CA1096337A - Telescoping aerial lift - Google Patents
Telescoping aerial liftInfo
- Publication number
- CA1096337A CA1096337A CA305,705A CA305705A CA1096337A CA 1096337 A CA1096337 A CA 1096337A CA 305705 A CA305705 A CA 305705A CA 1096337 A CA1096337 A CA 1096337A
- Authority
- CA
- Canada
- Prior art keywords
- boom
- support arm
- intermediate section
- section
- sleeve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F11/00—Lifting devices specially adapted for particular uses not otherwise provided for
- B66F11/04—Lifting devices specially adapted for particular uses not otherwise provided for for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations
- B66F11/042—Lifting devices specially adapted for particular uses not otherwise provided for for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations actuated by lazy-tongs mechanisms or articulated levers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F11/00—Lifting devices specially adapted for particular uses not otherwise provided for
- B66F11/04—Lifting devices specially adapted for particular uses not otherwise provided for for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations
- B66F11/044—Working platforms suspended from booms
- B66F11/046—Working platforms suspended from booms of the telescoping type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
- B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
- B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
- B66F9/065—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks non-masted
- B66F9/0655—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks non-masted with a telescopic boom
Landscapes
- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mechanical Engineering (AREA)
- Transportation (AREA)
- Civil Engineering (AREA)
- Forklifts And Lifting Vehicles (AREA)
- Jib Cranes (AREA)
- Movable Scaffolding (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An aerial lift is described which has a pivotable boom with a load end and a pivot end. The boom is con-structed such that, as the pivot end of the boom pivots upwardly, the load end is raised substantially vertically.
In one embodiment, the boom is mounted on a telescoping scaffold to provide the boom with a greater reaching range.
In another embodiment, the boom itself is provided with telescoping members to extend its vertical reach.
An aerial lift is described which has a pivotable boom with a load end and a pivot end. The boom is con-structed such that, as the pivot end of the boom pivots upwardly, the load end is raised substantially vertically.
In one embodiment, the boom is mounted on a telescoping scaffold to provide the boom with a greater reaching range.
In another embodiment, the boom itself is provided with telescoping members to extend its vertical reach.
Description
~9G33~
BACKGROUND OF THE INVENTION
This invention relates generally to aerial lifts and more particularly to an aerial lift which has a pivot-able boom.
In building construction and maintenance, mining, storage/retrieval operations and many other fields, it is often necessary to provide aerial lifts for moving equipment and/or personnel. These lifts have generally been of two types; i.e., cranes and adjustable scaffolds. Conventional cranes are capable of lifting very large loads to relatively great heights. These cranes are usually vehicular to facilitate movement to the job site. When actual lifting is performed, however, the base of the crane, or the vehicle on which it is mounted, is ordinarily fixed in position by stabilizing pads. Since most cranes consist essentially of pivotable booms, this results in the pivot point being fixed. Thus, unless the boom is extensible, as the position of the boom is varied, the load end of the boom moves in an arc. If a load is suspended from the boom, this action will cause the load to swing toward the boom pivot end and, more importantly, toward the boom operator, thus increasing the safety hazards inherent in such operations. If the crane is being utilized to elevate workmen and/or equipment along a vertical plane, the load end necessarily moves increasingly further from said plane as the boom angle increases.
These disadvantages are often overcome by providing 1~9G337 extensible, ordinarily telescoping, boom scctiolls. Thesc boom sections are ordinarily extended by power cylinders which extend to force the telescoping boom section outward.
Thus, as the boom angle is increased, the power cylindcl-is extended by the operator thus increasing the length of the boom. This insures that the boom load end moves in a substantially vertical line. This extellsible power cylinder dramatically increases the cost of such units. ~lso, to insure proper, safe operation, a highly skilled operator is required. The operator must pay close attention to retain the load in the original vertical plane. Even with a higllly skilled, attentive operator this is often a very difficult procedure since the operator's line of sight is often inadequate to provide accurate adjustments. Due to the linc-of-sight problem a second operator is often placed in closer proximity to the load end. This not only increases the cost of operating the crane, but also increases safety hazards since the possibility of mis-understanding between operators is ever present. While boom mechanism may be automated to retain the load in the same vertical plane, such au-tomation systems are quite expensive.
Adjustable scaffolds are often utilized to move loads-along a vertical plane. Scissors-type scaffolds, such as that described in my U.S. patent No. 4,088,203 issued May 9, 1978, have been found to be ad-vantageous. However, since such apparatuses do not provide a capability of lateral movement, they are limited in their scope of operation. If a simple, nonextensible crane were mounted on an adjustable scaffold, the reaching coverage of the apparatus is still limited, as discussed further here-inbelow and illustrated in the drawings.
~9~337 ~ Accordingly, one object of the presellt inventioll is thc~
provision of a crane which need not have an extensible power cylinder for lengthening the boom but which can move a load in a substantially vertical plane. Another object is provision of a crane which can be easily automated. Yet another object is prov-ision of an aerial lift which is simpler than present lifts but which has greater versatility and lifting range. These and ot~ler objects, features, and advantages of the present invention will be apparent from the following description, appended claims, and annexed drawings.
SUMMARY OF T~IF INVENTION
In one broad aspect the invention comprehends an aerial lift which comprises a supporting means, a boom having a load end, a lower section terminating in a pivot end, an intermediate section telescoping with the lower section, and an upper section telescop-ing with the intermediate section. Means mount the boom to the supporting means such that the pivot end is horizontally movable, and a support arm extends between and pivotally connects the support means and the boom. Means rigidly couple the support arm to the 20 intermediate section of the boom, means are prcvided for extending the upper section of the boom as the intermediate section is extend-ed, and means are provided for raising and lowering the boom such that, as the boom is raised, the pivot end of the boom moves sub-stantially horizontally, the support arm pivots about the supporting means and the boom, and the means coupling the support arm to the intermediate section of the boom causes the intermediate section to extend for raising the load end of the boom substantially vertic-ally.
The novel features which are believed to be character-istic of the invention are set forth in the appended claims.
It is believed the invention will be best understood by reference to the following description taken in connection with the accompanying drawings.
'~
;33 7 BRIEF DESCRIPTION OF THE DRAWlNGS
Figure 1 is an elevation view of the invention in an in-termedia-te position;
Figure 2 is a sectional view taken along line 2-2 of Figure l;
Figure 3 is a sectional view taken along line 3-3 of Figure 2;
Figure 4 is an elevation view of the invention in the fully elevated position;
Figure 5 is an elevation view of the invention in the .fully lowered position;
Figures 6 and 7 show top and side elevation views, respectively, of another embodiment of the invention, shown in a lowered position;
Figure 8 is a side elevational view of the embodi-ment of Figures 6 and 7, shown in a partially extended posi-tion;
Figure 9 is a side view of the embodiment of Figure 8, shown in a more fully extended position;
Figure 10 is a fragmentary side view showing a portion of the side of the embodiment not visible in Figure 9; and Figure 11 is a side view of yet another embodiment of the invention, shown in an extended position.
DET~ILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In that form of the invention depicted in the drawings, the aerial lift is indicated generally at 10. A
pivotable boom 12 is shown to support a basket 14 which may be designed to carry a load. This load may include workmen but may alternatively or additionally include ~9~i33~
machinery of any conceivable type. In the depicted embodi-ment the basket 14 is allowed to rotate on pins 16 to maintain its upright position. The load end of the boom may include conventional lifting forks and automated or manual leveling mechanisms of conventional design to maintain the forks parallel to the ground. If the load is designed to be suspended from the boom, of course, no such leveling mech-anism is required.
The pivot end of the boom 12 is pivotally mounted at joint 18 to a sliding beam 20 which is slidably mounted in a channel 22 which may alternatively be described either as being mounted to a mounting table 24, or as being a part of said mounting table. The channel 22 is rotatably mounted to the mounting table, or the remainder of the table, on a substantially vertical cylinder 26, to be described in more detail hereinbelow. The function of the channel 22 is to prevent axial displacement of the beam 20 with respect to the mounting table 24. Ordinarily both the beam 20 and ~he table 24 will be substantially horizontal as depicted, but this is not necessary for the proper operation of the ap-paratus. Rollers 28a and b, 30a and b, and 32 a and b are provided as depicted in Figure 3 to insure that the beam 20 is slidable within the channel 22. Since a downward loading of the boom load end will tend to force clockwise axial displacement of the beam 20 with respect to cylinder 26, rollers 28a and b, and 32a and b will ordinarily carry mos-t of the load.
