Abstract: An apparently conventional playing card is invisibly coded so that it can only be read face down, by an electrooptic reading means. The card may be of non-laminated conventional card stock which has a substantially white surface conventionally printed with the identification of the suit and value of the card with inks chosen because they are visible but substantially transparent to wavelengths outside the visible range. The face of the card is coded with indicia inklessly marked across its surface with a compound which absorbs wavelengths (outside the visible range) which wavelengths are used by the reading means to read the indicia. The indicia, invisible to the human eye, correspond to a code which uniquely identifies the card. The card may be laminated from top and base sheets and the code concealed behind the front printed face of the top sheet. The upper surface of the top sheet is imprinted with the face value of the card with the inks described.

Abstract: An apparently conventional playing card is invisibly coded so that it can only be read face down, by an electro-optic reading means. The card may be of non-laminated conventional card stock which has a substantially white surface conventionally printed with the identification of the suit and value of the card with inks chosen because they are visible but substantially transparent to wavelengths outside the visible range. The face of the card is coded with indicia inklessly marked across its surface with a compound which absorbs wavelengths (outside the visible range) which wavelengths are used by the reading means to read the indicia. The indicia, invisible to the human eye, correspond to a code which uniquely identifies the card. The card may be laminated from top and base sheets and the code concealed behind the front printed face of the top sheet. The upper surface of the top sheet is imprinted with the face value of the card with the inks described.

Abstract: A reflector provided on a land is automatically collimated in such a way that it always comes to the center of the field of view of an automatic tracking type measuring apparatus provided on a platform. When the platform moves vertically or horizontally in this state, the reflector moves within the field of view. Then, a drive signal is supplied to a servo system to cause the reflector to come to the center of the field of view. Based on data measured by the apparatus, the platform is positioned.

Abstract: A deck of cards is coded by marking each card on its face with a bar code which is essentially invisible to the human eye, but can be read by a detector matched to the source of wavelength of the light used to irradiate each card as it is passed over the surface of a portable housing which houses the detector and the associated reading means. Appropriate hardware is also housed in the housing to process the coded information read. The software provided stores a number of predetermined "hands" which are to be dealt. It can also deal a random deal, more random than can be dealt by human shuffling of the deck. A method is provided to deal a preselected "deal" to a chosen number of players, typically four, the apparatus indicating to the human dealer to which location each card is to be dealt.

Abstract: A ribbon re-inking device includes an ink reservoir having at least one outlet for dispensing ink therefrom and a drive operable to displace a ribbon past the outlet of the reservoir, thereby to permit the ink to be dispensed from the reservoir and applied to the ribbon. The reservoir is displaceable between an inoperative position wherein release of ink via the reservoir outlet is prevented, and at least one static operative dispensing position. The drive is controllably energizable to cause displacement of the ribbon past the reservoir outlet upon displacement of the reservoir to its operative dispensing position.

Abstract: A new robotic system is provided in which the robotic tool is mounted for movement on a gantry above the work piece upon which the work is to be performed. The tool is supported on two carriages each of which is movable with respect to each other and with respect to the gantry so that the tool has the capacity to move through five degrees of freedom and permit a more accurate response to a sensing system which determines the position of the work piece relative to a master and then moves the tool to a working position in substantial operational compliance with the master position.

Abstract: A symmetry sensing safety circuit for automatically stopping electrical current flow through a thyristor to an electrical device which is supplied by a source of alternating current electrical energy.

Abstract: A fluid detector device and method capable of detecting the presence of a first fluid such as a gas, which may be mixed with a second fluid, in an external atmosphere where the first fluid is a hydrocarbon gas such as methane or the like, mixed with air, a semi permeable membrane, which extends across an opening of a detection chamber is utilized. Air and the gas have different rates of permeability across the membrane causing a volume change in the chamber. A volume sensitive device signals the presence of the gas. A displaceable element is shiftable in response to the volumetric change in the chamber, allowing the change without significant pressure changes. A capacitive plate can be integral with a displaceable element so that capacitance varies with the change in volume caused by the presence of the gas.

Abstract: A case (1) comprises a pile of bank notes (2). An air supply circuit (13, 14, 15) forms a jet of air (16) in the vicinity of an edge of the first note (2a).In order to separate the note (2a) from its pile (2) in a simple manner, a succession of states of pressure and of reduced pressure is created downstream of the edge (d) of the opening (17). The interruption in profile creates a reduced pressure over the face of the note (2a) in the vicinity of this opening (17). The edge of the note is then raised and enters the jet of air (16). A change of state occurs and a pressure applies the note (2a) against the moving rollers (5) while holding the following note applied against the pile (2).

Abstract: A coin dispenser having a plurality of columns holding coins of different denominations in linear alignment one with the others, a plurality of extraction fingers each moving successively beneath the stacks and a cam arranged for movement in alignment with and beneath the fingers with movement of the cam being effected by engagement with one of the fingers when coins are not to be extracted and is displaced relative to the fingers beneath a selected column when a coin to be extracted therefrom to permit a cam follower carried by a finger to engage and be displaced by the cam and thereby dislodge a coin carried by the selected column.

Abstract: An apparatus and method for automatically de-energizing electrically operable equipment in response to a lack of animal activity in a specified environment for predetermined time period. The apparatus of the present invention utilizes a circuit which is designed to detect activity which generates energy in a certain wavelength range and particularly, sonic energy in a certain environment and is responsive to the lack of activity within a certain predetermined time delay period or interval. Thus, if an activity which generates sonic energy is detected within a confined environment within the predetermined time interval, a signal is generated to energize or maintain energization of one or more electrical devices connected to the system of the invention. Contrariwise, if no sonic energy is detected within the predetermined time interval, there is a resultant de-energization of the electrically operable equipment. A control is provided to adjust the predetermined time delay period.

Abstract: An improved desilter for drilling muds consists of one or more hydrocyclones with certain features providing for better separation of large particles from the mud. Drilling muds used in drilling oil wells and the like give substantially improved performance when the larger particles are removed therefrom and the mud consists of fine particles having a narrow range of particle size.An improved hydrocyclone for removing coarser particles from the drilling mud has overflow and underflow outlets which discharge openly rather than into a collection manifold. The overflow outlet is in the form of a controllable syphon which may be adjusted in syphon length or which may include means to adjust the effective length of the syphon leg. The adjustment of the syphon leg controls the overflow of the thin, more uniform mud and effects a superior separation of the larger particles from the mud.