HOT MELT INK SUPPLY UNIT

Abstract: In the embodiment of the hot melt ink supply unit described in the specification, a block (10) of solid hot melt ink has a peripheral surface formed with a key configuration (22) and a handle (14) is removably connected to the block by a threaded projection. After insertion of the block into a correspondingly keyed opening (24) in a heated reservoir (23), the handle is turned to separate the handle portion from the block of solid ink. A container provided with a removable seal encloses the block of solid ink and handle to protect the ink from contamination.

Description: Description Hot Melt Ink Supply Unit Technical Field This invention relates to arrangements for stor- ing and supplying unit quantities of hot melt ink for use in hot melt ink printing systems and, more par¬ ticularly, to a new and improved hot melt ink supply unit which effectively protects the hot melt ink dur¬ ing storage and transit and permits delivery of the ink in a simple and convenient manner to a molten ink reservoir without contamination. Background Art In printing systems which use inks that are solid at room temperature and melted by heating for applica- tion to an ink-receiving substrate, such as certain ink jet printing systems, the solid ink must be deliv¬ ered to a molten ink reservoir associated with the printing system in such a way that contamination of the ink is avoided. In addition, where different colored inks are contained in different reservoirs, in the printing system, care must be taken to assure that ink of the proper color is delivered to the corre¬ sponding reservoir. Furthermore, exposure of the operator to molten ink splashed from the reservoir when solid ink is delivered must be avoided. Heretofore, hot melt ink has been supplied to reservoirs in ink jet systems by selective heating of ink in a replaceable cartridge as described, for exam¬ ple, in U.S. Patent No. 4,631,557, by selective heat- ing of an ink block as described in U.S. Patent No. 4,593,292, or by advancing ink pellets or granules toward the reservoir by a complex pellet drive or granule conveyer system as described in U.S. Patents Nos. 4,636,803 and 4,667,206. Those arrangements. - - however, require either melting of the ink in a car¬ tridge or block outside the reservoir to transfer ink into the reservoir or necessitate complicated mechani¬ cal advancing and delivery systems to move pellets or granules from a supply into a reservoir. Thus, the prior art does not permit simple and convenient manual loading of individual solid hot melt ink supply units without exposing the solid ink to potential contamina¬ tion and the operator to possible injury from splash- ing of molten ink in the reservoir. Disclosure of Invention Accordingly, it is an object of the present in¬ vention to provide a new and improved hot melt ink supply unit which overcomes the above-mentioned disad- vantages of the prior art. Another object of the present invention is to provide a hot melt ink supply unit arranged for con¬ venient and efficient manual delivery of measured quantities of solid hot melt ink to a reservoir while avoiding contamination of the ink and danger to the operator. These and other objects of the invention are attained by providing a block of solid hot melt ink having a keyed peripheral configuration and a handle member removably affixed to the block of hot melt ink and separable therefrom by relative rotation with respect to the block. In a preferred embodiment the handle member is formed with a splash guard covering the adjacent surface of the hot melt ink block and a container conforming to the keyed peripheral surface of the hot melt ink block and encloses both the ink block and the handle member to provide a convenient package for transportation and storage. Brief Description of Drawings Further objects and advantages of the invention will be apparent from a reading of the following de¬ scription in conjunction with the accompanying draw- ings in which: Fig. 1 is a transverse cross-sectional view il¬ lustrating a representative embodiment of a hot melt ink supply unit and container arranged in accordance with the present invention; Fig..2 is a perspective view illustrating the hot melt ink supply unit of Fig. 1 partially removed from the container; and Fig. 3 is a perspective view illustrating the manner in which the hot melt ink supply unit of Fig. 1 is inserted into a typical molten ink reservoir and separated from the handle member. Best Mode for Carrying Out the Invention In the representative embodiment of a hot melt ink supply unit in accordance with the invention shown . in Fig. 1, a solid block 10 of hot melt ink is dis¬ posed in the lower portion 11 of a cup-shaped con¬ tainer 12. A handle member 13 consisting of an up¬ wardly projecting handle 14, a disc-shaped splash guard 15 and a threaded central projection 16 is seated on a shoulder 17 in the wall of th-e cup-shaped container 12. The shoulder 17 is located and handle member 13 is formed so that the projection 16 extends downwardly a short distance into the solid ink block 10 disposed in the lower portion of the container and a narrow space 18 separates the top of the block 10 and the splash guard 15. The handle member 13 may be made of any material, such as plastic or metal, to which the ink block 10 does not strongly adhere. In order to provide a releasable connection be- tween the ink block 10 and the handle member 13 by means of the threaded projection 16 while