US3621259A

US3621259A - Sheet-gauging apparatus

Info

Publication number: US3621259A
Application number: US792007*A
Authority: US
Inventors: Mathew G Boissevain
Original assignee: Measurex Corp
Current assignee: Honeywell Measurex Corp
Priority date: 1969-01-17
Filing date: 1969-01-17
Publication date: 1971-11-16
Anticipated expiration: 1988-11-16
Also published as: CA923330A

Abstract

Sheet-gauging apparatus for gauging properties of sheet material and having upper and lower gauging heads with timing belt means for precisely moving the gauging heads with respect to the sheet material.

Description

Unite States Ptent Inventor App No.

Filed Patented Assignee Mathew G. Boissevaln Los Altos Hills, Calill. 792,007

Jan. 17, 11969 Nov. 16, 19711 Measurex Corporation Santa Clara, Calif.

SHEET-GAUGING APPARATUS 13 Claims, 10 Drawing Figs.

us. Cl 250/833 10, 250/106 s, 250/219 TH Int. Cl

....... G2llh 5/00 Field 011' Search 250/83 D, 92, 106 S; 73/159 References Cited UNITED STATES PATENTS Mamas Hansen Hansen et a1. Lehman et a1.

Primary Examiner-James W. Lawrence Assistant ExaminerDavis L1 Willis Attorney-Flehr, Hohbach, Test, Albritton & Herbert ABSTRACT: Sheet-gauging apparatus for gauging properties of sheet material and having upper and lower gauging heads with timing belt means for precisely moving the gauging heads with respect to the sheet material.

PATENTEBHuv 16 Ian 3,621,259

sum 1 or 6 INVENTOR Y Mathew G. Boissevain florneys PATENTEBNUY 1s |97l 3,621,259

sum 2 OF INVENTOR Mathew G. Bar'ssevain PAIENIEUMW 1s I97| Fig. 3

SHEET 3 OF 6 INVENTOR.

Mathew G. Boissevain PATENTEBuuv 16 197i 31. 621 ,259

sum 0F 6 INVENTOR. Mathew G. Boissevain Attorneys PATENTEUHUV 16 mm 3,621 ,259

sum 5 {1F 6 INVENTOR. Mathew G. Baissevain Attorneys BACKGROUND OF THE INVENTION Sheet-gauging apparatus has heretofore been provided. However, such sheet-gauging apparatus have had some disadvantages. For example, with such apparatus it has been difficult to precisely move the gauging heads in a precise manner with respect to each other and with respect to the sheet of paper being gauged. In addition, it has been difficult to maintainthe necessary desired precise positioning of the gauging heads during movement of thesame. There is, therefore, a need for a new and improved sheet-gauging apparatus.

SUMMARY OF THE INVENTION AND OBJECTS The sheet-gauging apparatus for gauging properties of a sheet of material consists of a frame which has a pair of spaced upper and lower parallel beams extending laterally of the sheet. Upper and lower track means are carried by the upper and lower beams respectively. Upper and lower gauging heads are provided which are adapted to be disposed on opposite sides of the sheet. Carriage means is provided for mounting the gauging heads on the upper and lower track means. Drive means is also provided and timing belt means is connected to the drive means and tothe carriage means for shifting the gauging heads longitudinally of the beams and laterally of the sheet of paper. Gauging means is carried by the gauging heads for sensing a property of the sheet as the heads are shifted relative to the sheet.

In general, it is an object of the present invention to provide a sheet-gauging apparatus having gauging heads which are precisely positioned with respect to each other as they are shifted relative to the sheet being gauged.

Another object of the invention is to provide sheet-gauging apparatus of the above character in which track means is provided on which the gauging heads travel.

Another object of the invention is to provide a sheet-gauging apparatus of the above character in which means is provided for maintaining a substantially uniform temperature along the track means.

Another object of the invention is to provide sheet-gauging apparatus of the above character in which means is provided for rotecting the track means from dust, dirt and the like.

Another object of the invention is to provide sheet-gauging apparatus of the above character in which precision stepping means is utilized for driving timing means for shifting the gauging heads longitudinally of the track means.

