembly pneumatic connections. 
           [0023]      FIG. 7  is a bottom view of the intensifier adaptor housing. 
       
    
    
     REFERENCE NUMERALS 
       [0024]    The same reference numbers are used to refer to the same or similar parts in the various views.
     10 —Rotary Reciprocating Intensified Hydraulic Actuator     12 —oil supply distributor assembly     14 —air inlet port     16 —cylinder retract hydraulic supply front port     18 —cylinder retract and hydraulic pressure intensifier drain to tank     20 —bearings     22 —outer non-rotating housing     24 —inner rotating spindle     26 —hydraulic supply ports for cylinder extend and hydraulic pressure intensifier     28 —distributor end cap     30 —intensifier adaptor end cap     32 —air or lubricating/cooling fluid line     34 —screw for proximity target connector shaft     36 —proximity target     38 —bracket for proximity sensors     40 —proximity sensors     42 —intensifier adaptor housing     44 —proximity target connector shaft     46 —proximity target connector stud     48 —clamp cylinder piston     50 —piston guide post and cylinder retract hydraulic feed     52 —seal     54 —seal     55 —seal     56 —clamp cylinder housing     57 —seal     58 —spindle     60 —spindle draw bar     62 —steel tube     64 —wedge seal     66 —hi-pressure steel tube     68 —chuck assembly housing (not part of this invention)     70 —back of clamp or work holder (not part of this invention)     72 —intensifier assembly (not part of this invention)     74 —intensifier adaptor assembly     76 —clamp cylinder assembly     78 —spindle assembly     80 —chuck or work holder assembly (not part of this invention)     82 —distributor assembly to adaptor assembly mounting screws     84 —intensifier adaptor end cover to housing bolt     86 —hydraulic return-intensifier pilot     88 —hydraulic feed-intensifier pressure middle port     90 —hi-prussure out     92 —intensifier adaptor housing to clamp cylinder mounting bolt     94 —intensifier adaptor base fittings     96 —intensifier adaptor top fitting     98 —steel tube sleeve     100 —steel tube sleeve mounting screws     102 —proximal shallow bore     104 —distal shallow bore     106 —pocket   
 
       DESCRIPTION 
       [0076]    In order that Rotary Reciprocating Intensified Hydraulic Actuator  10  may be more fully understood, it will now be described by way of example with reference to the accompanying drawings. 
         [0077]      FIG. 1  illustrates the five major subassemblies that combine to provide the aforementioned benefits. These are a) intensifier assembly  72 ; b) mounted within intensifier adaptor assembly  74 ; c) with oil supply distributor assembly  12  mounted to proximal end of intensifier adaptor assembly  74 ; d) with clamp cylinder assembly  76  mounted to the distal end of intensifier adaptor assembly  74 ; and e) spindle assembly  78  mounted to the distal end of clamp cylinder assembly  76 . 
         [0078]      FIG. 1  is a section view disclosing the connections between oil supply distributor assembly  12  and intensifier adaptor assembly  74  which contains intensifier assembly  72 , clamp cylinder assembly  76 , spindle assembly  78 , and in phantom lines a partial view of chuck or work holder assembly  80  that is not claimed as part of this invention. This section view features the hydraulic feeds and returns into intensifier assembly  72  and the high pressure output  90  that is transferred though the clamp cylinder  76  and spindle assembly  78  to the proximal surface of some form of chuck or work holder assembly  80  to supply sufficient clamping or holding forces to withstand the forces from the high speed rotation of the work piece. 
         [0079]      FIG. 2  again illustrates the five major subassemblies, but in this view the featured connections are shown between oil supply distributor assembly  12  and clamp cylinder assembly  76 . When the clamp cylinder is extended it moves the spindle assembly  78  forward and when retracted moves spindle assembly  78  in reverse, activating a clamping and unclamping of chuck or work holder assembly  80  that rotates with a work piece and is not claimed as part of this invention. 
