Human powered can flattening machine

The can crusher herein is a pedal, and optionally arm powered, safe, can folding crusher which is vertically hopper fed. An optional flywheel stores mechanical energy during periods of non-maximum power demand to enable the crushing process to proceed with an even application of power. The form of the can folding crusher is that of an exercise bicycle having a horizontal ram which engages cans in a first stroke to prepare the can to be creased into a folded relationship, and in a second stroke in which the folding crushing occurs. The exit chamber is barely the diameter of an adult finger, and is designed to have a length which prohibits both adult and child fingers and hands from reaching any point near the crushing chamber. The feed hopper is adjustable for a variety of lengths of cans, and the seat is adjustable to accommodate a wide variety of human power providers.

FIELD OF THE INVENTION 
The present invention relates to the field of devices which reduce the 
volume of cans, and more specifically, to a human powered can flattening 
machine which leaves the ends of the can exposed for inspection and is 
safe to operate. 
BACKGROUND OF THE INVENTION 
The need to recycle aluminum cans over the past ten years has been 
responsible for a recycling infrastructure in which a variety of 
considerations need to be met. In some states, a mandatory fee is charged 
to the consumer in conjunction with the sale of the can which can be 
refunded when the can is turned back to the retailer. In other states, the 
recycling function is governed solely by the weight of the returned cans 
and the price for scrap aluminum. Other mechanisms for the return of 
aluminum cans include machines in which a can is deposited and within 
which the bar code is read to determine both the number and type of cans 
turned in before automatically paying the customer. 
In instances where cans are purchased because of their weight, the crushing 
of the can will assist in having a storage mass of considerably less 
volume for a given weight. Because of this advantage, a myriad of can 
crushing devices have found their way onto the market. Of these, some are 
safer than others. Some can crushers are industrial strength, massively 
powered and intended to perform bulk crushing of a high volume of cans. 
This type of application is ideal for situations where the cans may be 
rapidly and continuously fed without much starting and stopping which 
would be present at the point of sale. After crushing, and particularly 
with the larger machines, the identity of the can may be undiscernible. In 
fact, where the crushing is particularly violent, the portion of the can 
having writing and the end portions may be partially shredded. 
At the other end of the spectrum is the manual crusher. This item is 
usually hand fed a single can at a time, and may require both arms to 
crush the can. Usually a lever is employed to give mechanical advantage. 
The can's lid is usually laterally partially crushed along with the body. 
The volume reduction will usually not be as great as that achievable with 
the large electrically powered machines. In both instances, however, the 
ends of the cans are deformed, which may not present a problem where the 
cans are sold based upon weight. 
In the case of pre-sale crushing of cans, it may be desirable to carefully 
crush the cans so as to leave the ends intact for several reasons. First, 
the ends are usually made of thicker material than the can's side. If a 
choice between two materials is to be made with regard to which will be 
folded, the folding of the thicker material will yield a larger internal 
airspace, for a given amount of crushing energy. 
Second, the end portions may carry information, impressed at the time of 
the can's formation, relating to the can's refund amount. More 
specifically the inforation may include the state within the United 
States, or country with which the can was designated at the time the can 
was formed. Some states have a higher refund amount than other states, and 
typically the states with the higher refund amounts will also carry a 
state identification which has to match with the locale of the facility at 
which it is being returned, usually a grocery store. This problem can be 
especially keen in communities located near state borders where the 
cross-flow of cans from one jurisdiction to another is very likely. 
The third problem relates back to the problem of identification of the type 
of can. If a can is crushed, it will likely be impossible to tell the size 
of the can, unless the volume label is present and can be read. Most 
crushing, even where the crushed can product is generally of a uniform 
type, leaves the can in a condition where it is impossible to readily 
ascertain its volume. 
A fourth problem relates to the energy for crushing cans. In most crusher 
configurations, the crushing is a partial crushing, or where an attempt is 
made to insure that the can is identifiable, there is usually a tradeoff 
between identifiability of the can and the amount of crushing applied. In 
the case of human powered, or manual can crushers, the degree to which the 
cans are crushed is depend upon the playoff between two factors, 
simplicity and applied power. Since the human power input from a simple 
machine is limited, a simple lever type machine will be limited in the 
amount of crushing power which the can may receive. Where more power is 
sought to be applied to the can, further mechanics can be employed. These 
further mechanics increase the complexity of the can crusher, and the 
power which can be applied to the can. 
