GB1591116A

GB1591116A - Elevating hand truck

Info

Publication number: GB1591116A
Application number: GB3897777A
Authority: GB
Original assignee: Jeavons P K
Current assignee: Jeavons P K
Priority date: 1976-09-27
Filing date: 1977-09-19
Publication date: 1981-06-17
Also published as: DE7729766U1; FR2365514A1; DE2743214A1; NL7710378A

Description

(54) ELEVATING HAND TRUCK (71) I, PETER KENNETH JEAVONS, trading as Power Truck Industries, a Canadian citizen of P.O. Box 491, Simcoe, Ontario, Canada, do hereby declare the invention for which I pray that a Patent may be granted to me, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates generally to a hand truck and more particularly to a novel type of elevating hand truck.

Conventional non-elevating hand trucks can bring a load to the tail of a vehicle. Unless the vehicle is provided with an expensive tail-gate elevator or the like, transfer of the load from the hand truck to the vehicle can be acomplished only by manual lifting. Similarly, when conventional hand trucks are used to carry a load up or down a flight of stairs, the hand truck carrying the load must be manhandled step by step up or down the stairs.

These activities are not only hazardous but require the services of two or more men.

More advanced prior art hand trucks provide devices for overcoming some of the above problems as by use of belt or chain travel devices or telescoping elevator devices.

For example, in some prior art hand trucks a belt or chain travelling device is affixed to the underside of the truck frame. This allows the truck to be moved with relative ease over a flight of stairs. When the height of the steps is relatively large, for example in excess of about 30 centimeters, these devices become effectively inoperative.

Certain other prior art elevator hand trucks use a telescoping inner sub frame which telescope into the outer main frame of the hand truck. The inner sub frame carries the load, and may be extended beyond the outer main frame.

The wheels of the truck are attached to the main frame. As such, the load moves relative to the outer main frame and away from the wheels. After extension, the wheels of the outer main frame can then be placed on a next elevated step and the inner sub-frame telescoped back into the outer main frame whereby the load is restored to its original position relative to the frame and the truck and load now are at an elevated position from the point of initiation.

This telescoping is usually achieved mechanically by a prime mover powering either a hydraulic cylinder or chain or screw like mechanism, as in Canadian patent 603 369 issued August 16, 1960 to Chester E. Rhodes for "Elevator Hand Truck" (U.S. Patent 2 904 201 issued 15 September, 1959).

A difficulty in elevator hand trucks, such as those of Rhodes and various improvements thereof, is that by virtue of the telescoping inner sub-frame there is migration of the load relative to the outer main frame. This necessitates additional care during usage of the elevator hand truck. With heavy or awkward loads there is need for two lateral strap belts to hold the load adequately on the telescopingly moving sub-frame.

According to the present invention, there is provided an elevating hand truck for carrying a load over a smooth running surface or between stepped elevations, comprising: a rigid main frame having parallel inward facing channel section side members extending between two fixed ends and defining an article supporting surface therebetween, said frame having an article-supporting ledge at one of the fixed ends and handle means at the other end, a subframe longitudinally movable between and having guide members engaging within said channel section side members, a set of wheels secured to the under portion of one end of the sub frame to form therewith a trolley, said wheel set being adapted, on longitudinal movement of said sub frame between the side members, to travel between the article supporting ledge and said handle of the main frame towards and away from said article-supporting ledge, and power means for moving the subframe of the trolley within said main frame, the wheel set of said trolley acting as a movable fulcrum with respect to the main frame, said power means placing the wheel set of the trolley at any predetermined point beneath the main frame.

Arrangements embodying the invention will now be described by way of example and with reference to the accompanying drawings in which: Figures 1 to 4 are somewhat schematic views to illustrate the method by which a load is transfered along a stair case utilizing the elevating hand truck of the invention.

Figures 5 and 6 illustrate, somewhat schematically, the method of employing the truck for elevating the load onto a lorry.

Figures 7 to 10 are somewhat schematic views to illustrate comparatively a method by which a load is transferred along a stair case employing a prior art elevating hand truck.

Figures 11 and 12 illustrate somewhat schematically a method of employing said prior art hand truck to elevate a load onto a lorry.

Figure 13 is a front elevation of an elevating hand truck according to one embodiment of the present invention.

Figure 14 is a longitudinal sectional view along lines XIV-XIV of the elevating hand truck of Figure 13.

Figure 15 is a sectional view along lines XV-XV of Figure 13.

Figure 16 is a front view of an alternative embodiment of the present invention.

Figure 17 is a sectional view along lines XVII-XVII of Figure 16.

