The opinion of the court was delivered by: KNIGHT
This action is brought to restrain the defendant from further infringing the rights claimed to be secured to the plaintiff by letters patent No. 1,948,191 covering certain improvements relating to a price indicator, and to recover damages suffered by reason of the alleged infringement by the defendant. The defenses are noninfringement, invalidity of the patent over the prior art, and misconduct of the plaintiff in the course of the prosecution of the application to the final grant of the patent.
Claim 4 of the patent reads as follows: "In apparatus of the class described, the combination of a supporting frame having channels secured to an outer surface thereof, said channels being arranged to form a longitudinal slot open at one end, and an indicating strip folded to provide a plurality of flat display sections of substantially the same width and having characterbearing surfaces thereon, said channels being of such width and so positioned relative to the thickness of the folded indicating strip and to the width of the sections of the folded indicating strip respectively, as to firmly hold the indicating strip when closely folded and inserted in the said slot."
Although not mentioned in the claim, the supporting frame is described in the specification as comprising a long, narrow, and deep tray open at its upper end, providing storage space for display strips which are not in use. For one of the slots a total indicating strip is provided. This consists of an accordion fold strip having 10 faces, each face bearing a printed table listing the total prices, corresponding to a given unit price, for quantities of from 1 to 20 units. One strip is provided for each unit price and fractional values. For example, one strip contains tables showing multiple unit prices based on a unit price of 18 cents, 18 1/10 cents, and for each additional 1/10 cent up to 18 9/10 cents. To cover a normal price range additional strips are provided which may be stored as previously described.
Defendant's sign consists of a metal frame having channel members on each side thereof so positioned as to form a number of horizontal slots, into which may be inserted cards or folded paper strips. One vertical slot is provided. The center part of said frame is available for storage of cards, display strips, or books. This frame fits into a casing having glass panes positioned to allow the words or figures on the cards or strips inserted in the slots to be visible. The display strips used by defendant may be folded into sections of substantially equal size, each section bearing a numeral on each side. The display book is made up of a plurality of pieces sewed together to form a book type display. This also may be folded so as to display the figure on any particular section of the book. The vertical slot holds a total indicator strip similar to that used by plaintiff; the extra strips being stored in the center of the frame.
Defendant asserts that its signs do not read within this claim, because horizontal slots are employed and not the vertical slots of the patent. A careful reading of the claim discloses that a longitudinal slot is specified. Longitudinal means extending in a lengthwise direction. Inasmuch as the channels of defendant's sign run the long way of the sign, I conclude that it reads within the claim in this respect. While the patent drawings indicate vertical slots and some of the claims also specify that they shall be vertical, it might be assumed that the word "longitudinal" used in this claim was intended to cover a different arrangement. This would necessarily be so were it not for the fact that the claim later specifies that the channels are of such width and so positioned relative to the width of the sections of the folded indicating strip as to firmly hold the indicating strip when closely folded and inserted in the said slot. This language indicates that the claim was drawn with vertical channels in mind, as otherwise the claim would have specified that channels should be of such width and so positioned relative to the height of the sections of the folded indicating strips as to firmly hold said strips when folded and inserted in said slot. The specification suggests that, if desired, the indicating strip may be folded on an horizontal rather than a vertical axis, but does not suggest that the channels might be changed from a vertical to a horizontal plane.
The question arises whether the mounting of the slots or channels on a horizontal instead of a vertical plane is not an equivalent. The substitution of an equivalent does not avoid a charge of infringement. Walker on Patents, par. 74, and cases there cited. If the sign as changed by defendant is an equivalent, the above-mentioned rule applies even though no mention was made in the patent of the possibility of using such an equivalent. Walker on Patents, par. 412, and cases there cited.
In New Departure Bell Co. v. Hardware Specialty Co. (C.C.) 69 F. 152, it was held not inventive to substitute a horizontally working thumb lever for a vertically operated push bar. The use of horizontal slots is an expedient well known to the sign industry, so that a variation of the sign consisting only of changing the slots from vertical to horizontal involves identity of function and substantial identity of means of performing that function. Such a change is an equivalent and will not avoid the charge of infringement.
