Does it exist: Obstruction style lifting arm

[rslaback]

At work we have a somewhat regular task which entails installing a hydraulic pump set into a reservoir that is obstructed from the top but has a side access panel. The pump assemblies are anywhere from 60 to 120 pounds and you are trying to remove and reinstall them overtop of a pan 5 or so inches deep with hydraulic oil. An overhead crane exists that covers the entire footprint of the room. The ergonomics of this job absolutely **** and there is a fairly high mode of failure as it can be difficult to get the gaskets in place correctly when balancing and bolting it in.

Has anyone ever seen a commercially available offset lift arm similar to an obstruction style wrench but much bigger? Something that would allow us to use the crane from above but still be able to slide the pump in through the side access and then support it?

In my kindergarten CAD below the machine would be in green. The proposed lift arm would be yellow.



Custom building this isn't out of the question but our safety group is going to be much more comfortable with a pre-built commercial solution than they are with us having the engineering math done to determine load ratings. I've never seen one but that doesn't mean it doesn't exist.

Because this is GJ and the land of the second guessers, allow me to add some more facts:

• The heights are different on each machine so a cart isn't a great solution.
• The pump assemblies do have hanging eyes on the top of them.
• There is not good access underneath the machines to make a C style cart
• It is necessary for the technicians to be able to adjust the height of the pump assemblies during the installation process.
• Draining the hydraulic tanks is not an option.
• The top of the reservoir does also open.
• Removing the items above the reservoir is not an option.

 

[BlitzcrankJapan]

Yes.
An offset lifting beam sounds like it will do the job. It allows you to lift an object into a space when access for the boom directly above the space is not possible.
This way you lift the object and can slide it in from the side.

Offset lifting beam
Counter balance beam

Or what is actually more 'handy' for people that just want to maneuver items into spaces without the safety of being a lift specialist.
Something like this.

Adjustable Pallet Hook | MHA Products

The PH2906 Pallet Hook features variable body height and adjustable tine width, making this versatile attachment ideal for the transport and construction industry. Load balancing is via the moveable lifting ring.

www.mhaproducts.com.au

 

[Ricky Joe]

Are the circles the reservoir? Is this a side view or overhead?

 

[BlitzcrankJapan]

Here you can see how a counter balance beam can be used to lift objects inside of raised openings.

 

[rslaback]

Are the circles the reservoir? Is this a side view or overhead?

The circles are parts of the machine. This is an end view. The reservoir chamber is the large C. Here are some edits for clarity including the proximity of the next machine which is another limiting factor to a solution.

 

[midshipmen89]

Is there access from the side for a forklift? A 60-120 pound pump makes it sound like this is smaller scale work, but if the access hole is large enough for a single fork, it would provide the control and stability you need. If it is smaller scale, the way you've drawn the reservoir makes it seem like there may be enough clearance between the top of the pump eye and the upper lip of the reservoir for a cherry picker. Slightly harder to align, depending on your floor condition, but the clipboard warriors would have a hard time saying no to either. If you have dedicated employees doing math for a 120 pound pick, however, forklift or cherry picker may be too improvisational for your outfit.

 

[LXCam]

How about just using wheeled leverage. This might give you an idea but it certainly isn’t exactly what I’d run if I had safety nazi’s to deal with.

I recently had some 140lb pots to set that where just to awkward to do by hand. So I build mobile stanchion with a lever to offset that weight to a much more manageable amount.


I don’t know how much free egress space you have available but you could do basically the same thing with a hydraulic cart as well.

 

[dscheidt]

The circles are parts of the machine. This is an end view. The reservoir chamber is the large C. Here are some edits for clarity including the proximity of the next machine which is another limiting factor to a solution.

A frame like this will want to rotate so that the center of mass of the whole thing is straight down from the attachment point. it either needs a counter weight, or two lift points, so the lengths of the two straps can be adjusted, to keep it level enough. (using a beam with two points to hang off of, and one to pull from lets you do that with a single point overhead lift crane. Think about the balance bars used for engine hoists.

 

[larry_g]

At our plant we had a cherry picker with the lift arm reversed and a counter weight on the legs.

Something like this https://www.ebay.com/itm/113918357109?hash=item1a86102e75:g:ZaUAAOSwF-Fdnbvs

search https://www.google.com/search?q=rev...g&ei=3OoSZbaQCKzg0PEPxOWVgAs&bih=625&biw=1280

lg
no neat sig line.

 

[seber]

If you have an engineer on staff this can be designed and have the stresses calculated. It is a straightforward process for the math. Most drafting programs will do it for you.

