Automatic packaging machines with wear resistant parts

An automatic packaging machine transports an object over a path having a freedom for both horizontal and vertical movement. Horizontal rails support a pair of guide blocks positioned to slide over the rails. Each of the guide blocks has a pair of spaced parallel slots with a T-shaped cross-section confronting individually associated one of the rails. A replaceable wear resistant track is slidably captured within each of the T-shaped slots, to slide over an individually associated one of the rails. A vertical support bar interconnects the second guide blocks. An upper and a lower U-shaped block is attached to the vertical support bar at vertically spaced locations. A keeper is secured over the open space of each of the U-shaped blocks. A block of wear resistant material is positioned in a recess in each of four interior surfaces of the U-shaped block and keeper, a slidable vertical bar being captured and sliding within the embrace of the U-shaped blocks. There is enough play within the sleeve member for the slidable vertical bar to swing out of a sleeve member having a keeper removed while the other keeper remains in place, to enable the wear blocks to be replaced. The slidable vertical bar carrys the object over the path.

This invention relates to automatic packaging machines and more 
particularly to providing wear resistant parts for such machines. 
One known example of an automatic packaging machine is found in U.S. Pat. 
No. 4,578,929. Heretofore, this type of machine has been maintained by a 
crew of men who would repair or replace parts, change or adapt machines to 
set up a new production run, or the like. With the advent of 
microprocessors and microcomputers these packaging machines are being 
equipped to operate as unattended robots. As the machines become more 
self-sufficient, the number of repair men and operators is sharply 
reduced. The skill level of those who remain is greatly increased to 
become computer operators. Then, the cost of repair and replacement 
becomes more expensive because there are fewer people to make the repairs 
and those who do remain command higher salaries and wages while knowing 
less about mechanical aspects of the machine. Therefore, it is desirable 
either to elimininate those parts which require frequent maintenance or to 
make it very easy to replace such parts. 
For example, automatic packaging machines may include a plurality of rails, 
along which mechanical parts may slide. The rails may be both horizontal 
or vertical. Either way, the member which slides on the rail is likely to 
wear out rather quickly. 
Accordingly, an object of the invention is to provide new and improved 
packaging machines. In particular, an object is to provide wear resistant 
parts at locations where a part slides along a rail. Still another object 
is to provide wear resistant parts which may be replaced quickly and 
easily by persons having little or no special training. 
In keeping with an aspect of the invention, these and other objects are 
accomplished by providing wear resistant, preferably plastic bushings at 
points where wear is most likely to occur. The bushings may be replaced 
quickly and easily by simply removing one or two screws, and without any 
further disassembly. Then, the screws are replaced and the replacement is 
complete.

