The present invention relates to a gauge for measuring the height of a bead of adhesive used in the assembly of components.
Many components are assembled together with the use of adhesives or glues. Robotic machines are commercially available to apply controlled amounts of adhesive during assembly processes. Such machines inject or apply adhesive so that a layer or “bead” of adhesive is formed on an outer surface of the component or components to which the adhesive is applied. To achieve a proper assembly, it is often necessary to use a proper amount of adhesive, and to assure quality assemblies it is necessary to periodically measure the amount of applied adhesive to insure the correct operation of the adhesive applying machine. Various methods and tools have been used to measure the height of an adhesive bead on a part, such as machine vision systems and laser triangulation systems. But such systems are expensive and unreliable. Adhesive bead height has also been measured with a commercially available digital height gauge which has a measuring probe. However, with this type of gauge it is nearly impossible to measure the height of a soft wet bead of adhesive, because, when positioning the measuring probe, the probe may be above the bead or the probe may plunge into the bead, creating high measurement error.
A Technical Data Sheet for LOCTITE® adhesive Product 5910 describes a “PTFE block” which can be used to determine the depth of cure of an adhesive in a given amount of time. The block includes a channel which gradually increases in depth from 0 to 10 millimeters. The channel is filled with adhesive and allowed to cure for a certain time period, after which the adhesive is peeled away from the channel. The channel depth at the point where the adhesive remains is the cure depth for that particular cure time. However, because adhesive is applied to the tool and not applied by the production adhesive applying machine, and is not applied to a sample part, this tool cannot be used to determine whether an adhesive applying machine is set up properly to apply an adhesive bead with a proper height.
Accordingly, an object of this invention is to provide an accurate and reliable tool for measuring the height of an adhesive bead applied to a test piece.
A further object of the invention is to provide such a bead height measuring tool which is inexpensive and simple to use.
These and other objects are achieved by the present invention, wherein an adhesive bead depth or height measuring system includes a slide base to which a bead of adhesive is applied by a production adhesive applying machine, and a slide gauge which slides over the base. The gauge has a pair of rails which are separated by a slot, each rail having a bottom surface which slidably engages the base. The slot forms a planar ramp surface which extends in a longitudinal direction from a first end spaced apart from the bottom surfaces by a first larger distance to a second end spaced apart from the bottom surfaces by a second smaller distance. The gauge slides over the bead with the ramp surface facing the bead and with the first end of the ramp surface leading so that the bead engages and adheres to the ramp surface at a position between the first and second ends. This position is proportional to a height of the bead above a surface of the base. The base includes a guide slot which slidably receives and guides the gauge.
Referring to
The generally rectangular slide gauge 20 is placed in the slot 14 against the floor surface 16. As best seen in
Preferably, a plurality of regularly spaced marks 38 are distributed over the ramp surface 32, each mark extending perpendicularly with respect to the laterally outer edges of the rails 22, 24. Also, depth numbers 40 are placed on the slide gauge 20 in association with at least some of the marks, so that the depth numbers represent the depth of the slot 26 at the mark associated with that depth number, with respect to a plane surface which contains the bottom surfaces 28, 30 of rails 22, 24. Shallow recesses 35 are formed in both sides of guide 20 (one side being visible in
Referring now to
After the slide gauge 20 is moved completely over bead 19, the slide gauge 20 is pulled away from slide base 10 so that the surface 32 of slot 26 can be examined. As best seen in
This bead height measuring system 8 does not require repetitive set-up, programming, and calibration. Initial tooling costs are low and a small fraction of the cost of a vision system. Compared to lasers or vision system, the system 8 is not sensitive to the effects of light, vibration or power glitches. The slide gage 20 and base 10 are rugged, simple and easy to use. The system 8 does not require specialized or advanced training.
While the present invention has been described in conjunction with a specific embodiment, it is understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
1909652 | Bower | May 1933 | A |
2351105 | Casali | Jun 1944 | A |
3171205 | Kurtz | Mar 1965 | A |
4062121 | Fried et al. | Dec 1977 | A |
4703648 | Baresh | Nov 1987 | A |
5134785 | Gilpatrick | Aug 1992 | A |
D411808 | Irwin | Jul 1999 | S |
6138374 | Friedersdorf et al. | Oct 2000 | A |
6336275 | Shigyo | Jan 2002 | B1 |
6792691 | Genal et al. | Sep 2004 | B2 |