Pattern Duplicator

Abstract

A pattern duplicating apparatus including a large rigid frame suspended by trolleys from an I-beam and carrying longitudinally spaced tracer and cutter assemblies. The frame is manually displaceable linearly in the longitudinal and vertical directions and pivotally about the longitudinal axis. The frame suspension includes interconnected sprockets and chains to ensure a pure rectilinear vertical displacement.

Description

This invention relates to pattern making and more particularly to a pattern duplicating apparatus which may be manually operated to trace a model and simultaneously duplicate the model in a pattern stock.

There is a need in the pattern making industry for a pattern or model duplicator which is relatively inexpensive, easily installed, and easily operated, yet which is capable of producing pattern duplication rapidly and accurately in the hands of a semiskilled operator. The duplication of patterns, molds, models, and the like is generally accomplished through the use of a large floor-mounted triaxial tracer-cutter machine which is both expensive and reasonably difficult to use. Such a machine ordinarily includes a probe which is displaced over a surface to direct the displacement of a cutter over a block of pattern stock such as polystyrene foam. The tracer and cutter are normally linearly displaceable along three mutually perpendicular axis to permit the tracer probe to follow the surface contour of the model. This triaxial suspension usually requires that the machine be heavy, bulky, and expensive as previously indicated.

The present invention represents an improvement in pattern duplicating apparatus in that it provides a relatively inexpensive, easily installed and easily operated duplicator apparatus which does not require an intricate and expensive triaxial suspension, but yet produces accurate results. In general, the present invention includes a rigid frame adapted for vertical suspension and carrying longitudinally spaced tracer and cutter portions both of which depend from the frame, and overhead suspension means for permitting the frame to be manually displaced along the longitudinal axis, in the vertical direction, and pivotally displaced about the longitudinal axis thereby to permit the tracer probe to follow the surface contour of a model to be duplicated. The pivotal displacement facility permits a simplification of the apparatus and yet facilitates the tracing of concave surfaces which may not be readily traceable by means of a conventional triaxial machine.

The present invention permits the tracing of complicated and unusually oriented or "reentrant" surface contours without significant difficulty. In general this is accomplished by connecting the tracer probe and cutter means to the frame by means of mechanical plates which permit the tracer probe and cutter portions to be disposed relative to a vertical axis in each of several angular orientations thereby to either depend or extend from the frame as is required by the tracing situation at hand.

The present invention, though accurate and reliable in operation, may be quickly and easily installed in most pattern shop facilities without the need for extensive structural modification of the facility. The overhead support means may, in a preferred form, include a trolley arrangement together with a pivotal pin connection to the frame to permit linear longitudinal displacement as well as pivotal displacement about the longitudinal axis. The overhead support means further comprises in the preferred form, a telescopic arrangement of vertical members to permit the vertical displacement of the longitudinal ends of the frame in unison with one another thereby to ensure a unison vertical displacement of the tracer probe and cutter portions.

In an illustrative embodiment, the invention is fabricated such that the support frame is addressed by an operator who stands longitudinally between the tracer and cutter areas and grasps the frame with both hands thereby to control the linear and pivotal displacements thereof.

The invention may be best understood by reference to the following specification which describes the specific embodiment of the invention. This specification is to be taken with the accompanying drawing of which:

FIG. 1 is a front view of an assembly embodying the invention;

FIG. 2 is a side view of the FIG. 1 apparatus looking along a line 2--2;

FIG. 3 is a perspective view of a suitable platform for use with the apparatus of FIG. 1;

FIG. 4 is an enlarged view of the probe assembly in the apparatus of FIG. 1;

FIG. 5 is an enlarged view of the trolley in the apparatus of FIG. 1; and,

FIG. 6 is an enlarged view looking along a section line 6--6 of FIG. 1.

Referring now to FIGS. 1 and 2, the illustrative embodiment of the invention is shown to comprise a rigid frame 10 suspended by overhead support means 12 relative to a platform 14 which defines a model and pattern stock support surface. Frame 10 carries a tracer probe assembly 16 and, longitudinally spaced therefrom, a pattern cutter assembly 18, both of which depend from the frame 10 in a generally vertical direction.

