Cutlery – Cutting tools – Scrapers
Reexamination Certificate
1999-06-14
2001-09-11
Watts, Douglas D. (Department: 3724)
Cutlery
Cutting tools
Scrapers
C030S335000
Reexamination Certificate
active
06286215
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to blade scrapers used for removing paint, glue, caulking, adhesives, tape, stickers or other materials from surfaces, particularly, hard, smooth surfaces, such as glass and tile. Specifically, the invention relates to a scraper wherein the scraping blade is alternately retractable into a housing for storage, and extendible from the housing for use or replacement.
BACKGROUND
There are numerous scraping tools on the market, many of which are the subject matter of patents. Such patents include U.S. Pat. No. 4,955,138 to Henke; U.S. Pat. No. 2,291,514 to Warner and Tessmer; U.S. Pat. No. 3,855,700 to Gerson and Caprio; U.S. Pat. No. 4,558,517 to Gringer; U.S. Pat. No. 5,433,004 to Thompson and Henke; U.S. Design Pat. No. 282,881 to Gringer and U.S. Design Pat. No. 346,319 to Lavallee et al.
Some previous scrapers provide for alternately retracting and extending scraping blades. Of these, some include blade holders with vertically depressable buttons which, when depressed, release the blade holder from any of a number of locking positions for longitudinal reciprocation within a housing for alternate extension and retraction of a scraping blade through an opening in the housing.
SUMMARY
The present invention relates to a retractable blade scraper which utilizes a scraping blade for removing paint, glue, caulking, adhesives, tape, stickers or other materials from surfaces, particularly, hard, smooth surfaces, such as glass and tile.
In one embodiment, a retractable blade scraper is adapted to receive and utilize a trapezoidal utility knife blade, while in an alternative embodiment, a retractable blade scraper is adapted to utilize a rectangular scraping blade.
One embodiment of a retractable blade scraper includes a handle having an upper surface, a lower surface, a left side, a right side, an open forward end and a rear end opposite the open forward end. Proximate its open forward end, the handle includes an integral blade slide housing that begins at the open forward end and extends longitudinally rearwardly toward the rear end of the handle. The blade slide housing is bounded by top, bottom, left and right walls that define an interior blade-slide cavity designed to receive and house a utility knife blade.
The retractable blade scraper further includes a blade slide which is slidably received and retained in the blade slide housing and which includes a blade platform designed to removably receive and retain the scraping blade, with its scraping edge extending substantially perpendicularly to the longitudinal axis of the handle, for longitudinal reciprocation into and out of the open forward end of the handle and housing between a forwardmost blade-changing position and a rearwardmost blade storage position. The forwardmost blade-changing position is such that the blade platform extends out of the blade-slide cavity beyond the open forward end by an amount sufficient to permit the removal and replacement of scraping blades therefrom and thereon. The rearwardmost blade-storage position is such that the scraping edge of a scraping blade in place on the blade platform does not extend beyond the open forward end.
The blade slide further includes a resilient lever and a force actuated thumb button connected to the resilient lever. Depending from the resilient lever is a slide-locking detent. The slide-locking detent is normally biased by the resilient lever for alternative locking engagement with at least a first detent-receiving notch within the handle corresponding to the blade storage position and a second detent-receiving notch within the handle corresponding to a scraping position. The scraping position lies between the storage and blade changing positions and is such that the scraping edge of a scraping blade properly in place on the blade platform extends beyond the open forward end of the handle for use. The slide-locking detent is movable into a sliding position in which it is disengaged from the detent-receiving notches by the depression of the thumb button, against the biasing force of the resilient lever, in a substantially lateral direction toward one side of the handle so that the blade slide may be longitudinally reciprocated between the blade-changing and storage positions. In one version, the blade-changing position is, a locking position. In version in which the blade-changing position is a locking position, a third detent-receiving notch may be provided within the handle that corresponds to the blade-changing position.
In one version, the handle and blade slide housing are substantially symmetrical about the longitudinal axis of the handle when viewed from either the left or right side. Furthermore, the upper and lower surfaces of the handle are tapered toward one another in the vicinity of the open forward end, thereby permitting a user to obtain a favorable angle of approach (e.g., less than 24°) between the blade and the surface to be scraped, facilitating efficient removal of the unwanted material on the surface being scraped, whether the scraper is held with its upper surface up or down. Another advantage of the scraper's symmetry and minimal thickness of preferably less than {fraction (9/16)}″ is that, when one side of the blade's scraping edge becomes worn, the user can simply turn the scraper over so that the other side of the blade's scraping edge may be put into contact with the surface to be scraped. This same feature is equally applicable when a blade corner becomes chipped or worn. This feature eliminates the need for the user to remove the blade from the blade platform, turn the blade over, and reinstall it on the blade platform. The symmetry of a version intended for use with its upper surface either face up or face down, renders the designation of upper and lower surfaces arbitrary.
In one version, a significant advantage of the first is provided by the location of the thumb button. Existing scrapers with retractable blades have thumb buttons projecting through a thumb button opening located at or near the center of the top surface of the handle as illustrated, for example, in U.S. Pat. No. 4,955,138 to Henke and U.S. Pat. No. 4,558,517 to Gringer. In these prior scrapers, the user actuates the blade slide with his or her thumb or index finger by pushing downwardly on the thumb button in a substantially vertical direction toward the lower surface of the handle or housing in order to disengage it from a locked position. The user may then slide the blade slide either forward or backward depending on the desired blade position. On one version of the present scraper, the thumb button is located to one side of the center of the upper surface of the handle and slides forward and backward in a thumb-button opening that is located partially in one side of the scraper handle and partially in the adjacent portion of the upper surface of the scraper. It makes no difference whether the thumb button and its thumb button opening are on the left or right side of the scraper and, in actuality, either location is accommodating to both right-handed and left-handed users. In contrast to the thumb buttons of its predecessors, the thumb button of the present scraper is actuated by depressing it with thumb or index finger in a lateral direction substantially toward the side surface opposite the side surface having the thumb button opening, substantially along a plane lying between the upper and lower surfaces of the tool. In other words, the direction in which the thumb button is depressed in the present scraper to disengage it from a locked position is roughly 90° out of alignment with the direction of depression of the thumb buttons in prior scraper; instead of pushing generally vertically downward on the thumb button, the user pushes generally laterally toward one side of the scraper. Another advantage of the location and direction of depression of the thumb button in the present scraper is that the thumb button is located very near the natural position of the user's thumb or index finger
Franco Louis J.
Hyde Manufacturing Company
Watts Douglas D.
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