BRIEF DESCRIPTION OF THE DRAWING FIGS. 1A and 1B are side elevation views with certain parts broken away of a sheet-gauging apparatus incorporating the present invention.

FIG. 2 is an end elevational view of the left-hand end of the apparatus shown in FIGS. 1A and 18 with certain parts broken away.

FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 1B.

FIG. 4 is an end elevational view of the left-hand end of the apparatus shown in FIGS. IAand 113.

FIG. 5 is a side elevational view of the apparatus shown in FIG. 1B but showing the opposite side with certain portions broken away.

FIG. 6 is a side elevational view of the gauging head assem bly apparatus shown in FIGS. 1A and 1B.

FIG. 7 is a cross-sectional view taken along the line 7-7 of FIG. 6.

FIG. 8 is an end elevational view of the gauging head assembly shown in FIG. 6.

FIG. 9 is a top plan view of the head assembly shown in FIG. 8.

2 DESCRIPTION OF THE PREFERRED EMBODIMENT The sheet-gauging apparatus consists of a main frame 11. The main frame 11 consists of a pair of spaced end supports 12 and H3 which extend generally in a vertical direction and a pair of spaced substantially parallel I-

beams

14 and 16 which extend generally in a horizontal direction and are secured to the end supports 12 and 13.

For reasons hereinafter described, the end support 12 can be considered as a drive-in support and consists of a flat vertical plate 17 which has a vertical reinforcing web 18 secured thereto so that the end support is substantially T shaped in cross section. A bottom pad I9 is secured to the lower extremities of the

plates

17 and 18. The end support 13 is formed of a vertical plate 21 and is provided with a pair of spaced vertical reinforcing webs 22 so that in cross section the end support 13 is generally in the form of a double 'l." A horizontally disposed pad 23 is secured to the lower extremities of the plates 21 and the webs 22. The pad 23 is provided with an elongaterecess 24 which is adapted to receive a large roller 26. The recess 24 has a width which is substantially greater than the diameter of the roller 26, as can be seen from FIG. 1B. The roller also seats in a similar recess 27 provided in a lower pad28 which is adapted to be secured to the foundation for the apparatus by bolts. 29. The pad 19 of the end support 12 is secured to a lower pad (not shown) provided by the customer by bolts 31.

The end supports 12 and 13 include parallel spaced vertical flanges 32 provided on the inner surfaceof the

plates

17 and 21. The l-beams M and 16 are secured to the flanges 32 by bolts 33. In order to assure exact alignment, pins 34 are provided on the end-of the I-beams and are adapted to be inserted in the flanges to precisely position the l-beams prior to tightening of the bolts 33. This arrangement permits the apparatus to be disassembled and then reassembled while still retaining the same exact alignment.

Upper and lower track means 36 and 37 are provided and which are secured by the [beams 14 and 16. They are generally similar in construction as shown in the drawings and each consists of aflat plate 38 disposed below the l-beam and supported therefrom by a plurality of pairs of bolts 39 which are spaced longitudinally of the plate 38 and which are secured opposite flanges (see FIG. 3) of the associated lbeam. Nuts 41 on the bolts 39 are provided for retaining the plate in the desired adjusted position. For the apparatus to operate satisfactorily, it is desirable to have the plates 38 be as exactly level as possible and also that they are exactly straight in a sidewise direction for the entire length of the main frame. Thus, it is desirable that the tolerance in a vertical direction and also in a sideways direction be within 0.0020 of an inch.

An upper gauging head assembly 46 is carried by the upper track means 36 and a lower gauging head assembly 47 is carried by the lower track means 37. The

head assemblies

46 and 47 are very similar and include a head housing or casting 48 formed of suitable material, such as aluminum, and which is provided with a pair of spaced generally parallel ears 49. A head pivot plate 51 is secured to each of the ears 49 by bolts 52 which extend through