Defendant claims as an added function for the sign with horizontal channels, that the base card which is used in plaintiff's structure need not be used, since the display strips may be snapped into place in the slot and need not be inserted by means of the open end of the slot. It is claimed that this is not possible with the vertical channels because, unless a base card is used to support the display strips, the upper strips will slide down over the lower ones under the vibration of the gasoline pump, and when a base card is used, insertion must be by means of the open end of the slot. This contention overlooks the fact that the patent specifies no specific depth for the channel slots nor any specific thickness for the display strips, and that these dimensions may be arranged to obviate the possibility of a slipping of the display strip even though not mounted on a base card, and that the display strips may be snapped into a vertical slot as well as into a horizontal slot. Defendant claims also that in its signs the channels are not of such width or so positioned relative to the thickness of the folded indicating strip and the width of the sections of the folded indicating strip, respectively, as to hold the indicating strip "firmly" when closely folded and inserted in the slot. Defendant further explains that it is not necessary to "closely" fold its indicating strip to insert it in the slot. The function of the close folding of the indicating strip is to enable it to be inserted into the slot formed by the channels. Beyond this there is no useful accomplishment. The function of the firm holding of the folded indicating strip is to maintain it in a position to display the proper figure and to maintain it in its proper position with respect to the other figures and words displayed. The degree of firmness or closeness required is that degree which will perform the function to which reference has been made above. Plaintiff's Exhibit 19, a model of the patented sign, and Plaintiff's Exhibit 28, the infringing sign, are found to contain channels of practically identical depth. Each will hold approximately the same quantity of display material as the other. Difference in the firmness of the holding of the display strip is apparent only when plaintiff's display strip is mounted on a base. Inasmuch as the claim does not specify that a base must be used with plaintiff's indicating strip, it is evident that defendant's structure does infringe this claim. Were the claim to be construed strictly according to the specifications, a base card would be required, in which case there would be no infringement by the defendant's structure.
By its answers to interrogatories propounded by the defendant, plaintiff has indicated that it makes no claim to infringement as to the casing or frame or display strips or books separately, but limits its claim to the use of the combination of casing, frame, and accordion folded or book type display material. The patent describes only the accordion or fan fold type of display strip, but it is claimed that the book type display is an equivalent, and therefore its use in combination with the other elements of the claim constitutes an infringement. It is true that both the fan fold and book display strip have a plurality of sections each bearing numbers, any one of which may be displayed by proper folding of the strip or book. Both are well known in the art as means of obtaining a compact grouping for a number of letters or figures. To substitute one of these forms for the other would not be regarded as invention, nor will such substitution avoid infringement. The function of the folded display strips and the books is to allow display of any figure desired. The means of performing this function is in the adaptability to folding so as to expose any section of the strip or book. Thus the function and the means are the same in both the fan fold strip and the book type display, and they must be regarded as equivalents. While the patent can by no means be considered a primary patent, because of the development of the art, it is entitled to a range of equivalents which will protect that addition, if any, to the art, which was contributed by its inventor. To regard the book type display as other than an equivalent and an infringement would deprive the inventor of such protection.
Claim 5 reads as follows: "In apparatus of the class described, the combination of a supporting frame having channels secured to an outer surface thereof, said channels being arranged to form a plurality of longitudinal slots open at one end, and a plurality of indicating strips each folded to provide a plurality of flat display sections having character-bearing surfaces thereon, the flat sections of each indicating strip being of substantially the same width, said channels being so positioned and of such width relative to the width of the sections of the folded indicating strips and the thickness of the folded indicating strips respectively, as to firmly hold one of the closely folded indicating strips when inserted in each of said slots."
This claim is in effect a repetition of claim 4, with the exception that it specifies a plurality of longitudinal slots and a plurality of indicating strips. Claim 4 having been found infringed, the same result must be reached in regard to claim 5.
Claim 12 reads as follows: "In apparatus of the class described, the combination of a casing provided with a transparent section in at least one side thereof, a supporting frame proportioned to snugly fit within said casing and removably disposed therein, a plurality of channels attached to an outer surface of said supporting frame and arranged to form a plurality of retaining slots open at one end and positioned to register with the transparent section of said casing, and a plurality of indicating strips each folded to provide a plurality of flat display sections ...