The boom 12 is also pivotably mounted to support arms 34a and b at point 36. These support arms 34a and b in turn are pivotally mounted to the channel 22 at joint 1~9~337 38. Thus, as the boom 12 is raised and lowered, the boom, beam and support arm structure will pivot on joints 18, 36, and 38 to cause the beam to reciproca-te with respect to the channel 22 and the mounting table 24.
Drive means for raising and lowering the boom 12 ordinarily comprises a hydraulic pivot cylinder 40 having one end pivotally mounted to the channel at a point no closer to the boom pivot end than the support arm joint 38, and the other end pivotally mounted to the boom 12 at a point remote from the support arm boom joint 36. The term "re~te from" means only that the joints may not be coaxial.
As depicted in the Figures, this pivot cylinder joint 42 is mounted to the boom 12 via plate 44 which is rigidly secured to the boom and which lies closer to the boom load end than does support arm joint 36. Also as depicted in the Figures, the other end of the pivot cylinder 40 is pivotally con-` nected to the channel 22 at joint 38, coaxial with the point at which the support arm is mounted to the channel. This - joint 38 will be further described hereinbelow.
While the above-described means of driving the lift is the preferred design, other means (not depicted) may alternately be utilized. For example, sliding beam 20 and rollers 18a and b, 30a and b, and 32a and b may act as a rack and pinion so that rotation of the rollers in either direction will change the lateral position of the beam 20, thus causing a change in the vertical position of the beam load end.
As stated hereinabove, the channel 22 is rotatable with respect to the mounting table 24. This feature obviously increases the versatility of the lift to a substantial degree.
l~G337~
The channel is rotatable on the vertical cylinder 26 which, as depicted in Figure 2, is offset from the channel 22 and the remainder of the boom apparatus. The channel 22 is mounted on the vertical cylinder 26 by the member 45 wllicl extends from the channel 22 and surrounds the vertical cylinder 26. Extending from member 45 is a leg 46 to which is pivotally mounted the rotational drive means, here a conventional hydraulic cylinder 48. The opposite end of this cylinder 48 is pivotally mounted to the mounting table 24.
One of the advantages of the present invention is that it allows a load to be elevated along a path which is much closer to a vertical line than do conventional booms which, when inextensible, swing the load in an arc. To provide a crane which can elevate a load along a line which is even closer to vertical, a telescoping section 50 can be added to the apparatus along with a telescoping cylinder 52.
As shown, one end of the telescoping cylinder 52 is pivotally connected to a support arm extension 56 at joint 58. The telescoping cylinder itself need not be extensible, i.e., it may be rigid. As the boom is adjusted to various levels of inclination, the movement of the support arm extension causes the telescoping cylinder to automatically extend and retract the telescoping section of the boom. ~s sllowll in the Figures, however, the telescoping cylinder 52 ordinarily is a conventional extensible hydraulic cylinder. This pro-vides a crane with even greater versatility.
As indicated in the Figures, the slidable beam 20 is ordinarily of rectangular configuration. The pivotable boom 12 and its telescoping section 50 are preferably also ~i, .`J. ~`>
1~9633~7 rectangular in cross section. Thus, the rollcrs 18a and b, 30a and b, and 32a and b are mounted on opposite sides of the slidable beam 20. Similarly, joints 18 and 36 extend across the entire cross section of the boom. Bc~m 1~
60a and 60b extend from each side of the end portion of the beam to meet legs 62a and 62b (not visible) at pivo-t joint 18. A suitable bearing 64 is provided.
As shown in Figure 2 the support arms 34a and b extend between joints 36 and 38, one Oll each side of the boom 12. The support arm extension 56 is ordinarily a extension of one of these arms since the telescoping cylinder 52 extends from joint 58 to only one side of the telescoping section 50 at joint 58.
As mentioned hereinabove and shown in Figurc 2, the points at which the support arms 34 and thc pivot cylinder 40 are mounted to the channel 22 are preferably coaxial at joint 38. A joint plate 66 is fixed to tlle top of the channel and extends across the entire cross section of the slidable beam 20. This joint 38 is actually comprised of three separate joints, with the support arms 34a and b pivotable on pins 68a and b, respectively. The pivot cylinder pivots on pin 70.
The mounting table 24 to which the above-described apparatus is mounted is preferably vertically adjustable above a base 72. The means for raising and lowering the table 24 may be of scissors design, such as that described in my U.S. patent No. 4,088,203 issued May 9, 1978. This scissors mechanism shown generally at 74 includes scissors arms 76 and power cylinders 78. The base 72 is preferably provided with wheels 80 to insure ~9~33~
., .
mobility. Brakes (not shown) would also be desirable.
The scissors mechanism 74 may also be of the telescoping type for greater lift, as described in my Canadian co-pending application Serial No. 290,775, filed November 14, 1977.
In operation the above-described scissors mechanism co-operates with the pivotable boom apparatus to provide an aerial lift with greater reaching range. Figures 4 and 5 show the boom in raised and lowered positions, respectively, and Figure 1 shows it in an intermediate position. A box 82 is included in these Figures to show that the aerial lift provides a reaching capability to all portions of the wall 84 with which the box 82 abuts. If the boom apparatus alone was mounted adjacent the wheels 80, the area indicated generally at X would be unreachable. Assuming the box 82 was substantially lower and the scissors mechanism 74 was fully collapsed, a conventional non-extensible boom would - be unable to reach both area X and the area indicated at Y
since the boom load end would necessarily move in a arc.
With the boom in the fully lowered position of Figure 5 the pivot cylinder 40 is fully retracted and the slidable beam 20 is fully extended from the channel 22.
The basket 14 is in its lowest position, nearly abutting the wall 84. To elevate the boom 12 the operator starts to extend the pivot cylinder 40, resulting in a rotational movement between joints 42 and 36. This causes joint 36 to swing upward and to the left, and the beam 20 to retract into the channel 22. The movement of the support arm ex-tension 56 toward the boom load end causes the telescoping cylinder 52 to extend the telescoping section 50 of the boo ~ .
33'7 12, thus causing the basket 14 to elevate and remain in close proximity to the wall 84. To reach the position shown in Figure 4, the pivot cylinder 4Q is fully extended, causing the beam 20 to fully retract through the channel 22, and causing joint 36 to swing to its uppermost position. At the same time telescoping section 50 has become fully fixed extended.
To lower the apparatus, the pivot cylinder 40 is retracted and the process is repeated. If lateral movement of the - basket is desired, the boom telescoping section 50 can be further extended or retracted by activating the telescoping cylinder 52. For axial translation the rotation drive cylinder 48 is utilized. To rotate the boom apparatus in a clockwise direction with reference to Figure 3, the rotation drive cylinder 48 is retracted and for counter-clockwise rotation the cylinder is extended.
Referring now to Figures 6-10, there is ShOWII all alternate embodiment 100 of the previously described aerial lift. The alternate aerial lift 100 employs the same principles of boom extension as described previously and additionally achieves greater elevational height. As shown in Figures 6 (top view) and 7 (side view) the aerial lift 100 is mounted on a wheeled supporting frame 102. Rotational movement of the lift 100 is provided by a swivel cylinder 104 which may be powered by conventional means (not shown) for rotating the lift with respect to the frame 102.
Mounted atop the cylinder 104 is a platform 106 for pivotally supporting the upper structure of the lift 100.
Connection between the platform 106 and the upper structure of the lift 100 is made at pivot points 108, 110, 112, and 114 (best seen in Figure 6) to which a pair of pivotable rods ~, ~
, ., ~v, ., 116 and 118 are connected. As explained in more detail here-inafter, the rods 116 and 118 rotate about their longitudi-nal axis as the lift is raised. In addition, the rod 118 moves horizontally within a channel 120 (Figure 7) as the lift 100 moves vertically.
Rigidly connected to the rod 116 is a pair of support arms 122 and 124, the latter of which is shown in Figure 10 which illustrates a portion of the reverse side of the lift 100. Thus, as the rod 116 pivots about its longi-tudinal axis, the support arms 122 and 124 will pivot upwardly as shown in Figures 8, 9 and 10.