arcuate slots

53 and 54 provided in the head pivot plates 51. A pair of spaced generally parallel platelike lever arms 55 are pivotally secured to the head pivot plate 51 by bolts v56 and to a lever support plate 57 by bolts 58. The lever support plate 57 is secured to head support castings 59 by screws 60 for the lower gauging head assembly 47. The head castings 59 are mounted upon a pad support casting 61 by screws 62. For the upper gauging head assembly, the platelike lever arms 55 are directly secured to the pad support casting 611 by, screws 62. Removable pins 63 are provided which extend through the platelike lever arms 55 and into one of the holes 70 in the head support member 57 and are utilized for retaining the gauging head assemblies in a predetermined angular position with respect to the sheet of paper as shown by the broken lines in FIG. 3. The pins 63 can be shifted between the upper and lower holes 70 in the support member 57 to position the lever arms 55 between the solid line position shown in FIG. 3 and the broken line position also shown in FIG. 3 to adjust the position of the gauging

head assemblies

46 and 47 as hereinafter described.

As can be seen particularly from FIG. 7, the pad support casting 61 is provided with four padlike portions 61a provided on the four comers of the casting. A U-shaped member 64 is secured to each of the padlike portions 51a by bolts 65. A pair of side support wheels or rollers 66 are rotatably mounted upon Teflon bearings (not shown) between each of the U- shaped members 64 and the pad portion 61a associated therewith and are adapted to engage the sides of the plate 38 which forms a part of the upper track means 36. Each of the U-shaped members 64 also carries a pair of spaced top support wheels or rollers 67 rotatably mounted thereon by suitable means such as ball bearings. It has been found desirable to provide rubber-tired wheels for the side support wheels 66 and the top support wheels 67 because it may be necessary to mount the sheet-gauging apparatus in corrosive atmospheres. When such is the case, it also is desirable to coat the upper and lower track means with a suitable protective covering such as an epoxy resin. The rubbertired wheels or rollers prevent the wheels or rollers from chipping the epoxy resin off of the track means.

The lower head assembly 47 is mounted in a somewhat similar manner upon a pad support casting 61 on the lower track means with the use of the head support castings 59. The pad portions 61a carry side support wheels 66 and top support wheels 67 in the same manner as for the upper head assembly so that the lower head assembly also is secured by and is guided by lower track means 37. The pad support castings 61 with their side support rollers 66 and top support rollers 67 serve as carriage means for the associated head assembly for travel on the associated track means.

The castings 48 are provided with passages 68 through which a cooling fluid such as water can be introduced for cooling the casting. A sheet guide plate 69 formed of suitable material such as aluminum is secured to each of the head castings 48 by suitable means such as countersunk screws 70. As can be seen and particularly from FIG. 6, the sheet guide plate 69 is provided with upturned outer side margins 69a.

The head castings 48 have certain devices mounted thereon as hereinafter described. In addition, each of the head assemblies has a water-in connector 71, a water-out connector 72, a compressed air connector 73 and a pair of

electrical connectors

74 and 76.

A cover 81 formed of a suitable material such as fiberglass is provided for each of the

head assemblies

46 and 47 and is provided with a rubber molding 82 on its outer edge which is adapted to engage the casting 48. The cover is held in place by a suitable means such as clamps 83.

Means is provided for advancing the upper gauging head assembly 46 and the lower gauging head assembly 47 in a precision manner with respect to each other and to the frame 11. This means consists of a bracket 86 which is secured to the pad support casting 61 by suitable means such as screws 87. A nonslip timing belt 88 having teeth 880 has its ends secured to a pair of spaced shafts 89 secured to the upper ends of the brackets 86 by capscrews 91. The shafts 89 are provided with flats 92 and have the ends of the timing belt clamped thereto by a clamping plate 93 and capscrews 94. The shafts 89 have hexagonal portions 89a to facilitate rotation of the shaft to tighten the timing belt 88.

The two timing belts 88 are driven by a main toothed drive sprocket 96 (see FIG. 1A) and are rotatably mounted upon a shaft 97 carried by the end support 12. As can be seen from FIG. 2, the main drive sprocket 96 is wide enough to accommodate three timing belts. Thus, it drives the two timing belts 88 and is driven by separate timing belt 99 that is driven by a drive sprocket 101 mounted upon the output shaft 102 of a suitable stepper motor 103 such as a Slosyn motor manufactured by the Superior Electric Company of Bristol, Conn. The motor 103 is mounted upon a bracket 104 by bolts 106 and the bracket 104 is secured to the end support 12 by the bolts 107.

