US3281879A - Street sweeper - Google Patents

Description

T. F. MURPHY Nov. 1, 1966 STREET SWEEPER 5 Sheets-Sheet 1 Filed June 17, 1964 MW jyc mzcas fi 9 04M {Mina T. F. MURPHY STREET SWEEPER Nov. 1, 1966 5 Sheets-Sheet 2 Filed June 17, 1964 WWW Nov. 1, 1966 T. F. MURPHY 3,281,879

STREET SWEEPER Filed June 17, 1964 5 Sheets-Sheet 5 T. F. MURPHY Nov. 1, 1966 STREET SWEEPER 5 Sheets-Sheet 4 Filed June 17, 1964 T. F. MURPHY Nov. 1, 1966 STREET SWEEPER 5 Sheets-Sheet 5 Filed June 17, 1964 United States Patent 3,281,879 STREET SWEEPER Thomas F. Murphy, 1625 Terrace Road, Homewood, 1111. Filed time 17, 1964,Ser.No. 375,808 14 Claims. (til. 15-84) This invention relates to a novel street sweeper and more particularly to a four wheel street sweeper which, by reason of novel design features incorporated into its structure, has efliciency, flexibility and adaptability for operation under varied local street and highway condi tions.

There are basically two types of street sweepers currently available on the market. Both possess serious limitations. The seemingly more popular three wheel sweepers require a chassis structure specially designed for the task. The less popular four wheel sweeper is usually a modified truck chassis, which is more economical for a starting point in constructing a street sweeper.

In the three wheel sweeper, there is a single Wheel which steers the vehicle and paired wheels which usually support the major weight of the sweeper. Rear or front wheel steering appears to be optionaldepending upon the design. A main broom generally located near the paired wheels, sweeps the debris, kicked out by one of two gutter brooms at the front of the vehicle, from the gutter of the street being swept, forwardly up a chute. Usually the chute is an independent continuous moving belt or other like conveyor which conveys swept debris into a hopper. Various clutching mechanisms to operate the main broom, the gutter brooms, and the conveyor off the main sweeper propelling motor are usually required. Because broom speeds of about 80 rpm. are optimiurn for sweeping and because clutching off the main motor is used to operate the broom and because of the basic instability of three wheel support, three wheel sweepers are generally slow operating. This is obviously undesirable for high speed highway cleaning and for transport of the sweeper to distant spaced sites of use. To overcome this, the trade has resorted to the four wheel sweeper. A truck chassis is drastically modified and sweeper attachments, the main broom, the gutter brooms, the conveyor and the hopper are positioned thereon. Usually the chassis frame is cut immediately behind the cab. Then, a rearwardly extending wider replacement chassis frame is welded to the cut frame. This wider replacement chassis permits support of a wide main broom and an equally wide conveyor for receiving the swept debris. To avoid being limited by optimum broom speeds, a separate motor is positioned on the replacernent chassis to operate the main broom, the conveyor and the gutter brooms, one on each side, at the front or side of the vehicle. Even with such separate drive means, complicated gearing, clutching, drive shaft or chain belt propulsion devices are needed to drive all the elements and these are relatively delicate for the environment under which the street sweeper is used. The use of a replacement chassis bed also presents new problems. The wider spaced rear wheels necessitated, by the width of the main broom and the conveyor, prevents adequate spring support so that there is frequent rear axle breakage. The need to position the hopper forwardly of the sweeper causes undesirable unloading of debris under the chassis and tire damaging back up over the deposited debris. Indeed, the prior art four wheel sweepers are not only ungainly in appearance but also oftentimes dangerous to operate because of the obstructed views of the gutter broom etc. There have been a few instances where curious sidewalk superintendents, particularly children, have been injured by such sweepers. One must therefore conclude that four wheel sweepers currently available on the market are not the complete solu- 328L879 Patented Nov. 1, 1966 tion which the trade desired. Apparently each type sweeper is limited to certain sweeping operation. The optimum versatile sweeper has yet to be marketed.

An object of this invention is to provide an improved street sweeper which is not only efiicient in operation, but also flexible in design and adaptable to perform under Various operating conditions.

Another object is to provide a street sweeper, of the above character, which utilizes a standard stock truck chassis making it unnecessary to design or substantially alter the prime moving element of the street sweeper.

Still another object is to provide a street sweeper of the above character which has four Wheels so that it is easier to handle without danger of upset due to off balance loads.

A further object is to provide a sweeper which is mounted on the chassis of a standard stock truck whereby an operator can easily adapted himself to its operation since it operates in a fashion similar to any other truck.

A still further object is to provide a street sweeper of the above character, which is particularly suited for use on high-speed roadways.

