Investors often attempt to ferret out a feel for the economy's direction by paying special attention to bellwether companies like Caterpillar (NYSE: CAT) and the big international delivery pair, United Parcel Service and FedEx.

The first two companies named above reported encouraging results on Thursday. Caterpillar, which was hit hard for a time by the recession, appears to have regained its sea legs. Its net income reached $707 million, or $1.09 per share, up year-over-year from a net of $371 million, or $0.60 a share.

At the same time, Caterpillar's sales increased by 31% to $10.4 billion. Coming out of a recession, it was the sort of performance that trounced analysts' forecasts, which were in the vicinity of $0.85 per share on revenues of $9.8 billion.

Furthermore, Caterpillar obviously isn't finished improving its lot. For 2010, management's guidance has been raised to the admittedly wide range of $3.15 to $3.85 per share, up from an earlier $2.50 to $3.25.

Looking at the two operating segments, machinery sales increased by 55% over the same quarter a year ago, and sales in all four of the company's geographic regions improved from a year ago. On the engine side, sales were up a less impressive 3%, but only Europe/Africa/the Middle East experienced a decline.

Terex (NYSE: TEX) released its results on Wednesday, as my colleague Christopher Barker told you. It recorded a relatively small loss, attributable to restructuring and other charges. I'm therefore eager for reports from companies like Deere (NYSE: DE) and Joy Global (Nasdaq: JOYG), two other equipment manufacturers that will report in August.

I've never before seen an investor-relations person carry most of a company's load during a post-release call. But Caterpillar's Mike DeWalt did so quite well. As he wrapped up prior to the Q&A, he said:

In summary, the second quarter reflected continuing improvement. Dealer sales to end users continued to strengthen, and thanks to our suppliers and a lot of hard work in our factories, we were able to raise production significantly in the second quarter and do it with reasonable efficiency. Sales and profit were up. We raised the outlook for the year.

Clearly, Caterpillar is back, and its results just might be telling us that the economy is stronger than we thought. Fools should take note on both counts.