Figure 18 is a perspective view of a further embodiment of the hand truck including a transporter shown holding the load in an inclined position.

Figure 19 is a perspective view of the truck and transporter of Figure 18, with the transporter holding the load in the horizontal position.

Figure 20 is a perspective view of the hand truck and transporter in an intermediate position between the inclined and horizontal positions of Figures 18 and 19.

Figures 21 to 23 are perspective details, Figure 21 showing an articulating connection between the transporter and the main frame; Figure 22 showing an articulating connection between the transporter and a support arm; and Figure 23 showing an articulating connection between the transporter and a trolley.

Referring now to Figure 13, an elevating hand truck 20 comprises a main frame 21 having at its lower end an article supporting ledge 22 extending forwardly from said frame.

A trolley 23 has a sub-frame which carries a transverse axle 24 onto which truck running wheels 25 are mounted. The trolley 23 is caused to move along the main frame 21 in the following manner. A load screw 26 extends from the upper portion of the frame, where it is terminated at a bearing 27, to a prime mover 28 located at the other end of the frame. The prime mover 28 preferably is a reversible electric motor. The sides of the frame are formed by inward facing channel members within each of which is defined a race 30, within which are engaged fore and aft roller assemblies 31 of the trolley so that the sub-frame can move longitudinally between the frame side members.

Each roller assembly includes a transverse axle 32 which terminates in rollers 33. A ball nut 34 is affixed to the trolley sub-frame via an upper cross member 36 and depending thrust plate 37'. Rotation of the load screw 26 in the ball nut 34 is translated into relative movement of the trolley sub-frame relative to the main frame 21. This effectively locates the axle 24 (which acts as the fulcrum to the load) and hence the truck running wheels 25 anywhere along but within the frame 21. As shown in Figures 14 and 15 the axle 24 extends through lateral support members 29 depending from and attached to the sub-frame trolley of the 23.

A power pack 38, for example batteries, is located near the top of the frame and power from the power pack is delivered through suitable control means, not shown, to a prime mover 28 to rotate the load screw 26 in either direction.

A friction brake 40 is mounted on a lower cross member 41 of the main frame. The prime mover 28 is also affixed to this lower cross member 41 but extends between it and the inside face of the prolongation of the lifting ledge 22.

The friction brake 40 consists of an adjustable belt 42 which partially circumscribes a drum 43 coaxially affixed to the screw 26 near the union of the screw with the rotating axle of the prime mover 28. The belt 42 is fastened at one end to a gusset 45 mounted on the cross member 41. The outer end is secured to a fastening bolt by a wing nut 44. When the wing nut 44 is turned down on the bolt, the friction between the drum 43 and the belt 42 is increased and an enhanced braking effort is applied to the screw 26 at all times whether the prime mover 28 is in operation or not. The prime mover 28 is such that it is of sufficient power to overcome the brake cfrition and to drive the trolley 23 into any position along but within the frame 21.This friction brake mechanism 40 assures that when the trolley is located in a position and a large load is on the support ledge 22, the screw 26 will not turn when no power is applied to the prime mover, and thus allow the wheels to migrate relative to the main frame.

The frame 21 is provided with slits 39 which act as handles. An auxiliary U-shaped handle 46 may be affixed directly to the trolley 23 (see Figure 13) via a pair of bolts.

In another embodiment, Figure 16, the handle 46 is affixed directly to the trolley 23 as by welding. The trolley has only one roller assembly 32, the other being omitted. Instead, the side members of the main frame are provided near their upper ends with a pair of idler wheels 47. The side members of the handle 46 are U shaped in section and extend outward embracing each of the idler wheels 47. In this manner the trolley 23 is held relatively stable in the frame 21 and a constant distance is maintained, irrespective of the location of the trolley vis a vis the frame, between the wheels 25 and the grip portion 48 of the auxiliary handle 46.

In one form of operation, referring to Figures 1 to 4, the elevating hand truck 20, carrying a load which rests on the article sup port ledge 22, is located at the bottom of a flight of stairs. It is tipped into the dotted position of Figure 1 and the prime mover 28 is activated to move the trolley 23 into an essentially midway position on the main frame 21.

The truck is tipped forward so that the wheels 25 rest on the second from the bottom step as in Figure 2. The prime mover is reversed and the trolley 23 moves relative to the frame toward the article support ledge 22. This effectively lifts the load off the ground. When the trolley 23 has been returned about half its distance from the base of the article support ledge 22 the load will have effectively moved to an elevation relative to the first step as shown in Figure 3. The truck is then tilted back as shown in Figure 4, and the procedure repeated step by step until the load has climbed the flight of stairs.