Another object is to provide a street sweeper of the above character with a single gutter sweeper mounted visibly to the operator, on the front of the truck and capable of being swung to either side of the truck so that only a single gutter broom is required.

Another object is to provide an improved street sweeper of the above character having an improved conveyor system for carrying the debris to the hopper.

Another object is to provide an improved street sweeper, of the above character having a unique hydraulic system for driving the individual sweeper elements and for lifting those elements to enable high speed travel between distant sites of use which is independent of the sweeper drive means whereby the elements, may be operated at an optimum speed of rotation.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

Briefly, the street sweeper 10 of this invention comprises a standard unmodified truck body 11, upon which is mounted a single swing-type gutter broom assembly 12, a pick-up or main broom assembly 14, a unique conveyor means 13, a hydraulic circuit for operating and/ or lifting the gutter broom, the sweeper broom and the conveyor and a hopper 19 for storing the debris.

The gutter broom assembly 12 is mounted on the front of the truck 11 and i adapted to be swung to either side of the truck 11, so that only a single broom is rerequired. Furthermore, the gutter broom 20 may be rotated in either a clockwise or counter-clockwise direction, and may 'be lowered or raised for sweeping or for high speed travel from site to site by the hydraulic system.

The main or pick-up broom assembly 14 is attached to the rear of the truck 11. It has a sweeper broom 76 tranversely disposed to the truck 11 for sweeping debis into the conveyor means 18. It is designed so that the position of the broom 76 with respect to the surface of the road is adjustable as the bristles of the broom Wear. And like the gutter broom, the main broom assembly can also be lowered or raised, as required for sweeping or transporting the street sweeper.

The gutter sweeper assembly 12 and the main broom assembly 14 are also designed for easy disconnect from the truck 11 whereby replacement or repair is facilitated.

The conveyor 18 is a unique T-shaped conveyor having transverse screws 119 and 120 which feed an upwardly sloped central screw or belt or chain plow 122 whereby the debris is easily conveyed to the hopper 19. The conveyor 18 is also arranged to be pivotal so that it and the main broom assembly 14 can be easily swung up for fast transport or disconnect from the truck 11 for replacement and/or repair.

The hydraulic system is independently powered and is arranged to rotate the gutter broom 20 and the pick-up broom 76 in either a clockwise or counter-clockwise direction and to raise and lower both the gutter broom assembly 12 and the pick-up broom assembly 14. The operation of the hydraulic system may be controlled from a central position, which may be within the cab of the truck 11.

The hopper 19 is designed to straddle the chassis of the truck 11 and 'has doors on each side thereof so that the debris may be dumped to the sides of the truck 11. It is therefore unnecessary, as in the past, to dump the debris and then to back the truck over the debris with consequent damage to the front tires. The hopper 19 also has sloped walls wihin its interior to direct the debris towards the doors of the hopper to facilitate its removal.

The above description is not intended to be complete in all the features and advantages of the various components of the street sweeper, but is intended only to briefly set forth the principal components thereof.

The invention accordingly comprises the features of construction, combinations of elements, and arrangements of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a side view of an embodiment of the street sweeper of this invention;

FIG. 2 is a top view;

FIG. 3 is a front view;

FIG. 4 is a side view of the gutter broom assembly;

FIG. 5 is a partial sectional view of said gutter broom assembly, taken along the lines 55 of FIG. 4;

FIG. 6 is another partial sectional view of the gutter broom assembly taken along lines 6-6 of FIG. 4;

FIG. 7 is a rear view of the street sweeper showing the pick-up or main broom assembly;

FIG. 8 is a side detailed view of the pick-up broom assembly;

FIG. 9 is a partial perspective view of the pick-up broom assembly illustrating the skid arrangement used for guiding the debris as it is swept by the main broom;

FIG. 10 is a partial perspective view illustrating the pick-up linkage for the pick-up broom assembly;

FIG. 11 is a partial top view illustrating the conveyor of the street sweeper;

FIG. 12 is a partial sectional view of the conveyor, taken along line 12--12 of FIG. 11.

FIG. 13 is a top plan view of an alternate pick-up broom arrangement; and

FIG. 14 is a schematic block diagram of the hydraulic system used with the street sweeper shown.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Referring now to the drawings, a street sweeper 10 exemplary of the present invention is shown including a truck 11 equipped with a cab and the means for motivating the same, such as a motor, transmission, etc., the details of which are well-known in the art. The street sweeper 10 is designed and constructed so that the truck 11 can be of any standard production type of sufficient size to support and transport the individual components hereinafter described, and the novelty and advantages of such arrangement will be apparent from the description which follows.