Both of the belts 88 travel over a pair of

idler rollers

108 and 109. The

idler rollers

108 and 109 are rotatably mounted upon the shafts 11] mounted in shaft supports 112 secured to the end support 12 by capscrews 113. The

idler rollers

108 and 109 are positioned so as to guide the upper and lower runs of each of the timing belts 88 through openings 1 16 provided in the end support 12. The openings 116 are substantially larger than that required for the timing belt for the admission of air as hereinafter described. The timing belts 88 travel longitudinally of the I-beams l4 and 16 as shown in FIGS. 1A and 13. over small idler rollers mounted on the I-beams l4 and 16, and over large idler rollers 117 mounted upon shafts 1 18 carried by the I-beams adjacent end support 13.

Means is provided for supporting the conduits and/or cables 121 which are utilized for supplying the water, air and electrical energy in signals to the

connectors

71, 72, 73, 74 and 76 for each of the upper and

lower head assemblies

46 and 47 and consists of a bracket 122 which is mounted upon the pad portions 61a by capscrews 123. The

brackets

122 and 86 are mounted on opposite sides of the casting. The conduits are secured to the brackets 122 by clamps 124 and fastened thereto by capscrews 126. The conduits 12] extend upwardly through the bracket 122 and then extend into a carrier 127 of a conventional type such as that disclosed in U.S. Pat. Nos. 2,864,907 and 2,975,807. As is well known to those skilled in the art, the carrier 127 is capable of supporting the conduits while accommodating the travel of the

head assemblies

46 and 47. Thus, the conduits extend through the upper run of the carrier 127 and down through the lower run to the end support 12 where they are connected to the appropriate exterior sources (not shown).

As shown particularly in FIG. 3, the timing belts 88 are mounted on one side of the l-beams, whereas the carrier 127 is mounted on the other side of the I-beam. As also shown in FIG. 3, a support channel 128 is provided for the lower run of the carrier 127 as it is laid down. The support channel 128 is carried by the lower portion of the associated I-beam as shown in FIG. 3.

Means is provided for supplying energy to the stepper motor 103 and controlling its operation. Generally, the control is such that when the sheet-gauging apparatus is placed in operation, the stepper motor 103 rotates in small, precise, discrete steps to advance the timing belts. It accelerates gradually to drive the

head assemblies

46 and 47 across the main frame 11 and then the stepper motor 103 decelerates but continues to move in the same direction until a vane 131 carried by the bracket 86 enters a vane oscillator switch 132 of conventional type mounted upon the l-beam 14 by bracket 133. At the same time this is occurring, a vane 136 carried by the bracket 86 on the lower head assembly 47 enters a vane oscillator switch 137 carried by a bracket 138. As soon as the vanes BI and 136 enter the vane oscillator switches 132 and 137 which are adjacent the end support 13, the control circuitry associated therewith reverses the movement of the

head assemblies

46 and 47 by bringing the same to a stop and gradually accelerating them to move in an opposite direction across the main frame II. This movement continues until the

vanes

131 and 136 enter similar vane oscillator switches 132 and 137 provided adjacent to the end support 12. This, again,.causes a reversal of the stepper motor 103 and reversal movement of the

head assemblies

46 and 47 to cause them again to travel down the main frame in a direction towards the end support 13. This repeated traversing of the main frame 11 continues during operation of the sheet-gauging apparatus.

Auxiliary safety stop means is provided to prevent further movement of the

head assemblies

46 and 47 in the event that the vane oscillator switches 132 and 137 fail to operate. This stop means consists of limit switches 141 mounted upon the end supports 12 and 13 which are adapted to be engaged by the

head assemblies

46 and 47 in the event their travel is not arrested by the vane oscillator switches 132 and 137 so as to prevent damage to the entire apparatus and particularly to the head assemblies 416 and 47. Such limit switches consist of a plunger 141.7. which is mounted on a fitting 143 secured to the associated

end support

12 or 13 by a nut 16 1. A rubber bumper 1416 is mounted over the plunger 1 1.2. The plunger is adapted to engage a microswitch 1 17 carried by bracket 1413. The bracket 166 and the switch 167 are protected by a dust cover M9.