FIG. 1 includes a part 20 which may be moved vertically by the movement of 
a rail or support member 22 or horizontally by sliding along rails 24-30. 
Each of two upper rails 28, 30 is shown by dotted lines, so that the wear 
resistant track may be seen. The purpose of part 20 is irrelevant. For 
example, this could be the assembly 102 in FIG. 9 of U.S. Pat. No. 
4,578,929, or the like. Therefore, it will hereinafter be generically 
referred to as a "tool". 
A pair of guide blocks 32, 34 are mounted on and affixed at spaced 
locations along a vertical support bar 36. Each guide block has upper and 
lower tracks 38, 40 which slide along the rails 24-30, as the assembly 
moves horizontally. 
On the opposite side of the support bar are upper and lower sleeve or 
support members 42, 44 through which the tool support member 22 may slide. 
Thus, the tool 20 may move along an X-axis, as guide blocks 32, 34 slide 
along the rails 24-30 and along the Y-axis when the rail or tool support 
member slides 22 within the sleeve or support members 42, 44. 
It should be apparent that much of the wear caused by this X-Y motion 
occurs at the rails 24-30 and at the interior of the sleeve or support 
members 42, 44. Heretofore a substantial amount of disassembly was 
required to remove the supported equipment and to replace these parts, 
when they wear out. 
In keeping with the invention, the sleeve members 42, 44 are constructed, 
as shown in FIGS. 2, 3. Each sleeve member comprises a generally U-shaped 
block 50 which surrounds and embraces rail or the sliding tool support 
member 22. A keeper 52 is bolted across the open ends of the U-shaped 
block 50 to capture and hold rail or the sliding tool support member 22, 
one of the bolts being shown at 54. Inside the U-shaped support member 42, 
on each of the three interior walls thereof and on the inside of keeper 52 
(FIG. 3), are wear resistant blocks 56-60 made of any suitable wear 
resistant material. (On the inside of block 50, at 61, there is another 
wear resistant block which can not be seen in FIG. 2.) As should be clear 
from FIG. 3, the metal forming the keeper 52 is also shaped to form 
recesses for receiving a block 60 of the wear resistant material. Since 
the presence of the vertical rail or tool support member 22 provides a 
fairly tight fit which holds blocks 56-60 in place, it is not necessary to 
provide any bonding. Thus, the blocks may be easily picked out and 
replaced when the vertical rail or tool support member 22 is moved out of 
the way. 
In FIG. 1, the lower keeper 62 may be removed and the rail or vertical tool 
support member 22 may swing somewhat as a pendulum, about an axis 
established by the upper sleeve a support member or 42 in order to clear 
and to be out of the embrace of the U-shaped member 64, without loss of 
the capture by the upper sleeve member. The old worn out wear resistant 
blocks 56-60 may be removed and replaced by new blocks while rail or 
member 22 is out of the embrace of the lower support or sleeve member 44. 
Then, the lower keeper 62 may again be bolted into place. 
Next, the upper keeper 66 is removed and the rail or tool support member 22 
is swung away from the upper U-shaped block 66. The worn out wear 
resistant blocks 56-60 are removed and replaced at support or sleeve 
member 42. Then, the tool support member 22 is returned to the capture 
position and keeper 66 is again bolted into position. The rail or vertical 
tool support member 22 may now slide up and down in the support or sleeve 
members 42, 44, riding on the new wear resistant blocks 56-60. 
FIGS. 4, 5 show the wear resistant tracks which ride on the horizontal 
rails 24-30. In greater detail, the guide block 32 is a part which is made 
of metal. For example, it may be machined from hard aluminum. The back of 
guide block 32 has a projecting vertical key 70 which fits into a suitable 
recess in the support bar 36 (FIG. 1); therefore, when bolted to the 
support bar 36, the guide blocks and support bar form a rigid, 
interlocking structure. 
The upper and lower surfaces of the guide block 32 contain "T" shaped slots 
72, 74. These T-slots slidingly receive hard nylon track sections 76, 78, 
each of which is in the form of a base plate 80 (FIG. 5) having two 
upstanding flanges 82, 84 defining between them the track 38 (40, for the 
lower track) which slides over one of the rails 24-30. The dimensions are 
such that the track section 76 slides into and is held by the T-slot 72. 
Track section 40 is shown already in the place within the T-slot 74. The 
screws 86, 88 fit into the threaded hole 90 and another hole (not seen) on 
the far side of the guide block 32 to hold the hard nylon track 76 in 
place within the T-slot 76. The screw 92 is shown holding the nylon track 
section 78 in place in T-slot 74. 
To replace nylon track sections in the upper guide block 32, the screws 
86-92 are removed. New track sections 76, 78 are placed over rails 28,24 
(FIG. 1). and the guide block 32 is then moved toward the new track 
sections. As these track sections enter into the T-slots 72, 74, they push 
the worn tracks sections out of the slots. After the new tracks section 
76, 78 are properly positioned, the screws 86, 88, 92 (and a fourth screw 
not seen in FIG. 4) are returned to the threaded holes to capture the 
nylon track sections. 
If the guide block 32, 34 are attached to parts of the machine and can not 
be manually moved over the rails 24-30, the machine may be either 
programmed to move at an appropriate speed and over a distance equal to 
the length of the new track section; or, it may be moved responsive to 
repeated movement of an "inching" control which causes the machine to take 
small incremental movements. 
Those who are skilled in the art will readily perceive how to modify the 
system. Therefore, the appended claims are to be construed to cover all 
equivalent structures which fall within the true scope and spirit of the 
invention.