A gutter broom assembly 12 is mounted on the front bumper 21 or the like of truck 11 and is positioned such that the driver may have it in his sight while driving the street sweeper 10, rather than being mounted on the side and to the rear of the street sweeper, as in the majority of the prior art arrangements, which position required the driver to alternate between watching the path of travel of the street sweeper or the gutter broom. This arrangement therefore is considerably safer than those of the prior art, and is also more convenient since the driver can always keep it in his sight.

The gutter broom assembly 12 is pivotally connected and is arranged to be shifted from one side to the other of the street sweeper 10 so that only one gutter broom assembly is required.

The pivotal connection with the truck 11 is provided by an attachment assembly 22 formed of the two horizontally extending bumper bars 13 to which are connected in spaced relation, in positions hereinafter described, a pair of spaced T-shaped gutter broom support brackets 54 formed of two angle bars with pins 52 between them and a U-shaped gutter broom rpivot bracket 24. Bracket 24 is centrally located on the bumper bars 13 between the pair of T-shaped brackets. The attachment assembly 22 can be constructed as a unit and can therefore be easily and conveniently secured to the truck 11, by means of nuts and bolts or by welding.

The arms 26 of gutter broom bracket 22 extend outwardly from the bumper 21 substantially parallel with the surface of the street. The arms 26 each have an aperture (not shown) therein for receiving the pivotal sockets 28 attached to the ends of the support arms 31 and 32 respectively. The pivotal sockets 28 are of the type which allow the support arms 31 and 32 to pivot both vertically and horizontally, as well as in both directions simultaneously.

The pivotal sockets 28 are fixedly secured within the apertures in the arms 26 by' means of threaded nuts. Therefore the gutter broom attachment 112 can be easily connected to and removed from the truck 11 by merely removing these nuts and by disconnecting the hydraulic lines 29 and 30, which may include quick disconnect couplers.

The support arms 31 and 32 extend horizontally from the pivotal sockets 28 and are secured in parallel relation by means of a transversely positioned spanner bracket 34, the support arms 31 and 32 and the bracket 34 each having apertures therein for receiving bolts 36 and 37. Secured to spanner bracket 34 is a platform 40 which supports gutter broom drive hydraulic motor 41, and a bearing retaining member 38 which receives and retains the drive shaft 39 of the gutter broom 20, the drive shaft 39 being coupled to the hydraulic motor 41.

The support arms 31 and 32 are secured between a pair of upright supports 42 and 43 (see FIGS. 4 and 6) and are arranged to be longitudinally moved therebetween for adjusting the horizontal position of the gutter broom 20, by means of gutter broom positioning spring 47 and gutter broom hydraulic cylinder 56.

Gutter broom positioning spring 47 is connected, at its lower end, to the support arm 31 and at its upper end to a threaded shaft 46, which is threadably received within an extending plate 44 secured to the top of the upright supports 42 and 43. The shaft 46 has a handle 48 secured to its upper end, for adjusting the tensional force of the spring 47, in a manner and for reasons explained in greater detail below.

The hydraulic cylinder 56 is pivotally secured at its lower end to the support arm 31 and at its upper end to an extending bracket connected to the top of the support arms 42 and 43.

At the lower end of support arms 42 and 43 are locking plates 49 and 51, respectively, which have locking slots 51 formed therein that extend inwardly from their outer edges in an upwardly angled direction, and which are arranged to engage pins 52 of the T-shaped gutter broom support 54.

In use, the gutter broom sweeper attachment 12 is positioned to one side or the other of the street sweeper 10, with the pins 52 of the corresponding bracket 54 slidably received in the locking slots 51 in the locking plate 49 or 50. The spring 47 is adjusted, by rotating the handle 43 in either a clockwise or counter-clockwise direction, to exert a downwardly directed force on the support arm 31, which force is effective to both retain the pins 52 in the slots Sit and to constantly urge the gutter broom 20 against the surface of the street. It may be noted that the support arms 31 and 32, being secured in parallel, retain the sweeping surface of the gutter broom 20 in the same angular position With respect to the surface of the street, as the gutter broom 20 follows the surface contour.

Lower support arm 32 has a shock absorb shaft 60 connected to its front end which slidably receives a spanner connecting bar 61 secured to the spanner bracket 34. Retained between the connecting member 61 and the lower support arm end 32 is a shock absorb spring 62 which uniquely functions to maintain the gutter broom 20 in the same angular position with respect to the surface of the street and also to absorb the shocks exerted on the support structure by the gutter broom 26 being rammed against a curb or the like.

In operation, the gutter broom attachment 112 is positioned to one side or the other of the street sweeper 10, in the manner described above, and the gutter broom rotated in a clockwise or counter-clockwise direction depending on the position of the gutter broom attachment 12 by means of the hydraulic motor 41 which is activated by the main hydraulic system. The gutter broom 20 is maintained or urged against the surface of the street by means of the spring 47 and against the gutter or curb by means of the spring 62, so that the gutter broom follows the surface contour of the street and of the curb, Within the limits defined by the maximum expansion of the springs 47 and 62.