 

[rslaback]

A frame like this will want to rotate so that the center of mass of the whole thing is straight down from the attachment point. it either needs a counter weight, or two lift points, so the lengths of the two straps can be adjusted, to keep it level enough. (using a beam with two points to hang off of, and one to pull from lets you do that with a single point overhead lift crane. Think about the balance bars used for engine hoists.

I'm not too worried about the rotation of the arm. We could move the top connection point to any point along the top beam similar to a cable roll lift hook if it was an issue but it also doesn't actually matter if the lift arm rotates some. Truth be told it might actually be an advantage to get us up higher inside the reservoir as some of the tanks have an accumulator mounted across the top right corner.

Is there access from the side for a forklift? A 60-120 pound pump makes it sound like this is smaller scale work, but if the access hole is large enough for a single fork, it would provide the control and stability you need. If it is smaller scale, the way you've drawn the reservoir makes it seem like there may be enough clearance between the top of the pump eye and the upper lip of the reservoir for a cherry picker. Slightly harder to align, depending on your floor condition, but the clipboard warriors would have a hard time saying no to either. If you have dedicated employees doing math for a 120 pound pick, however, forklift or cherry picker may be too improvisational for your outfit.

There isn't. There is only about 4 feet in between machines.

 

[KomatsuTech]

We have a few of these at work, I believe that they are older than I am, they only have load ratings on them and no manufacturer information so I can't help you there.

Do you have a local shop that makes certified chains and slings? If you do, they most likely could point you in the right direction to where you could source one. You could also reach out to heavy equipment dealerships and ask them if they know where to purchase them. We use them for removing and installing certain items.

 

[Zewnten]

.

 

[Zewnten]

At work we have a somewhat regular task which entails installing a hydraulic pump set into a reservoir that is obstructed from the top but has a side access panel. The pump assemblies are anywhere from 60 to 120 pounds and you are trying to remove and reinstall them overtop of a pan 5 or so inches deep with hydraulic oil. An overhead crane exists that covers the entire footprint of the room. The ergonomics of this job absolutely **** and there is a fairly high mode of failure as it can be difficult to get the gaskets in place correctly when balancing and bolting it in.

Has anyone ever seen a commercially available offset lift arm similar to an obstruction style wrench but much bigger? Something that would allow us to use the crane from above but still be able to slide the pump in through the side access and then support it?

In my kindergarten CAD below the machine would be in green. The proposed lift arm would be yellow.



Custom building this isn't out of the question but our safety group is going to be much more comfortable with a pre-built commercial solution than they are with us having the engineering math done to determine load ratings. I've never seen one but that doesn't mean it doesn't exist.

Because this is GJ and the land of the second guessers, allow me to add some more facts:

• The heights are different on each machine so a cart isn't a great solution.
• The pump assemblies do have hanging eyes on the top of them.
• There is not good access underneath the machines to make a C style cart
• It is necessary for the technicians to be able to adjust the height of the pump assemblies during the installation process.
• Draining the hydraulic tanks is not an option.
• The top of the reservoir does also open.
• Removing the items above the reservoir is not an option.

Yes heavy equipment shops use one exactly like your drawing almost everyday. Call a local yellow iron dealer and they can get you either very detailed drawings from an engineer approved plan or sell you something premade with a manufacturer's part number.

 

[crewchief888]

FWIW
Bobcat has a device very similar to what your drawing looks like.
Used with various adapters to lift engine/pumps out of skid steers

 

[PoorUB]

Does it really need to be engineered? how about building some thing, and destructive testing, or simply testing it to 3x the working load? Figure out what the heaviest item it will lift, say 100 pounds. Test it to 360 pounds and prove it will handle the load, then rate it for 120 pounds max. Wouldn't that please your safety groupies?

From my experience, I would think building it out of some 2"x 1/8" wall square tube would met the requirements. if it doesn't survive testing, go to a thicker wall and try again. It might be less money that paying for engineering.

 

[nadogail]

This seems to be something you could hang from an extended fork, or a boom supported by a forklift.

 

[cannuck]

I have designed/built a number of those up to 6,400 lbs. design load. Your drawing is very close to what I would do, but instead of one eye for the crane I would suggest extending the top beam a few inches and putting one eye there and after calculating the CofG of the lift rig plus the lifted load put the other one same offset from CofG but down the top beam. Lift with two matched slings (wire rope in this case better than synthetic straps as every time I see those around an overhead crane someone has overloaded one more than the other and they are no long identical length) and instead of a tilt situation you only have a mild swing for loaded vs empty. The higher your crane hook is from the load, the less the deviations at the other end.

BTW: the calcs for this are child's play. The bill for engineering should be tiny.