Rigidly connected to the rod 118 is a three pieceextensible boom comprising a pivot end 126, an intermediate section 128, and an upper section 130, from the latter of which a load, shown in the form of a fork lift 132, extends.
The intermediate boom section 128 telescopes within the pivot end 126 and the upper boom section 130 telescopes within the intermediate section 128 as best shown in Figure 8. To pivot the section 126 during elevation of the lift 100, the pivot end 126 includes a rigidly connected offset portion 134 coupled to a boom sleeve 136. The sleeve 136 slides on a boom shaft 138 which is rigidly connected to the rod 118 and the sleeve 136 via the shaft 138 permits the lift 100 to be elevated to a relatively great height without the use of an additional scissors-type scaffold. In effect, a small scissors-type scaffold is built into the lift 100.
Referring now to the support arm 122 (Figures 8 and 9), it includes a support arm shaft 140 upon which a sup-port arm sleeve 142 rides in a telescoping manner. The sup-port arm sleeve 142 is pivotally coupled to the boom sleeve136 at 144.
~1~9~i337 Extendiny beyond the boom and the pivot 144 is a support arm extension 146 which, in this embodiment, is an integral extension of -the support arm sleeve 142. Pivotally coupled to the support arm extension 146 at 148 is a rigid linkage which preferably includes a telescoping cylinder 150 and a bar 152. One end of the bar 152 is fixed to the inter-mediate boom section 128 at 154 and the other end thereof is pivotally connected to the cylinder 150 at 156. This connection between the intermediate boom section 128 and the support arm extension 146 causes the intermediate boom secti~n 128 to telescope or extend out of the pivot section 126 as the lift 100 is elevated.
To extend the upper boom section 130, a cable 158 (Figures 8 and 9) is run from a connection 160 on the pivot boom ena 126, through a cable guide 162, around a sheave 164 mounted on the intermediate boom section 128, back down l through the intermediate boom section 128, and connected to the bottom of the upper boom section 130. The connection of the cable 158 is conventional and is, therefore, not shown in detail. Suffice it to say that the cable 158 pulls the upper boom section 130 out of the intermediate boom section 128 as the latter is extended.
The means by which the lift 100 is elevated is shown most clearly in Figures 9 and 10 to which reference is now made. As shown, one end of a telescoping cylinder 166 is pivotally connected to the boom pivot end 126 at 168.
The other end of the cylinder 166 is pivotally connected to a bracket 170 at 172. The bracket 170, in turn, is connected to the support arm 124 (Figure 10). As with the support arm 122, the support arm 124 also includes a support arm .
1~ii96337 shaft 174 telescoped wi-thin a suppor-t arm sleeve 176. The shaft 174 is mounted on the rod 116 (Figure 6) for rotation therewith as the lift 100 rises. The sleeve 176 is pivotally coupled to the boom pivot end 126 at 180.
As described above, the boom pivot end 126 and the support arms 122 and 124 each include a shaft and a sleeve in telescoping relation. To extend the various sleeves upwardly from their respective shafts, a set of link arms which pull the sleeves upwardly about the shafts are included.
More specifically, and as shown in Figure 9, a link arm 182 is piv~tally coupled at one end to the support arm sleeve 142 at 184 and at its other end to a bracket 186 at 188.
The bracket 188, in turn, is mounted on the rod 118 for ro-tation therewith.
Another link arm 190 is pivotally coupled at 192 to the boom sleeve 136 and at its other end to a bracket 194 at 196. The bracket 194, in turn, is mounted on the rod 116 for rotation therewith.
Referring to Figure 10, there is shown a pair of link arms 198 and 200 for raising the support arm sleeve 176 and the boom sleeve 136, respectively. Specifically, the link arm 198 is pivotally coupled at one end to the support arm sleeve 176 at 202 and at its other end to a bracket 204 at 206. The bracket 204 is mounted on the rod 118 for rotation therewith. As shown, the rod 118 engages a channel 205 for rotation and horizontal movement therein.
The link arm 200 is pivotally coupled at one end to the boom sleeve 136 at 208 and at its other end to a bracket 210 at 212. The bracket 210 is mounted on the rod 116 for rotation therewith.
~9G33~
In operation, the raising of the lift 100 is ini-tiated by actuation of the cylinder 166. This raises the boom pivot end 126 and the support arms 122 (Figure 9) and 124 (Figure 10). Simultaneously, the rods 116 and 118 (Figure 6) begin to rotate abou-t their longitudinal axes, thereby also rotating the brackets 186 and 194 (Figure 9) and the brackets 204 and 210 (Figure 10). As the brackets 186 and 194 rotate, they cause the link arms 182 and 190 to telescope the support arm sleeve 142 and the boom sleeve 136 upwardly. Concurrently, the rotation of the brackets 204 and 210 causes the link arms 198 and 200 (Figure 10) to telescope the boom sleeve 136 and the support arm sleeve 176 upwardly. As a result of the simultaneous extension of the boom sleeve 136 and the support arm sleeves 142 and 176, the point 144 (connecting the support arms to the boom pivot end 126) rises substantially vertically.
As the support arm sleeve 142 extends, the con-nection 148 between the cylinder 150 and the support arm extension 146 moves upwardly and to the left in Figure 9.
This motion is translated to the intermediate boom section 128 via the cylinder 150 (unextended) and the bar 152. As a result, the intermediate boom section 128 is extended out of the boom pivot end 126 such that the upper end of the intermediate boom section 126 rises substantially vertically.
The extension of the intermediate boom section 128 results in the upper boom section 130 being simul-taneously extended by the cable 158, thereby raising the fork lift 132 substantially vertically.
During the raising of the lift 100, the point ~633t7 110 on the rod 118 moves from its initial position shown in Figure 7 to the right as shown in Figure 9. This motion occurs as the lift 100 extends somewhat more than half its maximum elevation. When the cylinder 166 is actuated to raise the lift further, the point 110 moves to the left until it reaches approximately its original position. At this point, the lif-t 100 will have been raised to its fullest elevation which is greater than that shown in Figure 9~
Up un-til now, the operation of the lift 100 has been described with the cylinder 150 acting merely to translate the motion of the support arm extension 146 to the bar 152 and thence to the intermediate boom section 128.
However, if greater extension of the intermediate boom section 128 is desired, the cylinder 150 is actuated. As shown in the dashed lines of Figure 9, the actuation of the cylinder 150 drives a cylinder rod 214 in the direction of the arrow 216. As a result, the intermediate boom section 128 is further extended in the direction of the arrow 218.
The distance between the solid line sheave 164 and the dashed line sheave 164 indicates the increased extension of the intermediate boom section 128 resulting from the actuation of the cylinder 150. In addition, because the intermediate boom section 128 and the upper boom section 130 are joined by the cable 158, this further extension of the intermediate boom section 128 also results in further extension of the upper boom section 130.
As illustrated in Figure 9, the cylinder 150 may be actuated prior to full extension of the cylinder 166 and oper-ates to independently extend the intermediate and upper boomsections 128 and 130.
~3i963;37 When the cylinder 166 is deactuated, the lift 100 folds from the extension shown in Figure 9 to that of Figure 8, and finally to the folded position shown in Figure 7.
Thus, a very compact but high reaching lift is provided by the illustrated structure.
In the descrip-tion above, it has been mentioned that the cylinder 150 and the bar 152 rigidly couple the support arm extension 146 to the intermediate boom section 128. Obviously, the components have a number of pivot points and the cylinder 150 may be extended and retracted as required. A rigid coupling is, therefore, meant to include any linkage which translates the pivoting motion of the support arm extension 146 to a sliding motion of the intermediate boom section 128.
Referring now to Figure 11, there is shown another embodiment of the invention which extends a boom in accord-ance with the principles set forth above but which achieves even greater height. The aerial lift 220 of Figure 11 is shown in an extended position in which a fork lift 222 is elevated, and also in its folded position at the bottom of Figure 11.
The lift 220 may be mounted on a wheeled platform 224 as shown, above which a supporting base 226 is mounted.
The base 226 supports a pair of scissors members 228 and 230, preferably of the telescoping variety as shown, and pivot-ally coupled at 231.