The gutter broom 20 is shifted to the opposite side of the street sweeper it by activating the hydraulic cylinder 56 to raise the gutter broom 20 above the surface of the street. A force is then manually exerted upwardly upon the support arms 31 and 32, which force will be effective to disengage pins 52 from the locking notches 51 formed in one of the locking plates 49 or 50. The entire assembly is then pivoted about the gutter broom pivot bracket 24 until the other locking plate 49 or 50, as the case may be, engages the other T-shaped gutter broom support bracket 54 on the opposite side of the street sweeper l0, and a downward force is again exerted on the support arms 31 and 32 to slidably engage pins 52 in locking notches 51. The hydraulic cylinder 56 is then actuated to lower the gutter broom 20 to contact the surface of the street. It should be evident, from this description that the gutter broom 20 may be switched in minutes from one side to the other of the street sweeper in a very simple and convenient manner.

The gutter broom sweeps the debris from the gutter to .a position between the wheels of the truck Ill, as should be evident from FIGS. 1 and 2. The pick-up or main broom at the rear of the truck lll, then sweeps up the debris and deposits it in the hopper.

As seen in FIGS. 1, 2, 8 and 10, the pick-up or main broom assembly or attachment 14 comprises a horizontally disposed U-shaped broom support frame 65 with two rearwardly extending arms 63 and 64. Frame 65, is connected to the truck Ill by means of a trailer hitch (see FIG. 1) 1118.

Each rear end of each arm 63 and 64 connects to an angularly positioned broom axle take-up frame 72 which acts as the journal for the broom axle. Since each frame is similar in structure, only one will be described in detail hereinafter.

Slidably received within frame 72 is a journal block 76 which receives and retains the end of main broom axle 77.

Bolt 74, threaded to the frame 72, with lock-nut '75 permits positioning and locking of the pick-up broom 76 with respect to the street being swept.

A forwardly extending broom arm securement tube 67, preferably square to fit the cross-sectional configuration of arm 64, and welded to frame 72, secures the frame on the arm. It is retained there, in an easily removable but firm manner, by pin 66 which fits through an orifice extending through the tube and the arm. It should be evident that this securement means facilitates any removal of the main broom for repair or replacement. The mere removal of pin 66 enables rearward displacement of the main broom with respect to broom support frame 65. Then by outward displacement of broom end plates 78, a single operator can very easily replace the broom.

The large, substantially circular-shaped broom end plate 78, secured to bearing housing 72 prevents debris which is swept up by the pick-up broom 76 from being blown outwardly of the broom. It also functions to support the broom at a certain distance from the street surface with the help of a wheel assembly 79 and a skid 80.

As shown, best in FIG. 8, wheel assembly 79 is adjustably secured to plate 78 via pivot 85, and screws 82, within angular slots 81. Wheel assembly leveling bolt 84 threadably journaled within block 86 of the plate 78, and lock nut 88, enables simplified positioning of the pick-up broom with respect to the surface of the street.

As seen in FIG. 9, main broom skid comprises a horizontally positioned angle iron with upturned ends which allow them to follow or ride over obstructions on the surface of the street. It is movably secured to the plate 78 by bolts 89 which extend through elongated apertures 90, so that skid 80 may freely ride up and down in accord with the contour of the street.

Just forward of plate 78 and secured to each arm 63 is a vertically disposed plate 83, which has a channelshaped member 91 angularly secured thereto for slidably receiving a forward removable main broom cover 92. The cover 92 spans across the entire width of the broom 76 and is similarly secured to arm 69 at its far end. It prevents debris sweep up by the pick-up broom 76 from being thrown over its top.

As seen in FIGS. 2 and 7, a hydraulic motor 99 is secured to one broom axle take-up frame 72 and is coupled to the axle 77 for rotating the broom, in either a clockwise or counter-clockwise direction. Usually the broom is rotated to sweep debris forwardly. The hydraulic motor 99 is activated and controlled through the main hydraulic system, in a manner hereinafter described.

Debris swept forwardly by the pick-up broom 76 is directed, by the mechanism described, into a transversely positioned trough 16 (see FIGS. 1 and 11). A pick-up apron 96, is affixed to the rear end of trough 16 and extends rearwardly and underneath the front of the pick-up broom '76. Apron 96 is secured to trough 16 by a piano hinge 98. It is preferably made of rubber or similar flexible material.