maintaining a. space 18 between the ink block and the splash guard 15 in a convenient manner, a measured quantity of the ink is preferably introduced into the lower portion 11 of the container 12 in molten form so as to reach a level just below the shoulder 17 and the handle member 14 is positioned with the projection 16 inserted into the molten ink and the splash guard 15 resting on the shoulder 17, after which the ink is solidified. In a typical arrangement for holding 20cc of solid ink, the lower portion 11 of the container is approximately 32mm in diameter and the shoulder 17 is approximately 25mm from the bottom of the container. To facilitate separation of the handle member 13 from the ink block, the threaded projection, which is tapered by about 10°, extends approximately 6.4mm into the ink block and the thread on the projection is at an angle of about 45° to the axis of the projection. To avoid the possible introduction of contami- -nants into the container 12 during storage and ship¬ ment, the container includes an upper portion 19 which surrounds the handle member 13 and the opening at the top of the cup-shaped container is sealed by a layer 20 of plastic sheet material which may be peeled off when the ink supply unit is to be removed and used. Preferably the container 12 is made of transparent or translucent plastic material and the wall of at least the lower portion 11 is shaped with a slight taper, for example, 2°, to facilitate removal of the block of solid ink. In addition, the material of which the container is made should have a low adherence to the ink and should preferably be slightly resilient to facilitate separation of the ink block from the con¬ tainer. The ink supply unit is removed from the container 12 by separating the sealing sheet 20 and pulling upwardly on the handle 14 without twisting while hold¬ ing the container, as indicated by the arrow 21 in Fig * 2» As shown in Fig. 2, the lower portion 11 of the container 12 has a keyed peripheral configuration which, in the illustrated embodiment, consists of a recess 21 having a specific angular extent, such as 30°. As a result, a correspondingly shaped recess 22 is formed in the block 10 to provide a keyed shape which can be received in a correspondingly keyed open¬ ing in the reservoir which is to receive the ink block. By providing a different key configuration for each color of ink, and correspondingly different key configurations for the ink reservoirs, the possibility of supplying ink of the wrong color to a reservoir is positively prevented. For example, two or more reces¬ ses narrower than the recess 21 may be provided at differing peripheral angles in other ink supply units so that none of them can be received in the reservoir opening conforming to any other key configuration. In Fig. 3, a heated reservoir portion 23 of a hot melt ink printing system, which may contain molten hot melt ink, is illustrated schematically. The reservoir 23 has an ink-receiving opening provided with a collar 24 which is formed with a key comprising an inward projection 25 corresponding in shape to the recess 22 providing the key in the periphery of the block of hot melt ink 10. To supply the ink block 10 to the reser¬ voir after removal from the container 12, the recess 22 in the block is aligned with the inward projection 25 of the collar and the combined block and handle member are inserted downwardly into the reservoir in the direction of the arrow 26 in Fig. 3. When the splash guard 15 engages the top of the collar 24, the handle 14 is rotated in the counterclockwise direction as indicated by the arrow 27 so that the threaded por¬ tion 16 is turned to unscrew it from the block 10 while the block 10 is held in angularly fixed posi¬ tion. Preferably, the screw connection is designed so that approximately one-quarter turn of the handle is sufficient to release the handle member from the block of solid ink. Since the splash guard 15 is held against the collar 24 during rotation, the angle of the thread on the projection 16 moves the block 10 downwardly as the handle is turned. Consequently, after the block 10 is disconnected from the handle member, it drops into the molten ink in the reservoir and the operator is pro¬ tected from any resulting splash of the molten ink by the splash guard 15 which completely covers the open¬ ing in the collar 24. Thereafter, the reservoir open- ing may be closed by a cover (not shown) to avoid contamination of the ink in the reservoir. Thus, the packaging, storage, transportation and removal of a block of hot melt ink and insertion of the hot melt ink into a reservoir containing molten ink is conveniently accomplished while avoiding con¬ tamination of the ink and danger to the operator from the hot melt ink in the reservoir ' . Although the invention has been described herein with reference to a specific embodiment, many modifi- cations and variations therein will readily occur to those skilled in the art. For example, the connection between the handle member and the block of hot melt ink, rather than being a single central threaded pro¬ jection from the handle, might consist of several projections extending downwardly from the splash guard into the block at locations spaced from the center and into the ink block at an angle so that they are with¬ drawn from the block upon rotation of the handle. Accordingly, all such variations and modifications are included within the intended scope of the invention as defined by the following claims.

