SWITCH MECHANISM FOR OVERHEAD TROLLEY

The present invention provides a switch mechanism that may be interposed between spaced apart end sections of overhead main track elements having circular cross-section. The track network is adapted for carrying a suspended trolley from one point to another, the switch mechanism necessary to direct a trolley along the overhead main track or an adjacent overhead spur track having like cross-section and having an end element disposed near the main track. The switch mechanism comprises a first elongate switch element and a second elongate switch element each being selectively engageable with a primary end of the main track and each coupled to independent secondary track elements, the elongate switch elements being pivotally connected to a singular track and selectively joined with the primary track element to direct the trolley thereacross.

All of the components of the track network and the switch mechanism are of circular cross section, permitting internal hinging and coupling elements to be utilized between the elongate switch elements and the end sections of the various track elements, thus reducing the interference encountered by a trolley passing thereacross. Utilization of switch and track elements of circular cross section further permits operation without requiring specific angular displacement of componentSi making installation more efficient and economical.

As illustrated in FIG. 1, the overhead track network 5 embodying the present invention is of circular cross section, having an overhead main track designated generally as 8, and at least one adjacent overhead spur track 9, each track being supported by a number of suitable suspending hangar supports 13. The switch 1( mechanism of the present invention is interposed between the ends 8a and 8b of the main track and adjacent the end 9a of the spur track for selectively directing trolley along main track 8 or spur track 9.

The trolley may carry any variety of objects, for example, garments 12, suspended from rod 11. Flanged wheels 14, rotatably carried in frames and secured to depending support arms 16 are pivotally attached to rod 11 at 18 to permit cornering of the trolley as it passes along the track network. As best illustrated in 2C FIG. 2, wheels 14 are "V" flanged to seat properly on the circular track elements without regard to the angular displacement thereof, and to ensure proper suspension of trolley without interference in travel.

The switch mechanism for transferring trolley 2 from the main track to the spur track, or vice versa, is best illustrated in FIGS. 2-7. When a switch element is said to be open, trolley cannot pass onto the track controlled by the switch element; and conversely, when a switch element is said to be closed, the trolley may 3C pass uninterruptedly onto the track so controlled. The switch mechanism is adapted to be interposed between spaced apart ends 8a and 8b of the main track, and end 8a of the main track and end 9a of the spur track. Since the switch mechanism always couples end 8a with ei3-ther end 9a or end 8b, end 8a is designated as the primary track end and ends 9a and 8b are designated as secondary ends.

By utilizing tubular track elements having substantially uniform inner and outer diameters, a primary 4C coupling insert may be simply introduced into primary end 8a by providing a reduced end portion 17 having an outer diameter substantially conforming to the inner diameter of the track element. The central portion of the coupling has a diameter substantially conforming to the outer diameter of the track element, thus providing a smooth, continuous surface for the wheels 14. Likewise, pivot coupling inserts 19 and 21 are inserted into respective secondary end 8b and 9a. Elongate switch elements 58 and are each pivotally secured to their respective pivot coupling inserts 19 and 21 and are adapted to be selectively engaged with the primary coupling insert 10, to alternately close the switch between ends 8a and 8b or ends 8a and 9a.

A countermotion for switch elements 58 and 60, requiring that at all times one element is closed and one element is open, is provided by the mechanism carried by the rigid yoke designated generally by the numeral 22. Depending legs 26 and 28 of the yoke are fixedly 6Q secured to their respective pivot couplings 19 and 21 at 30. By securing the yoke mechanism in this manner, rather than to track elements 8 and 9, no alteration of the track elements is required when it is desired to install a switch mechanism in an existing track network. 6 Thus, switches may be added to or deleted from a track system efficiently and economically, permitting alteration of the network at minimal cost by inserting orwithdrawing couplings and 19, and 21 attached to the appropriate switch.