Elongate covers 156 and 157, which are substantially U shaped in cross section as shown in P10. 3, are mounted over the upper and lower I-beams M and 16 and extend the entire length of the ll-bearns between the end supports 12 and 13. The

covers

136 and 157 also cover the upper track means 36 and the lower track means 37. As can be seen from FIG. 3, the lower extremities of the

covers

156 and 157 are laterally spaced from the outer margins of the plates 36 which form a part of the upper track means 36 and the lower track means 37.

A large end cover 161 is mounted on the end support 12 and is provided with an upper section 161a and a lower section 1611b. The lower section 16112 is secured to the end sup port 13 by brackets 16?; and the upper section 161a is removably secured to the end support 12 by clamps 163. The upper section 161a of the end cover 161 is provided with a large framed opening 166 which has mounted therein a large filter 163. A pair of spaced fans 171 are mounted within the upper section 161a immediately behind the filter 163 and draw air through the filter 163, forcing it through the openings 116 in the end support into the

covers

156 and 157. The air in troduced into the

covers

156 and 157 travels longitudinally of the [-

beams

16 and 16 and gradually discharges downwardly through the spaces provided between the lower ends of the

covers

156 and 157 and the plates 36 forming parts of the upper track means 36 and lower track means 37.

A cover 176 also formed of a suitable material such as im pregnated fiberglass is mounted upon the end support 13 so that the appearance of the end support 13 is similar to the end support 12.

As hereinbefore indicated, certain devices are mounted in the upper head assembly 16 and the lower head assembly 47 which are useful for sheet gauging. Thus, for example, the lower head assembly 66 can contain a radiation source 181 of the type described in copending application Ser. No. 792,088, filed Jan. 17, 1969 in the event that basis weight measurements are to be made. A power supply 162 of a conventional type is mounted within the head assembly. If moisture measurements are to be made, an infrared source 163 of a type described in copending application Ser. No. 799,784, filed Feb. 17, 1969 can be utilized.

When the above-identified measurements are to be made, a basis weight gauge detector assembly 136 of the type described in copending application Ser, No. 791,915, filed Jan. 17, 1969 is provided in the upper head assembly 16. A power supply of a conventional type 1117 is also provided in the upper head assembly. A moisture detector 166 of a conventional type can also be provided in the upper head assembly. The radiation source 161 and the basis weight gauge detector assembly 166 are arranged so they are opposite each other and so that the radiation from the radiation source travels through the sheet of paper indicated at 191 to the basis weight gauge detector assembly. Similarly, the radiation from the infrared source 163 is positioned so the radiation therefrom travels through the sheet 191 to the moisture detector 133.

in operation of the sheet-gauging apparatus, the sheet travels through the large Otype frame 11 between the upper head assembly 16 and the lower head assembly 17. The sheet being gauged is normally advanced continuously, and during this time the

head assemblies

66 and 17 travel transversely of the sheet. As explained previously, the head assemblies 46 and d7 reciprocate longitudinally of the frame 11 and, therefore, travel back and forth in a lateral direction across the sheet 191 which is travelling through the main frame. During this travel of the

head assemblies

46 and 67, the desired measurements are being made by the devices within the head assemblies 416 and 67.

As explained previously, the main frame 11 and the upper and lower track means 36 and 37 are constructed in a very precise manner so that the

head assemblies

46 and 67 travel in a fixed relationship with respect to each other as they move longitudinally of the main frame. As it can be seen, considerable efiort has been made to maintain the upper track means 36 and lower track means 37 and the l-

beams

14 and 16 which carry the same relatively stable in temperature so that there is no change in the relative positioning of the head assembly because of temperature changes. Thus, although the sheet 191 travelling through the apparatus and being gauged may be very hot, precise measurements are still made. The sheet guide plates 66 serve as radiant heat shields and the heat support castings 63 are water cooled so that the electronic devices mounted within the

head assemblies

46 and 67 remain relatively cool.

