COMPENSATING Quadrant Crane THERE is a certain type of machine now in common use that has been handed down to us, with little change, from the very earliest days of history. The crane as employed by the Egyptians in building the Pyramids was not radically different from the derrick of the present day. It consisted then, as it does now, essentially of an upright mast with a boom or gaff. Practically the only advances made in this type of machinery have been in the manipulation of the crane or the motive power utilized. Recently, a patent has been granted on a crane which is a decided innovation. The crane has no mast, but consists merely of a beam mounted on a frame in such a way that it can swing forward like the boom of a derrick while the load it carries moves on a virtually horizontal line as the beam is raised to the vertical position. The beam is built up of rolled steel and is secured to a pair of quadrants of cast steel formed with teeth, to engage racks at the foot of the frame. The frame is mounted on a swivel base. The beam is raised or lowered by means of a horizontal screw which passes through a nut journaled to the quadrants. As the screw is operated, the quadrants roll on the toothed foot of the frame. Hence, the fulcrum, which is the point of contact of the quadrant with the frame, moves outward as the beam moves toward the horizontal and at the same time the length of the lever from load to fulcrum is reduced, owing to the bell-crank form of the beam and quadrants. The compensating mechanism consists of a pair of arms hinged to the beam near the upper end, and secured to one end of a cable, which passes over a sheave at the top of the beam, and then runs to a point on the frame where it is permanently secured. As the beam is moved backward or forward, the arms are correspondingly swung on their hinges, so that their outer ends traoe a practically horizontal line. At these outer ends the arms support the upper blocks of the hoisting tackle over which the hoisting cables run to a pair of winding drums. As a result of this “parallel motion” the load is not materially lifted as the crane is swung upward, and the bending moment on the beam is greatly reduced. The accompanying illustrations show a model of a full-sized 4-ton crane, which has a lifting capacity of 2 Y2 tons. In this crane the actual reduction in bending moment of the beam due to the compensating device is five-sixths; that is, a load of 120 foot-tons is reduced to 20 foot-tons, while the maximum thrust on the screw is less than 27: tons. The screw may thus be regarded as a simple controlling device rather than a means for shifting the load, the load being practically balanced. There is no bending moment on the screw, the thrust being exerted in line with its axis. In use the crane is provided with separate motors for actuating the screw and the winding drums, and the gear by which the crane isJlswiveled on its base. Thus the crane is self-con tained, making it a very serviceable piece of machinery for docks, ships, wrecking cars, etc. It is the present practice in the construction of buildings to operate the cranes from a plant on the ground floor. Greater facility of operation would be afforded by the use of self-contained cranes, particularly in tall buildings. Another Confederate Patent TN the Scientific American of November 4th appeared a reproduction and account of a Confederate Patent No. 13. We have just examined a reproduction of another Confederate patent, which except as to names, number, title, date and signatures is like that already published, so its reproduction would not be interesting. This other patent is No. 149, issued February 18th, 1863, to D. W. Hughes of Arizona, and disclosed an improvement in breech plugs. An illustration accompanied the patent, in style and execution quite similar to the patent drawings of to-day. The patent describes a removable plug of a breach loading cannon, the plug having radially projecting lugs which turn into interlocking engagement with seats in the bore of the gun. The patentee, D. W. Hughes, is still living at the age of 83 at 437 North 3rd St., Hamilton, Ohio. Mr. Hughes' patent, like the earlier patent No. 13, above referred to, is signed by Rufus R. Rhodes as Commissioner of Patents. Mr. Rhodes was a former official of the United States Patent Office, having been appointed an assignment examiner on June 20th, 1857, and promoted to principal examiner in July, 1858. He resigned February 15th, 1861. The patent No. 13 was issued August 23rd, 1861, just a little more than six months after Mr. Rhodes left the United States Patent Office. A New Patent Office Ruling on Perpetual Motion Machines ALTHOUGH it might be supposed that the absurdity of perpetual motion had been completely exploded long ere this, every patent lawyer can cite numerous cases to show that even in this twentieth century Of alleged scientific enlightenment many a deluded inventor is still trying to get a mechanical something out of nothing. To the credit of the patent profession at large be it said that the inventor is usually told that he is wasting his time and his money. It is frequently difficult, however, to convince an inventor that his schemes are impracticable, so that many an attorney, much against his will, is compelled to prepare specifications and claims which relate to an invention that is inoperative. In the past it has been the practice of the Patent Office to demand a working model from the inventor of perpetual motion machines. The man who can not be convinced by an attorney that his machine is inoperative is not likely to be discouraged by any such requirement. The result is that many an inventor spends hundreds and perhaps thousands of hard-earned dollars in trying to build an operative perpetual motion model—a task which any one with an elementary knowledge of mechanics can tell him is hopeless. To meet this peculiar situation the Patent Office has now made a ruling which must commend itself to every member of the patent bar, as well as to those engineers and inventors who come into frequent contact with the Patent Office Examiners. The Commissioner, in order to spare the inventor the necessity of parting with at least the government fees for an application, which must inevitably be rejected, has decided that hereafter no application for a patent on a perpetual motion machine will be considered at all unless a working model is filed in the very first place. The exact wording of the Commissioner's ruling is as follows: "The views of the Patent Office are in accord with those of the scientists who have investigated this subject and are to the effect that such devices are physical impossibilities. The position of the Office can be rebutted only by the exhibition of a working model. Were the application to be forwarded to the Examiner for consideration, he would make no examination as to the merits, but his first action would be the requirement that a working model be filed. "In view of all circumstances, the Commissioner has instructed that applications for patent on Perpetual Motion, complete in all other particulars, shall be held in the Application Rooms as incomplete until a working model has been filed. Such model must be filed within one year from the date of application, or the application will become abandoned. The Office hesitates to accept the filing fees from applicants who believe they have discovered Perpetual Motion, and deems it only fair to give such applicants a word of warning that the fees paid cannot be recovered after the case has been considered by the Examiner. For these reasons it has been thought best to meet the inventor at the threshold of the Office. and give him an opportunity to recover the moneys paid into the Office, in the event of his failure to comply with the requirement." Altho ugh misgui ded inventors may still persist in spending their money in attempts to furnish working models, there is much consolation to be found in a ruling which, at least, saves them the government fees on a hopeless application.
This article was originally published with the title "The Inventor's Department" in Scientific American 105, 25, 561-562 (December 1911)