Claims: Claims 1. A hot melt ink supply unit comprising a block of solid hot melt ink having a k ' eyed peripheral configuration and handle means removably con- nected to the block of- hot melt ink and separable therefrom upon relative rotation between the handle means and the block. 2. A hot melt ink supply unit according to Claim 1 wherein the handle means includes splash guard means substantially covering the adjacent portion of the hot melt ink block. 3. A hot melt ink supply unit according to Claim 2 wherein the splash guard means is spaced from the adjacent portion of the hot melt ink block. 4. A hot melt ink supply unit according to Claim 1 including container means enclosing the hot melt ink block and the handle means and having -a shape conforming to the keyed peripheral configuration of the hot melt ink block. 5. A hot melt ink supply unit according to Claim 4 wherein the handle means includes splash guard means and the container means includes shoulder means abutting the splash guard means. 6. A hot melt ink supply unit according to Claim 4 including sealing means for sealing the container means so as to prevent contamination of the hot melt ink block. 7. A hot melt ink supply unit according to Claim S wherein the container means comprises a cup- shaped container enclosing the hot melt ink block and the- handle means and the sealing means in¬ cludes a removable sheet member covering the opening in the cup-shaped container. 8. A hot melt ink supply unit according to Claim 1 wherein the handle means includes at least one projecting element into the hot melt ink block and adapted to be withdrawn from the block by rotation of the handle means with respect to the block. 9. A hot melt ink supply unit according to Claim 8 wherein the projecting element is a threaded element. 10. In combination, a hot melt ink supply unit according to Claim 1 and a hot melt ink reservoir having a keyed opening conforming to the keyed peripheral configuration of the hot melt ink supply unit. 11. A plurality of hot melt ink supply units, each comprising a plurality of blocks of solid hot melt ink of different colors and having different keyed peripheral configuations, each correspond¬ ing to the color of the ink, and handle means for each block of solid hot melt ink removably con¬ nected to the block and separable therefrom upon relative rotation between the handle means and the block. 12. In combination, a plurality of hot melt ink sup¬ ply units according to Claim 11 and a correspond¬ ing plurality of ink reservoirs having keyed openings conforming to the keyed peripheral con¬ figuration of the hot melt ink supply units. 13. A method for delivering a block of solid hot melt ink having a keyed peripheral configuration to a reservoir having a keyed opening conforming to the keyed peripheral configuration comprising providing a handle means separably connected to the block of hot melt ink, inserting the hot melt ink into the opening in the reservoir, and im¬ parting relative motion between the handle means and the block of hot melt ink so as to separate the handle means from the block. 14. A method according to Claim 13 wherein the rela¬ tive motion comprises rotation of the handle means with respect to the block. 15. A method of forming a hot melt ink supply unit comprising providing a container shaped with a keying surface, introducing molfen hot melt ink into the container, supporting a handle member with a portion extending into the molten hot melt ink, and solidifying the ' hot melt ink. 16. A method according to Claim 15 wherein- the handle member includes splash guard means adjacent to the block of hot melt ink and including support¬ ing the splash guard means in spaced relation from the hot melt ink while the hot melt ink is being solidified. 17. A hot melt ink system comprising a block of hot melt ink having a selected shape, handle means attached to the block of hot melt ink and remova¬ ble therefrom upon relative motion with respect to the block, reservoir means for melting solid blocks of hot melt ink, and receiving means shaped in accordance with the selected shape of the hot melt ink block to receive the block of hot melt ink to be introduced into the reservoir and restrain motion of the block to permit rela¬ tive motion of the handle means with respect to the block. 18. A hot melt ink system according to Claim 17 wherein the block of hot melt ink and the receiv¬ ing means are shaped to restrain rotation of the block about an axis parallel to the direction of introduction of the block into the reservoir and the handle means is removable from the block by rotation about that axis.

Inventors: CRANSTON DEAN H, CREAGH LINDA T, HINE NATHAN P, MACDONALD JACK B, SPEHRLEY CHARLES W JR, CRANSTON, DEAN, H., CREAGH, LINDA, T., HINE, NATHAN, P., MACDONALD, JACK, B., SPEHRLEY, CHARLES, W., JR.
Applicants: SPECTRA INC, SPECTRA, INC.
Application year: 1988
Main classification: G01D15
IPC codes: B41J2