Pivotally mounted to the scissors member 228 at 232 is a boom pivot end 234. The pivot end 234 receives within it, in telescoping relation, an intermediate boom section 236 and an upper boom section 238 telescopes within 1~9~;337 the intermediate section 236. The fork lift 222 is mounted at the upper end of the upper boom section 238. As in the previously described embodiment, the upper boom section 238 is caused to extend out of the intermediate section 236 by a cable 240 whenever the intermediate section 236 extends. As shown, one end of the cable 240 is fixed to the boom pivot end 234 at 242 and the other end passes through a cable guide 244, through a sheave 246, and is . attached in a conventional manner (not shown) to the bottom of the upper boom section 238.
Pivotally connected to the scissors member 230 at 248 is a support arm 250 for extending the intermediate boom section 236. The support arm 250 is pivotally coupled to the boom pivot end 234 at 252 and extends beyond the pivot end 234 as a support arm extension 254. When the lift 220 is elevated, the support arm 250 pivots about the point 248 and the extension 254 moves upwardly and to the left in Figure 11. The pivoting motion of the support arm 250 is translated to a sliding or telescoping motion of the intermediate boom section 236 by means of a rigid coupling which, as shown, is preferably an extendable cylinder 256 and a bar 258. One end of the cylinder 256 is pivotally coupled at 260 to the support arm extension 254 and the other end thereof is pivotally coupled to the bar 258 at 262.
The bar 262, in turn, is connected to the intermediate boom section 236 at 264.
Referring now to the scissors members 228, it preferably comprises a sleeve 266 in telescoping relation with a shaft 268, the latter of which is mounted on a rotatable rod 270. The rod 270 extends in a plane perpen-33~;' dicular to the plane of Figure 11 and has its ends mounted for rotation in the supporting base 226, similarly to the rod 116 of Figure 6.
The scissors member 230 is similar to the scissors member 228 in that member 230 also comprises a sleeve 272 in telescoping relation with a shaft 274. The latter is mounted on a rod 276 which extends in a plane perpendicular to the plane of Figure 11, similarly to the rod 118 of Figure 6. One end of the rod 276 is mounted for rotation and horizontal sliding motion in a channel 278 in the supporting base 226. The other end of the rod 276 is mounted for rotation and sliding horizontal motion in a channel (not shown) on the opposite side of the supporting base 226.
To telescope the scissors members 228 and 230, a pair of link bars 280 and 282 couple the sleeves 266 and 272 to the rods 270 and 276. The ends of the link bars 280 and 282 may be mounted on the rods 270 and 276 in a manner similar to that of the bars 182 and 190 of Figure 9.
Although not shown in the view of Figure 11, another scissors member may be included paralleling the member 228 but on the opposite side of the scissors member 230. This additional scissors member would preferably have a shaft section mounted on the rod 270 and a sleeve section pivotally coupled at 232 to the boom pivot end 234. An example of such construction is illustrated in Figure 2 of my co-pending application Serial No. 290,775.
In order to elevate the lift 220, a pair of extendable cylinders 284 and 286 may be connected as shown, the cylinder 284 being pivotally connected between the ,' '~
~1633~
support arm 250 and the scissors 230, and the cylinder 286 bein~ pivotally coupled between the boom pivot end 234 and the scissors 228. Upon the actuation of these cylinders, their cylinder rods 288 and 290 extend as shown, whereupon the scissors members 228 and 230 pivot about the longitudinal axes of the rods 270 and 276. In response to such pivoting, the link arms 280 and 282 extend the sleeves 266 and 272 upwardly. Simultaneously, the boom pivot end 234 is raised and the support arm 250 pivots about the point 248 to swing the support arm extension 254 upwardly and to the left. The cylinder 256 and the bar 258 then urge the intermediate boom section 236 upwardly to extend out of the boom pivot end 234. Simultaneously, the upper boom section 238 is extended out of the intermediate section 236, as a result of which the fork lift 222 is raised substantially vertically.
To achieve even further extension of the inter-mediate and upper boom sections, the cylinder 256 may be extended as shown in the dashed lines. This extension of the cylinder 256 urges the bar 258 upwardly, whereupon the intermediate boom section 236 and the upper boom section 238 further extend the fork lift 222 as shown in the dashed lines.
When the cylinders 256, 284 and 286 are deactivated, the lift 220 folds compactly as shown at the bottom of Figure 11. A housing 292 may be mounted on the base 226 as shown for enclosing a control mechanism for actuating the various cylinders.
Of course, it should be understood that various changes and modifications to the preferred embodiments des-cribed therein will be apparent to those skilled in the l~g633~
art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is, therefore, intended that such changes and modifications be covered by the following claims.
c.
BACKGROUND OF THE INVENTION
This invention relates generally to aerial lifts and more particularly to an aerial lift which has a pivot-able boom.
In building construction and maintenance, mining, storage/retrieval operations and many other fields, it is often necessary to provide aerial lifts for moving equipment and/or personnel. These lifts have generally been of two types; i.e., cranes and adjustable scaffolds. Conventional cranes are capable of lifting very large loads to relatively great heights. These cranes are usually vehicular to facilitate movement to the job site. When actual lifting is performed, however, the base of the crane, or the vehicle on which it is mounted, is ordinarily fixed in position by stabilizing pads. Since most cranes consist essentially of pivotable booms, this results in the pivot point being fixed. Thus, unless the boom is extensible, as the position of the boom is varied, the load end of the boom moves in an arc. If a load is suspended from the boom, this action will cause the load to swing toward the boom pivot end and, more importantly, toward the boom operator, thus increasing the safety hazards inherent in such operations. If the crane is being utilized to elevate workmen and/or equipment along a vertical plane, the load end necessarily moves increasingly further from said plane as the boom angle increases.
These disadvantages are often overcome by providing 1~9G337 extensible, ordinarily telescoping, boom scctiolls. Thesc boom sections are ordinarily extended by power cylinders which extend to force the telescoping boom section outward.
Thus, as the boom angle is increased, the power cylindcl-is extended by the operator thus increasing the length of the boom. This insures that the boom load end moves in a substantially vertical line. This extellsible power cylinder dramatically increases the cost of such units. ~lso, to insure proper, safe operation, a highly skilled operator is required. The operator must pay close attention to retain the load in the original vertical plane. Even with a higllly skilled, attentive operator this is often a very difficult procedure since the operator's line of sight is often inadequate to provide accurate adjustments. Due to the linc-of-sight problem a second operator is often placed in closer proximity to the load end. This not only increases the cost of operating the crane, but also increases safety hazards since the possibility of mis-understanding between operators is ever present. While boom mechanism may be automated to retain the load in the same vertical plane, such au-tomation systems are quite expensive.
Adjustable scaffolds are often utilized to move loads-along a vertical plane. Scissors-type scaffolds, such as that described in my U.S. patent No. 4,088,203 issued May 9, 1978, have been found to be ad-vantageous. However, since such apparatuses do not provide a capability of lateral movement, they are limited in their scope of operation. If a simple, nonextensible crane were mounted on an adjustable scaffold, the reaching coverage of the apparatus is still limited, as discussed further here-inbelow and illustrated in the drawings.
~9~337 ~ Accordingly, one object of the presellt inventioll is thc~
provision of a crane which need not have an extensible power cylinder for lengthening the boom but which can move a load in a substantially vertical plane. Another object is provision of a crane which can be easily automated. Yet another object is prov-ision of an aerial lift which is simpler than present lifts but which has greater versatility and lifting range. These and ot~ler objects, features, and advantages of the present invention will be apparent from the following description, appended claims, and annexed drawings.
SUMMARY OF T~IF INVENTION
In one broad aspect the invention comprehends an aerial lift which comprises a supporting means, a boom having a load end, a lower section terminating in a pivot end, an intermediate section telescoping with the lower section, and an upper section telescop-ing with the intermediate section. Means mount the boom to the supporting means such that the pivot end is horizontally movable, and a support arm extends between and pivotally connects the support means and the boom. Means rigidly couple the support arm to the 20 intermediate section of the boom, means are prcvided for extending the upper section of the boom as the intermediate section is extend-ed, and means are provided for raising and lowering the boom such that, as the boom is raised, the pivot end of the boom moves sub-stantially horizontally, the support arm pivots about the supporting means and the boom, and the means coupling the support arm to the intermediate section of the boom causes the intermediate section to extend for raising the load end of the boom substantially vertic-ally.
