摘要:
An alarm system sensor (10) monitoring movement of an object (D) and placing the system into alarm when the object moves more than a predetermined distance from a predetermined position. First and second reed switches (16, 18) are located in a predetermined orientation relative to each other and in tandem to the object. Bias magnets (24, 26) are used with the reed switches. A magnet (20) is movable with the object and produces a force simultaneously sensed by both reed switches. This force maintains both reed switches in a state keeping the alarm system in a non-alarm condition so long as the object substantially remains in its predetermined position. The object, when it moves, moves toward one of the reed switches and away from the other reed switch. Movement of the object more than the predetermined distance results in the force sensed by one of the reed switches increasing and the force sensed by the other reed switch decreasing. Either change in sensed force activates the appropriate reed switch causing the alarm system to go into alarm.
摘要:
A method is disclosed for preventing segregation of particles within a finely divided powder having disparate particle size ranges, compositions or densities. The method includes working the powder with a minute amount, preferably less than about 1% by weight of the powder, of a finely divided fibrillatable polytetrafluoroethylene resin (hereinafter referred to as PTFE) to form a mixture with the powder. The PTFE resin may be added to the powder as a colloidal aqueous dispersion or as a fine powder obtained by coagulation of the colloidal dispersion. Whichever form is used, the PTFE is intimately mixed with the finely divided powder to form a dry mixture. Alternatively, the PTFE resin may be blended with the powder in a wet treatment to facilitate the homogenous dispersion of the resin. In any event, the mixture of resin and powder is worked either in the wet state, preferably as a paste, or as a dry blend, using a masticating or kneading action to fibrillate the PTFE. Sufficient working is carried out to produce a random network of PTFE fibers sufficient to loosely entrap the powdery material and to prevent segregation thereof.
摘要:
An orthodontic bite jumping device includes a metal cylinder for receiving a telescoping plunger, for attachment to and between the orthodontic braces fixed to a patient's upper and lower teeth to achieve desired movement in otherwise conventional fashion. This appliance is at each end provided with connectors which slidingly interact with the orthodontic braces. A spring is attached between the cylinder and the plunger in a manner which causes the application of relatively consistent pushing forces to the teeth, to achieve desired tooth and jaw movements while buffering the relatively heavy forces that are produced so as not to cause damage to the orthodontic braces or to the appliances which interconnect them. Such forces are applied to and between the orthodontic braces in a substantially horizontal direction, avoiding the application of major forces in a vertical direction as was characteristic of prior bite jumping devices. The bite jumping device is further provided with a stop mechanism for preventing separation of the telescoping elements when the patient's mouth is fully opened, while otherwise ensuring free movement of the patient's jaws.
摘要:
Methods for producing furfural-4-boronic acid by the reaction of furfural acetals (I), which are substituted by halogen in position 4, with boronic acid esters or anhydrides, by the subsequent metalation of compound (I) and the simultaneous or subsequent reaction with a boronic acid ester or anhydride to form an acetal-protected furfural-4-boronic acid ester. This product is subjected to acid hydrolysis to form furfural-4-boronic acid. In the formulae: X represents chlorine, bromine or iodine; R represents a branched, unbranched and/or cyclic, optionally substituted C1-C20 alkyl group, an optionally substituted C6-C12 aryl group or an optionally substituted C3-C8 cycloalkyl group, the two groups R together can form a ring; R′, R″, R′″ independently of one another represent acylic or cyclic, branched or unbranched, optionally substituted C1-C20 alkyl groups, or optionally substituted aryl groups, optionally two of the groups R′, R″ and R′″ together form a ring, or represent additional groups B(OR)3.
摘要:
An orthodontic interarch device includes a recurve bend located adjacent a shepherd's hook or loop-type attachment that makes the anterior end of the device rotate downwardly rather than upwardly when force is applied. As the person's jaws move, a cam action against the archwire is produced that does not allow the hook or loop attachment end of the device to move above the horizontal plane of the bite as the connection rotates. The recurve bend should be a minimum of 120 degrees from the longitudinal axis of the interarch device in the backward direction. As the degree of this backward curvature approaches 210 degrees, the recurve bend further positions a hook attachment pivot point below axis of the body of the interarch device in the vertical plane. This further prevents the appliance from rotating into the bite.
摘要:
An orthodontic appliance having improved devices for interconnecting the braces associated with a patient's upper and lower teeth. Each connecting device generally takes the form of a unitary, thin band of material that can be connected between the braces associated with the patient's upper and lower teeth to achieve the forces that are desired for a particular treatment. The connecting device has a body that is substantially flat and rectangular, with bent end portions that are preferably rounded for purposes of comfort. Each end portion includes an aperture for attachment to the braces associated with the patient's teeth. Preferably, at least one of the apertures of each connecting device is keyed so that upon its attachment to the braces, swivelling of the connecting device is effectively precluded without compromising desired movements of the connecting device relative to the orthodontic appliance and the patient's mouth. As a result, interaction between the connecting devices and the patient's jaws, lips and cheeks is minimized, and breakage is effectively precluded. The connecting device is capable of being formed of a material that can produce forces, upon use of the connecting device, that are sufficiently small to produce desired movements of the teeth without producing undesired movements of the patient's jaws.
摘要:
A length of tubular material of unitary construction is formed into the approximate shape of a human dental arch for use as an orthodontic arch wire. The tubular material is composed of a super-elastic nickel titanium alloy which may also have shape memory. The cross-sectional shape of the arch wire tube can be round, oval, square, or rectangular. The preferred thickness of the tube is preferably 20 percent of its outside diameter and the tube may be perforated to alter its performance.
摘要:
A confocal microscope including a first light source for emitting an incoming light beam with which a sample to be observed is irradiated; a scan engine dimensioned and configured to scan the incoming light beam prior to its irradiating the sample, thereby generating a scanned incoming light beam; a second light source for emitting an excitation light beam with which the sample is radiated; and a polarizing beam-combining cube and/or dichroic mirror for combining the scanned incoming light beam and the excitation light beam is disclosed.
摘要:
An orthodontic appliance for moving the upper teeth relative to lower teeth in either a backward or a forward direction contains a resilient body coupled to at least one rotating end portion that allows the device to spin freely. Since the ends of the device spin freely, the stress of twisting on the flexible portion will be eliminated thus reducing breakage. Furthermore, the need for a different right and left device is eliminated. In addition, the end portion may also be telescoping in order to make the device expandable, thus allowing the patient to open his/her mouth more fully which results in the additional benefit of less appliance breakage. Also, because the device is expandable, the flexible portion can be made one size that will result in a more consistent force output and reduce the number of parts needed to manufacture the appliance.