Frame 10 is a rigid assembly of light, tubular stock such as aluminum including a pair of longitudinally spaced vertical members 20 and 22 joined by an upper cross member 24 and a pair of diagonal cross members 26 and 28. The junction of the cross members 26 and 28 is preferably joined to the upper cross member 24 by means of a short, vertical member 30. In addition, the diagonal cross members 26 and 28 are joined to one another by means of short vertical members 32 and 34 to provide increased rigidity for the entire structure. The tubular members 20, 22, 24, 26, 28, 30, 32, and 34 are preferably disposed in a common plane and welded together.

Frame 10 further comprises a short strut 36 which extends from the junction of the diagonal cross members 26 and 28 in a direction normal to the plane of the cross members and is secured such as by welding to the common junction of four diagonal members 38, 40, 42, and 44. The radially outward ends of the diagonal members 38, 40, 42, and 44 are secured to the four corners of the frame defined by the upper and lower end points of the vertical side members 20 and 22, as indicated.

The diagonal members 26, 28, 42, and 44 together with the strut 36 define an A-shaped opening which permits an operator to address the frame 10 in a position longitudinally between the tracer probe assembly 16 and the cutter assembly 18. In this position the operator may grasp the diagonal members 42 and 44 with his hands to manually direct the tracer probe assembly 16 over the model thereby to control the duplicating action of the rotary cutter assembly 18 also carried by the rigid frame 10. As an illustrative example the dimensions of the frame 10 are approximately 8 feet high by 10 feet wide, thus to accommodate various patterns and model sizes and to permit manipulation by an operator in the manner previously described.

Describing the tracer probe 16 assembly in greater detail, the assembly is shown in FIG. 4 to comprise a bullet-shaped wood probe 46 having a longitudinally extending shaft 48 which is insertable into an axially aligned hole in a short cylindrical extension 50. A set screw 52 is provided for holding the pin 48 in the hole of the extension 50. The extension 50 is further provided with a longitudinally oriented slot which is adapted to receive a plate 56 which is secured to an which depends vertically from the lower end of the frame member 20. Extension 50 is pivotally connected to the plate 56 by means of a pin 58. Below pin 58 plate 56 is provided with a plurality of arcuately arranged holes 60, any one of which may be aligned with a hole in extension 50 simply by pivoting the extension about pin 58. A pin 62 may be inserted through the extension and the aligned hole 60 to fix the extension 50 in the selected angular orientation. Should the center hole 60 be selected, the extension 50 is vertical; if either of the side holes 60 is selected, the extension is oriented at an angle with respect to the member 20. Normally, the extension 50 is disposed in a vertical orientation such that it represents a straight extension of the frame member 20. However, for normally reentrant shapes of the model, the extension 50 may be angularly oriented about the longitudinal axis of the frame 10 by removal of the pin 62 and rotation of the extension 50 about the pin 58.

Describing the rotary cutter assembly 18 in somewhat greater detail with reference to FIG. 1, the cutter assembly is shown to comprise a plate 68 which is substantially identical to the plate 56 in the tracer probe assembly 16 and which serves substantially the same purpose. Plate 68 is fixed to the lower end of frame member 22 and pivotally connected to a motor frame 70 to permit the frame 70 to be disposed in alignment with member 22 or in either of two angular orientations, as selected by the operator. Suffice it to say that the plate 68 bears the same relation to frame 70 as the plate 56 bears to the extension 50 and that normally both extension 50 and frame 70 are disposed in the same relative orientation.

Frame 70 supports a rotary motor 72 which is energizable to rotate a cutter 74 depending therefrom. The rotating cutter 74 removes material from the block of pattern stock as it is displaced by the operator, synchronism with the model being obtained by the rigid frame 10.

Considering now the overhead support means 12 in greater detail, reference will be made to FIGS. 1, 5, and 6. Assembly 12 includes a horizontally disposed longitudinally extending channel 80 having longitudinally spaced trolleys 82 and 84 affixed thereto. The trolleys 82 and 84 include wheels which are adapted to engage and ride on the lower flange of an I beam 86 which may be part of the building structure within which the apparatus is installed. The trolleys 82 and 84 thus serve to permit the frame 10 to be displaced longitudinally along the I beam 86.