A major consideration is can crusher safety. If the crushing chamber can be 
accessed by the human limbs and digits, the potential for serious injury 
will be present. Where manual crushers are configured to increase the 
application of power to the crushing chamber, and such chamber is 
accessible to the fingers and hands, the potential for injury is high. 
A further problem with manual crushers is the time and energy application 
of power to the crushing process. Most manual crushers require the 
operator to perform a two-step process. In one step, requiring little or 
no energy, the can is loaded into the crusher. In the second step, human 
power is applied to crushing chamber. The energy capacity of the human 
during the loading step is under utilized. Further, most manual crushers 
are hand and arm powered, rather than foot and leg powered. A larger 
supply of power can be derived from the latter than the former. 
One electrically powered attempt at foldably crushing cans is described in 
U.S. Pat. No. 4,291,618 to Warren R. Heiser and entitled "Method and 
Apparatus for Folding and Crushing Empty Cylindrical Cans." The 
configuration there involved a zig-zag hopper feeding a chamber having a 
complex ram set in which a center ram operated in coordination with a 
following central ram. A complex set of gears and levers processes each 
can with a two step motion in the chamber. A set of fingers are used to 
hold the can during the dual action crushing process. 
In this configuration, however, the can exit chute is not long enough nor 
narrow enough to preclude an operator from inserting fingers and hands 
into the chute. Such an accident may occur if a can becomes trapped in the 
chute or upon the complex fingers which hold the can in place. In the 
above mentioned machine there is no easy, safe way to clear the crushing 
chamber and exit chute. This is particularly dangerous in an electric 
powered device, and virtually precludes the possibility of operation by 
children and young adults due to the danger potential. 
SUMMARY OF THE INVENTION 
The can crusher of the present invention is a pedal powered, optionally 
hand crank assisted, safe, can folding crusher which is vertically hopper 
fed. An optional flywheel stores mechanical energy during periods of 
non-maximum power demand to enable the crushing process to proceed with an 
even application of power. 
The form of the can folding crusher of the present invention is that of an 
exercise bicycle having a horizontal ram which engages cans in a first 
stroke to prepare the can to be crushed into a folded relationship, and in 
a second stroke in which the folding crushing occurs. The exit chamber is 
barely the diameter of an adult finger, and is designed to have a length 
which prohibits both adult and child fingers and hands from reaching any 
point near the crushing chamber. 
The feed hopper is adjustable for a variety of lengths of cans, and the 
seat is adjustable to accommodate a wide variety of human power providers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The description and operation of the invention will be initiated with 
reference to FIG. 1. FIG. 1 clearly shows a can crusher 21 in a 
configuration similar to that of an exercise machine. A seat 23 is 
supported on a tubular seat support 25 by means of a bracket 27. Tubular 
seat support 25 is received in a height adjustment support tube 29 having 
a series of apertures 31 which permit seat 23 and its support structures 
to be secured at varying heights with a pin or button or other securing 
structure operable in conjunction with the apertures 31. 
Can crusher 21 may be supported on a flat surface 33 by a horizontal 
support, including a central support 35 and extending leg supports 37. The 
extending leg supports 37 include threaded adjustable height pads 39 which 
are threadably received into the leg supports 37. 
Can crusher 21 includes a main housing 41 having a shallow angled 
transition 43 as it extends rearwardly under the seat 23. A foot pedal 
crank 45A extends outwardly of the main housing 41 and includes a foot 
pedal 47A. The foot pedal crank 45A revolves about a main shaft 49. 
A detachable upper rear panel section 51 lies upward and to the rear of 
main housing 41. A hand crank 53A extends outwardly of the rear panel 
section 51 and includes a handle 55A. The hand crank 53A revolves about a 
shaft 57. 
The cranks and pedals described being right-side hand crank 53A and foot 
pedal crank 45A, a portion of the left-side hand crank 53B and handle 55B 
is also seen. Note that the orientation of the crank 45A and the hand 
crank 53A are both horizontal, indicating that these two structures may be 
made to be rotationally in synchronization. Slippage clutch mechanisms may 
be employed to enable the synchronization to be adjusted by the user, 
although they are not employed in this configuration. 