At the same time that water cooling is being utilized for the head assemblies 46 and 417, the upper and lower track means 36 and 37 are being continuously cooled by the stream of air passing longitudinally of the l-beams from the fans 171 provided in the end support 12. This serves to stabilize the temperature of the ]-beams and the upper track means 36 and the lower track means 37 along their entire length. This serves to retain the desired spacing between the

head assemblies

16 and 17 as they traverse the main frame. The

covers

156 and 157 covering the ]-beams, in addition to providing channels for the passage of air for cooling of the l-beams, also serve to protect the upper and lower track means 36 and 37 by keeping dust, dirt and the like off of the tracks. In addition, the slight overpressure created in the

covers

156 and 157 by introducing air into the

covers

156 and 157 prevents corrosive vapors and the like from coming into contact with the upper and lower track means.

The covers 81 provided as a part of the

head assemblies

46 and 47 have relatively smooth surfaces so that in the event the sheet travelling through the apparatus should strike the same, the sheet will not be torn. The covers 81 also serve as a shield against heat radiating from the sheet being gauged to protect the electronic devices within the head assemblies. in addition, the covers prevent the entrance of dust, dirt and the like into the head assemblies.

The upper and lower gauging

head assemblies

46 and 47 are mounted upon the carriage means in such a manner so that any radiation introduced through the sheet by the devices carried by the

head assemblies

46 and 17 passes through the sheet substantially perpendicular regardless of the inclination of the sheet relative to the main frame. It can be appreciated that this is important so that the measurements are made in the same position with respect to the sheet being gauged. As can be seen from H6. 3, the

head assemblies

16 and 47 can be adjusted through substantial angles. First, the positions of the lever arms 55 can be adjusted between two positions by shifting the pins 63 from the position shown in FIG. 3 to the upper holes provided in the support member 57. Additional, more precise adjustment can be accomplished by shifting of the pivot plates 51 and then tightening the bolts 52. in this way, it is possible to accommodate the various paths of travel for the sheet through the main frame while still maintaining the

head assemblies

46 and 47 and the radiation passing therebetween substantially perpendicular to the sheet passing through the main frame.

It is apparent from the foregoing that there has been provided a new and improved apparatus for the gauging ofsheets. The apparatus is particularly of a precision type which can be utilized for making a plurality of precision measurements at many different positions on sheets of material which are moving continuously.

I claim:

1. in a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced, upper and lower beams extending laterally of the sheet, spaced upper and lower track means carried by the upper and lower beams, upper and lower gauging head assemblies disposed on opposite sides of the sheet, upper and lower carriage means mounting said upper and lower gauging head assemblies on said upper and lower track means, motor drive means and nonslip timing belt means connected to said motor drive means and to said carriage means for shifting said gauging head assemblies longitudinally of the beams and laterally of the sheet, said nonslip timing belt means including a flexible belt having toothlike portions formed therein extending transversely of the belt and pulleys engaged by the belt and having recesses therein extending axially of the pulleys for receiving the toothlike portions and gauging means carried by said upper and lower gauging head assemblies for gauging a property of said sheet as the heads are shifted longitudinally of the beams.

2. Apparatus as in claim 1 together with means for mounting said frame on a foundation and means carried by at least one end of said frame permitting shifting of one end of the frame with respect to the foundation to accommodate expansion and contraction of the frame.

3. Apparatus as in claim 1 wherein said upper and lower track means each includes a plate extending the length of the frame and having at least one flat surface extending the length of the frame and wherein said carriage means includes roller means travelling on said surface.

4. In a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced, upper and lower beams extending laterally of the sheet, spaced upper and lower track means carried by the upper and lower beams, cover means for protecting said upper and lower track means, means for introducing cooling air into the cover means to maintain said upper and lower track means at a substantially uniform temperature, upper and lower gauging head assemblies disposed on opposite sides of the sheet, upper and lower carriage means mounting said upper and lower gauging head assemblies on said upper and lower track means, motor drive means connected to said carriage means for shifting said gauging head assemblies longitudinally of the beams and laterally of the sheet, and gauging means carried by said upper and lower head assemblies for gauging a property of said sheet as the heads are shifted longitudinally of the beam.

