This invention relates generally to sliding doors and in particular, to a self adjusting track chain adjustment trolley used with side folding accordion partitions.
Side folding accordion partitions are used to provide space separation, often with the additional goal of providing one or more of security separation, sound control, and prevention of the spread of fire and smoke.
Panels which form the partition are attached to ball bearing rollers which ride within a mounted overhead track. A lead panel is attached to a lead post which in turn is attached to a trolley having ball bearing rollers which also rides within the overhead track. A powered looped chain is attached to the trolley, thereby providing the mechanical action required to open and close the partition.
Through usage and/or ambient temperature changes, the chain can expand. In order to effectuate smooth movement of the partition, the chain must be kept at a predetermined tension. Various designs have been utilized to provide the required chain tension. Known designs require periodic technician intervention to maintain proper chain tension. Once such design uses a threaded rod to engage a nut welded to the bottom of a chain attachment bracket. The rod must be periodically manually further threadably engaged to maintain proper chain tension as the chain stretches with use and/or environmental conditions.
Known designs do not allow for self-adjustment of the chain tension. Rather, as the chain expands from use or due to environmental conditions with concomitant decrease in chain tension, technician intervention is required to re-tension the chain.
Accordingly, there is still a continuing need for improved chain tensioning designs. The present invention fulfills this need by presenting a novel self adjusting chain tensioning trolley and further provides related advantages.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
Turning now to
Chain tensioner assembly 4 comprises tube 10, preferably a hollow bar, upon which spring bracket 12 is slidably engaged. Spring bracket 12 has superior portion 14 for receiving chain first end 16 and inferior portion 18 for receiving spring tensioning rod 20 as described in detail below. Superior portion 14 is dimensioned to travel unrestricted within track inner channel 68 (
Rod bracket 22 is affixed to tube 10 for example with one or more bolt 24 and nut 26. Rod first threaded end 28 passes through a rod bracket orifice (not shown) to receive nut 30. Rod second threaded end 32 is slidably engaged by channel 34 fabricated into spring bracket inferior portion 18 thereafter receiving a restrictor, for example, nut 36 and jamb nut 38. Rod 40 passes through spring 42 to maintain spring 42 engagement between rod bracket 22 and spring bracket inferior portion 18.
Stabilizer bar trolley assembly 6 comprises a plurality of rollers 44, preferably ball bearing rollers, which engage chain guide 46 at inner channel 68 as shown in
Bearings 53 (
Stabilizer bar trolley assembly 6 is mounted to tube 10 with bolts 54 and nut 56. Spacers 58 provide a predetermined amount of spacing from tube 10. Primary attachment point, for example, orifice 95, receives lead post 66 (
Track engagement assembly 8 is mounted to spacer 70 with screws 72 and recessed bolts 74 and nuts 76. Recessed bolts 74 pass through spacer 70 and tube 10, thereby fixing spacer 70 and in turn, track engagement assembly 8, to tube 10. Recessed bolts 74 are of predetermined length so as not to interfere with spring 42. Track engagement assembly 8 has opposing wings 78 having rollers 80, preferably ball bearing rollers, rotably affixed thereto, positioned to engage track outer channel 82 as shown in
After chain guide 46 (
Referring to
Spring 42 is fully compressed by tightening nut 36 and jamb nut 38. Compression is achieved as spring bracket 12 slides along tube 10 as nut 36 and jamb nut 38 continue to further engage rod second threaded end 32. Once spring 42 is compressed, chain first end 16 is attached to spring bracket superior portion 14 for example, by using a master link attached to orifice 88. Chain is thereafter looped around chain pulley 86 and conventional power sprocket (not shown) remotely located from chain pulley 86 in conventional manner with chain second end 50 terminating in conventional attachment to stabilizer bar trolley assembly receiver plate 52 for example, by using a master link attached to orifice 92.
Chain 94 is of predetermined length to provide a predetermined initial tension. Once chain 94 is fully engaged, jamb nut 38 and nut 36 are loosed, thereby permitting spring 42 to apply a predetermined amount of force upon chain 94 to maintain a predetermined operating tension. It should be apparent that the predetermined amount of force spring 42 provides can be varied by utilizing predetermined spring coil thickness and/or spring material.
In this manner, the novel force applicator arrangement of the present invention maintains continuous predetermined chain operating tension regardless of chain stretching; all without technician intervention. The arrangement also serves as a shock absorber, in that as lead post 66 encounters an obstruction or is pushed upon, spring 42 compresses, thereby helping to prevent chain 94 from jumping on the sprocket.
Although the present invention has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present invention is capable of other variations and modifications within its scope. For example, while the preferred embodiment utilized two distinct sets of rollers (stabilizer bar trolley assembly 6 and track engagement assembly 8), a single translational assembly (for example, only stabilizer bar trolley assembly 6) is also contemplated.
These examples and embodiments are intended as typical of, rather than in any way limiting on, the scope of the present invention as presented in the appended claims.