         [0080]      FIG. 3  illustrates again the five major subassemblies, but in this view the featured connections are shown between oil supply distributor assembly  12 &#39;s air inlet port  14 , through intensifier adaptor assembly  74  and through spindle assembly  78 , providing another controllable fluid at the distal end of spindle assembly  78  which can be utilized for a parts presence sensor, lubricant, cooling fluid or any other hydraulic or pneumatic article activation. 
         [0081]      FIGS. 4 ,  4 A,  4 B,  4 C and  5  disclose the design of intensifier adaptor end cap  30 . 
         [0082]      FIG. 4  is a top view showing proximal shallow bore  102  into the proximal surface of cap  30  that is facilitated to receive inner rotating spindle  24  from oil distributor assembly  12 . Towards the outer perimeter of bore  102  are four evenly spaced tapped holes  82  for fastening cap  30  securely to inner rotating spindle  24 . Inboard are 4 evenly spaced counter bored through bolt holes  84  that are used for fastening cap  30  to proximal surface of intensifier adaptor housing  42 . 
         [0083]      FIG. 4A  is a section view through a mounting screw and bolt hole described above and also through the clearance holes for intensifier adaptor base fittings  94  and hydraulic return—intensifier pilot  86  and hydraulic feed—intensifier  88  as shown in  FIG. 1 . 
         [0084]      FIG. 4B  is a stepped section view that discloses the counter bored holes  16 / 18  and  26  for hydraulic fluid flow to and from clamp cylinder assembly  76  with cross drilled holes from the perimeter towards the center, plugged on the outside and output holes drilled up from the surface of distal shallow bore  104 , expanded outward from the top entrance holes as shown in  FIG. 2 . 
         [0085]      FIG. 4C  shows center bore  14  which is the input channel for the air feed or other low viscosity fluid that will be passed on to the chuck or work holder assembly  80 . This center bore is penetrated by two cross drilled holes plugged on the outside and penetrated from the distal surface expanded toward the perimeter output holes as shown in  FIG. 3 . 
         [0086]      FIG. 5  is a bottom view of cap  30  that shows distal shallow bore  104  which is facilitated to receive the proximal surface of intensifier adaptor housing  42 . 
         [0087]      FIG. 6  is a top view of intensifier adaptor housing  42 . 
         [0088]      FIG. 6A  is a section view through the center showing tapped mounting holes  84  for connecting bolts between end cap  30  and housing  42 . It also shows counter bored bolt holes for mounting housing  42  to clamp cylinder housing  56 . This view illustrates pocket  106  which is facilitated to receive commercially available intensifier assembly  72 . The distal end of pocket  106  is where intensifier adaptor top fitting  96  is sealed and is screwed into the top of intensifier assembly  72  as shown in  FIG. 1 . FIG.  6 A also shows tapped mounting screw holes  100  for steel tube sleeve  98  also shown in  FIG. 1 . 
         [0089]      FIG. 6B  shows the hydraulic fluid channels  26  and  16 / 18  and their entrance into the sealed wells for the piston guide posts and hydraulic feeds  50  and  51  as shown in  FIG. 2 . 
         [0090]      FIG. 6C  shows the air or other fluid lines  32  coming down both sides of pocket  106  angling into the tapered surface leading out of the threaded opening for steel tube  66  as shown in  FIG. 3 . 
         [0091]      FIG. 7  is a bottom view of housing  42 . 
       Operation: 
       [0092]    Rotary Reciprocating Intensified Hydraulic Actuator  10  is to be mounted on the back end of a CNC lathe or a vertical or inverted machining center and actuates a work piece holding chuck on the opposite end of the spindle. Hydraulic connection to chuck assembly  80  is through rotating concentric steel tubes  66  and  62 . Mechanical connection to chuck assembly  80  is through concentric rotating and reciprocating spindle  58  and spindle draw bar  60 . 
         [0093]    The functions of Actuator  10  are to stroke piston  48  internal to clamp cylinder assembly  76  that is connected through spindle  58  to spindle draw bar  60  that is connected to chuck assembly  80 , thereby moving chuck jaws to clamp or un-clamp a work piece. Actuator  10  uses an internally mounted commercially available hydraulic pressure intensifier assembly  72  to supply a predetermined hydraulic pressure boost to chuck assembly  80  via steel connecting tube  66 . Actuator  10  also supplies air to chuck assembly or another low viscosity fluid for the purpose of sensing work piece presence, lubricating, cooling or any other hydraulic or pneumatic driven operation via the gap between the outside diameter of tube  66  and the inside diameter of tube  62 . 