Spring tensioner arm 49, pivotally attached to depending leg 28 at 50, controls the position of switch elements 58 and by positioning operating pitman of bell crank 34 pivotally attached at to header 24 of the yoke 22. A first upright link 42 of the bellcrank is located on one side 36 of pivot and is pivotally attached to control arm 52 which is rigidly secured to ele-) ment 58 at 53. To provide element with a counter-motion, a second upright link 44 is located on the other side 38 of pivot and is pivotally secured to control arm 54 which is attached to element at 55. Thus, when spring tensioner arm 49 is in the position shown in FIG. 4, element of the switch is closed, coupling primary end 8a with secondary end 8b. The counterpo-sition is shown in FIG. 5, wherein the spring tensioner arm is rotated past pivot 50, closing element 58 and opening element 60, thus coupling primary end 8a with ) secondary end 9a.

To ensure proper closing of elements 58 or when the spring tensioner arm is rotated, a spring 46 is secured at one end to stud 47 of the arm and at the other end to stud 48 extending from and fixedly secured to depending leg 28. The spring tension will draw arm 49 toward stud 48 whenever the arm is rotated in either direction past pivot thus properly seating each element 58 or on end portion 72 of primary coupling 10.

Switch elements 58 and may be activated either by pulling tether line 51, thus rotating arm 49 past center 50, or by motion of trolley 15. As wheel 14 approaches the switch mechanism along track 9, see arrow A, FIGS. 4 and 5, it will progress along the track forcing element 58 to close and alternatively, element to open. As this happens, bellcrank 34 rocks on pivot 35, arm 48 rotates past the center 50, spring 46 pulling the arm and the switch element into place. The elements will then be locked in this position until another trolley approaches along track 8, or the switch is reversed by pulling tether line 51.

By utilizing track and switch elements of circular cross section it is possible to provide internal pivots in and element seats or guides for the switch mechanism, thus reducing the interference of trolley advancement normally encountered at switch mechanisms. Primary coupling includes two reduced end portions 17 and 72, conforming substantially to the inner diameter of the track elements. End 17 of the coupling is simply inserted in primary end 8a and embraced by the interior wall of the track element 8. The coupling may be secured to the track by epoxy or other suitable adhesive substances if desired. End portion 72 provides a suitable seat for the switch elements, each element having an arcuate surface 68 extending beyond end for that purpose. Each arcuate extension has an outer peripheral surface conforming to the outer diameter of the track elements and the coupling 10, and an internal surface conforming to the outer diameter of the reduced end portion 72. The arcuate surface spans less than 180, allowing each element 58 and to be simply lifted or pivoted away from and/or toward coupling 10, opening and/or closing the switch. By providing the track elements, coupling 10, arcuate extension 68, and each switch element 58 and with an outer peripheral surface generated by a constant radius, a smooth continuous track is provided, even over the switch cou3,818,:

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plings. Further, angular displacement of the various components is not critical since the wheel 14 will be seated on any portion of the peripheral surface without creating interference.

The pivot end of each switch element is likewise adapted to the circular track to provide minimum interference. Pivot or secondary coupling 19 and 21, as primary coupling 10, include a reduced end portion 17 adapted to be inserted in the end of the track elements. The remaining body of the pivot coupling conforms to the outer diameter of the track elements to provide a smooth continuous track surface.

The opposite end of each pivot coupling is bifurcated to provide socket 66 adapted to receive ear 64 of each switch element. A pivot pin 62 is then placed through a diameter of the coupling body and perpendicular to the walls of the bifurcated end portion to provide an internal pivot for each switch element 58 and 60. Thus, it can be seen that the switch elements 58 and are pivoted on pin 62 whenever spring tensioner arm 49 is activated thereby, selectively seating extension 68 of either element 58 or element on end portion 72 of coupling 10, while simultaneously withdrawing the other switch element.

To improve the rigidity of the switch mechanism, support arm 56 may be secured to the primary end of the switch at coupling and one of the secondary ends of the switch at one of the secondary pivot couplings here shown at coupling 21. For light weight applications the arm is not necessary, however, it may be desirable to improve the rigidity and durability of the track system.

While most switch mechanisms elevate the open element, by utilizing the mechanism here shown, the elements may be opened and closed from a variety of positions without increasing the interference encountered by wheel 14 progressing from track elements to switch elements. Further, while the particular embodiments here shown include a pair of switch elements, it should be understood that the teachings of the invention may be utilized with any number of elements.