At the front of the can crusher 21, a vertical can processing housing 61 
can be seen. This structure forms a vertical can feed, leading down into a 
first area where the can will be creased, and into a second area where it 
will be folded. A step up support 63A can also be seen vertically beneath 
the seat 23, which may be used by riders to mount the seat 23. 
Referring to FIG. 2, a front view better illustrates many of the structures 
seen in FIG. 1. In addition, a width adjustment handle 65 can be seen on 
the left side of the can crusher 21. The handle 65 enables adjustment for 
cans of various heights to be received into the crusher 21, and engages a 
lead screw (not yet shown). At the upper portion of the view of FIG. 2, 
the vertical can processing housing 61 can be seen to have a feed opening 
67. 
The vertical can processing housing 61 also has a reinforced door 69 
secured to the vertical can processing housing 61 by a hinge 71. The other 
side of door 69 may be secured to vertical can processing housing by any 
suitable means sufficient to withstand the forces which will be impressed 
upon it including another hinge, or other closure mechanism. The cans 
which are fed into the feed opening 67, after making their way down to the 
vicinity of the door 69, will be successively creased, and then folded 
against the door 69. The hinge 71 will enable the door 69 to open, giving 
full access to the area in which cans are creased and folded, or foldably 
crushed. 
FIG. 3 looks down on the crusher 21 and illustrates again many of the 
structures previously seen in FIGS. 1 and 2. In addition, a partial 
section is provided at the top of the vertical can processing housing 61 
to give a partial view of an internal wall 73 which is moveable to adjust 
the height of cans which can be received in the vertical can processing 
housing 61. 
Referring to FIG. 4, an overall sectional view illustrates the basic 
mechanical connections and components in the can crusher 21. Shaft 57 can 
be seen to have a small sprocket 75 supporting a vertical chain 77. Chain 
77 extends to a small sprocket 79 which engages main shaft 49. It is 
through these structures that power from the hand crank 55 is transmitted 
to the main shaft 49. 
Main shaft 49 also supports a large sprocket 83 supporting a chain 85 which 
extends to a flywheel sprocket 87 which rotatably connects with a flywheel 
89 on a flywheel shaft 91. The flywheel system described herein is 
optional, because in most cases, sufficient power may be obtained from the 
foot pedal cranks 45 and the hand cranks 55, to foldably crush cans. An 
overrunning clutch may be employed to enable the flywheel 89 to spin 
without the necessity for the human actuated structures to continue 
movement. Also the flywheel 89 may be omitted where it is desirable for 
the operator to "feel" the cans crush during the power cycle. It has been 
experienced that the flywheel system thus described does such a good job 
of leveling the power required to crush cans, that the crushing action can 
scarcely be felt by the can crusher 21's human power provider. 
Also from the main shaft 49, a crusher drive chain 93 is driven by a 
sprocket (not yet shown) to drive the crusher crank shaft 95. Crusher 
crank shaft 95 turns a pair of cranks 97 (only 97B is visible) which 
engage slots 99 on a pair of slide plates 101, (of which plate 101B is 
visible). Turning of the crusher crank shaft 95 causes the slide plates 
101 to move forward and rearward to provide the crushing motion, which is 
a simple harmonic motion. 
Also shown in FIG. 4 is a permanently mounted stop 103 within the vertical 
feed space 105 of vertical can processing housing 61. Cans which have not 
been creased cannot pass this point. The area immediately above stop 103 
is the area at which the can creasing occurs, while the area beneath the 
stop 103 is the area where the final and complete foldable crushing of the 
cans occurs. 
Also shown are the structures which relate to the width adjustment handle 
65. The width adjustment handle is attached to an upper lead screw 107. 
Upper lead screw 107 engages an upper lead screw sprocket 109 which is 
attached to a vertically looped chain 111. Chain 111 is similarly attached 
to a lower lead screw sprocket 113 which is attached to a lower lead screw 
115. In this manner, the mechanism for crushing cans, particularly the 
internal wall 73 previously referred to, can be adjusted to accommodate 
cans of different heights. Since the cans are fed into the crusher 21 
horizontally, the changing height of the can translates into the need for 
a width of changing magnitude for the crusher 21. 
