US 2592805 A
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April 15, 1952 H. H. HUTCHINSON 2,592,805
I MEANS FOR PROTECTING WINDOWS AGAINST SUPERFICIAL DAMAGE Filed Sept. 27, 1949 2 Sl-IEETS-SHEET 1 April 15,1952 H. H. HUTCHINSON 2,592,805
MEANS FOR PROTECTING WINDOWS AGAINST SUPERFICIAL DAMAGE 2 smqETs smzs'r 2 Filed Sept. 27; 1949 Patented Apr. 15, 1952 MEANS FOR PROTECTING WINDOWS AGAINST SUPERFICIAL DAMAGE Harry H. Hutchinson, Higher Crumpsall, Manchester, England Application September 27, 1949, Serial No. 118,018
In Great Britain October 1, 1948 Claims.
This invention relates to the protection against superficial damage of viewing and lighting windows such, for example, as the vision windows of the helmets or work cabinets used in sandor shot-blasting and in spraying operations, as well as the lighting windows or lamp fronts associated with chambers in which the above operations are carried out.
Depending upon the nature of the flyin particles with which they are bombarded during working hours, such windows rapidly become pitted or frosted, or obscured by deposit, in such a way that the viewing of the operation is hindered or the lighting of the working chamber reduced.
When this occurs, and more especially in the case of sandor shot-blasting where the damage to the window cannot otherwise be made good, the operators onl remedy has been to fit a fresh panel of glass or equivalent material. Even when it is possible, without mechanical re-polishing, to restore the window to its original transparency, the periodical attention which is called for involves a considerable loss of working time.
The expense and loss of time involved in window replacement is particularly serious in connection with sandor shot-blasters helmet visors and work cabinets, which, in order to reduce the risk of breakage, are usually made of Celluloid or a thermoplastic resin such as that known under the registered name Perspex. Glass, although harder and thus less quickly frosted than these materials, cannot be recommended for use in the situations aforesaid unless protected by wire gauze which, of course, is a further impediment to vision.
The object of the present invention is to provide a simple method and means whereby a window may be protected against superficial damage, as distinct from breakage, and its lightpassing efficiency thus maintained, with a minimum of periodical attention and expense.
The method according to the invention consists in overlaying the exposed surface of the window with a suitable transparent sheet material and progressively moving such material to bring undamaged portions thereof into position over the window.
In carrying the invention into effect, provision is made in the window frame for guiding a strip of transparent sheet material across the exposed face of the actual window panel, and preferably the frame is arranged to accommodate a supply of such material adjacent one edge of the said panel, as well as for clamping'the temporarily-operative portion of such material against the exposed face of the panel.
The protective sheet material may consist of a thin flexible film of, say, regenerated cellulose, which is capable of being stored in rolled condition.
In the accompanying drawings:
Fig. 1 is a front view of a viewing window for a sandor shot-blast cabinet, having the transparent panel protected in accordance with the present invention,
Fig. 2 is a section on the line 2-2 of Fig. 1,
Fig. 3 corresponds to Fig. 2, but shews an alternative form of cabinet window,
Figs. 4 and 5 are views corresponding to Figs. 1 and 2, illustrating the application of the invention to a lighting window or lamp front for a sandor shot-blast chamber,
Fig. 6 shews the invention applied to the visor of a sandor shot-blast worker's helmet,
Fig. 7 is a section on the line 11 of Fig. 6.
In the construction illustrated in Figs. 1 and 2, the invention is applied to a viewing window for a sandor shot-blast cabinet, which window will normally comprise a rectangular panel A of Perspex or similar material secured between inner and outer metal frame elements, the inner frame B having holes C for screws or bolts whereby it is aflixed to the cabinet wall.
For the purposes of the present invention, the original outer frame is replaced by a corresponding member D, preferably of aluminium, which is drilled at or near the corners to fit over studs E projecting from the inner frame B.
The transparent panel A, as well as a third metal frame F adapted for interposition between the latter and the inner frame B, are similarly drilled to accommodate the studs E, the window assembly above described being normally clamped tight by manually-operable nuts G on the studs E, with gaskets H of soft rubber or the equivalent at both sides of the intermediate frame F which is preferably of aluminium.
An extension of the frame F beyond one end or lateral edge of the transparent panel A is formed with an outwardly-facing trough I which extends parallel to the adjacent edge of the window opening and may have a part-cylindrical base.
Within the trough I, and located therein in any suitable manner, as by means of a spindle J supported in the end walls of suchtrough, is a rolled web of very thin transparent sheet material K, preferably a film of regenerated cellulose.
The free end of this film K is drawn over the outer rubber gasket H before the panel A and frame D are applied to the studs E, so that, on completion and tightening of the window assembly, such film is clamped in contact with, and completely covers, the inner face of the panel A which would otherwise be exposed to bombardment by flying particles during use of the cabinet.
In this way, the panel A is completely protected against superficial abrasion, and when the exposed part of the film K becomes itself obsoured, it is a simple matter to slackenoff the nuts G and, by pulling on the end of such film to draw a fresh section thereof intoposition over the panel A before re-tightening the nuts.
The exposed surface of the composite transparency (consisting of the panel A and film K) can thus be renewed in a matter of seconds whenever necessary, and owing to the thinness of the film. a very large number of such renewals can be carried out before the roll becomes exhausted.