Channel 80 carries at the left end as shown in FIG. 1 a pair of parallel depending brackets 88 which receive a cylindrical member 90 which, in turn, is telescopically engaged within the vertical frame member 20. On the longitudinally opposite end of the channel 80, a second pair of parallel depending brackets 92 receive a cylindrical member 94 which is telescopically engaged with the vertical frame member 22. The brackets 88 and the cylindrical member 90 are provided with horizontally aligned holes which receive a pivot pin 96 to permit the cylindrical member 90 and the frame 10 to pivot about a longitudinal axis relative to the brackets 88. A cotter pin may be used to maintain the pivot pin 96 in place. A similar pivot pin 98 is provided at the opposite longitudinal end of the frame 10 to maintain the short cylindrical telescopic member 94 in engagement with the brackets 92. Accordingly, the entire frame 10 may be pivoted or swung about a longitudinal axis passing through pins 96 and 98.

It is very important that the longitudinally opposite ends of the frame 10 are displaced vertically in unison with one another thereby to maintain the tracer assembly 16 and the cutter assembly 18 at the same vertical level at all times. To provide this unison vertical displacement as well as to counterbalance the mass of the frame 10, a pair of longitudinally spaced chains 100 and 102 are affixed to the upper cross member 24 of the frame 10 and extend upwardly over sprockets 104 and 106. The sprockets are mounted on longitudinally opposite ends of a rod 108 which interconnects the sprockets 104 and 106 for unison rotation. Rod 108 passes through suitable bearings to permit the sprockets 104 and 106 and the rod 108 to rotate freely.

Chains 100 and 102 are carried horizontally and transverly back to idler assemblies from which the chains drop vertically to a counterweight 118. The idler assembly for chain 100 is shown in FIG. 4 to include a support arm 110 carried by channel 80 and a second sprocket 112. The idler assembly for chain 102 is identical. The counterweight 118 is preferably selected to equal the total suspended mass of the frame 10 so that in the absence of an input force applied to the frame 10 by an operator, both the frame 10 and the counterweight 118 tend to remain in whatever vertical position is previously established by the operator. Since the sprockets 104 and 106 must rotate in unison due to the interconnecting rod 108, and chains 100 and 102 cannot slip on the sprockets, vertical displacement of the frame 10 is rectilinear in nature, thus, preserving the vertical elevational equality as between the tracer assembly 16 and the cutter assembly 18.

Considering the platform 14 in greater detail, this assembly is shown in FIG. 3 to be fabricated from a substantially rigid and level plywood deck 120 which is rectangular in overall configuration. Deck 120 is mounted on a quadrangular frame 122 which elevates the deck 120 by approximately 10 inches. Care is taken to ensure that the surface of deck 120 is level such that the vertical distance between the deck and the probe 46 is equal to the vertical distance between the platform and the cutter blade 74. Blade 74 may be somewhat higher than probe 46 to leave extra stock on the model. A centerline 124 is drawn on the deck 120, this centerline representing the longitudinal displacement path of the probe assembly 16 and cutter assembly 18 when the frame 10 is vertically oriented. Care is taken to align the centerline of the model and the pattern stock with the centerline 124 when these elements are placed on the deck 120. The alignment between the tracer probe assembly and the platform centerline 124 may be quickly and easily checked by removing the tracer probe head 46 from the cylindrical extension 50 and placing a lead pencil or other suitable marking device in its place, lowering the frame 10 until the pencil engages the deck 120 of the platform 14 and then longitudinally displacing the frame 10 to determine whether the newly marked centerline corresponds with the preestablished centerline 124.

Although the operation of the illustrative embodiment of the invention is believed to be apparent from the foregoing structural description, a brief summary of the operation will now be made.

A hard surface model is placed on the deck 120 of the platform 14, the centerline of the model being aligned with the longitudinal centerline 124 of the deck 120 such that the probe head 46 may be displaced over the surface of the model. The angular orientation between the probe head extension 50 and the vertical member 20 is adjusted to correspond to the nature of the surface to be traced. A block of pattern stock, such as polystyrene foam, is placed on the deck 120 beneath the cutter assembly 18 with the centerline of the block on the centerline 124. At this point, the motor 72 is energized to rotate the cutter tool 74. When an ordinary router motor is used, the rpm is decreased by means of a suitable transformer type power supply such that the cutter tool 74 is rotated at a much lower speed than the ordinary operating speed of a router.

The operator then addresses the frame 10 placing himself in a facing relationship with the A-shaped opening defined by the cross members 42 and 44. The operator places his hands on the members 42 and 44 to direct the frame 10 longitudinally, vertically, and pivotally about the longitudinal axis as necessary. Counterweight 118 permits the frame 10 to be raised and lowered by the application of small forces thereto, the chains 100 and 102 and the sprockets 104 and 106 permitting the free vertical adjustment of the frame 10 as previously described. The rod 108 interconnecting sprockets 104 and 106 ensures a unison vertical displacement of the opposite longitudinal ends of the frame 10, thus to maintain the tracer probe assembly 16 and the cutter assembly 18 on the same horizontal level during vertical displacement of the entire frame 10. Trolleys 82 and 84 permit the frame 10 to be displaced in the longitudinal direction defined by the I-beam 86 and the pivotal connections between the brackets 88 and 92 and the telescopic vertical sections 90 and 94 permit the entire frame 10 to be pivoted about a longitudinal axis thereby to accomplish and afford 3.degree. of freedom in the movement of the frame 10 relative to the model and pattern stock surfaces.

It is to be understood that the invention has been described with reference to an illustrative embodiment and that various modifications thereof will be apparent to those skilled in the art.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A pattern duplicator comprising: a rigid, manually displaceable frame including a pair of longitudinally spaced vertical members and means rigidly connecting the members, said frame being adapted for overhead, vertical suspension and having a longitudinal axis, tracer means depending from the frame at one longitudinal end thereof, pattern stock cutter means depending from the frame at the other longitudinal end thereof, and overhead support means for vertically suspending the frame relative to a work surface, the support means permitting linear displacement of the frame along longitudinal and vertical axes and pivotal displacement about the longitudinal axis, said overhead support means including telescopic means for permitting vertical displacement of the vertical members in unison with one another.

2. A pattern duplicator as defined in claim 1 wherein said means rigidly connecting the members includes a pair of diagonal members defining an A-shaped opening to facilitate the addressing and manual grasping of the frame by an operator.

3. A pattern duplicator as defined in claim 1 wherein the tracer means is carried by one of the vertical members and the cutter means is carried by the other of the vertical members.

4. A pattern duplicator as defined in claim 3 including means for permitting the tracer means and the cutter means to be oriented relative to the vertical members at each of several angular displacements about a longitudinal axis.

5. A pattern duplicator as defined in claim 4 wherein the means for permitting said orientations includes at each longitudinal end of the frame a plate secured to the lower end of the vertical member and having a plurality of arcuately arranged holes, a support member pivotally connected to the plate and including pin means for locking the support member to each of the holes.

6. A pattern duplicator as defined in claim 1 wherein the stock cutter includes a motor and a rotary cutting blade carried by the frame.

7. A pattern duplicator as defined in claim 1 wherein the overhead support means includes at least one trolley for permitting free displacement of the frame along a longitudinally aligned overhead beam.

8. A pattern duplicator as defined in claim 1 wherein the telescopic means includes a pair of longitudinally spaced sprockets fixed over the frame, a pair of chains connected to the frame and engaging the sprockets for rotation thereof during vertical displacement and means interconnecting the sprockets to ensure unison rotation thereof.

9. A pattern duplicator as defined in claim 8 including a counterweight connected to the chains and suspended thereby.

10. A pattern duplicator as defined in claim 1 wherein the overhead support means includes a pair of longitudinally spaced vertical brackets for receiving the vertical members, and pin members for pivotally connecting the vertical members to the brackets.

11. A pattern duplicater as defined in claim 1 including a platform disposed vertically beneath the frame for supporting the pattern stock.