It may be noted from FIG. 1, that the U-shaped channel member 65 and the two arm members 63 and 64 are arranged to lie in a substantially horizontal plane parallel to the surface of the street. The pick-up broom 76 is secured within the channel member 65. With such an arrangement, positive control can be had over the horizontal positioning of the pick-up broom 76 and this extends its life. This is of great advantage because such brooms are relatively expensive. In the prior art the life of pick-up brooms were relatively short because they were suspended in brushing relationship with the surface of the street by means of springs or the like. With such prior structures, up and down bouncing or side to side rocking frequently occurred to cause the highly undesirable uneven wear of the bristles. If shock absorbers or the like were provided to prevent such bouncing or rocking, bristle or broom breakage frequently occurred.

Now, with the structure described, the broom is lightly urged against the surface of the street, so that a continuous, rather than a spotted, path is swept. Even more important is that the pick-up broom is protected against uneven wear and from damage caused by striking obstructions or ruts in the street surface. Wheel assembly 79 and skid 30 are highly instrumental in .such protection of the broom. Indeed, with proper positioning of the wheel assembly 79 and skid 80, one could almost use an unevenly worn broom and make it even. The benefits derived from the main broom structure now discovered are almost limitless.

For transport of the entire street sweeper to distant sites of use, the pick-up broom attachment 14 can be raised above the street surface while the sweeper is being driven over the highway. Such raising is accomplished by the linkage assembly 100, which may be best seen in FIG. 10. The linkage assembly 100 includes a pair of turnbuckles 101 and 102, the lower ends of which are pivotally secured to arms 64 and 63 by stirrups 104 and 105 respectively. The upper end of the turnbuckles are pivotally secured to lever arms 106 and 107, respectively which, in turn, are rigidly secured to the ends of a main broom lift shaft 108. The lift shaft 108 is rotatably secured within brackets 114 (see FIG. 2) which are rigidly secured to the end of the truck chassis 116. Lift arm 109 secured to shaft 108 and pivotally retained within forked piston rod 111 of a hydraulic cylinder 112 enables complete lifting of the entire main broom assembly. To raise the pick-up broom assembly 14, the sweeper operator merely activates hydraulic cylinder 112 through the main hydraulic system to draw piston 111 forwardly (as seen in FIG; 10). This causes the shaft 108 to rotate in a counter-clockwise direction within brackets 114. The arms 106 and 107 are therefore rotated in a counterclockwise direction to lift broom support member 65, thus raising the pick-up broom 76. To lower the pick-up broom 14, a reverse operation is instituted.

Now describing the conveyor 18 in detail, trough 16 is transversely positioned to face the pick-up broom 76. It contains two rotatable feed screws 119 and 120 which carry the debris swept into the trough 16 to a lift trough 121, angularly positioned over and partly through the back of the truck chassis.

In the prior art sweepers, the conveyor was generally a broom-wide belt arranged to span across the entire width of the pick-up broom 76. With this arrangement it was impossible to easily change broom widths for a similar change in the belt was also required. More detrimental however, to good street sweeper design, was the fact that the wide broom-belt arrangement required a wide rearwheel support structure. Thus, the need for a replacement chassis in the four-wheel sweeper should become evident. The ordinary truck chassis would not permit the use of a satisfactorily wide main broom or belt. So the trade resorted to the replacement chassis.

Unfortunately, the replacement chassis, because of its width, because of structural requirements for the street sweeper and because of the operating needs of the main broom elements, prevented adequate spring support for the axle and wheels of said chassis. Frequent axle breakage occurred. The operator, in ferrying the sweeper from site to site had to be extremely cautious not to drive over ruts etc. in the street or highway.

Frequent axle breakage also occurred because of the axles inability to provide the slight counter-reacting torque which is needed when trucks are started in forward motion, or are rapidly accelerated.

Within lift trough 121, are two endless lift chains 123 and 124 which have plows 122 spaced at intervals along the length thereof, for carrying the debris to the hopper 19. Chain 123 runs over sprockets 125 and 126, while chain 124 runs over sprockets 127 and 128. Sprockets 125 and 127 are secured to shaft 129 disposed within the hopper 19 while sprockets 126 and 128 are secured to the common shaft 130 which rotates the two screw conveyors 119 and 120. The latter are therefore driven by the same hydraulic motor as the chains 123 and 124 and this provides better control over the entire conveyor. It should be evident that with this arrangement the speed of the conveyor may be varied in accordance wih the needs of the situation. Also the preferred use of a hydraulic motor to power the conveyor prevents damage or burn-out of the motor. Should some clogging of the conveyor plow chain or feed screws occur by reason of a large piece of debris, the motor merely stalls.

It should also be evident that the chain plow could be replaced by a belt or by an auger enclosed within the lift trough.