Figure 3 illustrates a modified form of window assembly for a sandor shot-blast cabinet, in
which the transparent panel A is set at an angle to the vertical so as to facilitate downward vision.
In this case, the inner frame takes the form of a cast aluminium or other metal box B which is triangular in side elevation and has a marginal facing for attachment to the cabinet wall.
The transparent panel A is located .over a vision opening in the upper inclined face of the box B and is clampedin position by the outer frame D to which pressure is applied by the nuts G.
A rubber gasket H is interposed between the panel-A and the box B and the protective film K is led upwardly between the panel A ,and the gasket H from the trough I formed in the bov B at alower level.
Figures 4 and 5 show a further embodiment of the invention, as applied to a lighting window of a sandor shot-blast chamber, the transparent :panel A being adaptedeither to admit daylight or to form a cover for an electric lamp mounted in the ceiling ofthe chamber.
The inner and outer frames 13*, D in this case, have registering circular apertures whose ends are overlapped by the rectangular transparent panel-A a rubber gasket being interposed at H between such panel and the frame B The trough 1 1s formed in the frame 13 and the protective film K is led therefrom across the inner face of the panel A, which is held in place by the outer frame D and nut G the window assembly is mounted.
The inner frame B has lateral lugs O for attachment tothe exterior of thehelmet L, which latter is preferably recessed at P to accommodate the trough portion I of such frame.
The protective film K in this case .is lead over the outer face of the transparentpanel A the assembly being clamped by the corner nuts G with a rubber gasket between the panel A and the frame B Preferably the filmK is arrangedto be drawn downwardly so that the used portion thereof does 4 not obstruct the worker's vision, and it will be appreciated that the periodical adjustments of the film K may be effected without any need for the worker to leave the sandor shot-blast chamher.
It will be noticed that, in all the constructions above described the opening of the film trough is covered by an extension of the outer frame.
If desired, the window assembly may be provided with film-receiving troughs at opposite edges of the transparent panel, the film being wound as required from a spindle in one trough on to a second spindle in the other trough.
The spindle on which the unused film is stored, or the rolled material thereon, may be acted upon by a suitable brake, which controls its rotation.
It will be appreciated that the present invention, besides eliminating the expense and loss of time previously involved in window replacement atfrequent-intervals, also has the effect of increasing "productivity, since the utilization of the protection means as above described ensures the user working under the best conditions of vision and without eye strain of any risk thereof.
What-I claim is:
l. The combination with a window, of means for protecting the window from superficial damage caused by impact blows from flying particles, such means including inner and outer superimposed frames having aligned openings therein, and-means associated with the outer frame for supporting the window, a web of flexible transparent sheet material of at least twice the vlength of the window overlying the inner surface of the window, and a spindle carried by one of the frames for supporting the web in rolled condition and bolts which connect the frames and which can be tightened so as to clamp the transparent sheet therebetween in an adjusted, fixed position.
2'. Thecombination with a window, of means for protecting the-window from superficial damage caused by impact blows from flying par- "ticles, such means including inner and outer superimposed frames having registering openings therein, and means associated with the outer frame for supporting the window, a web of flexible transparent sheet material of at least twice the length of the window passing between the frames and overlying the inner surface of the window, and a spindle carried by the inner frame for supporting the web in rolled condition, and
a housing which encloses the web, the superimposed frames having. a clearance therebetween through which the transparent material may be drawn over-the inner surface of the window and clamping means connecting the frames to clamp the transparent sheet therebetween in an adjusted, fixed position.
3. The combination with a window, of means for protecting the window from superficial damage caused by impact blows from flying particles, such meansincluding inner and outer superimposed frames having registering openings therein, the window being positioned between the frames, a web of flexible transparent sheet material of at least twice the length of the window passing between the frames and overlying the inner surface of such window, a spindle carried by the inner frame for supporting the web in rolled condition, a housing carried by the inner frame which encloses the web, and a cover for the housing carried by the outer frame and releasable clamping means connecting the frames, such means when released permitting the transparent sheet to be drawn over the window to an adjusted, fixed position.
4. The combination with a window, of means for protecting the window from superficial damage caused by impact blows from flying particles, such means including three superimposed frames having registering openings therein, the window being positioned between the outermost and the intermediate frames, a web of flexible transparent sheet material of at least twice the length of the window overlying the inner surface of the window and passing between the two latter frames, a spindle carried by the intermediate frame for supporting the web in rolled condition, and a housing carried by such frame which encloses the web, a cover for the housing carried by the outer frame and clamping means connecting the frames to clamp the transparent sheet therebetween in an adjusted, fixed position.
5. The combination with a workers protective helmet provided with a window, of means forprotecting the window from superficial damage caused by impact blows from flying particles,
such means including plural superimposed frames having registering openings therein, and means associated with the frames for supporting the window therebetween, a web of flexible transparent sheet material of at least twice the length of the window overlying the inner surface of the window, a spindle carried by the inner frame for supporting the web in rolled condition, a two-part housing carried by the frames which encloses the web, and bolts connecting the frames to clamp the transparent sheet therebetween after it has been drawn to an adjusted, fixed position.
HARRY H. HU'TCHINSON.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,269,584 Downing June 18, 1918 1,498,767 Vitallo June 24, 1924 1,911,232 Large May 30, 1933