Adjustable carriage and optimized bearing surface means

A three-dimensional printer with improved adjustment mechanisms for calibrating the orientation of the build platform and an extrusion assembly to optimize the accuracy of models deposited on the build platform. The printer includes a frame carrying an extrusion assembly proximate the top, and a carriage within. A build platform is mounted on the top of the carriage. Carriage adjustment mechanisms are provided at at least two corners of the carriage for calibrating the orientation of the build platform with respect to the X-Y plane. An extrusion assembly adjustment mechanism is provided at at least one end of the extrusion mechanism for calibrating the orientation of the extrusion mechanism with respect to the Y-axis. A height adjustment mechanism is provided for translating the carriage within the frame along the Z-axis.

RELATED APPLICATIONS

This application claims the benefit of Provisional Patent Application No. 62/397,903, entitled “Adjustable Carriage and Optimized Bearing Surface Means”, filed on Sep. 21, 2016, the contents of which are incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present invention relates to the field of devices used to accomplish linear motion in a variety of machines used for three-dimensional (3D) applications including, but not limited to, 3D Printing and general machining.

BACKGROUND

Currently, there exist various carriages that ride on linear rails to achieve motion in various axes of movement. These axes are commonly known as X, Y, and Z. Current devices may use ball bearing wheels or polymer bearings as a medium to reduce friction and are driven by a series of motors and belts or lead screws to produce the necessary linear motion. Commonly, these mechanical systems use carriages which are set up to hold extruded or machined rails and these rails are attached by carriages which house ball bearing rollers to effect smooth movement. These carriages can be constructed from a variety of means, and inevitably secure cross-member rails to move in alignment in X, Y, or Z. Inevitably, these carriages can be difficult to adjust and normally, very precise placement of the rails and bearings is required, with great precision during manufacture to maintain an orientation which is perfectly square to the relative frame in which the machine is constructed.

Accordingly, there is a need for a compact, inexpensive carriage and related system whose function is to achieve adjustability evenly and square to the corresponding rails which the carriages are riding upon.

SUMMARY OF THE INVENTION

Therefore, this invention to provides users with a solution to easily adjust carriages which ride in a linear fashion on parallel rails to affect a true perpendicular motion.

This invention provides a method to adjust the perpendicularity of associated rails without using specialized tools.

This invention also provides a means to achieve true linear traveling relationships for machines using single or multiple axis linear systems.

This invention utilizes guide rails which are optimized for proper bearing surface and orientation.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is an improved adjustable carriage for use in applications in which a working head is movable in at least two directions, namely laterally along each of the X-, and Y-axes such that the working head is moveable along the X-Y plane. The adjustable carriage is mounted with a frame such that it is moveable at least laterally in along the Z-axis. The present invention further includes at least one adjustment mechanism for calibrating the orientation of a working surface carried or defined by the adjustable carriage is disposed in a plane substantially parallel to the X-Y plane.

Referring now to the drawings,FIG. 1is a perspective view of a 3-D printer10incorporating adjustable carriage and optimized bearing surface of the present invention. The 3-D printer10includes a frame12consisting of four stationary corner rails14disposed in a vertical orientation and disposed at the four corners of the frame12. A bottom structure26is provided to secure the lower end18of each corner rail14relative to each other. In the illustrated embodiment, the bottom structure26is a rectangular panel28defining four corners30, each configured to engage and be secured to the lower end18of one of the corner rails14in a conventional manner. Similarly, a top structure32is provided to secure the upper end16of each corner rail14relative to each other. In the illustrated embodiment, the top structure32includes four top rails34, each defining a first end36configured to engage and be secured to the upper end16of one corner rail14in a conventional manner and a second end38configured to engage and be secured to the upper end16of an adjacent corner rail14in a conventional manner. Thus, when the bottom structure26is secured to the lower end18of each corner rail14, and the top structure32is secured to the upper end16of each corner rail14, the various components of the frame12are substantially stationary relative to each other.

The working head of the 3-D printer10includes an extruder assembly40and the working surface is a build platform52, each carried by the frame12. The extruder assembly40is configured to move an extruder46in each of the X- and Y-axes along an X-Y plane. The extruder assembly40includes an extruder46provided for depositing a selected material onto the build platform52to form a selected three-dimensional model. In the illustrated embodiment, the extruder assembly40defines first and second ends42,44and is carried by opposing top rails34, with the first and second ends42,44being translatable along the top rails34in order to affect translation of the extruder46along the X-axis. The extruder assembly40is further configured to allow translation of the extruder46along the longitudinal axis of the extruder assembly40, which correlates with the Y-axis of the 3-D printer10.