Another advantage of the conveyor arrangement of the present invention is the ease with which the street sweeper 10 may be modified to sweep a wider surface, such as an airport runway. It is merely necessary to remove the end walls 131 and 132, which are removably secured to trough 16 by screws 133 and either replace or extend feed screws 119 and with larger feed screws or with extension screws to said feed screw. Screws 119 and 120 are telescopically received on shaft and secured thereon by bolts 134 or cotter pins or the like, and therefore may be easily replaced with lengthier feed screws. Trough extensions (not shown) designed to be addable onto the ends of trough 16 must also be used. A pick-up broom attachment having a correspondingly larger pick-up broom is also necessary for such enlargement of sweeping surface.

The lift trough 121 may be open, however, it is preferred that it 'be enclosed, to prevent debris from blowing out of it as the street sweeper is moving, and a top 135 is provided for enclosing the same.

The lift trough 121 terminates within hopper 19, which is straddle mounted on the chassis of the truck 11. The hopper 19 has doors, such as door 136, disposed on the lower end of each of its sides so that it may be emptied to the sides of the street sweeper 10. This avoids the prior art necessity of backing the street sweeper over the deposited debris.

Hopper 19 consists of a flat top wall 146 having a closed lift chain observation manhole 146a therein (see FIGS. 1 and 2). Four side walls 201, 202, 203 and 204 depend from the top wall 146, so that it is a closed construction, with the flight conveyor being passed through rear side wall thereof and arranged with an opening in its bottom wall through which the debris drops into the hopper 19.

The bottom comprises a pair of plates 137 and 138, angularly positioned (see FIG. 12) to straddle the truck chassis and to provide two inclines which are sloped in opposite direct-ions to direct the debris in the hopper to the doors 136 (see FIG. 1) on the sides of the hopper 19. The slope and position of the apex of these plates 137 and 138 not only facilitate emptying the hopper 19 but also help to equalize the load distribution in the hopper 19.

Each door 136 vertically slides within angle flanges 140 and 142 secured to opposite side edges of the hopper. Flange 141 seals the bottom of the door.

Door lift hydraulic cylinder 143, secured at 144 to the hopper 19 and its piston 145 secured to the top portion of door 136 provides the opening means for the door. The control for the hydraulic cylinder may be located within the cab of the truck so that remote control at a central location is possible.

With respect to the hydraulic system of the street sweeper 10, it is shown schematically in FIG. 14. It includes a hydraulic multisection pump driven prefer-ably by an independent gasoline engine 169 (see also FIG. 1) or a power take off drive from the transmission or fly wheel of the truck 11 or a direct drive from the engine of the truck 11. An independent gasoline engine 169 for the driving of pump 170 is preferred because rotation of the various sweeper brooms and the speed of the conveyor system can be maintained at a constant speed, regardless of the speed of the truck 11 or the engine of the truck 11. Thus, the truck 11 may be driven at various speeds, depending on the street trafiic, the amount of debris in the path of the street sweeper etc, and the rotational speed of the sweeper brooms maintained at the optimum speed for sweeping.

The several hydraulic motors 41, 9 and 115 for operating the brooms are connected through four-way valves 171 to 173, respectively, to the multisection pump 170. Adjustable flow regulating valves 174 to 176 are connected, as by-passes across each supply line to each hydraulic motor 4 1, 99 or 115, respectively, to adjust the speed of the motor.

Flow equalizing valves 177 to 179 are also connected across the supply line to each hydraulic motor 41, 99 or 115, respectively, to initially equalize the flow of fluid supplied to each motor and to establish a maximum speed of rotation therefor.

The four-way valves 171 to 173 and the adjustable flow regulating valves 174 to 176 are preferably mounted on a control panel (not shown) or mounted in the cab of the truck 11.

The hydraulic cylinders 56, 112 and 143 used to raise and lower the gutter broom attachment 12, the pick-up broom attachment 14 and the doors 13d of the hopper 19, respectively, are hydraulically powered through the hydraulic power steering system (not shown) of the truck 11. For this purpose, a diversion valve (not shown) is connected to the hydraulic system and it diverts a portion of the output to the power steering unit to control valves which control the operation of one of the above-mentioned units. These control valves may be located on the same control panel with the valves 171 to 173 and the adjustable fiow regulating valves 174 to 176.

With such a power steering diversion arrangement, the sweeper units and the hopper doors may be operated when the truck engine is running, without resort to the power of gasoline engine 169. It should be apparent that the main hydraulic system could be modified to also control cylinders 56, 112 and 143 but experience has shown that the power steering diversion approach is better.

A supply of oil for the hydraulic system is maintained in tank 220, located just above pump 170 (see FIGS. 1 and 7).