The novel features which are believed to be character-istic of the invention are set forth in the appended claims.
It is believed the invention will be best understood by reference to the following description taken in connection with the accompanying drawings.
'~
;33 7 BRIEF DESCRIPTION OF THE DRAWlNGS
Figure 1 is an elevation view of the invention in an in-termedia-te position;
Figure 2 is a sectional view taken along line 2-2 of Figure l;
Figure 3 is a sectional view taken along line 3-3 of Figure 2;
Figure 4 is an elevation view of the invention in the fully elevated position;
Figure 5 is an elevation view of the invention in the .fully lowered position;
Figures 6 and 7 show top and side elevation views, respectively, of another embodiment of the invention, shown in a lowered position;
Figure 8 is a side elevational view of the embodi-ment of Figures 6 and 7, shown in a partially extended posi-tion;
Figure 9 is a side view of the embodiment of Figure 8, shown in a more fully extended position;
Figure 10 is a fragmentary side view showing a portion of the side of the embodiment not visible in Figure 9; and Figure 11 is a side view of yet another embodiment of the invention, shown in an extended position.
DET~ILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In that form of the invention depicted in the drawings, the aerial lift is indicated generally at 10. A
pivotable boom 12 is shown to support a basket 14 which may be designed to carry a load. This load may include workmen but may alternatively or additionally include ~9~i33~
machinery of any conceivable type. In the depicted embodi-ment the basket 14 is allowed to rotate on pins 16 to maintain its upright position. The load end of the boom may include conventional lifting forks and automated or manual leveling mechanisms of conventional design to maintain the forks parallel to the ground. If the load is designed to be suspended from the boom, of course, no such leveling mech-anism is required.
The pivot end of the boom 12 is pivotally mounted at joint 18 to a sliding beam 20 which is slidably mounted in a channel 22 which may alternatively be described either as being mounted to a mounting table 24, or as being a part of said mounting table. The channel 22 is rotatably mounted to the mounting table, or the remainder of the table, on a substantially vertical cylinder 26, to be described in more detail hereinbelow. The function of the channel 22 is to prevent axial displacement of the beam 20 with respect to the mounting table 24. Ordinarily both the beam 20 and ~he table 24 will be substantially horizontal as depicted, but this is not necessary for the proper operation of the ap-paratus. Rollers 28a and b, 30a and b, and 32 a and b are provided as depicted in Figure 3 to insure that the beam 20 is slidable within the channel 22. Since a downward loading of the boom load end will tend to force clockwise axial displacement of the beam 20 with respect to cylinder 26, rollers 28a and b, and 32a and b will ordinarily carry mos-t of the load.
The boom 12 is also pivotably mounted to support arms 34a and b at point 36. These support arms 34a and b in turn are pivotally mounted to the channel 22 at joint 1~9~337 38. Thus, as the boom 12 is raised and lowered, the boom, beam and support arm structure will pivot on joints 18, 36, and 38 to cause the beam to reciproca-te with respect to the channel 22 and the mounting table 24.
Drive means for raising and lowering the boom 12 ordinarily comprises a hydraulic pivot cylinder 40 having one end pivotally mounted to the channel at a point no closer to the boom pivot end than the support arm joint 38, and the other end pivotally mounted to the boom 12 at a point remote from the support arm boom joint 36. The term "re~te from" means only that the joints may not be coaxial.
As depicted in the Figures, this pivot cylinder joint 42 is mounted to the boom 12 via plate 44 which is rigidly secured to the boom and which lies closer to the boom load end than does support arm joint 36. Also as depicted in the Figures, the other end of the pivot cylinder 40 is pivotally con-` nected to the channel 22 at joint 38, coaxial with the point at which the support arm is mounted to the channel. This - joint 38 will be further described hereinbelow.
While the above-described means of driving the lift is the preferred design, other means (not depicted) may alternately be utilized. For example, sliding beam 20 and rollers 18a and b, 30a and b, and 32a and b may act as a rack and pinion so that rotation of the rollers in either direction will change the lateral position of the beam 20, thus causing a change in the vertical position of the beam load end.
As stated hereinabove, the channel 22 is rotatable with respect to the mounting table 24. This feature obviously increases the versatility of the lift to a substantial degree.
l~G337~
The channel is rotatable on the vertical cylinder 26 which, as depicted in Figure 2, is offset from the channel 22 and the remainder of the boom apparatus. The channel 22 is mounted on the vertical cylinder 26 by the member 45 wllicl extends from the channel 22 and surrounds the vertical cylinder 26. Extending from member 45 is a leg 46 to which is pivotally mounted the rotational drive means, here a conventional hydraulic cylinder 48. The opposite end of this cylinder 48 is pivotally mounted to the mounting table 24.
One of the advantages of the present invention is that it allows a load to be elevated along a path which is much closer to a vertical line than do conventional booms which, when inextensible, swing the load in an arc. To provide a crane which can elevate a load along a line which is even closer to vertical, a telescoping section 50 can be added to the apparatus along with a telescoping cylinder 52.
As shown, one end of the telescoping cylinder 52 is pivotally connected to a support arm extension 56 at joint 58. The telescoping cylinder itself need not be extensible, i.e., it may be rigid. As the boom is adjusted to various levels of inclination, the movement of the support arm extension causes the telescoping cylinder to automatically extend and retract the telescoping section of the boom. ~s sllowll in the Figures, however, the telescoping cylinder 52 ordinarily is a conventional extensible hydraulic cylinder. This pro-vides a crane with even greater versatility.
As indicated in the Figures, the slidable beam 20 is ordinarily of rectangular configuration. The pivotable boom 12 and its telescoping section 50 are preferably also ~i, .`J. ~`>
1~9633~7 rectangular in cross section. Thus, the rollcrs 18a and b, 30a and b, and 32a and b are mounted on opposite sides of the slidable beam 20. Similarly, joints 18 and 36 extend across the entire cross section of the boom. Bc~m 1~
60a and 60b extend from each side of the end portion of the beam to meet legs 62a and 62b (not visible) at pivo-t joint 18. A suitable bearing 64 is provided.
As shown in Figure 2 the support arms 34a and b extend between joints 36 and 38, one Oll each side of the boom 12. The support arm extension 56 is ordinarily a extension of one of these arms since the telescoping cylinder 52 extends from joint 58 to only one side of the telescoping section 50 at joint 58.
As mentioned hereinabove and shown in Figurc 2, the points at which the support arms 34 and thc pivot cylinder 40 are mounted to the channel 22 are preferably coaxial at joint 38. A joint plate 66 is fixed to tlle top of the channel and extends across the entire cross section of the slidable beam 20. This joint 38 is actually comprised of three separate joints, with the support arms 34a and b pivotable on pins 68a and b, respectively. The pivot cylinder pivots on pin 70.
The mounting table 24 to which the above-described apparatus is mounted is preferably vertically adjustable above a base 72. The means for raising and lowering the table 24 may be of scissors design, such as that described in my U.S. patent No. 4,088,203 issued May 9, 1978. This scissors mechanism shown generally at 74 includes scissors arms 76 and power cylinders 78. The base 72 is preferably provided with wheels 80 to insure ~9~33~
., .
mobility. Brakes (not shown) would also be desirable.
The scissors mechanism 74 may also be of the telescoping type for greater lift, as described in my Canadian co-pending application Serial No. 290,775, filed November 14, 1977.
In operation the above-described scissors mechanism co-operates with the pivotable boom apparatus to provide an aerial lift with greater reaching range. Figures 4 and 5 show the boom in raised and lowered positions, respectively, and Figure 1 shows it in an intermediate position. A box 82 is included in these Figures to show that the aerial lift provides a reaching capability to all portions of the wall 84 with which the box 82 abuts. If the boom apparatus alone was mounted adjacent the wheels 80, the area indicated generally at X would be unreachable. Assuming the box 82 was substantially lower and the scissors mechanism 74 was fully collapsed, a conventional non-extensible boom would - be unable to reach both area X and the area indicated at Y
since the boom load end would necessarily move in a arc.