5, Apparatus as in claim 4 wherein said covers are mounted on said upper and lower beams and cover the upper and lower track means, said cover means having lower extremities spaced from the track means, and means for introducing cooling air into the cover and for causing it to discharge downwardly through the space between the track means and the lower extremities of the cover along the entire length of the track means to thereby maintain said track means at a substantially uniform temperature throughout their lengths.

6. Apparatus as in claim 5 wherein said means for preventing movement of said gauging head assemblies beyond predetermined spaced points on said beams includes a conducting vane and a vane-type oscillator adapted to receive said vane.

7. In a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced, upper and lower beams extending laterally of the sheet, spaced upper and lower elongated platelike track means carried by the upper and lower beams, adjustable means for mounting said upper and lower elongated platelike track means upon said upper and lower beams whereby each of said track means can be adjusted laterally and longitudinally so that they are level throughout their entire length, upper and lower gauging head assemblies disposed on opposite sides of the sheet, upper and lower carriage means mounting said upper and lower gauging head assemblies on said upper and lower track means, motor drive means connected to said carriage means for shifting said gauging head assemblies longitudinally of the beams and laterally of the sheet, and gauging means carried by said upper and lower gauging head assemblies for gauging a property of said sheet as the heads are shifted longitudinally of the beams.

8. In a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced, upper and lower beams extending laterally of the sheet, spaced upper and lower track means carried by the upper and lower beams, upper and lower gauging head assemblies disposed on opposite sides of the sheet, upper and lower carriage means mounting said upper and lower gauging head assemblies on said upper and lower track means, motor drive means connected to said carriage means for shifting said gauging head assemblies longitudinally of the beams and laterally of the sheet, gauging means carried by said upper and lower gauging head assemblies for gauging a property of said sheet as the heads are shifted longitudinally of the beams, said upper and lower gauging head assemblies including a housing, said housing having a passage therein for the travel of a cooling fluid therethrough, and a sheet guide mounted on said housing, said sheet guide having inclined outer side margins which are inclined away from the sheet travelling between the gauging head assemblies.

9. In a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced, upper and lower beams extending laterally of the sheet, spaced upper and lower track means carried by the upper and lower beams, upper and lower gauging head assemblies disposed on opposite sides of the sheet, upper and lower carriage means mounting said upper and lower gauging head assemblies on said upper and lower track means, motor drive means and nonslip timing belt means connected to said drive means and to said carriage means for shifting said gauging head assemblies longitudinally of the beams and laterally of the sheet, and gauging means carried by said upper and lower gauging head assemblies for gauging a property of said sheet as the heads are shifted longitudinally of the beams, said gauging means carried by said upper and lower gauging head assemblies including means for introducing radiation through said sheet and means for adjusting the positions of the upper and lower gauging head assemblies so that the radiation passing through the sheet is maintained perpendicular to the sheet regardless of the inclination of the sheet relative to the upper and lower track means of the frame.

10. In a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced, upper and lower beams extending laterally of the sheet, spaced upper and lower track means carried by the upper and lower beams, upper and lower gauging head assemblies disposed on opposite sides of the sheet, upper and lower carriage means mounting said upper and lower gauging head assemblies on said upper and lower track means, motor drive means connected to said carriage means for shifting said gauging head assemblies longitudinally of the beams and laterally of the sheet, gauging means carried by said upper and lower gauging head assemblies for gauging a property of said sheet as the heads are shifted longitudinally of the beams, said gauging means including means for introducing radiation through said sheet and means for adjusting the positions of the upper and lower gauging head assemblies so that the radiation passing through the sheet is maintained perpendicular to the sheet regardless of the inclination of the sheet relative to the upper and lower track means of the frame, said means for adjusting the positions of the upper and lower gauging head assemblies including a housing, a pair of pivot plates, cooperative means carried by the pivot plates and the housing for mounting said pivot plates on said housing and permitting movement of said pivot plates through a predetermined angle, a pair of lever arms pivotally secured to each of said pivot plates, means pivotally connecting said lever arms to said carriage means, and means for adjusting the position of said lever arms on said carriage means whereby the position of said gauging head assemblies can be adjusted.