To keep down dust during sweeping, the chassis also has a water tank 221 which feeds a spray bar 222 attached to the bumper of the truck. The bar 222 sprays water forwardly to wet and Wash down any dust caused by gutter broom 20.

In FIG. 13, there is shown an alternated pick-up broom design. This design utilizes a pair of angularly disposed pick-up brooms 150 and 151 in place of the singular pick-up broom 76 to aid in directing the debris up the conveyor. With this arrangement, the frame members 63 and 64 must be angled outwardly and a frame member 153 must be secured between the same to add rigidity to the structure and to support a gear box 155 positioned between the pick-up brooms 150 and 151 to receive the broom axles 152 and 154. Gear box 155 may also be used to drive the pick-up broom 150 and 151 by positioning hydraulic motor adjacent the box.

The pick-up brooms 150 and 151 are arranged to overlap in the center and a guide plate 156 is arranged to keep the overlapping brooms 150 and 151 from becoming meshed with each other.

One of the advantages of the broom design shown in FIG. 13 is that it eliminates the need for skids 80 which prevent the debris from flowing around the ends of the singular pick-up broom.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.

Now that the invention has been described, what is claimed as new and desired to be secured by Letters Patent is:

1. A street sweeper comprising, in combination: a motorized chassis for transporting said street sweeper, said chassis having a hopper mounted thereon for storing debris and the like, a conveyor mounted on said chassis for conveying debris and the like to said hopper, a pickup broom assembly for sweeping debris and the like into said conveyor, said pickup broom assembly comprising a broom having an axle, a substantially U-shaped trailerlike frame connected to said vehicle and having a pair of arms which extend rearwardly of said vehicle, axle support means on the end of said arms for receiving and retaining the axle of said broom, and means for operating said conveyor system and said pickup broom.

2. The street sweeper of claim 1 having, in addition, at least one gutter broom mounted on said chassis for sweeping the gutter of the street.

3. The street sweeper of claim 1 wherein said conveyor comprises an axially aligned debris lift means and transverse feed screw means positioned transversely on the lower end of said lift means and arranged to convey debris and the like thereto.

4. The street sweeper of claim 3 wherein said pair of transverse feed screws have means thereon wherein said screws may be replaced with larger screws and wherein said pickup broom has means thereon wherein said broom may be replaced with a wire broom so that greater widths may be swept by said street sweeper.

5. The street sweeper of claim 3 wherein said lift means comprises a pair of endless chains in spaced relation having a plurality of plows connected transversely thereto at spaced intervals, spaced pairs of sprocket means for said pair of endless chains, the first pair of which are connected to a common drive shaft rotatably secured to said hopper and the second pair of which are connected to a shaft common to said feed screws and drive means connected to said drive shaft.

6. The street sweeper of claim 1 having in addition a gutter broom pivotally connected on the front of said vehicle and arranged to be shifted from one side to the other of said vehicle for sweeping debris from a gutter into the path of said pickup broom.

7. The street sweeper of claim 1 wherein said means for operating said conveyor system and said pickup sweeper broom comprises a hydraulic motor means and a hydraulic system for driving said motor means, said hydraulic system comprising a hydraulic pump having connections with said hydraulic motor means and independent drive means for said hydraulic pump.

8. The street sweeper of claim 7, wherein said bydraulic pump is a multisection hydraulic pump having supply lines coupled to each of said hydraulic motor means, and wherein said hydraulic system further comprises valve means connected in each of said supply lines for controlling the operation and the speed of said hydraulic motor means, respectively.

9. A street sweeper comprising, in combination: a motorized chassis for transporting said street sweeper, said chassis having a hopper mounted thereon for storing debris and the like, a conveyor mounted on said chassis for conveying debris and the like to said hopper; a pickup broom assembly for sweeping debris and the like into said conveyor, said pick-up broom assembly comprising a broom having an axle; a substantially U-shaped trailerlike frame connected to said vehicle and having a pair of arms which extend rearwardly of said vehicle; axle support means on the end of said arms for receiving and retaining the axle of said broom, said support means being adjustable for adjusting the longitudinal positioning of said pick-up broom; and means secured to said frame for supporting and for adjusting the position of said pick-up broom attachment with respect to the surface of a street; and means for operating said conveyor system and said pick-up sweeper broom.

10. The street sweeper of claim 9, further including linkage means pivotally connected at one end to said chassis and at their other end to said U-shaped frame, and means to pivot said linkage means, to thereby raise and lower said pick-up broom assembly.