         [0094]    Actuator  10  is comprised of distributor assembly  12  which is facilitated for connection of all supply and drain hoses to Actuator  10 . Distributor assembly  12  has an outer non-rotating housing  22  with porting for the hose connections  14 ,  16 ,  18  and  26  and is supported by bearings  20  on inner rotating spindle  24 . The resulting capillary type seal provides separation between the ports and also allows for oil flow through the bearings. This oil flow necessitates the drain port returning this flowing oil back to tank. A hydraulic supply hose is connected to cylinder retract port  16  for cylinder retraction stroke. A hydraulic supply hose is connected to cylinder extend port  26  for cylinder extension stroke. The hydraulic supply hose connected to port  26  also supplies intensifier pressure-middle port  88  for feeding hydraulic fluid into intensifier assembly  72  through intensifier adaptor base fitting  94 . Commercially available intensifiers use an internal oscillating pump to boost the hydraulic pressure at outlet to predetermined multiples of inlet pressure as intensified outlet pressures  90  to chuck assembly  80  at the distal end of spindle assembly  78 . 
         [0095]    Control of the hydraulic oil supply to the distributor is accomplished with commercially available, external valves controlled at the machine control panel. The valves used are two conventional four-way, 2 position crossover valves. The first is for cylinder stroke shifting and the second for intensifier supply and relief. 
         [0096]    The logic sequence for these valves is as follows: 
         [0097]    Set Machine control to “Chuck Clamp:” Cylinder retract and intensifier supply are activated simultaneously. This simultaneous two valve shift allows the cylinder extend and intensifier pilot to depressurize for free flow back to tank. The pilot pushes open a check valve in the intensifier that releases the intensified pressure. 
         [0098]    Set Machine control to “Chuck Unclamp:” Cylinder extend and intensifier return to rest positions. This simultaneous two valve shift allows the “cylinder retract” and intensifier to depressurize for free oil flow back to tank. 
         [0099]    Control of the stroke of piston  48  is accomplished with adjustable proximity sensors  40  that are mounted on bracket for proximity sensors  38  that is mounted to distributor assembly  12 . Proximity target  36  is mounted around the small diameter of housing  42  with screws for proximity target connector shaft  34  into tapped holes in proximity target connector shafts  44  that slide in clearance holes in base of housing  42  and are mounted to threaded studs  46  that are screwed into the back side of piston  48 . 
         [0100]    Intensified hydraulic pressure  90  and a separate fluid flow  32  are supplied to the clamp or work holder assembly  80  distal end of Rotary Reciprocating Intensified Hydraulic Actuator  10  by concentric steel tubes that are a part of spindle assembly  78 . The inside and heaviest tube is hi-pressure steel tube  66  with its proximal end threaded into the backside small diameter opening in the center of housing  42  and its distal end protruding into the back of the chuck assembly  80 , facilitating the delivery of hydraulic fluid under hi-pressure  90  against the back side of a movable clamp  70 . A small air gap is created by the slightly larger inside diameter of steel tube  62  which runs concentrically with tube  66  from the angled well in the back of housing  42  to the end of wedge clamp  64  as it enters clamp assembly  80 . Steel tube  66  is concentrically entrapped by steel tube sleeve  98  at it proximal end and wedge clamp  64  at its distal end. Steel tube sleeve  98  is fastened to the back of housing  42  with screws  100  and has o-ring seals between it and spindle  58  and does not reciprocate with piston  48 . Spindle  58  is threaded into piston  48  and reciprocates with it. Spindle draw bar  60  is threaded over the distal end of spindle  58 . 
         [0101]    The preceding descriptions are for illustrative purposes and are not intended to limit the scope of this invention. One skilled in these fabrication arts will see many options for material thickness, masses, material selections that fit within the scope of this invention. The scope of the invention should be determined by the appended claims rather than by the specific examples given.