In the illustrated embodiment, the build platform52is translated along the Z-axis to provide the third dimension to the deposition process. In order for the deposition to remain undistorted, it is imperative that the build platform52define a deposition surface parallel to the X-Y plane in which the extruder46is translated. Electronics (not illustrated) are also provided and are in communication with the extruder assembly40, build platform52, and a computing device (not illustrated) for controlling the operation of the extruder46, the extruder assembly40, and the build platform52during a material deposition process.

In the illustrated embodiment, the build platform52includes a plate54supported by a substantially X-shaped support structure58. The support structure58is disposed below the plate54and includes four arms60extending from a center of the plate54toward the four corner rails14of the frame12.

A height adjustment mechanism64is provided for translating the build platform52along the Z-axis. The height adjustment mechanism64includes at least one threaded rod member66disposed parallel to the Z-axis, and at least one threaded member68configured to rotatably engage the threaded rod66, the threaded member68being disposed on the build platform support structure58. In the illustrated embodiment, two threaded rod members66and cooperating threaded members68are provided, with the threaded members68being disposed on the distal end62of opposing build platform support structure arms60. As either the threaded rods66or the threaded members68are rotated, the build platform52is translated along the Z-axis.

As illustrated inFIG. 2(and more clearly inFIG. 13), which is a plan view of the 3-D printer10illustrated inFIG. 1, each corner rail14defines first and second frame mounting surfaces20,22that are orthogonally-disposed with respect to one another. The first and second ends36,38of the top rails34engage and are secured to the first and second frame mounting surfaces20,22, respectively, such that the top rails34collectively define a rectangle. In the illustrated embodiment, the top rails34each define the same length, thus they are collectively disposed in a square. Each corner rail14further defines a bearing surface24disposed between the two frame mounting surfaces20,22and at a 45° (forty-five degree) angle with respect to each of the mounting surfaces20,22.

The build platform52is substantially rectangular, defining four corners30. In the illustrated embodiment, the build platform52is substantially square. At least two adjustment mechanisms72of the preferred embodiment are disposed on adjacent corners30of the build platform52and in engagement with the bearing surface24of the corresponding frame corner rail14in order to accomplish the calibration of the orientation of the build platform52with respect to the X-Y plane of the extruder assembly40. In the illustrated embodiment, four adjustment mechanisms72are provided, with one being disposed at the distal end62of each arm60extending from the support structure58, and each engaging a corresponding corner rail bearing surface24.

FIG. 3is a side elevation view of the 3-D printer illustrated inFIG. 2, and taken along section lines3-3therein. In this view, the relative orientation of the extruder assembly40—and specifically the X-Y plane in which the extruder46is translated—and the build platform52is shown. As discussed above, it is imperative during operation of the printer10that these be parallel. However, due to manufacturing tolerances of the various components of the printer10, at least one adjustment mechanism72is provided for calibrating the planar orientation of at least one of the extruder assembly40and the build platform52. In the illustrated embodiment, as will be described further below, at least two adjustment mechanisms72are provided for adjusting the planar orientation of the build platform52. Each adjustment mechanism72is disposed at a corner56of the build platform52to engage the bearing surface24a corresponding corner rail14of the frame12.

Further illustrated inFIG. 3is a height adjustment mechanism64for translating the build platform52along the Z-axis. As described above, as either of the threaded rod66or the threaded member68is rotated, the build platform52is raised or lowered along the Z-axis.

FIGS. 4 and 5illustrate one embodiment of the adjustment mechanism72of the present invention.FIG. 4illustrates a side elevation of the adjustment mechanism72in its assembled form, whileFIG. 5illustrates the same adjustment mechanism72in an exploded view. The adjustment mechanism72includes at least one bearing wheel90provided and positioned to engage the corresponding corner rail bearing surface24. In the illustrated embodiment, two bearing wheels90are provided. Each bearing wheel90is provided with an adjuster to move the wheel90along the longitudinal axis of the corresponding build platform support structure arm60, and more specifically, toward and away from the corresponding corner rail bearing surface24. Accordingly, in the illustrated embodiment, two adjusters are provided. Each adjuster includes a threaded screw92carried by the adjustment mechanism72.