11. in a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced upper and lower beams extending laterally of the sheet, spaced upper and lower track means carried by the upper and lower beams, upper and lower carriage means mounted on said upper and lower track means, upper and lower gauging head assemblies disposed on opposite sides of the sheet, and means for mounting said upper and lower gauging head assemblies on said upper and lower carriage means, said gaug'ng head assemblies including means for introducing radiation through the sheet of material, said adjustable means for mounting each of said upper and lower gauging head assemblies on said upper and lower carriage means including a pair of pivot plates, cooperative means carried by the pivot plates and by the gauging head assembly for mounting said pivot plates on the gauging head assembly and permitting limited pivotal movement of the pivot plate with respect to the gauging head assembly, a pair of pivot arms pivotally connected to said pivot plate, and means pivotally connecting said pivot arms to said carriage means and means for adjusting the angular position of said pivot arms on said carriage means whereby said gauging head assemblies can be adjusted so that the radiation extending through the sheet of material is substantially perpendicular to the sheet regardless of the inclination of the sheet.

B2. In a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced upper and lower beams extending laterally of the sheet, spaced upper and lower track means carried by the upper and lower beams, upper and lower gauging head assemblies disposed on opposite sides of the sheet, upper and lower carriage means mounting said upper and lower gauging head assemblies on said upper and lower track means. and drive means for moving said carriage means and said gauging head assemblies longitudinally of the beams and laterally of the sheet, covers mounted on said beams and covering said upper and lower track means, and means for introducing air into the cover means and to cause the same to pass over the entire length of the upper and lower track means whereby the upper and lower track means are maintained at a substantially uniform temperature throughout their lengths.

113. Apparatus as in claim 12 wherein said covers have lower extremities and wherein the lower extremities of the covers are spaced from the track means whereby air introduced into the covers can discharge downwardly between the track means and the lower extremities of the covers.

Claims

5. Apparatus as in claim 4 wheRein said covers are mounted on said upper and lower beams and cover the upper and lower track means, said cover means having lower extremities spaced from the track means, and means for introducing cooling air into the cover and for causing it to discharge downwardly through the space between the track means and the lower extremities of the cover along the entire length of the track means to thereby maintain said track means at a substantially uniform temperature throughout their lengths.

11. In a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced upper and lower beams extending laterally of the sheet, spaced upper and lower track means carried by the upper and lower beams, upper and lower carriage means mounted on said upper and lower track means, upper and lower gauging head assemblies disposed on opposite sides of the sheet, and means for mounting said upper and lower gauging head assemblies on said upper and lower carriage means, said gauging head assemblies including means for introducing radiation through the sheet of material, said adjustable means for mounting each of said upper and lower gauging head assemblies on said upper and lower carriage means including a pair of pivot plates, cooperative means carried by the pivot plates and by the gauging head assembly for mounting said pivot plates on the gauging head assembly and permitting limited pivotal movement of the pivot plate with respect to the gauging head assembly, a pair of pivot arms pivotally connected to said pivot plate, and means pivotally connecting said pivot arms to said carriage means and means for adjusting the angular position of said pivot arms on said carriage means whereby said gauging head assemblies can be adjusted so that the radiation extending through the sheet of material is substantially perpendicular to the sheet regardless of the inclination of the sheet.

12. In a sheet-gauging apparatus for gauging properties of a sheet of material, a frame having parallel-spaced upper and lower beams extending laterally of the sheet, spaced upper and lower track means carried by the upper and lower beams, upper and lower gauging head assemblies disposed on opposite sides of the sheet, upper and lower carriage means mounting said upper and lower gauging head assemblies on said upper and lower track means, and drive means for moving said carriage means and said gauging head assemblies longitudinally of the beams and laterally of the sheet, covers mounted on said beams and covering said upper and lower track means, and means for introducing air into the cover means and to cause the same to pass over the entire length of the upper and lower track means whereby the upper and lower track means are maintained at a substantially unifOrm temperature throughout their lengths.

13. Apparatus as in claim 12 wherein said covers have lower extremities and wherein the lower extremities of the covers are spaced from the track means whereby air introduced into the covers can discharge downwardly between the track means and the lower extremities of the covers.