The upper and lower lead screws 107 and 115 act to change and set the width 
of the crushing portion of the apparatus, including internal wall 73, at 
two heights to prevent "binding" of the portions of the mechanism which 
slide. The chain 111 not only sets the timing of the two lead screws 107 
and 115 in phase, but enables the energy with which the upper lead screw 
107 is turned, to be transmitted to the lower lead screw 115. 
As can also be seen in FIG. 4, the slide plates 101 slide upon and are 
bound by a lower slide block 117, and are bound upwardly by an upper slide 
block 119. Note that the lower slide block 117 extends into the vertical 
feed space 105, and forms a portion of the exit chute 121 with respect to 
the reinforced door 69. Reinforced door 69 is also shown in dashed line 
format in the open position. As can be seen, the crushed can must be of 
small depth to slide downward through the exit chute 121. Further, the 
exit chute 121 is sufficiently long and narrow that neither a child's hand 
nor an adult's fingers can fit wholly upwardly into the exit chute 121. 
Given that an aluminum soft drink can is a little over two and a half 
inches in diameter, it can be readily seen that the exit chute 121 is so 
much significantly smaller than the vertical feed space 105 that neither 
adult fingers nor children's hands can reach the portion of the vertical 
feed space 105 which is the crushing area below the stop 103 where the 
crushing takes place. 
FIG. 5 is a sectional view about line 5--5 of FIG. 4, looking downwardly 
into the operational portion of the can crushing mechanism. In FIG. 5, the 
slide plates 101 and therefore the crushing mechanism is in retracted 
position. A sprocket 123 is shown between chain 93 and one of a pair of 
outer crank shafts 125 engaging the cranks 97. A bearing shaft 127 
connects the ends of the cranks 97 and provides a surface to support 
engagement with slots 99 on slide plates 101. A brass bearing or other 
bearing structure may surround bearing shaft 127 to provide an 
interstitial bearing member for engagement with the slots 99. 
Note that the crushing mechanism has bilateral symmetry, separated by a gap 
129. The gap 129 widens when the adjustment handle 65 is adjusted for 
taller cans and narrows when adjusted for shorter cans. Also note that the 
main housing 41 forms the right side support structure for the crushing 
mechanism, while the abbreviated length internal wall 73 supports the 
sliding portions of the crushing mechanism on the left side. 
A support rod 131 is visible which slidably supports the left side of the 
mechanism shown in FIG. 5, including the lower left slide block 117B (not 
shown in FIG. 5), the left slide plate 101B, and upper left slide block 
119B, (also not shown in FIG. 5). Support rod 131 also supports the right 
side of the mechanism shown in FIG. 5, but not slidably, since it is 
laterally fixed with respect to the right side of the main housing 41. 
Various shafts are shown as held in place against portions of the main 
housing 41, usually with a flange pillow block bearing 133, preferably of 
the two bolt variety. The end face 135 and creasing anvil 137 are shown 
supported by the slide plates 101. The anvil 137 is located above the stop 
103, while the end face 135 is located below stop 103. 
A lower channel bracket 139 engages the lower left slide block 117B and is 
similar to an upper channel bracket (not shown) which engages the upper 
left slide block 119B. These brackets are threaded and threadably engage 
the upper and lower lead screws 107 and 115 and provide the support and 
urging movement of the left side of the crushing mechanism. A can 141 is 
shown in phantom adjacent the end face 135. This is the position which the 
cans 141 will assume when fed into the can crusher 21. Also shown are a 
pair of support plates 143 which partially bear against the slide plates 
101 to guide and allow the slide plates to have forward and rearward 
can-crushing motion. 
Referring to FIG. 6, the foot pedal crank 45 has been rotated 180.degree., 
the slide plates 101 urged to the forward position. The can 141 is shown 
in the creased position, due to its engagement with the anvil 137, but 
before engagement with end face 135. Note the change in position of the 
cranks 97. 
FIGS. 7 and 8 are isolated expanded views illustrating the crushing of cans 
141 as appearing from a side view 123. Now can be seen illustrated the 
positions of cans 141 as they are fed through the can crusher 21. The 
upper support rod 145 can now be seen supporting the upper slide block 
119. 
The lower of the whole, un-deformed cans 141 in FIG. 7 is supported against 
stop 103, and cannot pass because the space between the tip end of stop 
103 and the reinforced door 69 is not sufficient to enable the whole can 
141 to drop. The lowest can 141, which was creased or deformed slightly 
during the last compression stroke is shown with its ends turned away from 
the viewer, and as it sits in the crushing chamber awaiting folded 
flattening during the next crushing stroke. If it were not creased, it 
could not fall below the stop 103. 
Note that the cranks 97 are in a position urging the slide plates 101 
rearwardly, away from the cans 141 and the reinforced door 69. The energy 
for the movement of the slide plates 101, end face 135 and anvil 137 is 
via the chain 93 and its associated sprockets and shafts. 
Referring to FIG. 8, the slide plates 101, end face 135 and anvil 137 have 
been brought into crushing position. The lowest can 141 which was shown in 
FIG. 7 as partially deformed and creased, has now been crushed as a result 
of the direct action of the end face 135 against the inside surface of the 
reinforced door 69. The can 141 of FIG. 7 which was un-deformed has now 
been creased and partially deformed by the action of the anvil 137 against 
the inside surface of the reinforced door 69. This can waits for the 
withdrawal of the anvil 137 so that it may fall past the stop 103 and into 
the lower area. The can in the lower area which has just been crushed by 
the direct action of the end face 135 against the inside surface of the 
reinforced door 69, awaits the withdrawal of the end face 135 so that it 
may fall through the exit chute 121. 
As can be seen in both FIG. 8 and in FIG. 9, an optional set of spring 
plungers may be employed, namely upper spring plunger set 161 and lower 
spring plunger set 163, to prevent the cans 141 from sticking against the 
reinforced door 69. The spring plunger sets 161 and 163 will typically be 
round nosed plungers which may be set in bosses to give adequate 
structural support for mounting. 
Referring to FIGS. 9 and 10, the front of the can crusher, with the 
vertical can processing housing removed illustrates the action by which 
tall and short cans 141 may be accommodated. Prominent is the internal 
wall 73. FIG. 9 illustrates the can crusher 21 in its most narrow 
position. The internal wall 73 is furthest from the main housing 41 to 
which it is most adjacent. The slide plates 101 are close together, as are 
the end faces 135, and the stops 103. FIG. 10 illustrates the can crusher 
21 in its most wide position. The internal wall 73 is now nearest to the 
main housing 41. The slide plates 101 are far apart, as are the end faces 
135, and the stops 103. 
Exit chute 121 is shown. The view from about the height of the upper 
support rod 145 to the bottom of the exit chute is the same as would be 
had from the front of the can crusher 21 with the reinforced door 69 in 
the open position. As can be seen the opening of the reinforced door frees 
the front portion of the crushing mechanism. Any can 141 which is caught 
will either fall away instantly, once reinforced door 69 is opened, if it 
is hung on either the end face 135 or any of the exit chute 121's 
surfaces. Any can 141 which may be caught on the stops 103 can be pulled 
directly off. Cans 141 above the stops 103 will simply fall away. 
While the present invention has been described in terms of a human powered 
folding can crusher, one skilled in the art will realize that the 
structure and techniques of the present invention can be applied to many 
appliances. The present invention may be applied in any situation where a 
one or two step process with a feed is needed to ensure a completely 
processed, completely flattened product, without the concomitant safety 
risks of a high powered electric crusher. 
Although the invention has been derived with reference to particular 
illustrative embodiments thereof, many changes and modifications of the 
invention may become apparent to those skilled in the art without 
departing from the spirit and scope of the invention. Therefore, included 
within the patent warranted hereon are all such changes and modifications 
as may reasonably and properly be included within the scope of this 
contribution to the art. 
For example, by way of illustration and not limitation, since the can 
crusher 21 may be operated with or without the crushing of cans, the 
structures of the present invention could be connected to a generator to 
power a television, radio, or lighting device so that the rider can get a 
sense of his power output. A friction band may be placed on the flywheel 
to increase the amount of exertion required to operate the can crusher 21.