FIGS. 6A and 6Billustrate the adjustment mechanism72ofFIGS. 4 and 5in cross-section. In the illustrated embodiment, the adjustment mechanism72includes a housing74defining first and second ends76,78. A receptacle84disposed at the first end76is configured to loosely receive the distal end62of one of the build platform support structure arms60. Two bearing wheels90are rotatably carried at the upper and lower corners80,82of the second end78. Two threaded screws92are disposed within through openings88defined by the housing74, with the distal end96of each being extendable into the receptacle84in order to engage the distal end62of the build platform support structure arm60. The through openings88are configured to closely receive the head94of each screw92such that the screws92are limited to linear movement with the through openings88, and more specifically, prevented from rotation within the through openings88. A slotted opening86is defined on either side of the housing74and in cooperation with each through opening88and is dimensioned to receive an adjustment wheel98. The adjustment wheel98is configured to cooperatively receive a threaded screw92. Thus, when assembled, the adjustment wheel98is rotated to either translate the associated threaded screw92toward or away from the receptacle84.

In the illustration ofFIG. 6A, the build platform support structure arm60is shown to be disposed at an angle θ with respect to the X-Y plane. It is desired to calibrate the orientation of the build platform52in order to reduce angle θ to 0° (zero degrees). To accomplish this in the illustrated embodiment, the upper adjustment wheel98is engaged to translate its threaded screw92away from the support structure arm60(to the right in the illustration), and the lower adjustment wheel98is engaged in the opposite direction to translate its threaded screw92toward the support structure arm60(to the left in the illustration). In so doing, the build platform52is re-oriented as illustrated inFIG. 6B.

FIGS. 7 and 8illustrate an alternate embodiment of the adjustment mechanism72′ of the present invention. In this embodiment, the housing74′ includes front and rear sides100,102secured to each other via a plurality of spacers104. A receptacle84′ is defined between the front and rear sides100,102. A carrier106is received within the receptacle84′. The carrier106defines two through openings108for receiving the threaded screws92′ therethrough. The through openings108are configured to closely receive the head94′ of each threaded screw92′ such that rotation of the threaded screw92is prevented.

FIG. 9illustrates an enlarged view of the first end42of the extruder assembly40ofFIG. 2. An extruder assembly adjustment mechanism110(illustrated in cross-section) is disposed between the first end42of the extruder assembly40and the top rail34for calibrating the orientation of the extruder assembly40in the X-Y plane. The extruder assembly adjustment mechanism110generally includes a base112configured to be secured to an end42,44of the extruder assembly40and to carry at least one bearing wheel124for engaging the corresponding top rail34. In the illustrated embodiment, the extruder assembly40includes first and second rails48,50along which the extruder46is translated. The base112, accordingly, defines two receptacles114configured to closely receive one end42,44of each of the first and second rails48,50.

FIG. 10illustrates the extruder assembly after it has been calibrated, graphically represented with broken lines134. A skewed orientation is graphically represented with broken lines at136, prior to calibration.

FIG. 11illustrates one embodiment of the extruder assembly adjustment mechanism110.FIG. 12illustrates an exploded view of the extruder assembly adjustment mechanism110shown inFIG. 11. The base112further defines two articulated arms116, one each in cooperation with a threaded screw122. One of the bearing wheels124is rotatably mounted on the distal end126of each articulated arm116. A threaded member120is carried by an interior end118of each articulated arm for cooperatively engaging the threaded portion of a threaded screw122. As each screw122is rotated in a first direction, the articulated arm116is either extended or retracted. When the screw122is rotated in the opposite second direction, the articulated arm116is either retracted or extended. In order to calibrate the orientation of the extruder assembly40, the screws122are rotated in opposite directions with respect to each other until the orientation of the extruder assembly40is true.

FIG. 13is an enlarged view of the corner rail14of the frame12. In this illustration, two top rails34are secured to the first and second mounting surfaces20,22of the corner rail14in a conventional manner. Further illustrated is a bearing wheel90of a build platform adjustment mechanism72in engagement with the bearing surface24of the corner rail14.

A 3D printer incorporating an adjustable carriage and optimized bearing surface is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiments of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation.