Bumper lock for dishwashing machine rack support

A dishwashing machine has a tank defining a cleansing chamber, a rack within the chamber having a bottom and parallel sides and elongated tracks extend between the sides of the rack and the chamber side walls. Each track includes longitudinally extending guideways, one on each side of the track. Rollers mounted on the tank side walls are received within one guideway of each track, and rollers mounted on each side of said rack are received within the other guideway of the corresponding track. A bumper member mounted on each end of each said track has a retaining tab formed as an integral extension to the bumper member, and a lock part on the tab is engaged through a hole in the track. A retaining pin extends through the ends of the track and through the bumper member. The pin has a head preventing the pin from passing completely through the track and the tab extends over the head of the pin.

BACKGROUND OF THE INVENTION 
This invention involves the support of a rack within a dishwashing machine, 
especially the support of an upper rack within a front loading dishwashing 
machine. U.S. Pat. No. 3,472,573 issued Oct. 14, 1969, to Hobart 
Corporation, assignee of this invention, discloses and shows in FIG. 5 a 
form of bumper which contains rollers on the tank side wall and on the 
rack within the guideways of the track. Under some circumstances the pin 
74, which holds the bumper to the end of the track, may work loose. Then, 
if the rack is pulled or pushed against the bumper, this will dislodge the 
bumper and allow the rack to run out of the track, or cause the track to 
disengage from the chamber-mounted rollers. 
SUMMARY OF THE INVENTION 
The present invention thus is directed to a novel form of such a bumper, 
including an integral lock tab or keeper which retains the bumper to the 
track. In the preferred embodiment the lock tab is hinged to an end of the 
bumper and includes a compressible lock part that is snapped into a hole 
near the end of the track. The head of the retaining pin is located under 
the tab. Thus with an easy assembly operation the bumper is pinned to the 
end of the track (as before) and the bumper is locked into position, 
capturing the head of the pin. 
Other advantages and features provided by the rack support of the invention 
will be apparent from the following description, the drawing and the 
appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the drawing which illustrates a preferred embodiment of the 
invention, FIG. 1 shows a front loading dishwashing machine which includes 
a tank 10 defining a cleansing chamber 12 having a front opening and a 
door 14 pivotally mounted at the bottom of the opening and movable from a 
vertical closed position to a horizontally open position as illustrated by 
the dotted lines in FIG. 1. A lower rack 16 is supported within the 
chamber 12 by suitable tracks (not shown) and is adapted to be rolled out 
into the door 14 for loading and unloading when the door is open. 
In the upper portion of the tank 10, a pair of horizontally spaced rollers 
17 are mounted on each side wall of the tank by threaded stud shafts 18 
which extend through corresponding holes formed within the tank walls to 
receive nuts (not shown). At each side, an elongated track 20, preferably 
formed from stainless steel sheet and generally S-shaped in 
cross-sectional configuration, includes longitudinally extending bead 
portions 22 and 23 forming an upper guideway for receiving the 
corresponding rollers 17 in interfitting relationship. Each track 20 also 
includes corresponding bead portions 22' and 23' which form a lower 
guideway. 
An upper rack 30 is positioned within the chamber 12, supported on each 
side by the tracks 20 for horizontal movement between a position within 
the chamber 12 and a position above the open door 14, as shown in FIG. 1. 
Reference is made to U.S. Pat. No. 3,269,548 for a detailed description of 
a typical upper rack. 
An elongated strap or plate 38 is mounted on each side portion 35 of the 
upper rack 30. These plates may directly mount rollers in the case of a 
non-adjustable rack, or each plate 38 may be connected to a corresponding 
track 20 by a lever mechanism 40, which forms a height adjusting mechanism 
as described in U.S. Pat. No. 3,472,573. The mechanisms include rollers 42 
which fit into the lower track guideways. 
Referring to FIG. 3, a bumper member 45 is mounted on each end of each 
track 20, and is retained by a pin 46 extending through aligned holes 48 
formed through the bumper member and the upper and lower track ends. The 
bumper members serve to prevent the rollers 17 and 42 from leaving the 
ends of the tracks 20 when the rack 30 is extended out over the door 14, 
and to prevent the rear ends of the tracks 20 from engaging the rear wall 
of the tank 10 when the rack is moved into the chamber. 
Each bumper member 45 is preferably formed of a molded material such as 
polypropylene or the like. It includes a body 50 dimensioned to fit into 
the end of the track, and a flange 52 to engage the outer end of the track 
and position the bumper. Extending from one end of the bumper is an 
integrally hinged retaining tab 53, having an arcuate section 54 to fit 
over the head of pin 46, and a split lock part or insert 55. The insert 
fits tightly into an aperture 57 in the track, and spreads against the 
edge of the aperture to hold the lock tab in place. 
Thus, the bumper includes a means to lock its retaining pin 46 securely in 
place. This same means also functions to hold the bumper securely to the 
track. For best security, the pins 46 hold the bumpers against the force 
of the rollers striking the bumpers. However, it would be possible to use 
locking tabs at both ends of the bumper, and eliminate the pins, in 
constructions where the forces were less, or the bumpers and tabs were 
formed of a more expensive and stronger material. 
While the form of apparatus herein described constitutes a preferred 
embodiment of this invention, it is to be understood that the invention is 
not limited to this precise form of apparatus, and that changes may be 
made therein without departing from the scope of the invention.