With the boom in the fully lowered position of Figure 5 the pivot cylinder 40 is fully retracted and the slidable beam 20 is fully extended from the channel 22.
The basket 14 is in its lowest position, nearly abutting the wall 84. To elevate the boom 12 the operator starts to extend the pivot cylinder 40, resulting in a rotational movement between joints 42 and 36. This causes joint 36 to swing upward and to the left, and the beam 20 to retract into the channel 22. The movement of the support arm ex-tension 56 toward the boom load end causes the telescoping cylinder 52 to extend the telescoping section 50 of the boo ~ .
33'7 12, thus causing the basket 14 to elevate and remain in close proximity to the wall 84. To reach the position shown in Figure 4, the pivot cylinder 4Q is fully extended, causing the beam 20 to fully retract through the channel 22, and causing joint 36 to swing to its uppermost position. At the same time telescoping section 50 has become fully fixed extended.
To lower the apparatus, the pivot cylinder 40 is retracted and the process is repeated. If lateral movement of the - basket is desired, the boom telescoping section 50 can be further extended or retracted by activating the telescoping cylinder 52. For axial translation the rotation drive cylinder 48 is utilized. To rotate the boom apparatus in a clockwise direction with reference to Figure 3, the rotation drive cylinder 48 is retracted and for counter-clockwise rotation the cylinder is extended.
Referring now to Figures 6-10, there is ShOWII all alternate embodiment 100 of the previously described aerial lift. The alternate aerial lift 100 employs the same principles of boom extension as described previously and additionally achieves greater elevational height. As shown in Figures 6 (top view) and 7 (side view) the aerial lift 100 is mounted on a wheeled supporting frame 102. Rotational movement of the lift 100 is provided by a swivel cylinder 104 which may be powered by conventional means (not shown) for rotating the lift with respect to the frame 102.
Mounted atop the cylinder 104 is a platform 106 for pivotally supporting the upper structure of the lift 100.
Connection between the platform 106 and the upper structure of the lift 100 is made at pivot points 108, 110, 112, and 114 (best seen in Figure 6) to which a pair of pivotable rods ~, ~
, ., ~v, ., 116 and 118 are connected. As explained in more detail here-inafter, the rods 116 and 118 rotate about their longitudi-nal axis as the lift is raised. In addition, the rod 118 moves horizontally within a channel 120 (Figure 7) as the lift 100 moves vertically.
Rigidly connected to the rod 116 is a pair of support arms 122 and 124, the latter of which is shown in Figure 10 which illustrates a portion of the reverse side of the lift 100. Thus, as the rod 116 pivots about its longi-tudinal axis, the support arms 122 and 124 will pivot upwardly as shown in Figures 8, 9 and 10.
Rigidly connected to the rod 118 is a three pieceextensible boom comprising a pivot end 126, an intermediate section 128, and an upper section 130, from the latter of which a load, shown in the form of a fork lift 132, extends.
The intermediate boom section 128 telescopes within the pivot end 126 and the upper boom section 130 telescopes within the intermediate section 128 as best shown in Figure 8. To pivot the section 126 during elevation of the lift 100, the pivot end 126 includes a rigidly connected offset portion 134 coupled to a boom sleeve 136. The sleeve 136 slides on a boom shaft 138 which is rigidly connected to the rod 118 and the sleeve 136 via the shaft 138 permits the lift 100 to be elevated to a relatively great height without the use of an additional scissors-type scaffold. In effect, a small scissors-type scaffold is built into the lift 100.
Referring now to the support arm 122 (Figures 8 and 9), it includes a support arm shaft 140 upon which a sup-port arm sleeve 142 rides in a telescoping manner. The sup-port arm sleeve 142 is pivotally coupled to the boom sleeve136 at 144.
~1~9~i337 Extendiny beyond the boom and the pivot 144 is a support arm extension 146 which, in this embodiment, is an integral extension of -the support arm sleeve 142. Pivotally coupled to the support arm extension 146 at 148 is a rigid linkage which preferably includes a telescoping cylinder 150 and a bar 152. One end of the bar 152 is fixed to the inter-mediate boom section 128 at 154 and the other end thereof is pivotally connected to the cylinder 150 at 156. This connection between the intermediate boom section 128 and the support arm extension 146 causes the intermediate boom secti~n 128 to telescope or extend out of the pivot section 126 as the lift 100 is elevated.
To extend the upper boom section 130, a cable 158 (Figures 8 and 9) is run from a connection 160 on the pivot boom ena 126, through a cable guide 162, around a sheave 164 mounted on the intermediate boom section 128, back down l through the intermediate boom section 128, and connected to the bottom of the upper boom section 130. The connection of the cable 158 is conventional and is, therefore, not shown in detail. Suffice it to say that the cable 158 pulls the upper boom section 130 out of the intermediate boom section 128 as the latter is extended.
The means by which the lift 100 is elevated is shown most clearly in Figures 9 and 10 to which reference is now made. As shown, one end of a telescoping cylinder 166 is pivotally connected to the boom pivot end 126 at 168.
The other end of the cylinder 166 is pivotally connected to a bracket 170 at 172. The bracket 170, in turn, is connected to the support arm 124 (Figure 10). As with the support arm 122, the support arm 124 also includes a support arm .
1~ii96337 shaft 174 telescoped wi-thin a suppor-t arm sleeve 176. The shaft 174 is mounted on the rod 116 (Figure 6) for rotation therewith as the lift 100 rises. The sleeve 176 is pivotally coupled to the boom pivot end 126 at 180.
As described above, the boom pivot end 126 and the support arms 122 and 124 each include a shaft and a sleeve in telescoping relation. To extend the various sleeves upwardly from their respective shafts, a set of link arms which pull the sleeves upwardly about the shafts are included.
More specifically, and as shown in Figure 9, a link arm 182 is piv~tally coupled at one end to the support arm sleeve 142 at 184 and at its other end to a bracket 186 at 188.
The bracket 188, in turn, is mounted on the rod 118 for ro-tation therewith.
Another link arm 190 is pivotally coupled at 192 to the boom sleeve 136 and at its other end to a bracket 194 at 196. The bracket 194, in turn, is mounted on the rod 116 for rotation therewith.
Referring to Figure 10, there is shown a pair of link arms 198 and 200 for raising the support arm sleeve 176 and the boom sleeve 136, respectively. Specifically, the link arm 198 is pivotally coupled at one end to the support arm sleeve 176 at 202 and at its other end to a bracket 204 at 206. The bracket 204 is mounted on the rod 118 for rotation therewith. As shown, the rod 118 engages a channel 205 for rotation and horizontal movement therein.
The link arm 200 is pivotally coupled at one end to the boom sleeve 136 at 208 and at its other end to a bracket 210 at 212. The bracket 210 is mounted on the rod 116 for rotation therewith.
~9G33~
In operation, the raising of the lift 100 is ini-tiated by actuation of the cylinder 166. This raises the boom pivot end 126 and the support arms 122 (Figure 9) and 124 (Figure 10). Simultaneously, the rods 116 and 118 (Figure 6) begin to rotate abou-t their longitudinal axes, thereby also rotating the brackets 186 and 194 (Figure 9) and the brackets 204 and 210 (Figure 10). As the brackets 186 and 194 rotate, they cause the link arms 182 and 190 to telescope the support arm sleeve 142 and the boom sleeve 136 upwardly. Concurrently, the rotation of the brackets 204 and 210 causes the link arms 198 and 200 (Figure 10) to telescope the boom sleeve 136 and the support arm sleeve 176 upwardly. As a result of the simultaneous extension of the boom sleeve 136 and the support arm sleeves 142 and 176, the point 144 (connecting the support arms to the boom pivot end 126) rises substantially vertically.
As the support arm sleeve 142 extends, the con-nection 148 between the cylinder 150 and the support arm extension 146 moves upwardly and to the left in Figure 9.
This motion is translated to the intermediate boom section 128 via the cylinder 150 (unextended) and the bar 152. As a result, the intermediate boom section 128 is extended out of the boom pivot end 126 such that the upper end of the intermediate boom section 126 rises substantially vertically.
The extension of the intermediate boom section 128 results in the upper boom section 130 being simul-taneously extended by the cable 158, thereby raising the fork lift 132 substantially vertically.