By reversing the procedure the load can be moved down a flight of stairs.

Referring to Figures 5 and 6, it will be seen that, using a similar procedure to that described above, the load may be moved from the ground onto a lorry.

For a better understanding of the invention the prior art may be referred to. A prior art elevator hand truck 120 is shown in Figures 7 to 12. Figures 7 to 10 correspond, for the prior art elevator hand truck 120, to Figures 1 to 4 just described. On careful comparison of Figures 2 with 8, 3 with 10, and 4 with 9 it will be noted that the truck wheel 125 of the prior art device are rigidly affixed to the outer frame 121 of the prior art device; and that there is a telescoping inner sub-frame 121 that carries the article support ledge 122 and hence the load.

The inner frame is moved relative to the outer frame and to the wheels are attached to the outer frame. Hence, the load 143 moves relatively to the main frame. In my arrangement, the load is fixed relative to the main frame, and the trolley migrates along the main frame to position the wheels relatively to the load and the frame.

In Figures 18, 19 and 20, the hand truck 20 includes an auxiliary transporter 55. The transporter 55 includes a dolly frame 56 comprising two longitudinal lateral members 57 having their proximate ends attached to pivots 58 above the axle 24. The distal ends of the members 57 terminate at a cross member 58.

From each end of the cross member 58 depends a castor 59. A pair of support arms 60 are pivotay attached to the distal ends of the longitudinal members at 62 while the other end of each arm is detachably connected to a pivot anchor 63 affixed to the outside of the frame, 21. The pivot anchor 63 is provided with a securing pin 66 which holds the arms 60 on the pivot anchor. In this manner the arms 60 may be detached from the anchor 63 and folded down into adjacency with the longitudinal members or removed, whereupon the transporter may be folded into the frame 21 of the hand truck 20 and stored there out of the way, when not in use. To hold the transporter in its stored position, clips 68 are provided on the inside margins of the frame, as shown in Figure 23.

The arms 60 and the longitudinal members 57 are approximately equal in length so that the inclination of the truck, in its position of Figure 19 is approximately forty-five degrees.

To use the transporter, the trusk is placed in its vertical position (not shown) and the transporter arms 60 attached to pivot anchors 63.

The truck is tipped into the inclined transport position of Figure 20. As the motor 28 is activated to cause movement of the wheels of trolley 23 into the centre region of the frame 21, the hand truck assumes the transitional position of Figure 20, and then on further movement of the trolley 23, the horizontal position of Figure 18, wherein both wheels 25 and castors 59 are again in engagement with the running surface.

The load and truck 20 display a lower profile when in this horizontal position, and this permits their passage under counters and the like.

By reversing the procedure just explained, the load may be returned to its inclined position on the transporter.

WHAT I CLAIM IS: 1. An elevating hand truck for carrying a load over a smooth running surface or between stepped elevations, comprising: a rigid main frame having parallel inward facing channel section side members extending between two fixed ends and defining an article supporting surface therebetween, said frame having an article-supporting ledge at one of the fixed ends and handle means at the other end, a subframe longitudinally movable between and having guide members engaging within said channel section side members, a set of wheels secured to the under portion of one end of the subframe to form therewith a trolley, said wheel set being adapted, on longitudinal movement of said subframe between the side members, to travel between the article supporting ledge and said handle of the main frame towards and away from said article-supporting ledge, and power means for moving the subframe of the trolley within said main frame, the wheel set of said trolley acting as a movable fulcrum with respect to the main frame, said power means placing the wheel set of the trolley at any predetermined point beneath the main frame.

2. A hand truck as claimed in Claim 1, wherein the power means for moving the trolley includes a rotatable screw extending between the fixed ends of the main frame, a nut through which the screw extends, the nut being affixed to the sub frame of the trolley, and a reversible prime mover in driving connection with the screw, whereby rotation of the screw in either direction by the prime mover moves the wheel set of the trolley along the frame toward or

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. port ledge 22, is located at the bottom of a flight of stairs. It is tipped into the dotted position of Figure 1 and the prime mover 28 is activated to move the trolley 23 into an essentially midway position on the main frame 21. The truck is tipped forward so that the wheels 25 rest on the second from the bottom step as in Figure 2. The prime mover is reversed and the trolley 23 moves relative to the frame toward the article support ledge 22. This effectively lifts the load off the ground. When the trolley 23 has been returned about half its distance from the base of the article support ledge 22 the load will have effectively moved to an elevation relative to the first step as shown in Figure 3. The truck is then tilted back as shown in Figure 4, and the procedure repeated step by step until the load has climbed the flight of stairs. By reversing the procedure the load can be moved down a flight of stairs. Referring to Figures 5 and 6, it will be seen that, using a similar procedure to that described above, the load may be moved from the ground onto a lorry. For a better understanding of the invention the prior art may be referred to. A prior art elevator hand truck 120 is shown in Figures 7 to 12. Figures 7 to 10 correspond, for the prior art elevator hand truck 120, to Figures 1 to 4 just described. On careful comparison of Figures 2 with 8, 3 with 10, and 4 with 9 it will be noted that the truck wheel 125 of the prior art device are rigidly affixed to the outer frame 121 of the prior art device; and that there is a telescoping inner sub-frame 121 that carries the article support ledge 122 and hence the load. The inner frame is moved relative to the outer frame and to the wheels are attached to the outer frame. Hence, the load 143 moves relatively to the main frame. In my arrangement, the load is fixed relative to the main frame, and the trolley migrates along the main frame to position the wheels relatively to the load and the frame. In Figures 18, 19 and 20, the hand truck 20 includes an auxiliary transporter 55. The transporter 55 includes a dolly frame 56 comprising two longitudinal lateral members 57 having their proximate ends attached to pivots 58 above the axle 24. The distal ends of the members 57 terminate at a cross member 58. From each end of the cross member 58 depends a castor 59. A pair of support arms 60 are pivotay attached to the distal ends of the longitudinal members at 62 while the other end of each arm is detachably connected to a pivot anchor 63 affixed to the outside of the frame, 21. The pivot anchor 63 is provided with a securing pin 66 which holds the arms 60 on the pivot anchor. In this manner the arms 60 may be detached from the anchor 63 and folded down into adjacency with the longitudinal members or removed, whereupon the transporter may be folded into the frame 21 of the hand truck 20 and stored there out of the way, when not in use. To hold the transporter in its stored position, clips 68 are provided on the inside margins of the frame, as shown in Figure 23. The arms 60 and the longitudinal members 57 are approximately equal in length so that the inclination of the truck, in its position of Figure 19 is approximately forty-five degrees. To use the transporter, the trusk is placed in its vertical position (not shown) and the transporter arms 60 attached to pivot anchors 63. The truck is tipped into the inclined transport position of Figure 20. As the motor 28 is activated to cause movement of the wheels of trolley 23 into the centre region of the frame 21, the hand truck assumes the transitional position of Figure 20, and then on further movement of the trolley 23, the horizontal position of Figure 18, wherein both wheels 25 and castors 59 are again in engagement with the running surface. The load and truck 20 display a lower profile when in this horizontal position, and this permits their passage under counters and the like. By reversing the procedure just explained, the load may be returned to its inclined position on the transporter. WHAT I CLAIM IS:

1. An elevating hand truck for carrying a load over a smooth running surface or between stepped elevations, comprising: a rigid main frame having parallel inward facing channel section side members extending between two fixed ends and defining an article supporting surface therebetween, said frame having an article-supporting ledge at one of the fixed ends and handle means at the other end, a subframe longitudinally movable between and having guide members engaging within said channel section side members, a set of wheels secured to the under portion of one end of the subframe to form therewith a trolley, said wheel set being adapted, on longitudinal movement of said subframe between the side members, to travel between the article supporting ledge and said handle of the main frame towards and away from said article-supporting ledge, and power means for moving the subframe of the trolley within said main frame, the wheel set of said trolley acting as a movable fulcrum with respect to the main frame, said power means placing the wheel set of the trolley at any predetermined point beneath the main frame.

away from said article-supporting ledge.

3. A hand truck as claimed in Claim 1 or Claim 2, wherein an auxiliary handle means is provided which extends beyond the frame, said auxiliary handle means being fixedly attached to the trolley and hence relatively movable with the trolley with respect to the article-supporting ledge.

4. A hand truck as claimed in any one of the preceding Claims, further including a transporter that includes a dolly frame having a body structure with two ends, one end thereof pivotally affixed to the trolley, an articulating arm attached between the other end of the body structure and the first rigid frame, and castor means adapted to engage a running surface and depending from the body structure at said other end, whereby on movement of the trolley between the side members of said first rigid frame articulation takes place between the frame, transporter and trolley so as to move the castor means between a location supporting the frame in a position parallel to the supporting surface and a location supporting said frame in a position inclined to the supporting surface.

5. A hand truck according to Claim 1, substantially as described with reference to Figures 1 to 6 and 13 to 15, or Figures 16 and 17, or Figures 18 to 23, of the accompanying drawings.