 

[rust in the eye]

At work we have a somewhat regular task which entails installing a hydraulic pump set into a reservoir that is obstructed from the top but has a side access panel. The pump assemblies are anywhere from 60 to 120 pounds and you are trying to remove and reinstall them overtop of a pan 5 or so inches deep with hydraulic oil. An overhead crane exists that covers the entire footprint of the room. The ergonomics of this job absolutely **** and there is a fairly high mode of failure as it can be difficult to get the gaskets in place correctly when balancing and bolting it in.

Has anyone ever seen a commercially available offset lift arm similar to an obstruction style wrench but much bigger? Something that would allow us to use the crane from above but still be able to slide the pump in through the side access and then support it?

In my kindergarten CAD below the machine would be in green. The proposed lift arm would be yellow.



Custom building this isn't out of the question but our safety group is going to be much more comfortable with a pre-built commercial solution than they are with us having the engineering math done to determine load ratings. I've never seen one but that doesn't mean it doesn't exist.

Because this is GJ and the land of the second guessers, allow me to add some more facts:

• The heights are different on each machine so a cart isn't a great solution.
• The pump assemblies do have hanging eyes on the top of them.
• There is not good access underneath the machines to make a C style cart
• It is necessary for the technicians to be able to adjust the height of the pump assemblies during the installation process.
• Draining the hydraulic tanks is not an option.
• The top of the reservoir does also open.
• Removing the items above the reservoir is not an option.

"Custom building this isn't out of the question but our safety group is going to be much more comfortable with a pre-built commercial solution than they are with us having the engineering math done to determine load ratings."

Why all the hand wringing from your safety group? Your current method of installation sounds a bit dodgy already.
The device is only 120#, how much engineering needs to be done?
Your drawing looks simple enough to fab. up.

 

[rslaback]

"Custom building this isn't out of the question but our safety group is going to be much more comfortable with a pre-built commercial solution than they are with us having the engineering math done to determine load ratings."

Why all the hand wringing from your safety group? Your current method of installation sounds a bit dodgy already.
The device is only 120#, how much engineering needs to be done?
Your drawing looks simple enough to fab. up.

Large corporation. I could say more but that sums it up nicely.

 

[2oolhound]

At work we have a somewhat regular task which entails installing a hydraulic pump set into a reservoir that is obstructed from the top but has a side access panel. The pump assemblies are anywhere from 60 to 120 pounds. The ergonomics of this job absolutely **** and there is a fairly high mode of failure as it can be difficult to get the gaskets in place correctly when balancing and bolting it in.

Just use both hands when setting it in place with the gaskets. Then tighten it down.

 

[Not So Legendary]

This piece would qualify as a below the hook lifting device and IIRC you would need to have it tested to 5x the rated capacity (by a certified facility). you may also not be allowed to use the test unit, so you would have to make 2. Talks of custom lifting equipment come up at work at least twice a year, generally it is easier and cheaper to get one with a certificate than engineering your own.

 

[cannuck]

Just use both hands when setting it in place with the gaskets. Then tighten it down.

Geez. 2 hands? Wimp!

 

[Firebrick43]

The circles are parts of the machine. This is an end view. The reservoir chamber is the large C. Here are some edits for clarity including the proximity of the next machine which is another limiting factor to a solution.

When I worked for caterpillar they had hundreds of specialized lifting devices both for the product and for the maintenance of the large CNC machines. Probably a good 10-20 percent were like this. Unfortunately they almost always needed to be specially made. They had an engineer in Peoria that would do most of the calc and we had a skilled tradesman that's main responsibility was to make and inspect them. Also, a pump that large typically has a 4 bolt mount flange. Are you not using guide studs to get the pump or taking it apart?

 

[2oolhound]

Geez. 2 hands? Wimp!

Har har, you got me pegged. Youse SK guys can do it 1 hand but I'm watching this thread to see if it can be done hands free! I use levitation on jobs like this but in the past my clients have lacked the patience to wait the required time for me to get it off the ground. Frustrating ...

 

[wrenchguy]

100 year old lifting device, blacksmith made.

 

[JamieK]

Look into a "coil hook" or "chuck hook"

https://www.hobby-machinist.com/data/attachments/308/308278-844316cf222ea9c1c48fd50751ffe7c1.jpg

https://static.grainger.com/rp/s/is/image/Grainger/44N647_AS01?$adapimg$&hei=536&wid=536

 

[turbodave]

Would a counterweighted Genie Lift with a boom option work? not sure how deep into the machine it needs to reach.

Genie 5 Ft. 11 In. Counterweight Base Material Lift

Genie 5 Ft. 11 In. Counterweight Base Material Lift - GL-4-CW from Genie

www.acmetools.com

with:

Genie GL Series Boom Option

Genie GL Series Boom Option - 37086GT from Genie

www.acmetools.com