During the raising of the lift 100, the point ~633t7 110 on the rod 118 moves from its initial position shown in Figure 7 to the right as shown in Figure 9. This motion occurs as the lift 100 extends somewhat more than half its maximum elevation. When the cylinder 166 is actuated to raise the lift further, the point 110 moves to the left until it reaches approximately its original position. At this point, the lif-t 100 will have been raised to its fullest elevation which is greater than that shown in Figure 9~
Up un-til now, the operation of the lift 100 has been described with the cylinder 150 acting merely to translate the motion of the support arm extension 146 to the bar 152 and thence to the intermediate boom section 128.
However, if greater extension of the intermediate boom section 128 is desired, the cylinder 150 is actuated. As shown in the dashed lines of Figure 9, the actuation of the cylinder 150 drives a cylinder rod 214 in the direction of the arrow 216. As a result, the intermediate boom section 128 is further extended in the direction of the arrow 218.
The distance between the solid line sheave 164 and the dashed line sheave 164 indicates the increased extension of the intermediate boom section 128 resulting from the actuation of the cylinder 150. In addition, because the intermediate boom section 128 and the upper boom section 130 are joined by the cable 158, this further extension of the intermediate boom section 128 also results in further extension of the upper boom section 130.
As illustrated in Figure 9, the cylinder 150 may be actuated prior to full extension of the cylinder 166 and oper-ates to independently extend the intermediate and upper boomsections 128 and 130.
~3i963;37 When the cylinder 166 is deactuated, the lift 100 folds from the extension shown in Figure 9 to that of Figure 8, and finally to the folded position shown in Figure 7.
Thus, a very compact but high reaching lift is provided by the illustrated structure.
In the descrip-tion above, it has been mentioned that the cylinder 150 and the bar 152 rigidly couple the support arm extension 146 to the intermediate boom section 128. Obviously, the components have a number of pivot points and the cylinder 150 may be extended and retracted as required. A rigid coupling is, therefore, meant to include any linkage which translates the pivoting motion of the support arm extension 146 to a sliding motion of the intermediate boom section 128.
Referring now to Figure 11, there is shown another embodiment of the invention which extends a boom in accord-ance with the principles set forth above but which achieves even greater height. The aerial lift 220 of Figure 11 is shown in an extended position in which a fork lift 222 is elevated, and also in its folded position at the bottom of Figure 11.
The lift 220 may be mounted on a wheeled platform 224 as shown, above which a supporting base 226 is mounted.
The base 226 supports a pair of scissors members 228 and 230, preferably of the telescoping variety as shown, and pivot-ally coupled at 231.
Pivotally mounted to the scissors member 228 at 232 is a boom pivot end 234. The pivot end 234 receives within it, in telescoping relation, an intermediate boom section 236 and an upper boom section 238 telescopes within 1~9~;337 the intermediate section 236. The fork lift 222 is mounted at the upper end of the upper boom section 238. As in the previously described embodiment, the upper boom section 238 is caused to extend out of the intermediate section 236 by a cable 240 whenever the intermediate section 236 extends. As shown, one end of the cable 240 is fixed to the boom pivot end 234 at 242 and the other end passes through a cable guide 244, through a sheave 246, and is . attached in a conventional manner (not shown) to the bottom of the upper boom section 238.
Pivotally connected to the scissors member 230 at 248 is a support arm 250 for extending the intermediate boom section 236. The support arm 250 is pivotally coupled to the boom pivot end 234 at 252 and extends beyond the pivot end 234 as a support arm extension 254. When the lift 220 is elevated, the support arm 250 pivots about the point 248 and the extension 254 moves upwardly and to the left in Figure 11. The pivoting motion of the support arm 250 is translated to a sliding or telescoping motion of the intermediate boom section 236 by means of a rigid coupling which, as shown, is preferably an extendable cylinder 256 and a bar 258. One end of the cylinder 256 is pivotally coupled at 260 to the support arm extension 254 and the other end thereof is pivotally coupled to the bar 258 at 262.
The bar 262, in turn, is connected to the intermediate boom section 236 at 264.
Referring now to the scissors members 228, it preferably comprises a sleeve 266 in telescoping relation with a shaft 268, the latter of which is mounted on a rotatable rod 270. The rod 270 extends in a plane perpen-33~;' dicular to the plane of Figure 11 and has its ends mounted for rotation in the supporting base 226, similarly to the rod 116 of Figure 6.
The scissors member 230 is similar to the scissors member 228 in that member 230 also comprises a sleeve 272 in telescoping relation with a shaft 274. The latter is mounted on a rod 276 which extends in a plane perpendicular to the plane of Figure 11, similarly to the rod 118 of Figure 6. One end of the rod 276 is mounted for rotation and horizontal sliding motion in a channel 278 in the supporting base 226. The other end of the rod 276 is mounted for rotation and sliding horizontal motion in a channel (not shown) on the opposite side of the supporting base 226.
To telescope the scissors members 228 and 230, a pair of link bars 280 and 282 couple the sleeves 266 and 272 to the rods 270 and 276. The ends of the link bars 280 and 282 may be mounted on the rods 270 and 276 in a manner similar to that of the bars 182 and 190 of Figure 9.
Although not shown in the view of Figure 11, another scissors member may be included paralleling the member 228 but on the opposite side of the scissors member 230. This additional scissors member would preferably have a shaft section mounted on the rod 270 and a sleeve section pivotally coupled at 232 to the boom pivot end 234. An example of such construction is illustrated in Figure 2 of my co-pending application Serial No. 290,775.
In order to elevate the lift 220, a pair of extendable cylinders 284 and 286 may be connected as shown, the cylinder 284 being pivotally connected between the ,' '~
~1633~
support arm 250 and the scissors 230, and the cylinder 286 bein~ pivotally coupled between the boom pivot end 234 and the scissors 228. Upon the actuation of these cylinders, their cylinder rods 288 and 290 extend as shown, whereupon the scissors members 228 and 230 pivot about the longitudinal axes of the rods 270 and 276. In response to such pivoting, the link arms 280 and 282 extend the sleeves 266 and 272 upwardly. Simultaneously, the boom pivot end 234 is raised and the support arm 250 pivots about the point 248 to swing the support arm extension 254 upwardly and to the left. The cylinder 256 and the bar 258 then urge the intermediate boom section 236 upwardly to extend out of the boom pivot end 234. Simultaneously, the upper boom section 238 is extended out of the intermediate section 236, as a result of which the fork lift 222 is raised substantially vertically.
To achieve even further extension of the inter-mediate and upper boom sections, the cylinder 256 may be extended as shown in the dashed lines. This extension of the cylinder 256 urges the bar 258 upwardly, whereupon the intermediate boom section 236 and the upper boom section 238 further extend the fork lift 222 as shown in the dashed lines.
When the cylinders 256, 284 and 286 are deactivated, the lift 220 folds compactly as shown at the bottom of Figure 11. A housing 292 may be mounted on the base 226 as shown for enclosing a control mechanism for actuating the various cylinders.
Of course, it should be understood that various changes and modifications to the preferred embodiments des-cribed therein will be apparent to those skilled in the l~g633~
art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is, therefore, intended that such changes and modifications be covered by the following claims.
c.
Claims (11)
1. An aerial lift, comprising:
a supporting means;
a boom having a load end, a lower section terminating in a pivot end, an intermediate section telescoping with the lower section, and an upper section telescoping with the intermediate section;
means for mounting said boom to said supporting means such that said pivot end is horizontally movable;
a support arm extending between and pivotally connected to said support means and said boom;
means rigidly coupling the support arm to the intermediate section of the boom;
means for extending the upper section of the boom as the intermediate section is extended;
means for raising and lowering said boom such that, as said boom is raised, the pivot end of said boom moves substantially horizontally, said support arm pivots about said supporting means and said boom, and said means coupling said support arm to the intermediate section of said boom causes said intermediate section to extend for raising the load end of the boom substantially vertically.
a supporting means;
a boom having a load end, a lower section terminating in a pivot end, an intermediate section telescoping with the lower section, and an upper section telescoping with the intermediate section;
means for mounting said boom to said supporting means such that said pivot end is horizontally movable;
a support arm extending between and pivotally connected to said support means and said boom;
means rigidly coupling the support arm to the intermediate section of the boom;
means for extending the upper section of the boom as the intermediate section is extended;
means for raising and lowering said boom such that, as said boom is raised, the pivot end of said boom moves substantially horizontally, said support arm pivots about said supporting means and said boom, and said means coupling said support arm to the intermediate section of said boom causes said intermediate section to extend for raising the load end of the boom substantially vertically.