11. The street sweeper of claim 9 wherein said axle support means comprises a frame member removably secured to each of said arms of said trailer-like frame,

said frame member having axial retaining structures angularly connected thereto, axial support means for receiving and retaining said axle of said pickup broom adjustably supported by each of said axial retaining structures for adjusting the vertical positioning of said pickup broom, plate means secured to each of said frame members adjacent said pickup broom, support means adjustably secured to said plate means for supporting said pickup broom attachment in a fixed position with respect to the surface of the street, and skid means self-adjustably secured to each of said plate means and arranged to slide along the surface of the street.

12. The street sweeper of claim 1 wherein said arms have shock-absorbing means connected thereto for protecting the broom from damage.

13. A street sweeper comprising, in combination: a motorized chassis for transporting said street sweeper, said chassis having a hopper mounted thereon for storing debris and the like; a conveyor mounted on said chassis for conveying debris and the like to said hopper; a pickup broom assembly for sweeping debris and the like into said conveyor, said pick-up broom assembly comprising a broom having an axle; a substantially U-shaped trailerlike frame attached to said vehicle and having a pair of arms which extend rearwardly of said vehicle, a frame member removably secured to each of said arms having a take-up frome angularly connected thereto, said frame having broom axle support means which are adjustably supported for adjusting the longitudinal positioning of said pick-up broom; a plate secured to each of said arms adjacent said pick-up broom; support means adjustably secured to each of said plates for supporting said pick-up broom in a fixed position with respect to the surface of a street; and skid means self-adjustably secured to each of said plates and arranged to slide along the surface of 12 the street; and means for operating said conveyor and said pick-up broom.

14. A street sweeper comprising, in combination: a motorized chassis for transporting said street sweeper, said chassis having four wheels, and a spring suspension arrangement; a hopper mounted on said chassis for storing debris and the like, a conveyor system for conveying debris and the like to said hopper, said conveyor system comprising an axially aligned conveyor portion mounted between said chassis and a transverse conveyor portion connected to one end thereof and arranged to carry debris and the like thereto; a pick-up broom attachment connected to said vehicle having two angularly disposed pick-up brooms arranged to sweep debris and the like into said transverse conveyor portion, each of said pickup brooms having an axle, a substantially U-shaped frame connected to said vehicle having a pair of arms which extend rearwardly of said vehicle, a frame member removably secured to each of said arms each having axle retaining structure angularl connected thereto, axle support means for receiving and retaining said axle of said pick-up broom adjustably supported by each of said axle retaining structures for adjusting the longitudinal position of said pick-up brooms, plate means secured to said U-shaped frame and disposed between said pick-up brooms, gear means secured to said plate means and receiving said axles, support means for supporting said pick-up broom attachment in a fixed position with respect to the surface of a street, and driving means coupled to said conveyor system and to said axle of at least one of said pick-up brooms for driving said conveyor system and said pick-up brooms.

References Cited by the Examiner UNITED STATES PATENTS 542,571 7/1895 Reynolds 15-83 1,176,408 3/1916 Skrzyszewski 15-340 X 1,452,307 4/1923 Martin 15-87 1,454,884 5/1923 Donkers 15-83 1,585,768 5/1926 Clayton et al. 15-83 1,904,881 4/1935 Presbrey 15-82 2,641,356 6/1953 Hunter et al. 198-217 2,917,761 12/1959 Burgdorlf 15-84 2,978,097 4/1961 Blanshine 198-217 2,996,742 8/1961 Ainers 15-87 3,011,193 12/1961 Schmidt et al 15-87 3,114,923 12/1963 Jones 15-82 FOREIGN PATENTS 415,860 9/1934 Great Britain.

CHARLES A. WILLMUTH, Primary Examiner. S. E. BECK, Assistant Examiner.

Claims (1)

1. A STREET SWEEPER COMPRISING, IN COMBINATION: A MOTORIZED CHASSIS FOR TRANSPORTING SAID STREET SWEEPER, SAID CHASSIS HAVING A HOPPER MOUNTED THEREON FOR STORING DEBRIS AND THE LIKE, A CONVEYOR MOUNTED ON SAID CHASSIS FOR CONVEYING DEBRIS AND THE LIKE TO SAID HOPPER, A PICKUP BROOM ASSEMBLY FOR SWEEPING DEBRIS AND THE LIKE INTO SAID CONVEYOR, AND PICKUP BROOM ASSEMBLY COMPRISING A BROOM HAVING AN AXLE, A SUBSTANTIALLY U-SHAPED TRAILERLIKE FRAME CONNECTED TO SAID VEHICLE AND HAVING A PAIR OF ARMS WHICH EXTEND REARWARDLY OF SAID VEHICLE, AXLE SUPPORT MEANS ON THE END OF SAID ARMS FOR RECEIVING AND RETAINING THE AXLE OF SAID BROOM, AND MEANS FOR OPERATING SAID CONVEYOR SYSTEM AND SAID PICKUP BROOM.

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