2. An aerial lift as set forth in Claim 1, wherein said means rigidly coupling the support arm to the intermediate section of the boom includes an extension of said support arm extending beyond said boom, and a telescoping cylinder connect-ed between said support arm extension and the intermediate section of the boom for further extending the intermediate section of the boom independently of the pivoting of said support arm.
3. An aerial lift according to Claim 1, wherein the boom pivot end and the support arm each include telescoping sections adapted to be simultaneously extended when the boom is raised to increase the height to which the boom can be elevated.
4. An aerial lift as set forth in Claim 1, wherein the pivot end of the boom includes a boom shaft telescoped in a boom sleeve, wherein said support arm includes a support arm shaft telescoped in a support arm sleeve, and further including at least one link arm connecting the boom sleeve to the support arm shaft and at least one link arm connecting the boom shaft to the support arm sleeve such that, as said boom is elevated and said support arm pivots, the link arms telescope the boom sleeve and the support arm sleeve upwardly to further elevate the boom.
5. An aerial lift as set forth in Claim 3 wherein said means for extending the upper section of the boom includes a cable assembly connected between the intermediate and upper boom sections for pulling the upper section upwardly as the intermediate section extends.
6. An aerial lift as set forth in Claim 4 wherein said means rigidly coupling the support arm to the intermediate section of the boom includes an extension of the support arm sleeve extending beyond said boom and means connected between the support arm sleeve extension and the extensible end of the boom.
7. An aerial lift as set forth in Claim 6 wherein said means connected between the support arm sleeve extension and the intermediate section of the boom includes an extensible cylinder for further extending the intermediate section of the boom independently of the pivoting of said support arm.
8. An aerial lift as set forth in Claim 3, wherein said means rigidly coupling the support arm to the intermediate section of the boom includes an extension of said support arm sleeve extending beyond the lower section of said boom, and means connected between said support arm sleeve extension and the intermediate section of the boom for further extending the intermediate section of the boom independently of the pivoting of said support arm.
9. An aerial lift as set forth in Claim 8 wherein said means for further extending the intermediate section of the boom includes an extensible cylinder.
10. An aerial lift as set forth in Claim 1, 2 or 3 further including means for rotating said boom about a substantially vertical axis.
11. An aerial lift as set forth in Claim 4, 8 or 9 further including means for rotating said boom about a substantially vertical axis.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA353,201A CA1096338A (en) | 1977-10-05 | 1980-06-02 | Telescoping aerial lift |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/839,721 US4188757A (en) | 1977-01-12 | 1977-10-05 | Telescoping aerial lift |
| US839,721 | 1977-10-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1096337A true CA1096337A (en) | 1981-02-24 |
Family
ID=25280482
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA305,705A Expired CA1096337A (en) | 1977-10-05 | 1978-06-19 | Telescoping aerial lift |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS5458916A (en) |
| BR (1) | BR7802950A (en) |
| CA (1) | CA1096337A (en) |
| DE (2) | DE2843587C2 (en) |
| ES (2) | ES473887A1 (en) |
| FR (1) | FR2405213A2 (en) |
| GB (2) | GB1594178A (en) |
| IT (1) | IT1160630B (en) |
| SE (2) | SE419744B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4130178A (en) * | 1977-03-28 | 1978-12-19 | Smith Raymond E Jun | Elevating device |
| DE3120338C2 (en) * | 1981-05-22 | 1987-04-23 | Eisenwerke Kaiserslautern Entwicklungsgesellschaft mbH, 6750 Kaiserslautern | Combat vehicle |
| SE446525B (en) * | 1981-10-19 | 1986-09-22 | Soder Harry & Son Stenhuggeri | DEVICE FOR PREPARING THE PIECE OF THE DIFFERENT DOCTOR |
| JPS592800U (en) * | 1982-06-28 | 1984-01-09 | 株式会社犬塚製作所 | aerial work vehicle |
| JPS59195200U (en) * | 1983-06-14 | 1984-12-25 | 株式会社豊田自動織機製作所 | Vertical aerial work vehicle |
| US4694930A (en) * | 1985-04-03 | 1987-09-22 | Kabushiki Kaisha Hikoma Seisakusho | Lifting apparatus |
| JPH03127786U (en) * | 1990-04-06 | 1991-12-24 | ||
| JPH0747471B2 (en) * | 1990-10-31 | 1995-05-24 | 株式会社ジャパニック | lift device |
| US5249642A (en) * | 1991-03-22 | 1993-10-05 | Japanic Corporation | Lifting apparatus |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE444147C (en) * | 1925-05-02 | 1927-05-11 | Alfred Simon | Jib crane |
| US2003581A (en) * | 1934-09-06 | 1935-06-04 | Jr Charles Daly | Adjustable scaffold |
| CH234846A (en) * | 1941-02-20 | 1944-10-31 | Otto Dr Becker Alfred | Lifting device. |
| DE736623C (en) * | 1941-02-21 | 1943-06-28 | Dr Alfred Otto Becker | Lifting device |
| DE1080750B (en) * | 1955-05-16 | 1960-04-28 | Wilhelm Ludowici Dr Ing | Lifting device with Nuernberger scissors |
| DE2227471B2 (en) * | 1972-06-06 | 1976-01-08 | Heinz Dipl.-Ing. Wetzikon Schellenberg (Schweiz) | Mobile telescopic lifting mechanism - has ram opening at bottom with fluid passage through ram and piston |
| US3820631A (en) * | 1973-03-08 | 1974-06-28 | Aircraft Mechanics | Platform lift mechanism |
| US4070807A (en) * | 1977-01-12 | 1978-01-31 | Smith Raymond E Jun | Aerial lift |
| US4130178A (en) * | 1977-03-28 | 1978-12-19 | Smith Raymond E Jun | Elevating device |
-
1978
- 1978-04-27 GB GB28004/79A patent/GB1594178A/en not_active Expired
- 1978-04-27 GB GB16764/78A patent/GB1594177A/en not_active Expired
- 1978-05-11 BR BR7802950A patent/BR7802950A/en unknown
- 1978-06-12 FR FR7817554A patent/FR2405213A2/en active Granted
- 1978-06-19 CA CA305,705A patent/CA1096337A/en not_active Expired
- 1978-09-04 IT IT69039/78A patent/IT1160630B/en active
- 1978-09-07 SE SE7809446A patent/SE419744B/en not_active IP Right Cessation
- 1978-09-27 JP JP11905278A patent/JPS5458916A/en active Granted
- 1978-10-03 ES ES473887A patent/ES473887A1/en not_active Expired
- 1978-10-05 DE DE2843587A patent/DE2843587C2/en not_active Expired
- 1978-10-05 DE DE2857563A patent/DE2857563C2/en not_active Expired
-
1979
- 1979-05-16 ES ES480625A patent/ES480625A1/en not_active Expired
-
1980
- 1980-04-18 SE SE8002941A patent/SE431083B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE2857563C2 (en) | 1986-12-18 |
| FR2405213B2 (en) | 1984-05-18 |
| ES473887A1 (en) | 1979-10-16 |
| SE419744B (en) | 1981-08-24 |
| SE7809446L (en) | 1979-04-06 |
| BR7802950A (en) | 1979-05-22 |
| JPS5725480B2 (en) | 1982-05-29 |
| GB1594178A (en) | 1981-07-30 |
| FR2405213A2 (en) | 1979-05-04 |
| IT7869039A0 (en) | 1978-09-04 |
| DE2843587A1 (en) | 1979-04-12 |
| SE431083B (en) | 1984-01-16 |
| SE8002941L (en) | 1980-04-18 |
| JPS5458916A (en) | 1979-05-12 |
| DE2843587C2 (en) | 1986-08-07 |
| ES480625A1 (en) | 1980-01-16 |
| GB1594177A (en) | 1981-07-30 |
| IT1160630B (en) | 1987-03-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |